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Cover Page - USD ($)	12 Months Ended
Cover Page - USD ($)	Dec. 31, 2019	Jan. 31, 2020	Jun. 30, 2019
Document Information [Line Items]
Entity Central Index Key	0000891103
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	000-20570
Entity Registrant Name	IAC/INTERACTIVECORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	59-2712887
Entity Address, Address Line One	555 West 18th Street
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10011
City Area Code	212
Local Phone Number	314-7300
Title of 12(b) Security	Common Stock, par value $0.001
Trading Symbol	IAC
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 16,892,708,488
Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		78,970,141
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		5,789,499

CONSOLIDATED BALANCE SHEET - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
ASSETS
Cash and cash equivalents	$ 3,139,295	$ 2,131,632
Marketable securities	19,993	123,665
Accounts receivable, net of allowance and reserves of $24,726 and $18,860, respectively	298,334	279,189
Other current assets	249,367	228,253
Total current assets	3,706,989	2,762,739
Right-of-use assets, net	167,801	0
Property and equipment, net	371,353	318,800
Goodwill	2,854,462	2,726,859
Intangible assets, net	578,474	631,422
Long-term investments	353,052	235,055
Deferred income taxes	167,054	64,786
Other non-current assets	133,640	134,924
TOTAL ASSETS	8,332,825	6,874,585
LIABILITIES:
Current portion of long-term debt	13,750	13,750
Accounts payable, trade	94,356	74,907
Deferred revenue	397,490	360,015
Accrued expenses and other current liabilities	502,003	434,886
Total current liabilities	1,007,599	883,558
Long-term debt, net	3,121,572	2,245,548
Income taxes payable	36,489	37,584
Deferred income taxes	21,388	23,600
Other long-term liabilities	202,932	66,807
Redeemable noncontrolling interests	44,527	65,687
Commitments and contingencies
SHAREHOLDERS' EQUITY:
Additional paid-in capital	11,683,799	12,022,387
Retained earnings	1,689,925	1,258,794
Accumulated other comprehensive loss	(136,349)	(128,722)
Treasury stock 194,708 shares	(10,309,612)	(10,309,612)
Total IAC shareholders' equity	2,928,042	2,843,125
Noncontrolling interests	970,276	708,676
Total shareholders' equity	3,898,318	3,551,801
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	8,332,825	6,874,585
Common stock $.001 par value; authorized 1,600,000 shares; issued 263,230 and 262,303 shares, respectively, and outstanding 78,890 and 77,963 shares, respectively
SHAREHOLDERS' EQUITY:
Common stock	263	262
Class B convertible common stock $.001 par value; authorized 400,000 shares; issued 16,157 shares and outstanding 5,789 shares
SHAREHOLDERS' EQUITY:
Common stock	$ 16	$ 16

CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Allowance and reserves of accounts receivable	$ 24,726	$ 18,860
Treasury stock (shares)	194,708,000	194,708,000
Common Stock
Common stock, par value (USD per share)	$ 0.001	$ 0.001
Common stock authorized (shares)	1,600,000,000	1,600,000,000
Common stock issued (shares)	263,230,000	262,303,000
Common stock outstanding (shares)	78,890,000	77,963,000
Class B Convertible Common Stock
Common stock, par value (USD per share)	$ 0.001	$ 0.001
Common stock authorized (shares)	400,000,000	400,000,000
Common stock issued (shares)	16,157,000	16,157,000
Common stock outstanding (shares)	5,789,000	5,789,000

CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue	$ 4,757,055	$ 4,262,892	$ 3,307,239
Operating costs and expenses:
Cost of revenue (exclusive of depreciation shown separately below)	1,127,420	911,146	651,008
Selling and marketing expense	1,629,623	1,519,440	1,381,221
General and administrative expense	888,950	774,079	719,257
Product development expense	345,417	309,329	250,879
Depreciation	88,399	75,360	74,265
Amortization of intangibles	92,595	108,399	42,143
Goodwill impairment	3,318	0	0
Total operating costs and expenses	4,175,722	3,697,753	3,118,773
Operating income	581,333	565,139	188,466
Interest expense	(153,563)	(109,327)	(105,295)
Other income (expense), net	66,741	305,746	(16,213)
Earnings before income taxes	494,511	761,558	66,958
Income tax benefit (provision)	49,309	(3,811)	291,050
Net earnings	543,820	757,747	358,008
Net earnings attributable to noncontrolling interests	(112,689)	(130,786)	(53,084)
Net earnings attributable to IAC shareholders	$ 431,131	$ 626,961	$ 304,924
Per share information attributable to IAC shareholders:
Basic earnings per share (USD per share)	$ 5.12	$ 7.52	$ 3.81
Diluted earnings per share (USD per share)	$ 4.50	$ 6.59	$ 3.18
Stock-based compensation expense by function:
Total stock-based compensation expense	$ 240,788	$ 238,420	$ 264,618
Cost of revenue
Stock-based compensation expense by function:
Total stock-based compensation expense	3,767	2,482	1,881
Selling and marketing expense
Stock-based compensation expense by function:
Total stock-based compensation expense	10,298	7,943	31,318
General and administrative expense
Stock-based compensation expense by function:
Total stock-based compensation expense	178,298	188,510	192,957
Product development expense
Stock-based compensation expense by function:
Total stock-based compensation expense	$ 48,425	$ 39,485	$ 38,462

CONSOLIDATED STATEMENT OF COMPREHENSIVE OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net earnings	$ 543,820	$ 757,747	$ 358,008
Other comprehensive (loss) income, net of income taxes:
Change in foreign currency translation adjustment	(9,961)	(31,411)	80,269
Change in unrealized gains and losses on available-for-sale securities (net of tax benefit of $3,846 in 2017)	(5)	5	(4,026)
Total other comprehensive (loss) income, net of income taxes	(9,966)	(31,406)	76,243
Comprehensive income, net of income taxes	533,854	726,341	434,251
Components of comprehensive (income) loss attributable to noncontrolling interests:
Net earnings attributable to noncontrolling interests	(112,689)	(130,786)	(53,084)
Change in foreign currency translation adjustment attributable to noncontrolling interests	2,023	6,129	(13,797)
Change in unrealized gains and losses of available-for-sale securities attributable to noncontrolling interests	1	(1)	0
Comprehensive income attributable to noncontrolling interests	(110,665)	(124,658)	(66,881)
Comprehensive income attributable to IAC shareholders	$ 423,189	$ 601,683	$ 367,370

CONSOLIDATED STATEMENT OF COMPREHENSIVE OPERATIONS (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Statement of Comprehensive Income [Abstract]
Change in unrealized gains and losses on available-for-sale securities, tax provision (benefit)	$ (3,846)

CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Total IAC Shareholders' Equity	Redeemable Noncontrolling Interests	Common Stock Common Stock	Common Stock Class B Convertible Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income	Treasury Stock	Noncontrolling Interests
Balance at beginning of period at Dec. 31, 2016				$ 32,827
Increase (Decrease) in Temporary Equity [Roll Forward]
Net earnings				3,620
Other comprehensive income, net of income tax				1,291
Stock-based compensation expense				2,017
Distributions to and purchases of redeemable noncontrolling interests				(20,461)
Adjustment of redeemable noncontrolling interests to fair value				6,341
Noncontrolling interests created in acquisitions				17,758
Other				(526)
Balance at end of period at Dec. 31, 2017				42,867
Balance at beginning of period at Dec. 31, 2016	$ 2,010,670		$ 1,869,222		$ 256	$ 16	$ 11,921,559	$ 290,114	$ (166,123)	$ (10,176,600)	$ 141,448
Balance at beginning of period (shares) at Dec. 31, 2016					255,672,000	16,157,000
Increase (Decrease) in Shareholders' Equity
Net earnings	354,388		304,924					304,924			49,464
Other comprehensive income, net of income tax	74,952		62,446						62,446		12,506
Stock-based compensation expense	246,388		66,333				66,333				180,055
Issuance of common stock pursuant to stock-based awards, net of withholding taxes	(10,504)		(10,504)		$ 5		(10,509)
Issuance of common stock pursuant to stock-based awards, net of withholding taxes (shares)					4,952,000
Purchase of treasury stock	(50,121)	$ (50,100)	(50,121)							(50,121)
Distributions to and purchases of noncontrolling interests	(848)		0								(848)
Adjustment of redeemable noncontrolling interests to fair value	6,341		(6,341)				(6,341)
Issuance of Match Group and ANGI Homeservices common stock pursuant to stock-based awards, net of withholding taxes	(472,702)		(471,997)				(472,106)		109		(705)
Acquisition of Angie's List and creation of noncontrolling interests in ANGI Homeservices	779,471		645,475				645,475				133,996
Noncontrolling interests created in acquisitions				17,758
Purchase of exchangeable note hedge	(74,365)		(74,365)				(74,365)
Equity component of exchangeable debt issuance, net of deferred financing costs and deferred tax asset	71,158		71,158				71,158
Issuance of warrants	23,650		23,650				23,650
Other	1,027		148				148				879
Balance at end of period at Dec. 31, 2017	2,946,823		2,430,028		$ 261	$ 16	12,165,002	595,038	(103,568)	(10,226,721)	516,795
Balance at end of period (shares) at Dec. 31, 2017					260,624,000	16,157,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Net earnings				33,897
Other comprehensive income, net of income tax				(702)
Stock-based compensation expense				1,138
Distributions to and purchases of redeemable noncontrolling interests				(14,785)
Adjustment of redeemable noncontrolling interests to fair value				4,098
Noncontrolling interests created in acquisitions	14,307			2,261							14,307
Other				(3,087)
Balance at end of period at Dec. 31, 2018	65,687			65,687
Increase (Decrease) in Shareholders' Equity
Net earnings	723,850		626,961					626,961			96,889
Other comprehensive income, net of income tax	(30,704)		(25,278)						(25,278)		(5,426)
Stock-based compensation expense	237,282		75,311				75,311				161,971
Issuance of common stock pursuant to stock-based awards, net of withholding taxes	21,786		21,786		$ 1		21,785
Issuance of common stock pursuant to stock-based awards, net of withholding taxes (shares)					1,679,000
Purchase of treasury stock	(82,891)	$ (82,900)	(82,891)							(82,891)
Distributions to and purchases of noncontrolling interests	(9,364)										(9,364)
Adjustment of redeemable noncontrolling interests to fair value	(4,098)		(4,098)				(4,098)
Issuance of Match Group and ANGI Homeservices common stock pursuant to stock-based awards, net of withholding taxes	(200,694)		(236,253)				(236,377)		124		35,559
Noncontrolling interests created in acquisitions	14,307			2,261							14,307
Dividends paid to Match Group noncontrolling interests	(105,126)										(105,126)
Other	425		764				764				(339)
Balance at end of period at Dec. 31, 2018	3,551,801		2,843,125		$ 262	$ 16	12,022,387	1,258,794	(128,722)	(10,309,612)	708,676
Balance at end of period (shares) at Dec. 31, 2018					262,303,000	16,157,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Net earnings				2,835
Other comprehensive income, net of income tax				39
Stock-based compensation expense				148
Distributions to and purchases of redeemable noncontrolling interests				(40,432)
Adjustment of redeemable noncontrolling interests to fair value				11,554
Noncontrolling interests created in acquisitions				4,781
Other				(85)
Balance at end of period at Dec. 31, 2019	44,527			44,527
Increase (Decrease) in Shareholders' Equity
Net earnings	540,985		431,131					431,131			109,854
Other comprehensive income, net of income tax	(10,005)		(7,942)						(7,942)		(2,063)
Stock-based compensation expense	238,076		82,619				82,619				155,457
Issuance of common stock pursuant to stock-based awards, net of withholding taxes	(82,462)		(82,462)		$ 1		(82,463)
Issuance of common stock pursuant to stock-based awards, net of withholding taxes (shares)					927,000
Purchase of treasury stock	(274,302)		(274,302)				(274,302)
Adjustment of redeemable noncontrolling interests to fair value	(11,554)		(11,554)				(11,554)
Issuance of Match Group and ANGI Homeservices common stock pursuant to stock-based awards, net of withholding taxes	(238,376)		(236,582)				(236,897)		315		(1,794)
Noncontrolling interests created in acquisitions				$ 4,781
Purchase of exchangeable note hedge	(303,428)		(303,428)				(303,428)
Equity component of exchangeable debt issuance, net of deferred financing costs and deferred tax asset	320,998		320,998				320,998
Issuance of warrants	166,520		166,520				166,520
Other	65		(81)				(81)				146
Balance at end of period at Dec. 31, 2019	$ 3,898,318		$ 2,928,042		$ 263	$ 16	$ 11,683,799	$ 1,689,925	$ (136,349)	$ (10,309,612)	$ 970,276
Balance at end of period (shares) at Dec. 31, 2019					263,230,000	16,157,000

CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Common Stock
Common stock, par value (USD per share)	$ 0.001	$ 0.001
Class B Convertible Common Stock
Common stock, par value (USD per share)	0.001	0.001
Common Stock \| Common Stock
Common stock, par value (USD per share)	1.000	1.000	$ 1.000
Common Stock \| Class B Convertible Common Stock
Common stock, par value (USD per share)	$ 1.000	$ 1.000	$ 1.000

CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net earnings	$ 543,820	$ 757,747	$ 358,008
Adjustments to reconcile net earnings to net cash provided by operating activities:
Stock-based compensation expense	240,788	238,420	264,618
Amortization of intangibles	92,595	108,399	42,143
Depreciation	88,399	75,360	74,265
Bad debt expense	65,803	48,445	28,930
Goodwill impairment	3,318	0	0
Deferred income taxes	(80,101)	(34,679)	(285,278)
Gains on equity securities, net	(37,581)	(152,044)	(34,927)
Losses (gains) from the sale of businesses, net	8,239	(119,955)	2,254
Other adjustments, net	45,546	15,763	61,647
Changes in assets and liabilities, net of effects of acquisitions and dispositions:
Accounts receivable	(91,435)	(34,828)	(115,169)
Other assets	(17,661)	(44,557)	5,688
Accounts payable and other liabilities	41,882	53,555	(25,289)
Income taxes payable and receivable	(3,287)	27,034	655
Deferred revenue	37,614	49,468	39,154
Net cash provided by operating activities	937,939	988,128	416,699
Cash flows from investing activities:
Acquisitions, net of cash acquired	(205,726)	(64,496)	(146,553)
Capital expenditures	(136,652)	(85,634)	(75,523)
Proceeds from maturities of marketable debt securities	163,500	333,600	114,350
Purchases of marketable debt securities	(59,639)	(449,676)	(29,891)
Net proceeds from the sale of businesses and investments	165,124	136,719	185,778
Purchases of investments	(253,663)	(52,980)	(9,106)
Other, net	(2,473)	9,027	2,994
Net cash (used in) provided by investing activities	(329,529)	(173,440)	42,049
Cash flows from financing activities:
Purchase of exchangeable note hedges	(303,428)	0	(74,365)
Proceeds from issuance of warrants	166,520	0	23,650
Debt issuance costs	(27,815)	(5,449)	(33,744)
Dividends paid to Match Group noncontrolling interests	0	(105,126)	0
Distributions to and purchases of noncontrolling interests	(29,184)	(22,498)	(20,184)
Acquisition-related contingent consideration payments	0	(185)	(27,289)
Other, net	(3,868)	1,060	(255)
Net cash provided by (used in) financing activities	399,831	(312,798)	(196,869)
Total cash provided	1,008,241	501,890	261,879
Effect of exchange rate changes on cash and cash equivalents and restricted cash	(1,568)	(1,887)	11,604
Net increase in cash and cash equivalents and restricted cash	1,006,673	500,003	273,483
Cash and cash equivalents and restricted cash at beginning of period	2,133,685	1,633,682	1,360,199
Cash and cash equivalents and restricted cash at end of period	3,140,358	2,133,685	1,633,682
IAC/InterActiveCorp
Cash flows from financing activities:
Proceeds from issuance of debt	1,150,000	0	517,500
Repurchases of IAC debt	(35,035)	(363)	(393,464)
Purchase of treasury stock	0	(82,891)	(56,424)
Proceeds from the exercise of stock options	10,682	41,700	82,397
Withholding taxes paid on behalf of employees on net settled stock-based awards	(93,145)	(18,982)	(93,832)
Match Group and ANGI Homeservices
Cash flows from financing activities:
Purchase of treasury stock	(273,258)	(133,455)	0
Proceeds from the exercise of stock options	573	4,705	61,095
Withholding taxes paid on behalf of employees on net settled stock-based awards	(238,461)	(237,564)	(264,323)
Match Group
Cash flows from financing activities:
Proceeds from issuance of debt	350,000	260,000	525,000
Purchase of exchangeable note hedges	0	0	(445,172)
Borrowing under credit facility / term loan	40,000
Principal payments on debt	(300,000)	0	0
Purchase of Match Group stock-based awards	0	0	(272,459)
ANGI Homeservices
Cash flows from financing activities:
Borrowing under credit facility / term loan			275,000
Principal payments on debt	$ (13,750)	$ (13,750)	$ 0

ORGANIZATION

12 Months Ended

Dec. 31, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

ORGANIZATION

IAC operates Vimeo and Dotdash, among many other online businesses, and also has majority ownership of both Match Group, which includes Tinder, Match, PlentyOfFish, OkCupid and Hinge, and ANGI Homeservices, which includes HomeAdvisor, Angie’s List and Handy.

Separation

On December 19, 2019, IAC/InterActiveCorp ("IAC") entered into a Transaction Agreement (the "Transaction Agreement") with Match Group, Inc. ("MTCH"), IAC Holdings, Inc., a direct wholly owned subsidiary of IAC ("New IAC"), and Valentine Merger Sub LLC, an indirect wholly owned subsidiary of IAC. Subject to the terms and conditions set forth in the Transaction Agreement, the businesses of MTCH will be separated from the remaining businesses of IAC through a series of transactions that will result in the pre-transaction stockholders of IAC owning shares in two, separate public companies—(1) IAC, which will be renamed Match Group, Inc. ("New Match") and which will own the businesses of MTCH and certain IAC financing subsidiaries, and (2) New IAC, which will be renamed IAC/InterActiveCorp and which will own IAC's other businesses—and the pre-transaction stockholders of MTCH (other than IAC) owning shares in New Match. Completion of the Separation, which is expected to occur in mid-second quarter of 2020, is subject to a number of conditions, including approval by a majority of the disinterested shareholders of MTCH, approval of IAC’s shareholders and other customary conditions and approvals. We refer to the full separation as the "Separation".

As used herein, "IAC," the "Company," "we," "our" or "us" and similar terms refer to IAC/InterActiveCorp and its subsidiaries (unless the context requires otherwise).

Match Group

Our Match Group segment consists of the businesses and operations of Match Group, Inc. ("Match Group" or "MTCH").

MTCH completed its initial public offering ("IPO") on November 24, 2015. At December 31, 2019, IAC’s economic interest and voting interest in MTCH were 80.7% and 97.5%, respectively.

MTCH is a leading provider of dating products available in over 40 languages to our users all over the world through applications and websites that we own and operate. MTCH operates a portfolio of dating brands, including Tinder, Match, Meetic, OkCupid, Hinge, Pairs, PlentyOfFish and OurTime, as well as a number of other brands, each designed to increase users' likelihood of finding a meaningful connection. Through our portfolio of trusted brands, we provide tailored products to meet the varying preferences of our users.

ANGI Homeservices

Our ANGI Homeservices segment includes the North American (United States and Canada) and European businesses and operations of ANGI Homeservices Inc. ("ANGI"). On September 29, 2017, the Company's HomeAdvisor business and Angie's List Inc. ("Angie's List") combined under a new publicly traded company called ANGI Homeservices Inc. (the "Combination"). At December 31, 2019, IAC’s economic interest and voting interest in ANGI were 84.1% and 98.1%, respectively.

ANGI connects quality home service professionals across 500 different categories, from repairing and remodeling to cleaning and landscaping, with consumers. Over 250,000 domestic service professionals find work through ANGI and consumers turn to at least one of our brands to find a professional for more than 25 million projects each year. We established category-transforming products with brands such as HomeAdvisor, Angie's List, Handy and Fixd Repair.

On January 25, 2019, ANGI completed the acquisition of Fixd Repair, a home warranty and service company. On October 19, 2018, ANGI acquired Handy, a leading platform in the United States for connecting individuals looking for household services (primarily cleaning and handyman services) with top-quality, pre-screened independent service professionals. ANGI also owns and operates mHelpDesk, a provider of cloud-based field service software for small to mid-size businesses. Prior to its sale on December 31, 2018, ANGI also operated Felix, a pay-per-call advertising service business. In addition to its market-leading U.S. operations, ANGI owns leading home services online marketplaces in France (Travaux), Germany (MyHammer), Netherlands (Werkspot), United Kingdom (MyBuilder Limited or "MyBuilder," which we acquired a

controlling interest in on March 24, 2017), Canada (HomeStars Inc. or "HomeStars," which we acquired a controlling interest in on February 8, 2017) and Italy (Instapro), as well as operations in Austria (MyHammer).

Vimeo

Vimeo operates a global video platform for creative professionals, small and medium businesses ("SMBs"), organizations and enterprises to connect with their audiences, customers and employees. Vimeo provides cloud-based Software-as-a-Service ("SaaS") offerings that allow customers to create, host, stream, monetize, analyze and distribute videos online and across devices. Vimeo also sold live streaming accessories through its hardware business, which was sold on March 29, 2019.

On May 28, 2019, Vimeo completed the acquisition of Magisto, a video creation service enabling consumers and businesses to create short-form videos.

Dotdash

Dotdash is a portfolio of digital publishing brands providing expert information and inspiration in select vertical content categories.

Applications

Our Applications segment consists of our Desktop business and Mosaic Group, our mobile business. Through these businesses, we are a leading provider of global, advertising-driven desktop and subscription-based mobile applications.

Through our Desktop business, we own and operate a portfolio of desktop browser applications that provide users with access to a wide variety of online content, tools and services. We provide users who download our desktop browser applications with new tab search services, as well as the option of default browser search services. We distribute our desktop browser applications to consumers free of charge on an opt-in basis directly through direct-to-consumer (primarily Chrome Web Store) and partnership distribution channels.

Through Mosaic Group, we are a leading provider of global subscription mobile applications. Mosaic Group's products are developed by the following owned and operated businesses: Apalon, iTranslate, acquired in March 2018, TelTech, acquired in October 2018, and, effective April 1, 2018 upon its transfer from Emerging & Other, Daily Burn.

Apalon is a leading mobile development company with one of the largest and most popular application portfolios worldwide. iTranslate develops and distributes some of the world's most downloaded mobile translation applications, enabling users to read, write, speak and learn foreign languages anywhere in the world. TelTech develops and distributes unique and innovative mobile communications applications that help protect consumer privacy. Daily Burn is a health and fitness business that provides streaming fitness and workout videos across a variety of platforms (including mobile, web and other Internet-enabled television platforms).

Emerging & Other

Our Emerging & Other segment primarily includes:


•	Ask Media Group, a collection of websites providing general search services, and to a lesser extent, content that help users find the information they need;


•	Bluecrew, a technology driven staffing platform exclusively for flexible W-2 work, which we acquired a controlling interest in on February 26, 2018;


•	NurseFly, a platform to efficiently connect temporary healthcare professionals with job opportunities, which we acquired a controlling interest in on June 26, 2019;


•	The Daily Beast, a website dedicated to news, commentary, culture and entertainment that publishes original reporting and opinion from its roster of full-time journalists and contributors;


•	College Humor Media, a provider of digital content, including its subscription only property, Dropout.tv;


•	IAC Films, a provider of production and producer services for feature films, primarily for initial sale and distribution through theatrical releases and video-on-demand services in the United States and internationally; and


•	For periods prior to their sales:


◦	CityGrid, an advertising network that integrated local content and advertising for distribution to affiliated and third-party publishers across web and mobile platforms, sold December 31, 2018.


◦	Dictionary.com, an online and mobile dictionary and thesaurus service, sold November 13, 2018.


◦	Electus, including Notional, a provider of production and producer services for both unscripted and scripted television and digital content, primarily for initial sale and distribution in the United States, sold October 29, 2018.

◦

The Princeton Review, a provider of educational test preparation, academic tutoring and college counseling services, sold on March 31, 2017.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation and Consolidation

The Company prepares its consolidated financial statements in accordance with U.S. generally accepted accounting principles ("GAAP").

The consolidated financial statements include the accounts of the Company, all entities that are wholly-owned by the Company and all entities in which the Company has a controlling financial interest. Intercompany transactions and accounts have been eliminated.

Accounting for Investments in Equity Securities

Investments in the common stock or in-substance common stock of entities in which the Company has the ability to exercise significant influence over the operating and financial matters of the investee, but does not have a controlling financial interest, are accounted for using the equity method and are included in "Long-term investments" in the accompanying consolidated balance sheet. At December 31, 2019 and 2018, the Company did not have any investments accounted for using the equity method.

Investments in equity securities, other than those of our consolidated subsidiaries and those accounted for under the equity method, are accounted for at fair value or under the measurement alternative of Financial Accounting Standards Board ("FASB") Accounting Standards Update ("ASU") No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities, following its adoption on January 1, 2018, with any changes to fair value recognized within other income (expense), net each reporting period. Under the measurement alternative, equity investments without readily determinable fair values are carried at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar securities of the same issuer; value is generally determined based on a market approach as of the transaction date. A security will be considered identical or similar if it has identical or similar rights to the equity securities held by the Company. The Company reviews its investments in equity securities without readily determinable fair values for impairment each reporting period when there are qualitative factors or events that indicate possible impairment. Factors we consider in making this determination include negative changes in industry and market conditions, financial performance, business prospects, and other relevant events and factors. When indicators of impairment exist, the Company prepares quantitative assessments of the fair value of our investments in equity securities, which require judgment and the use of estimates. When our assessment indicates that the fair value of the investment is below its carrying value, the Company writes down the investment to its fair value and records the corresponding charge within other income (expense), net.

Accounting Estimates

Management of the Company is required to make certain estimates, judgments and assumptions during the preparation of its consolidated financial statements in accordance with GAAP. These estimates, judgments and assumptions impact the

reported amounts of assets, liabilities, revenue and expenses and the related disclosure of contingent assets and liabilities. Actual results could differ from these estimates.

On an ongoing basis, the Company evaluates its estimates and judgments, including those related to: the fair values of cash equivalents and marketable debt securities; the carrying value of accounts receivable, including the determination of the allowance for doubtful accounts; the determination of revenue reserves; the carrying value of right-of-use assets ("ROU assets"); the useful lives and recoverability of definite-lived intangible assets and property and equipment; the recoverability of goodwill and indefinite-lived intangible assets; the fair value of equity securities without readily determinable fair values; contingencies; the fair value of acquisition-related contingent consideration arrangements; unrecognized tax benefits; the valuation allowance for deferred income tax assets; and the fair value of and forfeiture rates for stock-based awards, among others. The Company bases its estimates and judgments on historical experience, its forecasts and budgets and other factors that the Company considers relevant.

Revenue Recognition

The Company adopted ASU No. 2014-09, Revenue from Contracts with Customers, effective January 1, 2018 using the modified retrospective transition method for open contracts as of the date of initial application. The cumulative effect to the Company's retained earnings at January 1, 2018 was an increase of $40.2 million, of which $3.4 million was related to the noncontrolling interest in ANGI; the adjustment to retained earnings was principally related to the Company’s ANGI and Applications segments.

•

Within ANGI, the effect of the adoption of ASU No. 2014-09 was that commissions paid to employees pursuant to certain sales incentive programs, which represent the incremental direct costs of obtaining a service professional contract, are now capitalized and amortized over the estimated life of a service professional (also referred to as the estimated customer relationship period). These costs were expensed as incurred prior to January 1, 2018. The cumulative effect of the adoption of ASU No. 2014-09 was the establishment of a current and non-current asset for capitalized sales commissions of $29.7 million and $4.2 million, respectively, and a related deferred tax liability of $8.0 million, resulting in a net increase to retained earnings of $25.9 million on January 1, 2018.

•

Within Applications, the primary effect of the adoption of ASU No. 2014-09 was to accelerate the recognition of the portion of the revenue of certain desktop applications sold by SlimWare that qualify as functional intellectual property ("functional IP") under ASU No. 2014-09. This revenue was previously deferred and recognized over the applicable subscription term. The cumulative effect of the adoption of ASU No. 2014-09 for SlimWare was a reduction in deferred revenue of $20.3 million and the establishment of a deferred tax liability of $4.9 million, resulting in a net increase to retained earnings of $15.5 million on January 1, 2018.

The Company's disaggregated revenue disclosures are presented in "Note 12—Segment Information."

The following table presents the impact of the adoption of ASU No. 2014-09 by segment under Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers, as reported, and ASC 605, Revenue Recognition, for the year ended December 31, 2018.



	Under ASC 606 (as reported)			Under ASC 605			Effect of adoption of ASU No. 2014-09
	(In thousands)
Revenue by segment:
Match Group	$	1,729,850		$	1,729,850		$	—
ANGI Homeservices	1,132,241			1,132,241			—
Vimeo	159,641			160,931			(1,290		)
Dotdash	130,991			130,991			—
Applications	582,287			581,492			795
Emerging & Other	528,250			528,250			—
Inter-segment eliminations	(368		)	(368		)	—
Total	$	4,262,892		$	4,263,387		$	(495	)

Operating costs and expenses by segment:
Match Group	$	1,176,556		$	1,176,556		$	—
ANGI Homeservices	1,068,335			1,073,275			(4,940		)
Vimeo	195,235			196,212			(977		)
Dotdash	112,213			112,213			—
Applications	487,453			484,644			2,809
Emerging & Other	498,286			498,286			—
Corporate	159,675			159,675			—
Total	$	3,697,753		$	3,700,861		$	(3,108	)

Operating income (loss) by segment:
Match Group	$	553,294		$	553,294		$	—
ANGI Homeservices	63,904			58,964			4,940
Vimeo	(35,594		)	(35,281		)	(313		)
Dotdash	18,778			18,778			—
Applications	94,834			96,848			(2,014		)
Emerging & Other	29,964			29,964			—
Corporate	(160,043		)	(160,043		)	—
Total	$	565,137		$	562,524		$	2,613

Net earnings	$	757,747		$	755,741		$	2,006

The Company accounts for a contract with a customer when it has approval and commitment from all parties, the rights of the parties and payment terms are identified, the contract has commercial substance and collectability of consideration is probable. Revenue is recognized when control of the promised services or goods is transferred to our customers and in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services or goods.

Transaction Price

The objective of determining the transaction price is to estimate the amount of consideration the Company is due in exchange for its services or goods, including amounts that are variable. The Company determines the total transaction price, including an estimate of any variable consideration, at contract inception and reassesses this estimate each reporting period.

The Company excludes from the measurement of transaction price all taxes assessed by governmental authorities that are both (i) imposed on and concurrent with a specific revenue-producing transaction and (ii) collected from customers. Accordingly, such tax amounts are not included as a component of revenue or cost of revenue.

For contracts that have an original duration of one year or less, the Company uses the practical expedient available under ASU No. 2014-09, applicable to such contracts and does not consider the time value of money.

Arrangements with Multiple Performance Obligations

The Company’s contracts with customers may include multiple performance obligations. For such arrangements, the Company allocates revenue to each performance obligation based on its relative standalone selling price. The Company generally determines standalone selling prices based on the prices charged to customers, which are directly observable or based on an estimate if not directly observable. For our multiple performance obligation arrangements that include functional IP, which comprise the downloadable apps and software of the Applications segment, the Company uses a residual approach to determine standalone selling prices for the functional IP.

Assets Recognized from the Costs to Obtain a Contract with a Customer

The Company has determined that certain costs, primarily commissions paid to employees pursuant to certain sales incentive programs and mobile app store fees, meet the requirements to be capitalized as a cost of obtaining a contract. Commissions paid to employees pursuant to certain sales incentive programs are amortized over the estimated customer relationship period. The Company calculates the estimated customer relationship period as the average customer life, which is based on historical data. When customer renewals are expected and the renewal commission is not commensurate with the initial commission, the average customer life includes renewal periods. For sales incentive programs where the customer relationship period is one year or less, the Company has elected the practical expedient to expense the costs as incurred. The Company generally capitalizes and amortizes mobile app store fees over the term of the applicable subscription.

During the years ended December 31, 2019 and 2018, the Company recognized expense of $464.6 million and $355.3 million related to the amortization of these costs. The current contract asset balances are $71.5 million, $69.8 million and $53.4 million at December 31, 2019 and 2018, and January 1, 2018, respectively. The non-current contract asset balances are $6.2 million, $4.5 million and $4.7 million at December 31, 2019 and 2018, and January 1, 2018, respectively. The current and non-current contract assets are included in "Other current assets" and "Other non-current assets," respectively, in the accompanying consolidated balance sheet.

Performance Obligations

As permitted under the practical expedient available under ASU No. 2014-09, the Company does not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less, (ii) contracts with variable consideration that is allocated entirely to unsatisfied performance obligations or to a wholly unsatisfied promise accounted for under the series guidance, and (iii) contracts for which the Company recognizes revenue at the amount which we have the right to invoice for services performed.

Match Group

Match Group revenue is primarily derived directly from users in the form of recurring subscriptions. Subscription revenue is presented net of credits and credit card chargebacks. Subscribers pay in advance, primarily by credit card or through mobile app stores, and, subject to certain conditions identified in our terms and conditions, generally all purchases are final and nonrefundable. Revenue is initially deferred and is recognized using the straight-line method over the term of the applicable subscription period, which generally ranges from one to six months. Revenue is also earned from online advertising, the

purchase of à la carte features and offline events. Online advertising revenue is recognized when an advertisement is displayed. Revenue from the purchase of à la carte features is recognized based on usage. Revenue associated with offline events is recognized when each event occurs.

ANGI Homeservices

ANGI revenue is primarily derived from (i) consumer connection revenue, which comprises fees paid by HomeAdvisor service professionals for consumer matches (regardless of whether the service professional ultimately provides the requested service) and fees from completed jobs sourced through the HomeAdvisor and Handy platforms, and (ii) HomeAdvisor service professional membership subscription fees. Consumer connection revenue varies based upon several factors, including the service requested, product experience offered and geographic location of service. The Company’s consumer connection revenue is generated and recognized when an in-network service professional is delivered a consumer match or when a job sourced through the HomeAdvisor and Handy platforms are completed. Service professional membership subscription revenue is initially deferred and is recognized using the straight-line method over the applicable subscription period, which is typically one year. Consumer connection revenue is generally billed one week following a consumer match, with payment due upon receipt of invoice or collected when a consumer schedules a job through the HomeAdvisor and Handy platforms. The Company maintains revenue reserves for potential credits for services provided by Handy service professionals to consumers.

ANGI revenue is also derived from (i) sales of time-based website, mobile and call center advertising to service professionals, (ii) membership subscription fees from consumers and (iii) service warranty subscription and other services. Angie's List service professionals generally pay for advertisements in advance on a monthly or annual basis at the option of the service professional, with the average advertising contract term being approximately one year. Angie's List website, mobile and call center advertising revenue is recognized ratably over the contract term. Revenue from the sale of advertising in the Angie’s List Magazine is recognized in the period in which the publication is distributed. Angie's List prepaid consumer membership subscription fees are recognized as revenue using the straight-line method over the term of the applicable subscription period, which is typically one year.

Prior to January 1, 2020, Handy recorded revenue on a net basis. Effective January 1, 2020, we modified the Handy terms and conditions so that Handy, rather than the service professional, has the contractual relationship with the consumer to deliver the service and Handy, rather than the consumer, has the contractual relationship with the service professional. Consumers request services and pay for such services directly through the Handy platform and then Handy fulfills the request with independently established home services providers engaged in a trade, occupation and/or business that customarily provides such services. This change in contractual terms requires gross revenue accounting treatment effective January 1, 2020. Also, in the case of certain tasks, HomeAdvisor provides a pre-priced product offering, pursuant to which consumers can request services through a HomeAdvisor platform and pay HomeAdvisor for the services directly. HomeAdvisor then fulfills the request with independently established home services providers engaged in a trade, occupation and/or business that customarily provides such services. Revenue from HomeAdvisor’s pre-priced product offering is also recorded on a gross basis effective January 1, 2020. In addition to changing the presentation of revenue to gross from net, the timing of revenue recognition will change for pre-priced jobs and will be later than the timing of existing consumer connection revenue for HomeAdvisor because we will not be able to record revenue, generally, until the service professional completes the job on our behalf.

Vimeo

Vimeo revenue is derived primarily from annual and monthly SaaS subscription fees paid by subscribers for self-serve and enterprise subscription plans. Subscription revenue is recognized over the terms of the applicable subscription period, which are typically one month or one year.

Dotdash

Dotdash revenue consists principally of display advertising revenue and performance marketing revenue. Display advertising revenue is generated primarily through digital display advertisements sold directly by our sales team and through programmatic advertising networks. Performance marketing revenue includes affiliate commerce and performance marketing commissions. Affiliate commerce commission revenue is generated when Dotdash refers users to commerce partner websites resulting in a purchase or transaction. Performance marketing commissions are generated on a cost-per-click or cost-per-new account basis.

Applications

Desktop revenue largely consists of advertising revenue generated principally through the display of paid listings in response to search queries. Paid listings are advertisements displayed on search results pages that generally contain a link to advertiser websites. The substantial majority of the paid listings displayed by our Desktop businesses is supplied to us by Google Inc. ("Google") pursuant to our services agreement with Google. Pursuant to this agreement, Desktop businesses that provide search services transmit search queries to Google, which in turn transmits a set of relevant and responsive paid listings back to these businesses for display in search results. This ad-serving process occurs independently of, but concurrently with, the generation of algorithmic search results for the same search queries. Google paid listings are displayed separately from algorithmic search results and are identified as sponsored listings on search results pages. Paid listings are priced on a price per click basis and when a user submits a search query through a Desktop business and then clicks on a Google paid listing displayed in response to the query, Google bills the advertiser that purchased the paid listing and shares a portion of the fee charged to the advertiser with the Desktop business. The Company recognizes paid listing revenue from Google when it delivers the user's click. In cases where the user’s click is generated due to the efforts of a third-party distributor, we recognize the amount due from Google as revenue and record a revenue share or other payment obligation to the third-party distributor as traffic acquisition costs.

To a lesser extent, Desktop revenue also includes fees related to subscription-based downloadable desktop applications as well as display advertisements. Fees related to subscription downloadable desktop applications are generally recognized over the term of the applicable subscription period, which is primarily one or two years. Fees related to display advertisements are recognized when an advertisement is displayed.

Mosaic Group revenue consists primarily of fees related to subscription downloadable mobile applications distributed through the Apple App Store and Google Play Store, as well as display advertisements. Fees related to subscription downloadable mobile applications are generally recognized at the time of the sale when the software license is delivered. To the extent updates or maintenance is required or expected, revenue is recognized over the term of the applicable subscription period, which is primarily one or two years. Fees related to display advertisements are recognized when an advertisement is displayed.

Emerging & Other

Revenue of Ask Media Group consists principally of advertising revenue generated principally through the display of paid listings in response to search queries, as well as from display advertisements appearing alongside content on its various websites and, to a lesser extent, affiliate commerce commission revenue. The majority of the paid listings displayed are supplied to us by Google in the manner, and pursuant to the services agreement with Google, described above under "Applications." Revenue from display advertising is generated through advertisements sold through programmatic advertising networks. Affiliate commerce commission revenue is generated when an Ask Media Group property refers users to commerce partner websites resulting in a purchase or transaction.

Bluecrew revenue consists of service revenue, which is generated through staffing workers and recognized as control of the promised services is transferred to our customers.

NurseFly revenue consists of subscription revenue, which is generated through recruiting agencies that seek access to qualified healthcare professionals and is recognized at the earlier of the full delivery of the promised services or the length of the subscription period.

The Daily Beast revenue consists of advertising revenue, which is generated primarily through display advertisements (sold directly and through programmatic ad sales), and to a lesser extent, affiliate commerce commission revenue.

Revenue of College Humor Media and IAC Films is generated primarily through media production and distribution and advertising. Production revenue is recognized when control is transferred to the customer to broadcast or exhibit, and advertising revenue is recognized when an advertisement is displayed or over the advertising period.

Accounts Receivables, Net of Allowance for Doubtful Accounts and Revenue Reserves

Accounts receivable include amounts billed and currently due from customers. The Company maintains an allowance for doubtful accounts to provide for the estimated amount of accounts receivable that will not be collected. The allowance for doubtful accounts is based upon a number of factors, including the length of time accounts receivable are past due, the Company’s previous loss history and the specific customer’s ability to pay its obligation. The time between the Company issuance of an invoice and payment due date is not significant; customer payments that are not collected in advance of the transfer of promised services or goods are generally due no later than 30 days from invoice date. The Company also maintains allowances to reserve for potential credits issued to consumers or other revenue adjustments. The amounts of these reserves are based primarily upon historical experience.

Deferred Revenue

Deferred revenue consists of advance payments that are received or are contractually due in advance of the Company's performance. The Company’s deferred revenue is reported on a contract by contract basis at the end of each reporting period. The Company classifies deferred revenue as current when the term of the applicable subscription period or expected completion of our performance obligation is one year or less. The deferred revenue balance is $398.8 million, $361.7 million and $332.2 million at December 31, 2019 and 2018, and January 1, 2018, respectively. During the years ended December 31, 2019 and 2018, the Company recognized $356.4 million and $330.2 million of revenue that was included in the deferred revenue balance as of December 31, 2018 and January 1, 2018, respectively. The current deferred revenue balances are $397.5 million and $360.0 million at December 31, 2019 and 2018, respectively. The non-current deferred revenue balances are $1.3 million and $1.7 million at December 31, 2019 and 2018, respectively. Non-current deferred revenue is included in "Other long-term liabilities" in the accompanying consolidated balance sheet.

Cash and Cash Equivalents

Cash and cash equivalents include cash and short-term investments, with maturities of less than 91 days from the date of purchase. Domestically, cash equivalents primarily consist of AAA rated government money market funds, treasury discount notes, time deposits and commercial paper rated A1/P1 or better. Internationally, cash equivalents primarily consist of AAA rated government money market funds and time deposits.

Investments in Debt Securities

The Company invests in marketable debt securities with active secondary or resale markets to ensure portfolio liquidity to fund current operations or satisfy other cash requirements as needed. Marketable debt securities are adjusted to fair value each quarter, and the unrealized gains and losses, net of tax, are included in accumulated other comprehensive income (loss) as a separate component of shareholders' equity. The specific-identification method is used to determine the cost of debt securities sold and the amount of unrealized gains and losses reclassified out of accumulated other comprehensive income (loss) into earnings. The Company also invests in non-marketable debt securities as part of its investment strategy. We review our debt securities for impairment each reporting period. The Company recognizes an unrealized loss on debt securities in net earnings when the impairment is determined to be other-than-temporary. Factors we consider in making such determination include the duration, severity and reason for the decline in value and the potential recovery and our intent to sell the debt security. We also consider whether we will be required to sell the security before recovery of its amortized cost basis and whether the amortized cost basis cannot be recovered because of credit losses. If an impairment is considered to be other-than-temporary, the debt security will be written down to its fair value and the loss will be recognized within other income (expense), net. At December 31, 2019 and 2018, marketable debt securities consist of commercial paper rated A1/P1 or better and treasury discount notes.

Certain Risks and Concentrations

A meaningful portion of the Company's revenue is attributable to a services agreement with Google (the "Services Agreement"). In addition, the Company earns certain other advertising revenue from Google that is not attributable to the Services Agreement. For the years ended December 31, 2019, 2018 and 2017, consolidated revenue earned from Google was $733.5 million, $825.2 million and $740.7 million, respectively, representing 15%, 19%, and 22%, respectively, of the Company's consolidated revenue. Accounts receivable related to revenue earned from Google totaled $53.0 million and

$69.1 million at December 31, 2019 and 2018, respectively.

Revenue attributable to the Services Agreement is earned by the Desktop business within the Applications segment and Ask Media Group within the Emerging & Other segment. For the years ended December 31, 2019, 2018 and 2017, revenue earned from the Services Agreement was $291.1 million, $426.5 million and $480.6 million, respectively, within the Applications segment and $385.9 million, $339.0 million and $203.5 million, respectively, within the Emerging & Other segment.

The current Services Agreement expires on March 31, 2020. On February 11, 2019, the Company and Google amended the Services Agreement, effective as of April 1, 2020. The amendment extends the expiration date of the agreement to March 31, 2023; provided that during September 2020 and during each September thereafter, either party may, after discussion with the other party, terminate the services agreement, effective on September 30 of the year following the year such notice is given. The Company believes that the amended agreement, taken as a whole, is comparable to the Company’s currently existing agreement with Google. The Services Agreement requires that the Company comply with certain guidelines promulgated by Google. Google may generally unilaterally update its policies and guidelines without advance notice. These updates may be specific to the Services Agreement or could be more general and thereby impact the Company as well as other companies. These policy and guideline updates could in turn require modifications to, or prohibit and/or render obsolete certain of our products, services and/or business practices, which could be costly to address or otherwise have an adverse effect on our consolidated financial condition and results of operations, particularly our Desktop business and Ask Media Group. As described below, Google has made changes to the policies under the Services Agreement and has also made industry-wide changes that have negatively impacted the Desktop business during both 2018 and 2019.

Google’s policy changes related to its Chrome browser, which became effective on September 12, 2018, negatively impacted the distribution of our B2C downloadable desktop products. The resultant reduction in projected profits and revenues of this business resulted in a $27.7 million impairment of the B2C trade name, which was recorded in the fourth quarter of 2018. On May 31, 2019, Google announced industry-wide policy changes, which became effective on July 1, 2019, related to all extensions distributed through the Chrome Web Store. These industry-wide changes, combined with other changes to polices under the Services Agreement during the second half of 2019, have had a negative impact on the historical and expected future results of operations of the Desktop business. As of December 31, 2019, the goodwill balance of the Desktop reporting unit and the carrying value of the related intangible asset are $265.1 million and $28.9 million, respectively. The fair values of the Desktop reporting unit and the related intangible asset approximate their carrying values; therefore, a modest reduction in the fair values of the Desktop reporting unit or the related intangible asset would result in an impairment charge, which would be equal to the excess of the carrying value over the fair value of such assets.

The Company’s business is subject to certain risks and concentrations including dependence on third-party technology providers, exposure to risks associated with online commerce security and credit card fraud.

Financial instruments, which potentially subject the Company to concentration of credit risk, consist primarily of cash and cash equivalents and marketable debt securities. Cash and cash equivalents are maintained with financial institutions and are in excess of Federal Deposit Insurance Corporation insurance limits.

Property and Equipment

Property and equipment, including significant improvements, are recorded at cost. Repairs and maintenance costs are expensed as incurred. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, or, in the case of leasehold improvements, the lease term, if shorter.



Asset Category	Estimated Useful Lives
Buildings and leasehold improvements	3 to 39 Years
Capitalized software and computer equipment	2 to 3 Years
Furniture and other equipment	3 to 12 Years

The Company capitalizes certain internal use software costs including external direct costs utilized in developing or obtaining the software and compensation for personnel directly associated with the development of the software. Capitalization of such costs begins when the preliminary project stage is complete and ceases when the project is substantially complete and ready for its intended purpose. The net book value of capitalized internal use software is $83.8 million and $58.1 million at December 31, 2019 and 2018, respectively.

Business Combinations

The purchase price of each acquisition is attributed to the assets acquired and liabilities assumed based on their fair values at the date of acquisition, including identifiable intangible assets that either arise from a contractual or legal right or are separable from goodwill. The Company usually uses the assistance of outside valuation experts to assist in the allocation of purchase price to the identifiable intangible assets acquired. While outside valuation experts may be used, management has ultimate responsibility for the valuation methods, models and inputs used and the resulting purchase price allocation. The excess purchase price over the net tangible and identifiable intangible assets is recorded as goodwill and is assigned to the reporting unit(s) that is expected to benefit from the combination as of the acquisition date.

In connection with certain business combinations, the Company has entered into contingent consideration arrangements that are determined to be part of the purchase price. Each of these arrangements is initially recorded at its fair value at the time of the acquisition and reflected at current fair value for each subsequent reporting period thereafter until settled. Generally, our contingent consideration arrangements are based upon financial performance and/or operating metric targets. The Company generally determines the fair value of the contingent consideration arrangements by using probability-weighted analyses to determine the amounts of the gross liability, and, if the arrangement is long-term in nature, applying a discount rate that appropriately captures the risk associated with the obligation to determine the net amount reflected in the consolidated financial statements. Significant changes in forecasted earnings or operating metrics would result in a significantly higher or lower fair value measurement. The changes in the remeasured fair value of the contingent consideration arrangements during each reporting period, including the accretion of the discount, if applicable, are recognized in "General and administrative expense" in the accompanying consolidated statement of operations. See "Note 6—Financial Instruments and Fair Value Measurements" for a discussion of contingent consideration arrangements.

Goodwill and Indefinite-Lived Intangible Assets

The Company assesses goodwill and indefinite-lived intangible assets for impairment annually as of October 1, or more frequently if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit or the fair value of an indefinite-lived intangible asset below its carrying value.

When the Company elects to perform a qualitative assessment and concludes it is not more likely than not that the fair value of the reporting unit is less than its carrying value, no further assessment of that reporting unit's goodwill is necessary; otherwise, a quantitative assessment is performed and the fair value of the reporting unit is determined. If the carrying value of the reporting unit exceeds its fair value, an impairment equal to the excess is recorded.

For the Company's annual goodwill test at October 1, 2019, a qualitative assessment of the MTCH, ANGI, Vimeo, Mosaic Group (included in the Applications segment), College Humor Media, Bluecrew and Nursefly reporting units' goodwill was performed because the Company concluded it was more likely than not that the fair value of these reporting units was in excess of their respective carrying values. The primary factors that the Company considered in its qualitative assessment for each of these reporting units are described below:


•	MTCH's October 1, 2019 market capitalization of $20.0 billion exceeded its carrying value by approximately $19.8 billion and MTCH's strong operating performance.


•	ANGI's October 1, 2019 market capitalization of $3.6 billion exceeded its carrying value by approximately $2.2 billion.

•

The Company prepared valuations of the Vimeo, Mosaic Group, Bluecrew and Nursefly reporting units primarily in connection with the issuance and/or settlement of equity awards that are denominated in the equity of these businesses subsequent to January 1, 2019. The valuations were prepared time proximate to, however, not as of, October 1, 2019. The fair value of each of these businesses was in excess of its October 1, 2019 carrying value.

The Company quantitatively tests goodwill for impairment as of October 1 when it concludes that it is more likely than not that there may be an impairment. For the Company's annual goodwill test at October 1, 2019, the Company quantitatively tested the Desktop reporting unit (included in the Applications segment). The Company's quantitative test indicated that there was no impairment. The Company's Dotdash, Ask Media Group and The Daily Beast reporting units have no goodwill.

The aggregate goodwill balance for the Desktop reporting unit for which the most recent estimate of fair value is less than 10% over its carrying value is approximately $265.1 million.

The fair value of the Company's reporting units (except for MTCH and ANGI described above) is determined using both an income approach based on discounted cash flows ("DCF") and a market approach when it tests goodwill for impairment, either on an interim basis or annual basis as of October 1 each year. The Company uses the same approach in determining the fair value of its businesses in connection with its non-public subsidiary denominated stock-based compensation plans, which can be a significant factor in the decision to apply the qualitative assessment rather than a quantitative test. Determining fair value using a DCF analysis requires the exercise of significant judgment with respect to several items, including the amount and timing of expected future cash flows and appropriate discount rates. The expected cash flows used in the DCF analyses are based on the Company's most recent forecast and budget and, for years beyond the budget, the Company's estimates, which are based, in part, on forecasted growth rates. The discount rates used in the DCF analyses are intended to reflect the risks inherent in the expected future cash flows of the respective reporting units. Assumptions used in the DCF analyses, including the discount rate, are assessed based on each reporting unit's current results and forecasted future performance, as well as macroeconomic and industry specific factors. The discount rates used in the quantitative test for determining the fair value of the Company's reporting units was 12.5% in 2019 and ranged from 12.5% to 15% in 2018. Determining fair value using a market approach considers multiples of financial metrics based on both acquisitions and trading multiples of a selected peer group of companies. From the comparable companies, a representative market multiple is determined which is applied to financial metrics to estimate the fair value of a reporting unit. To determine a peer group of companies for our respective reporting units, we considered companies relevant in terms of consumer use, monetization model, margin and growth characteristics, and brand strength operating in their respective sectors.

While the Company has the option to qualitatively assess whether it is more likely than not that the fair values of its indefinite-lived intangible assets are less than their carrying values, the Company's policy is to determine the fair value of each of its indefinite-lived intangible assets annually as of October 1, in part, because the level of effort required to perform the quantitative and qualitative assessments is essentially equivalent. The Company determines the fair value of indefinite-lived intangible assets using an avoided royalty DCF valuation analysis. Significant judgments inherent in this analysis include the selection of appropriate royalty and discount rates and estimating the amount and timing of expected future cash flows. The discount rates used in the DCF analyses are intended to reflect the risks inherent in the expected future cash flows generated by the respective intangible assets. The royalty rates used in the DCF analyses are based upon an estimate of the royalty rates that a market participant would pay to license the Company's trade names and trademarks. The future cash flows are based on the Company's most recent forecast and budget and, for years beyond the budget, the Company's estimates, which are based, in part, on forecasted growth rates. Assumptions used in the avoided royalty DCF analyses, including the discount rate and royalty rate, are assessed annually based on the actual and projected cash flows related to the asset, as well as macroeconomic and industry specific factors. The discount rates used in the Company's annual indefinite-lived impairment assessment ranged from 10.5% to 27.5% in 2019 and 10.5% to 35% in 2018, and the royalty rates used ranged from 1% to 8% in 2019 and 0.75% to 8% in 2018.

If the carrying value of an indefinite-lived intangible asset exceeds its estimated fair value, an impairment equal to the excess is recorded. The aggregate carrying value of indefinite-lived intangible assets for which the most recent estimate of the excess of fair value over carrying value is less than 10% is approximately $121.2 million.

The 2019 annual assessment of goodwill and indefinite-lived intangible assets identified a $3.3 million goodwill impairment charge and $0.7 million trade name impairment, both related to the College Humor Media business, and a $6.6 million impairment charge related to a trade name at MTCH.

The 2018 annual assessment of goodwill did not identify any impairments. The 2018 annual assessment of indefinite-lived intangible assets identified impairment charges of $27.7 million and $1.1 million related to certain Desktop and College Humor Media indefinite-lived trade names, respectively. The indefinite-lived intangible asset impairment charge at Desktop was due to Google’s policy changes related to its Chrome browser which became effective on September 12, 2018 and have

negatively impacted the distribution of our B2C downloadable desktop products. The impairment charge related to the B2C trade name was identified in our annual impairment assessment as of October 1, 2018 and reflects the projected reduction in profits and revenues and the resultant reduction in the assumed royalty rate from these policy changes. The impairment charges are included in "Amortization of intangibles" in the accompanying consolidated statement of operations.

The 2017 annual assessment of goodwill and indefinite-lived intangible assets did not identify any impairments.

The Company’s operating segments are MTCH, ANGI, Vimeo, Dotdash and Applications, which are also reportable segments, and within its Emerging & Other reportable segment, Ask Media Group, Bluecrew, Nursefly, The Daily Beast, College Humor Media and IAC Films. The Company’s reporting units are consistent with its operating segments, with the exception of Desktop and Mosaic Group, which are separate reporting units within the Applications operating segment. Goodwill is tested for impairment at the reporting unit level. See "Note 12—Segment Information" for additional information regarding the Company's method of determining operating and reportable segments.

Long-Lived Assets and Intangible Assets with Definite Lives

Long-lived assets, which consist of ROU assets, property and equipment and intangible assets with definite lives, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. The carrying value of a long-lived asset is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. If the carrying value is deemed not to be recoverable, an impairment loss is recorded equal to the amount by which the carrying value of the long-lived asset exceeds its fair value. Amortization of definite-lived intangible assets is computed either on a straight-line basis or based on the pattern in which the economic benefits of the asset will be realized.

Fair Value Measurements

The Company categorizes its financial instruments measured at fair value into a fair value hierarchy that prioritizes the inputs used in pricing the asset or liability. The three levels of the fair value hierarchy are:


•	Level 1: Observable inputs obtained from independent sources, such as quoted market prices for identical assets and liabilities in active markets.

•

Level 2: Other inputs, which are observable directly or indirectly, such as quoted market prices for similar assets or liabilities in active markets, quoted market prices for identical or similar assets or liabilities in markets that are not active and inputs that are derived principally from or corroborated by observable market data. The fair values of the Company's Level 2 financial assets are primarily obtained from observable market prices for identical underlying securities that may not be actively traded. Certain of these securities may have different market prices from multiple market data sources, in which case an average market price is used.

•

Level 3: Unobservable inputs for which there is little or no market data and require the Company to develop its own assumptions, based on the best information available in the circumstances, about the assumptions market participants would use in pricing the assets or liabilities. See "Note 6—Financial Instruments and Fair Value Measurements" for a discussion of fair value measurements made using Level 3 inputs.

The Company's non-financial assets, such as goodwill, intangible assets, ROU assets and property and equipment are adjusted to fair value only when an impairment is recognized. The Company's financial assets, comprising equity securities without readily determinable fair values, are adjusted to fair value when observable price changes are identified or an impairment is recognized. Such fair value measurements are based predominantly on Level 3 inputs.

Traffic Acquisition Costs

Traffic acquisition costs consist of (i) the amortization of fees paid to Apple and Google related to the distribution and the facilitation of in-app purchases and (ii) payments made to partners who direct traffic to our Ask Media Group websites, who distribute our business-to-business customized browser-based applications and who integrate our paid listings into their

websites. These payments include amounts based on revenue share and other arrangements. The Company expenses these payments in the period incurred as a component of cost of revenue.

Advertising Costs

Advertising costs are expensed in the period incurred (when the advertisement first runs for production costs that are initially capitalized) and represent online marketing, including fees paid to search engines, social media sites and third parties that distribute our B2C downloadable applications, offline marketing, which is primarily television advertising, and partner-related payments to those who direct traffic to the brands within our MTCH and ANGI segments. Advertising expense is $1.2 billion, $1.2 billion and $1.1 billion for the years ended December 31, 2019, 2018 and 2017, respectively.

The Company capitalizes and amortizes the costs associated with certain distribution arrangements that require us to pay a fee per access point delivered. These access points are generally in the form of downloadable applications associated with our direct-to consumer operations. These fees are amortized over the estimated useful lives of the access points to the extent the Company can reasonably estimate a probable future economic benefit and the period over which such benefit will be realized (generally 18 months). Otherwise, the fees are charged to expense as incurred.

Legal Costs

Legal costs are expensed as incurred.

Income Taxes

The Company accounts for income taxes under the liability method, and deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying values of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. A valuation allowance is provided if it is determined that it is more likely than not that the deferred tax asset will not be realized. The Company records interest, net of any applicable related income tax benefit, on potential income tax contingencies as a component of income tax expense.

The Company evaluates and accounts for uncertain tax positions using a two-step approach. Recognition (step one) occurs when the Company concludes that a tax position, based solely on its technical merits, is more-likely-than-not to be sustainable upon examination. Measurement (step two) determines the amount of benefit that is greater than 50% likely to be realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. De-recognition of a tax position that was previously recognized would occur when the Company subsequently determines that a tax position no longer meets the more-likely-than-not threshold of being sustained.

On December 22, 2017, the U.S. enacted the Tax Cuts and Jobs Act (the "Tax Act"). The Tax Act imposes a new minimum tax on global intangible low-taxed income ("GILTI") earned by foreign subsidiaries beginning in 2018. The FASB Staff Q&A, Topic 740 No. 5, Accounting for Global Intangible Low-Taxed Income, states that an entity may make an accounting policy election to either recognize deferred taxes for temporary differences expected to reverse as GILTI in future years or provide for the tax expense related to GILTI in the year the tax is incurred. The Company has elected to recognize the tax on GILTI as a period expense in the period the tax is incurred.

Earnings Per Share

Basic earnings per share is computed by dividing net earnings attributable to IAC shareholders by the weighted average number of common shares outstanding during the period. Diluted earnings per share reflects the potential dilution that could occur if stock options and other commitments to issue common stock were exercised or equity awards vested resulting in the issuance of common stock that could share in the earnings of the Company. See "Note 10—Earnings Per Share" for additional information on dilutive securities.

Foreign Currency Translation and Transaction Gains and Losses

The financial position and operating results of foreign entities whose primary economic environment is based on their local currency are consolidated using the local currency as the functional currency. These local currency assets and liabilities are translated at the rates of exchange as of the balance sheet date, and local currency revenue and expenses of these operations are translated at average rates of exchange during the period. Translation gains and losses are included in accumulated other comprehensive income as a component of shareholders' equity. Transaction gains and losses resulting from assets and liabilities denominated in a currency other than the functional currency are included in the consolidated statement of operations as a component of other income (expense), net. See "Note 17—Consolidated Financial Statement Details" for additional information regarding foreign currency exchange gains and losses.

Translation gains and losses relating to foreign entities that are liquidated or substantially liquidated are reclassified out of accumulated other comprehensive income (loss) into earnings. Such losses totaled $0.1 million and gains totaled $0.7 million during the years ended December 31, 2018 and 2017, respectively, and were included in "Other income (expense), net" in the accompanying consolidated statement of operations. There were no such gains or losses for the year ended December 31, 2019.

Stock-Based Compensation

Stock-based compensation is measured at the grant date based on the fair value of the award and is generally expensed over the requisite service period. See "Note 11—Stock-based Compensation" for a discussion of the Company's stock-based compensation plans.

Redeemable Noncontrolling Interests

Noncontrolling interests in the consolidated subsidiaries of the Company are ordinarily reported on the consolidated balance sheet within shareholders' equity, separately from the Company's equity. However, securities that are redeemable at the option of the holder and not solely within the control of the issuer must be classified outside of shareholders' equity. Accordingly, all noncontrolling interests that are redeemable at the option of the holder are presented outside of shareholders' equity in the accompanying consolidated balance sheet.

In connection with the acquisition of certain subsidiaries, management of these businesses has retained an ownership interest. The Company is party to fair value put and call arrangements with respect to these interests. These put and call arrangements allow management of these businesses to require the Company to purchase their interests or allow the Company to acquire such interests at fair value, respectively. The put arrangements do not meet the definition of a derivative instrument as the put agreements do not provide for net settlement. These put and call arrangements become exercisable by the Company and the counter-party at various dates in the future. One of these arrangements was exercised during the year ended December 31, 2019 and two of these arrangements were exercised during both of the years ended December 31, 2018 and 2017. These put arrangements are exercisable by the counter-party outside the control of the Company. Accordingly, to the extent that the fair value of these interests exceeds the value determined by normal noncontrolling interest accounting, the value of such interests is adjusted to fair value with a corresponding adjustment to additional paid-in capital. During the years ended December 31, 2019, 2018 and 2017, the Company recorded adjustments of $11.6 million, $4.1 million and $6.3 million, respectively, to increase these interests to fair value. Fair value determinations require high levels of judgment and are based on various valuation techniques, including market comparables and discounted cash flow projections.

Recent Accounting Pronouncements

Accounting Pronouncement adopted by the Company

Adoption of ASU No. 2016-02, Leases (Topic 842)

The Company adopted ASU No. 2016-02, Leases (Topic 842) ("ASC 842") effective January 1, 2019. ASC 842 superseded previously existing guidance on accounting for leases and generally requires all leases to be recognized in the statement of financial position.

The adoption of ASC 842 resulted in the recognition of $154.7 million of ROU assets and related lease liabilities as of January 1, 2019, with no cumulative effect adjustment. The adoption of ASC 842 had no impact on the Company’s consolidated results of operations or cash flows.

The Company adopted ASC 842 prospectively and, therefore, did not revise comparative period information or disclosure. In addition, the Company elected the package of practical expedients permitted under ASC 842.

See "Note 13—Leases" for additional information on the adoption of ASC 842.

Accounting Pronouncement Not Yet Adopted by the Company

ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes

In December 2019, the FASB issued ASU No. 2019-12, which simplifies the accounting for income taxes, eliminates certain exceptions within ASC 740, Income Taxes, and clarifies certain aspects of the current guidance to promote consistency among reporting entities. The provisions of ASU No. 2019-12 are effective for reporting periods beginning after December 15, 2020 with early adoption permitted. Most amendments within ASU No. 2019-12 are required to be applied on a prospective basis, while certain amendments must be applied on a retrospective or modified retrospective basis. The Company adopted ASU No. 2019-12 on January 1, 2020 using the modified retrospective basis for those amendments that are not applied on a prospective basis. The adoption of ASU No. 2019-12 will not have a material impact on the Company’s consolidated financial statements.

Reclassifications

Certain prior year amounts have been reclassified to conform to the current year presentation.

INCOME TAXES

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

INCOME TAXES

U.S. and foreign earnings (loss) before income taxes and noncontrolling interests are as follows:



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
U.S.	$	370,073	$	630,417	$	(52,606	)
Foreign	124,438		131,141		119,564
Total	$	494,511	$	761,558	$	66,958

The components of the income tax provision (benefit) are as follows:



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Current income tax provision (benefit):
Federal	$	278		$	(2,849	)	$	(31,844	)
State	807			2,569			1,964
Foreign	29,707			38,770			24,108
Current income tax provision (benefit)	30,792			38,490			(5,772		)

Deferred income tax provision (benefit):
Federal	(52,985		)	(21,792		)	(255,477		)
State	(25,128		)	172			(28,364		)
Foreign	(1,988		)	(13,059		)	(1,437		)
Deferred income tax benefit	(80,101		)	(34,679		)	(285,278		)
Income tax (benefit) provision	$	(49,309	)	$	3,811		$	(291,050	)

The tax effects of cumulative temporary differences that give rise to significant deferred tax assets and deferred tax liabilities are presented below. The valuation allowance relates to deferred tax assets for which it is more likely than not that the tax benefit will not be realized.



	December 31,
	2019			2018
	(In thousands)
Deferred tax assets:
Net operating loss carryforwards	$	340,472		$	291,639
Tax credit carryforwards	117,286			89,397
Stock-based compensation	79,108			82,698
Long-term lease liabilities	52,748			—
Other	71,328			53,631
Total deferred tax assets	660,942			517,365
Less valuation allowance	(129,620		)	(115,853		)
Net deferred tax assets	531,322			401,512

Deferred tax liabilities:
Investment in subsidiaries	(235,920		)	(238,650		)
Intangible assets	(70,830		)	(77,669		)
Right-of-use assets	(39,226		)	—
Investment in Pinterest	—			(22,927		)
Other	(39,680		)	(21,080		)
Total deferred tax liabilities	(385,656		)	(360,326		)
Net deferred tax assets	$	145,666		$	41,186

At December 31, 2019, the Company has federal and state net operating losses ("NOLs") of $990.3 million and $827.2 million, respectively. If not utilized, $80.2 million of federal NOLs can be carried forward indefinitely, and the remainder will expire at various times primarily between 2027 and 2037, and the state NOLs, if not utilized, will expire at various times between 2020 and 2039. Federal and state NOLs of $617.5 million and $457.4 million, respectively, can be used against future taxable income without restriction and the remaining NOLs will be subject to limitations under Section 382 of the Internal Revenue Code, separate return limitations, and applicable state law. At December 31, 2019, the Company has foreign NOLs of $436.2 million available to offset future income. Of these foreign NOLs, $402.7 million can be carried forward indefinitely and $33.5 million will expire at various times between 2020 and 2039. During 2019, the Company recognized tax benefits related to NOLs of $40.8 million. Included in this amount is $26.9 million of tax benefits of acquired attributes which was recorded as a reduction to goodwill. At December 31, 2019, the Company has federal and foreign disallowed interest carryforwards of $95.1 million and $46.4 million, respectively, that can be carried forward indefinitely and can be used against future taxable income.

At December 31, 2019, the Company has tax credit carryforwards of $159.5 million. Of this amount, $108.4 million relates to credits for research activities, $48.7 million relates to credits for foreign taxes, and $2.4 million relates to various other credits. Of these credit carryforwards, $41.2 million can be carried forward indefinitely and $118.3 million will expire between 2020 and 2039.

The Company regularly assesses the realizability of deferred tax assets considering all available evidence including, to the extent applicable, the nature, frequency and severity of prior cumulative losses, forecasts of future taxable income, tax filing status, the duration of statutory carryforward periods, available tax planning and historical experience.

During 2019, the Company's valuation allowance increased by $13.8 million primarily due to an increase in foreign net operating losses, partially offset by a net decrease in unbenefited capital losses. At December 31, 2019, the Company has a valuation allowance of $129.6 million related to the portion of tax loss carryforwards, foreign tax credits and other items for which it is more likely than not that the tax benefit will not be realized.

A reconciliation of the income tax (benefit) provision to the amounts computed by applying the statutory federal income tax rate to earnings before income taxes is shown as follows:



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Income tax provision at the federal statutory rate of 21% (35% for 2017)	$	103,847		$	159,927		$	23,435
State income taxes, net of effect of federal tax benefit	6,146			16,794			782
Stock-based compensation	(135,179		)	(129,654		)	(358,901		)
Research credits	(33,377		)	(14,276		)	(6,947		)
Realization of certain deferred tax assets	(9,281		)	(13,200		)	(3,133		)
Foreign income taxed at a different statutory tax rate	(3,333		)	(3,206		)	(14,725		)
Deferred tax adjustment for enacted changes in tax laws and rates	890			(7,488		)	705
Non-deductible impairments for certain cost method investments	—			—			2,669
Transition tax	—			(9,190		)	62,667
Withholding taxes	7,304			5,165			562
Other, net	13,674			(1,061		)	1,836
Income tax (benefit) provision	$	(49,309	)	$	3,811		$	(291,050	)

A reconciliation of the beginning and ending amount of unrecognized tax benefits, including penalties but excluding interest, is as follows:



	December 31,
	2019			2018			2017
	(In thousands)
Balance at January 1	$	48,875		$	36,732		$	38,372
Additions based on tax positions related to the current year	14,000			10,334			2,050
Additions for tax positions of prior years	8,949			4,716			1,994
Reductions for tax positions of prior years	(289		)	(400		)	(3,761		)
Settlements	—			—			—
Expiration of applicable statutes of limitations	(1,302		)	(2,507		)	(1,923		)
Balance at December 31	$	70,233		$	48,875		$	36,732

The Company recognizes interest and, if applicable, penalties related to unrecognized tax benefits in the income tax provision. Included in the income tax provision for the years ended December 31, 2019, 2018 and 2017 is a $0.5 million benefit, $0.3 million benefit and $0.1 million expense, respectively, net of related deferred taxes of $0.2 million, less than $0.1 million and $0.1 million, respectively, for interest on unrecognized tax benefits. At December 31, 2019 and 2018, the Company has accrued $4.1 million and $3.4 million, respectively, for the payment of interest. At December 31, 2019 and 2018, the Company has accrued $1.1 million and $1.4 million, respectively, for penalties.

The Company is routinely under audit by federal, state, local and foreign authorities in the area of income tax. These audits include questioning the timing and the amount of income and deductions and the allocation of income and deductions

among various tax jurisdictions. The Internal Revenue Service ("IRS") is currently auditing the Company’s federal income tax returns for the years ended December 31, 2010 through 2016. The statute of limitations for the years 2010 through 2012 has been extended to November 30, 2020 and the statute of limitations for the years 2013 through 2015 has been extended to December 31, 2020. Returns filed in various other jurisdictions are open to examination for tax years beginning with 2009. Income taxes payable include unrecognized tax benefits considered sufficient to pay assessments that may result from examination of prior year tax returns. We consider many factors when evaluating and estimating our tax positions and tax benefits, which may not accurately anticipate actual outcomes and, therefore, may require periodic adjustment. Although management currently believes changes in unrecognized tax benefits from period to period and differences between amounts paid, if any, upon resolution of issues raised in audits and amounts previously provided will not have a material impact on the liquidity, results of operations, or financial condition of the Company, these matters are subject to inherent uncertainties and management’s view of these matters may change in the future.

At December 31, 2019 and 2018, unrecognized tax benefits, including interest and penalties, were $74.4 million and $52.3 million, respectively. If unrecognized tax benefits at December 31, 2019 are subsequently recognized, $69.2 million, net of related deferred tax assets and interest, would reduce income tax expense. The comparable amount as of December 31, 2018 was $49.1 million. The Company believes that it is reasonably possible that its unrecognized tax benefits could decrease by $24.5 million by December 31, 2020, due to expirations of statutes of limitations or other settlements; $24.3 million of which would reduce the income tax provision.

On December 22, 2017, the U.S. enacted the Tax Act. The Tax Act subjected to U.S. taxation certain previously deferred earnings of foreign subsidiaries as of December 31, 2017 ("Transition Tax") and implemented a number of changes that took effect on January 1, 2018, including but not limited to, a reduction of the U.S. federal corporate tax rate from 35% to 21% and a new minimum tax on GILTI earned by foreign subsidiaries. The Company was able to make a reasonable estimate of the Transition Tax and recorded a provisional tax expense in the fourth quarter of 2018. In the third quarter of 2018, the Company finalized this calculation, which resulted in a $9.2 million reduction in the Transition Tax. The net reduction in the Transition Tax was due primarily to the utilization of additional foreign tax credits and a reduction in state taxes, partially offset by additional taxable earnings and profits of our foreign subsidiaries based on guidance issued by the IRS subsequent to December 31, 2017.

The Company has not provided for approximately $2.1 million of deferred taxes on $41.8 million of international cash earnings that are indefinitely reinvested outside the U.S. The remaining $171.2 million of international cash can be repatriated without any significant tax consequences. The Company reassesses its intention to remit or permanently reinvest these cash earnings each reporting period; any required adjustment to the income tax provision would be reflected in the period that the company changes this judgment.

BUSINESS COMBINATION

12 Months Ended

Dec. 31, 2019

Business Combinations [Abstract]

BUSINESS COMBINATION

Through the Combination, ANGI acquired 100% of the common stock of Angie's List on September 29, 2017 for a total purchase price valued at $781.4 million.

The purchase price of $781.4 million was determined based on the sum of (i) the fair value of the 61.3 million shares of Angie's List common stock outstanding immediately prior to the Combination based on the closing stock price of Angie's List common stock on the NASDAQ on September 29, 2017 of $12.46 per share; (ii) the cash consideration of $1.9 million paid to holders of Angie's List common stock who elected to receive $8.50 in cash per share; and (iii) the fair value of vested equity awards (including the pro rata portion of unvested awards attributable to pre-combination services) outstanding under Angie's List stock plans on September 29, 2017. Each stock option to purchase shares of Angie's List common stock that was outstanding immediately prior to the effective time of the Combination was, as of the effective time of the Combination, converted into an option to purchase (i) that number of Class A shares of ANGI Homeservices equal to the total number of shares of Angie's List common stock subject to such Angie's List option immediately prior to the effective time of the Combination, (ii) at a per-share exercise price equal to the exercise price per share of Angie's List common stock at which such Angie's List option was exercisable immediately prior to the effective time of the Combination. Each award of Angie's List restricted stock units that was outstanding immediately prior to the effective time of the Combination was, as of the effective time of the Combination, converted into an ANGI Homeservices restricted stock unit award with respect to a number of Class A

shares of ANGI Homeservices equal to the total number of shares of Angie's List common stock subject to such Angie's List restricted stock unit award immediately prior to the effective time of the Combination.

The table below summarizes the purchase price:



	Angie's List
	(In thousands)
Class A common stock	$	763,684
Cash consideration for holders who elected to receive $8.50 in cash per share of Angie's List common stock	1,913
Fair value of vested and pro rata portion of unvested stock options attributable to pre-combination services	11,749
Fair value of the pro rata portion of unvested restricted stock units attributable to pre-combination services	4,038
Total purchase price	$	781,384

The financial results of Angie's List are included in the Company's consolidated financial statements, within the ANGI Homeservices segment, beginning September 29, 2017. For the year ended December 31, 2017, the Company included $58.9 million of revenue and $21.8 million of net loss in its consolidated statement of operations related to Angie's List. The net loss of Angie's List reflects $28.7 million in stock-based compensation expense related to (i) the acceleration of previously issued Angie's List equity awards held by employees terminated in connection with the Combination and (ii) the expense related to previously issued Angie's List equity awards, severance and retention costs of $19.8 million related to the Combination and a reduction in revenue of $7.8 million due to the write-off of deferred revenue related to the Combination.

The table below summarizes the fair values of the assets acquired and liabilities assumed at the date of combination:



	Angie's List
	(In thousands)
Cash and cash equivalents	$	44,270
Other current assets	11,280
Property and equipment	16,341
Goodwill	543,674
Intangible assets	317,300
Total assets	932,865
Deferred revenue	(32,595		)
Other current liabilities	(46,150		)
Long-term debt—related party	(61,498		)
Deferred income taxes	(9,833		)
Other long-term liabilities	(1,405		)
Net assets acquired	$	781,384

The purchase price was based on the expected financial performance of Angie's List, not on the value of the net identifiable assets at the time of combination. This resulted in a significant portion of the purchase price being attributed to goodwill because Angie's List is complementary and synergistic to the other North America businesses of ANGI Homeservices.

The fair values of the identifiable intangible assets acquired at the date of combination are as follows:



	Angie's List
	(In thousands)		Weighted-Average Useful Life (Years)
Indefinite-lived trade name and trademarks	$	137,000	Indefinite
Service professionals	90,500		3
Developed technology	63,900		6
Memberships	15,900		3
User base	10,000		1
Total identifiable intangible assets acquired	$	317,300

Other current assets, current liabilities and other long-term liabilities of Angie's List were reviewed and adjusted to their fair values at the date of combination, as necessary. The fair value of deferred revenue was determined using an income approach that utilized a cost to fulfill analysis. The fair value of the trade name and trademarks was determined using an income approach that utilized the relief from royalty methodology. The fair values of developed technology and user base were determined using a cost approach that utilized the cost to replace methodology. The fair values of the service professionals and memberships were determined using an income approach that utilized the excess earnings methodology. The valuations of deferred revenue and intangible assets incorporate significant unobservable inputs and require significant judgment and estimates, including the amount and timing of future cash flows, cost and profit margins related to deferred revenue and the determination of royalty and discount rates. The amount attributed to goodwill is not tax deductible.

Unaudited Pro Forma Financial Information

The unaudited pro forma financial information in the table below presents the combined results of the Company and Angie's List as if the Combination had occurred on January 1, 2016. The unaudited pro forma financial information includes adjustments required under the acquisition method of accounting and is presented for informational purposes only and is not necessarily indicative of the results that would have been achieved had the Combination actually occurred on January 1, 2016. For the year ended December 31, 2017, pro forma adjustments include (i) reductions in stock-based compensation expense of $77.1 million and transaction related costs of $34.1 million because they are one-time in nature and will not have a continuing impact on operations; and (ii) an increase in amortization of intangibles of $31.9 million. The stock-based compensation expense is related to the modification of previously issued HomeAdvisor equity awards and previously issued Angie's List equity awards, both of which were converted into ANGI Homeservices' equity awards in the Combination, and the acceleration of certain converted equity awards resulting from the termination of Angie's List employees in connection with the Combination. The transaction related costs include severance and retention costs of $19.8 million related to the Combination.



	Year Ended December 31, 2017
	(In thousands, except per share data)
Revenue	$	3,529,600
Net earnings attributable to IAC shareholders	$	364,496
Basic earnings per share attributable to IAC shareholders	$	4.55
Diluted earnings per share attributable to IAC shareholders	$	4.27

GOODWILL AND INTANGIBLE ASSETS

12 Months Ended

Dec. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

GOODWILL AND INTANGIBLE ASSETS

Goodwill and intangible assets, net are as follows:



	December 31,
	2019		2018
	(In thousands)
Goodwill	$	2,854,462	$	2,726,859
Intangible assets with indefinite lives	446,495		458,104
Intangible assets with definite lives, net of accumulated amortization	131,979		173,318
Total goodwill and intangible assets, net	$	3,432,936	$	3,358,281

The following table presents the balance of goodwill by reportable segment, including the changes in the carrying value of goodwill, for the year ended December 31, 2019:



	Balance at December 31, 2018		Additions		(Deductions)			Impairment			Foreign Exchange Translation			Balance at December 31, 2019
	(In thousands)
Match Group	$	1,245,013	$	3,553	$	—		$	—		$	(8,726	)	$	1,239,840
ANGI Homeservices	892,800		18,326		(29,267		)	—			192			882,051
Vimeo	77,152		142,222		—			—			—			219,374
Applications:
Desktop	265,146		—		—			—			—			265,146
Mosaic Group	239,746		—		—			—			(144		)	239,602
Total Applications	504,892		—		—			—			(144		)	504,748
Emerging & Other	7,002		4,765		—			(3,318		)	—			8,449
Total	$	2,726,859	$	168,866	$	(29,267	)	$	(3,318	)	$	(8,678	)	$	2,854,462

Additions primarily relate to the acquisitions of Magisto (included in the Vimeo segment) and Fixd Repair (included in the ANGI Homeservices segment). Deductions primarily relate to tax benefits of acquired attributes related to the acquisition of Handy (included in the ANGI Homeservices segment). During the fourth quarter of 2019, the Company recorded an impairment charge of $3.3 million related to the goodwill of the College Humor Media business (included in the Emerging & Other Segment).

The following table presents the balance of goodwill by reportable segment, including the changes in the carrying value of goodwill, for the year ended December 31, 2018:



	Balance at December 31, 2017		Additions		(Deductions)			Transfers In/(Out)			Foreign Exchange Translation			Balance at December 31, 2018
	(In thousands)
Match Group	$	1,247,899	$	11,187	$	—		$	—		$	(14,073	)	$	1,245,013
ANGI Homeservices	768,317		142,768		(14,373		)	—			(3,912		)	892,800
Vimeo	77,303		—		(151		)	—			—			77,152
Applications:
Desktop	265,146		—		—			—			—			265,146
Mosaic Group	182,096		50,784		—			7,323			$	(457	)	239,746
Total Applications	447,242		50,784		—			7,323			(457		)	504,892
Emerging & Other	18,305		3,684		(7,664		)	(7,323		)	—			7,002
Total	$	2,559,066	$	208,423	$	(22,188	)	$	—		$	(18,442	)	$	2,726,859

Additions primarily relate to the acquisitions of Handy (included in the ANGI Homeservices segment), TelTech and iTranslate (included in the Applications segment), Hinge (included in the Match Group segment), and Bluecrew (included in the Emerging & Other segment). Deductions relate to the sales of Felix (included in the ANGI Homeservices segment) and Electus (included in the Emerging & Other segment).

Prior to the fourth quarter of 2018, IAC Publishing was a reportable segment consisting of one operating segment and one reporting unit. In the fourth quarter of 2018, IAC Publishing was split into the Dotdash and the Emerging & Other segments (related to the remaining businesses previously included in the IAC Publishing segment). The accumulated goodwill impairment of IAC Publishing was allocated to these businesses based upon their relative fair values as of October 1, 2018.

The December 31, 2019 and 2018 goodwill balances reflect accumulated impairment losses of $529.1 million, $399.7 million and $198.3 million at Applications, the businesses previously included in the IAC Publishing segment (excluding Dotdash, included in the Emerging & Other segment) and Dotdash, respectively. The December 31, 2019 and 2018 goodwill balances also reflect accumulated impairment losses of $14.9 million and $11.6 million, respectively, at College Humor Media (included in the Emerging & Other segment).

Intangible assets with indefinite lives are trade names and trademarks acquired in various acquisitions. At December 31, 2019 and 2018, intangible assets with definite lives are as follows:



	December 31, 2019
	Gross Carrying Amount		Accumulated Amortization			Net		Weighted-Average Useful Life (Years)
	(In thousands)
Technology	$	154,052	$	(79,358	)	$	74,694	4.6
Service professional relationships	99,651		(76,445		)	23,206		2.9
Customer lists and user base	44,548		(24,488		)	20,060		3.3
Trade names	19,074		(13,068		)	6,006		3.2
Memberships	15,900		(11,940		)	3,960		3.0
Other	13,952		(9,899		)	4,053		3.7
Total	$	347,177	$	(215,198	)	$	131,979	3.8



	December 31, 2018
	Gross Carrying Amount		Accumulated Amortization			Net		Weighted-Average Useful Life (Years)
	(In thousands)
Technology	$	143,303	$	(53,199	)	$	90,104	4.7
Service professional relationships	99,528		(44,674		)	54,854		2.9
Customer lists and user base	30,099		(15,126		)	14,973		2.9
Memberships	15,900		(6,640		)	9,260		3.0
Trade names	12,393		(9,393		)	3,000		3.3
Other	8,500		(7,373		)	1,127		4.8
Total	$	309,723	$	(136,405	)	$	173,318	3.8

At December 31, 2019, amortization of intangible assets with definite lives for each of the next five years and thereafter is estimated to be as follows:



Years Ending December 31,	(In thousands)
2020	$	63,844
2021	27,454
2022	22,781
2023	12,870
2024	1,766
Thereafter	3,264
Total	$	131,979

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS

Marketable Securities

At December 31, 2019 and 2018, the fair value of marketable securities are as follows:



	December 31,
	2019		2018
	(In thousands)
Available-for-sale marketable debt securities	$	19,993	$	123,246
Marketable equity security	—		419
Total marketable securities	$	19,993	$	123,665

At December 31, 2019, current available-for-sale marketable debt securities are as follows:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(In thousands)
Commercial paper	$	19,993	$	—	$	—	$	19,993
Total available-for-sale marketable debt securities	$	19,993	$	—	$	—	$	19,993

The contractual maturities of debt securities classified as current available-for-sale at December 31, 2019 are within one year. There are no investments in available-for-sale marketable debt securities that have been in a continuous unrealized loss position for longer than twelve months as of December 31, 2019 and 2018.

At December 31, 2018, current available-for-sale marketable debt securities are as follows:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(In thousands)
Treasury discount notes	$	112,291	$	3	$	(3	)	$	112,291
Commercial paper	10,955		—		—			10,955
Total available-for-sale marketable debt securities	$	123,246	$	3	$	(3	)	$	123,246

The following table presents the proceeds from maturities of available-for-sale marketable debt securities:



	December 31,
	2019		2018		2017
	(In thousands)
Proceeds from maturities of available-for-sale marketable debt securities	$	163,500	$	333,600	$	114,350

There were no gross realized gains or losses from the sales of available-for-sale marketable debt securities for the years ended December 31, 2019, 2018, and 2017.

Long-term investments

Long-term investments consist of:



	December 31,
	2019		2018
	(In thousands)
Equity securities without readily determinable fair values	$	353,052	$	235,055
Total long-term investments	$	353,052	$	235,055

Equity securities without readily determinable fair values

In the third quarter of 2019, the Company made a $250 million investment in Turo, a peer-to-peer car sharing marketplace. As part of its investment, the Company received a warrant that is net settleable at the Company's option and is recorded at fair value each reporting period with any change included in "Other income, net" in the accompany consolidated statement of operations. The warrant is measured using significant unobservable inputs and is classified in the fair value hierarchy table below as Level 3. The warrant is included in "Other non-current assets" in the accompanying consolidated balance sheet.

The Company had an investment in Pinterest, which was carried at fair value following the initial public offering of Pinterest in April 2019. Prior to this, the Company accounted for its investment in Pinterest as an equity security without a readily determinable fair value. The Company sold its remaining shares in Pinterest during the fourth quarter of 2019. For the year ended December 31, 2019, the Company recognized a net gain of $20.5 million related to its investment in Pinterest, which is included in "Other income, net" in the accompanying consolidated statement of operations.

The following table presents a summary of realized and unrealized gains and losses recorded in other income (expense), net,

as adjustments to the carrying value of equity securities without readily determinable fair values held as of December 31, 2019 and 2018.



	Years Ended December 31,
	2019			2018
	(In thousands)
Upward adjustments (gross unrealized gains)	$	19,698		$	128,986
Downward adjustments including impairments (gross unrealized losses)	(5,193		)	(4,931		)
Total	$	14,505		$	124,055

The cumulative upward and downward adjustments (including impairments) to the carrying value of equity securities without readily determinable fair values held at December 31, 2019 were $19.9 million and $7.0 million, respectively.

Realized and unrealized gains and losses for the Company's marketable equity security and investments without readily determinable fair values for the years ended December 31, 2019 and 2018 are as follows:



	Years Ended December 31,
	2019		2018
	(In thousands)
Realized gains, net, for equity securities sold	$	23,076	$	27,874
Unrealized gains, net, on equity securities held	14,505		124,170
Total gains recognized, net, in other income (expense), net	$	37,581	$	152,044

Equity method investments

In 2018 and 2017, the Company recorded other-than-temporary impairment charges on certain of its investments of $0.6 million and $2.7 million, respectively. These charges are included in "Other income (expense), net" in the accompanying consolidated statement of operations.

Cost method investments (prior to the adoption of ASU No. 2016-01)

In 2017, the Company recorded $9.5 million of other-than-temporary impairment charges for certain of its investments as a result of our assessment of the near-term prospects and financial condition of the investees. This charge is included in "Other income (expense), net" in the accompanying consolidated statement of operations.

On October 23, 2017, Match Group sold a cost method investment for net proceeds of $60.2 million. The gain on sale of $9.1 million is included in "Other income (expense), net" in the accompanying consolidated statement of operations.

Fair Value Measurements

The following tables present the Company's financial instruments that are measured at fair value on a recurring basis:



	December 31, 2019
	Quoted Market Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)			Total Fair Value Measurements
	(In thousands)
Assets:
Cash equivalents:
Money market funds	$	2,164,576	$	—	$	—		$	2,164,576
Treasury discount notes	—		199,896		—			199,896
Time deposits	—		128,075		—			128,075
Commercial paper	—		29,960		—			29,960
Marketable securities:
Commercial paper	—		19,993		—			19,993
Other non-current assets:
Warrant	—		—		8,495			8,495
Total	$	2,164,576	$	377,924	$	8,495		$	2,550,995

Liabilities:
Contingent consideration arrangements	$	—	$	—	$	(6,918	)	$	(6,918	)



	December 31, 2018
	Quoted Market Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)			Total Fair Value Measurements
	(In thousands)
Assets:
Cash equivalents:
Money market funds	$	880,815	$	—	$	—		$	880,815
Treasury discount notes	—		561,733		—			561,733
Commercial paper	—		162,417		—			162,417
Time deposits	—		90,036		—			90,036
Marketable securities:
Treasury discount notes	—		112,291		—			112,291
Commercial paper	—		10,955		—			10,955
Marketable equity security	419		—		—			419
Total	$	881,234	$	937,432	$	—		$	1,818,666

Liabilities:
Contingent consideration arrangements	$	—	$	—	$	(28,631	)	$	(28,631	)

The following table presents the changes in the Company's financial instruments that are measured at fair value on a recurring basis using significant unobservable inputs (Level 3):



	Years Ended December 31,
	2019						2018
	Warrant			Contingent Consideration Arrangements			Contingent Consideration Arrangements
	(In thousands)
Balance at January 1	$	—		$	(28,631	)	$	(2,647	)
Fair value at date of acquisition	17,618			—			(25,521		)
Total net (losses) gains:
Included in earnings:
Fair value adjustments	(9,123		)	19,739			(1,456		)
Included in other comprehensive (loss) income	—			(14		)	45
Settlements	—			1,988			948
Balance at December 31	$	8,495		$	(6,918	)	$	(28,631	)

Contingent consideration arrangements

At December 31, 2019, the Company has one outstanding contingent consideration arrangement related to a business acquisition. The arrangement has a total maximum contingent payment of $45.0 million. At December 31, 2019, the gross fair value of this arrangement, before unamortized discount, is $12.5 million. During the first quarter of 2019, the Company paid $2.0 million to settle a contingent consideration arrangement that was outstanding at December 31, 2018.

Generally, our contingent consideration arrangements are based upon financial performance and/or operating metric targets and the Company generally determines the fair value of the contingent consideration arrangements by using probability-weighted analyses to determine the amounts of the gross liability, and, if the arrangements are initially long-term in nature, applying a discount rate that appropriately captures the risks associated with the obligations to determine the net amount reflected in the consolidated financial statements. The fair value of the contingent consideration arrangement at December 31, 2019 reflects a discount rate of 25%. The fair values of the contingent consideration arrangements at December 31, 2018 reflect discount rates ranging from 12% to 25%.

The fair value of contingent consideration arrangements is sensitive to changes in the expected achievement of the applicable targets and changes in discount rates. The Company remeasures the fair value of the contingent consideration arrangements each reporting period, including the accretion of the discount, if applicable, and changes are recognized in "General and administrative expense" in the accompanying consolidated statement of operations. The contingent consideration arrangement liability at December 31, 2019 includes a non-current portion of $6.9 million. The contingent consideration arrangement liability at December 31, 2018 includes a current portion of $2.0 million and a non-current portion of $26.6 million, respectively. The current and non-current portions of the contingent consideration liability are included in “Accrued expenses and other current liabilities” and “Other long-term liabilities,” respectively, in the accompanying consolidated balance sheet.

Financial instruments measured at fair value only for disclosure purposes

The following table presents the carrying value and the fair value of financial instruments measured at fair value only for disclosure purposes:



	December 31, 2019						December 31, 2018
	Carrying Value			Fair Value			Carrying Value			Fair Value
	(In thousands)
Current portion of long-term debt	$	(13,750	)	$	(13,681	)	$	(13,750	)	$	(12,753	)
Long-term debt, net^(a)	(3,121,572		)	(4,136,988		)	(2,245,548		)	(2,460,204		)

_________________


^(a)	At December 31, 2019 and 2018, the carrying value of long-term debt, net includes unamortized original issue discount and debt issuance costs of $404.7 million and $88.9 million, respectively.

At December 31, 2019 and 2018, the fair value of long-term debt is estimated using observable market prices or indices for similar liabilities, which are Level 2 inputs. At December 31, 2018, the Company considered the outstanding borrowings under the MTCH's $500 million revolving credit facility ("MTCH Credit Facility"), which has a variable interest rate, to have a fair value equal to its carrying value. The outstanding borrowings under the MTCH Credit Facility were repaid with a portion of the net proceeds from MTCH's $350 million aggregate principal amount of its 5.625% Senior Notes issued on February 15, 2019. See "Note 7—Long-Term Debt" for additional information on the repayment of the MTCH Credit Facility.

LONG-TERM DEBT

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

LONG-TERM DEBT

Long-term debt consists of:



	December 31,
	2019		2018
	(In thousands)
MTCH Debt:
MTCH Term Loan due November 16, 2022	$	425,000	$	425,000
MTCH Credit Facility due December 7, 2023	—		260,000
6.375% Senior Notes due June 1, 2024 (the "6.375% MTCH Senior Notes"); interest payable each June 1 and December 1	400,000		400,000
5.00% Senior Notes due December 15, 2027 (the "5.00% MTCH Senior Notes"); interest payable each June 15 and December 15	450,000		450,000
5.625% Senior Notes due February 15, 2029 (the "5.625% MTCH Senior Notes"); interest payable each February 15 and August 15	350,000		—
Total MTCH long-term debt	1,625,000		1,535,000
Less: unamortized original issue discount	6,282		7,352
Less: unamortized debt issuance costs	15,235		11,737
Total MTCH debt, net	1,603,483		1,515,911

ANGI Debt:
ANGI Term Loan due November 5, 2023	247,500		261,250
Less: current portion of ANGI Term Loan	13,750		13,750
Less: unamortized debt issuance costs	1,804		2,529
Total ANGI debt, net	231,946		244,971

IAC Debt:
0.875% Exchangeable Senior Notes due October 1, 2022 (the "2022 Exchangeable Notes"); interest payable each April 1 and October 1	517,500		517,500
0.875% Exchangeable Senior Notes due June 15, 2026 (the "2026 Exchangeable Notes"); interest payable each June 15 and December 15	575,000		—
2.00% Exchangeable Senior Notes due January 15, 2030 (the "2030 Exchangeable Notes"); interest payable each January 15 and July 15; commencing on January 15, 2020	575,000		—
4.75% Senior Notes due December 15, 2022 (the "4.75% Senior Notes"); interest payable each June 15 and December 15	—		34,489
Total IAC long-term debt	1,667,500		551,989
Less: unamortized original issue discount	351,605		54,025
Less: unamortized debt issuance costs	29,752		13,298
Total IAC debt, net	1,286,143		484,666

Total long-term debt, net	$	3,121,572	$	2,245,548

MTCH Senior Notes

The 6.375% MTCH Senior Notes were issued on June 1, 2016, and are currently redeemable. These notes may be redeemed at redemption prices set forth below, together with accrued and unpaid interest thereon to the applicable redemption date, if redeemed during the twelve-month period beginning on June 1 of the years indicated below:



Year	Percentage
2019	104.781	%
2020	103.188	%
2021	101.594	%
2022 and thereafter	100.000	%

The 5.00% MTCH Senior Notes were issued on December 4, 2017. The proceeds from these notes, along with cash on hand, were used to redeem the $445.2 million outstanding balance of the 6.75% MTCH Senior Notes, which were due on December 15, 2022, and pay the related call premium. At any time prior to December 15, 2022, the 5.00% MTCH Senior Notes may be redeemed at a redemption price equal to the sum of the principal amount thereof, plus accrued and unpaid interest and a make-whole premium set forth in the indenture governing the notes. Thereafter, these notes may be redeemed at the redemption prices set forth below, together with accrued and unpaid interest thereon to the applicable redemption date, if redeemed during the twelve-month period beginning on December 15 of the years indicated below:



Year	Percentage
2022	102.500	%
2023	101.667	%
2024	100.833	%
2025 and thereafter	100.000	%

The 5.625% MTCH Senior Notes were issued on February 15, 2019. The proceeds were used to repay outstanding borrowings under the MTCH Credit Facility, to pay expenses associated with the offering, and for general corporate purposes. At any time prior to February 15, 2024, these notes may be redeemed at a redemption price equal to the sum of the principal amount thereof, plus accrued and unpaid interest and a make-whole premium set forth in the indenture governing the notes. Thereafter, these notes may be redeemed at redemption prices set forth in the indenture governing the notes, together with accrued and unpaid interest thereon to the applicable redemption date, if redeemed during the twelve-month period beginning on February 15 of the years indicated below:



Year	Percentage
2024	102.813	%
2025	101.875	%
2026	100.938	%
2027 and thereafter	100.000	%

The indentures governing the 6.375% and 5.00% MTCH Senior Notes contain covenants that would limit MTCH's ability to pay dividends, make distributions or repurchase MTCH stock in the event a default has occurred or MTCH's consolidated leverage ratio (as defined in the indentures) exceeds 5.0 to 1.0. At December 31, 2019, there were no limitations pursuant thereto. There are additional covenants in these indentures that limit MTCH's ability and the ability of its subsidiaries to, among other things, (i) incur indebtedness, make investments, or sell assets in the event MTCH is not in compliance with certain ratios set forth in the indentures, and (ii) incur liens, enter into agreements restricting MTCH subsidiaries' ability to pay dividends, enter into transactions with affiliates and consolidate, merge or sell substantially all of their assets. The indenture governing the 5.625% MTCH Senior Notes is less restrictive than the indentures governing the 6.375% and 5.00% MTCH

Senior Notes and generally only limits MTCH's ability and the ability of its subsidiaries to, among other things, create liens on assets and limits MTCH's ability to consolidate, merge, sell or otherwise dispose of all or substantially all of its assets.

MTCH's Senior Notes are ranked equally with each other.

MTCH Term Loan and MTCH Credit Facility

At both December 31, 2019 and 2018, the outstanding balance on the MTCH Term Loan was $425 million. The MTCH Term Loan bears interest at LIBOR plus 2.50% and was 4.44% and 5.09% at December 31, 2019 and 2018, respectively. The MTCH Term Loan provides for annual principal payments as part of an excess cash flow sweep provision, the amount of which, if any, is governed by the secured net leverage ratio contained in the credit agreement. Interest payments are due at least quarterly through the term of the loan.

On December 7, 2018, the MTCH $500 million revolving credit facility (the "MTCH Credit Facility") was amended and restated, and is due on December 7, 2023. At December 31, 2019, there were no outstanding borrowings under the MTCH Credit Facility. At December 31, 2018, the outstanding borrowings under the MTCH Credit Facility were $260.0 million, which bore interest at LIBOR plus 1.50%, or approximately 4.00%. The annual commitment fee on undrawn funds is based on the current consolidated net leverage ratio and is 25 basis points at both December 31, 2019 and 2018, respectively. Borrowings under the MTCH Credit Facility bear interest, at MTCH's option, at a base rate or LIBOR, in each case plus an applicable margin, which is based on MTCH's consolidated net leverage ratio. The terms of the MTCH Credit Facility require MTCH to maintain a consolidated net leverage ratio of not more than 5.0 to 1.0 and a minimum interest coverage ratio of not less than 2.0 to 1.0 (in each case as defined in the agreement).

The MTCH Term Loan and MTCH Credit Facility contain covenants that would limit MTCH’s ability to pay dividends, make distributions or repurchase MTCH stock in the event MTCH’s secured net leverage ratio exceeds 2.0 to 1.0, while the MTCH Term Loan remains outstanding and, thereafter, if the consolidated net leverage ratio exceeds 4.0 to 1.0, or in the event a default has occurred. There are additional covenants under these MTCH debt agreements that limit the ability of MTCH and its subsidiaries to, among other things, incur indebtedness, pay dividends or make distributions. Obligations under the MTCH Credit Facility and MTCH Term Loan are unconditionally guaranteed by certain MTCH wholly-owned domestic subsidiaries and are also secured by the stock of certain MTCH domestic and foreign subsidiaries. The MTCH Term Loan and outstanding borrowings, if any, under the MTCH Credit Facility rank equally with each other, and have priority over the MTCH Senior Notes to the extent of the value of the assets securing the borrowings under the MTCH credit agreement.

ANGI Term Loan and ANGI Credit Facility

On November 1, 2017, ANGI borrowed $275 million under a five-year term loan facility ("ANGI Term Loan"). On November 5, 2018, the ANGI Term Loan was amended and restated, and is now due on November 5, 2023. At both December 31, 2019 and 2018, the ANGI Term Loan bears interest at LIBOR plus 1.50%. The spread over LIBOR is subject to change in future periods based on ANGI's consolidated net leverage ratio. The interest rate was 3.25% and approximately 4.00% at December 31, 2019 and 2018, respectively. Interest payments are due at least quarterly through the term of the loan. Additionally, there are quarterly principal payments of $3.4 million through December 31, 2021, $6.9 million for the one-year period ending December 31, 2022 and $10.3 million through maturity of the loan when the final amount of $161.6 million is due.

The terms of the ANGI Term Loan require ANGI to maintain a consolidated net leverage ratio of not more than 4.5 to 1.0 and a minimum interest coverage ratio of not less than 2.0 to 1.0 (in each case as defined in the credit agreement). The ANGI Term Loan also contains covenants that would limit ANGI’s ability to pay dividends, make distributions or repurchase ANGI stock in the event a default has occurred or ANGI’s consolidated net leverage ratio exceeds 4.25 to 1.0. There are additional covenants under the ANGI Term Loan that limit the ability of ANGI and its subsidiaries to, among other things, incur indebtedness, pay dividends or make distributions.

On November 5, 2018, ANGI entered into a five-year $250 million revolving credit facility (the "ANGI Credit Facility"). At December 31, 2019 and 2018, there were no outstanding borrowings under the ANGI Credit Facility. The annual commitment fee on undrawn funds is based on the consolidated net leverage ratio most recently reported and is 25 basis points at both December 31, 2019 and 2018. Borrowings under the ANGI Credit Facility bear interest, at ANGI's option, at either a

base rate or LIBOR, in each case plus an applicable margin, which is based on ANGI's consolidated net leverage ratio. The financial and other covenants are the same as those for the ANGI Term Loan.

The ANGI Term Loan and ANGI Credit Facility are guaranteed by ANGI's wholly-owned material domestic subsidiaries and are secured by substantially all assets of ANGI and the guarantors, subject to certain exceptions.

IAC Exchangeable Notes

On October 2, 2017, IAC FinanceCo, Inc., a direct, wholly-owned subsidiary of the Company, issued $517.5 million aggregate principal amount of its 2022 Exchangeable Notes. During 2019, IAC FinanceCo 2, Inc. and IAC FinanceCo 3, Inc., direct, wholly-owned subsidiaries of the Company, issued $575.0 million aggregate principal amount of its 2026 Exchangeable Notes and $575.0 million aggregate principal amount of its 2030 Exchangeable Notes, respectively.

The net proceeds from the sales of the 2026 Exchangeable Notes and the 2030 Exchangeable Notes were approximately $1.1 billion, after deducting fees and expenses. A portion of the net proceeds from the offerings were used to pay the net premium of $136.9 million on the 2026 Exchangeable Notes Hedge and Warrants and the 2030 Exchangeable Notes Hedge and Warrants (described below). The remainder will be used for general corporate purposes.

The 2022, 2026 and 2030 Exchangeable Notes (collectively the "Exchangeable Notes") are guaranteed by the Company. At December 31, 2019, the Company, excluding MTCH and ANGI, held $2.3 billion in cash and cash equivalents and marketable securities, which is in excess of $1.7 billion of the Exchangeable Notes outstanding.

The following table presents detail of the exchangeable feature:



	Number of shares of the Company's Common Stock into which each $1,000 of Principal of the Exchangeable Notes is Exchangeable*	Approximate Equivalent Exchange Price per Share*		Exchangeable Date
2022 Exchangeable Notes	6.5713	$	152.18	July 1, 2022
2026 Exchangeable Notes	3.3028	$	302.77	March 15, 2026
2030 Exchangeable Notes	3.4323	$	291.35	October 15, 2029

_________________

^*Subject to adjustment upon the occurrence of specific events.

The Exchangeable Notes are exchangeable under the following circumstances:

(1) during any calendar quarter (and only during such calendar quarter), if the last reported sale price of the Company's common stock for at least 20 trading days during the period of 30 consecutive trading days during the immediately preceding calendar quarter is greater than or equal to 130% of the exchange price on each applicable trading day;

(2) during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company's common stock and the exchange rate on each such trading day;

(3) if the issuer calls the notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date; or

(4) upon the occurrence of specified corporate events as further described under the indenture governing the Exchangeable Notes.

On or after the respective exchangeable dates noted in the table above, until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may exchange all or any portion of their Exchangeable Notes

regardless of the foregoing conditions. Upon exchange, the Company, in its sole discretion, has the option to settle the Exchangeable Notes with any of the three following alternatives: (1) shares of the Company's common stock, (2) cash or (3) a combination of cash and shares of the Company's common stock. It is the Company's intention to settle the Exchangeable Notes with cash equal to the face amount of the notes upon exchange; any shares issued would be offset by shares received upon exercise of the Exchangeable Note Hedges (described below).

The Company’s 2022 Exchangeable Notes are currently exchangeable; during year ended December 31, 2019, no notes were exchanged. The if-converted value of the 2022 Exchangeable Notes exceeded its principal amount of $517.5 million by $329.6 million and $105.0 million based on the Company's stock price on December 31, 2019 and 2018, respectively. Any dilution arising from the 2022 Exchangeable Notes would be mitigated by the 2022 Exchangeable Notes Hedge.

Additionally, each of IAC FinanceCo 2, Inc. and IAC FinanceCo 3, Inc. may redeem for cash all or any portion of its applicable notes, at its option, on or after June 20, 2023 and July 20, 2026, respectively, if the last reported sale price of the common stock underlying the respective notes has been at least 130% of the exchange price then in effect for at least 20 trading days (whether or not consecutive), including at least one of the five trading days immediately preceding the date on which the notice of redemption is provided, during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which the applicable issuer provides notice of redemption, at a redemption price equal to 100% of the principal amount to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date.

We separately account for the debt and the equity components of the Exchangeable Notes and therefore, the Company recorded an original issue discount and corresponding increase to additional paid-in capital, which is the fair value attributed to the exchange feature of each series of debt at issuance. The Company is amortizing the original issue discount and debt issuance costs utilizing the effective interest method over the life of the Exchangeable Notes. The effective interest rates for the 2022, 2026 and 2030 Exchangeable Notes are 4.73%, 5.35% and 6.59%, respectively.

The following table sets forth the components of the Exchangeable Notes as of December 31, 2019 and 2018 (in thousands):



	2022 Exchangeable Notes		2026 Exchangeable Notes		2030 Exchangeable Notes
December 31, 2019
Liability component:
Principal	$	517,500	$	575,000	$	575,000
Less: unamortized original issue discount	40,768		129,037		181,800
Net carrying value of the liability component	$	476,732	$	445,963	$	393,200

Equity component	$	70,363	$	138,796	$	189,213


	2022 Exchangeable Notes
December 31, 2018
Liability component:
Principal	$	517,500
Less: unamortized original issue discount	54,025
Net carrying value of the liability component	$	463,475

Equity component	$	70,363

The following table sets forth interest expense recognized related to Exchangeable Notes (in thousands):



		Year Ended December 31, 2019
		2022 Exchangeable Notes		2026 Exchangeable Notes		2030 Exchangeable Notes
Contractual interest expense		$	4,528	$	2,963	$	6,772
Amortization of original issue discount		13,256		9,759		7,413
Amortization of debt issuance costs		2,981		758		420
Total interest expense recognized		$	20,765	$	13,480	$	14,605


	Year Ended December 31, 2018
		2022 Exchangeable Notes
Contractual interest expense		$	4,528
Amortization of original issue discount		13,134
Amortization of debt issuance costs		3,489
Total interest expense recognized		$	21,151

Exchangeable Notes Hedge and Warrants

In connection with the Exchange Notes offerings, the Company purchased call options allowing the Company to purchase initially (subject to adjustment upon the occurrence of specified events) the same number of shares that would be issuable upon the exchange of the applicable Exchangeable Notes at the price per share set forth below (the "Exchangeable Notes Hedge"), and sold warrants allowing the counterparty to purchase (subject to adjustment upon the occurrence of specified events) shares at the per share price set forth below (the "Exchangeable Notes Warrants").

Exchangeable Notes Hedges are expected to reduce the potential dilutive effect on the Company's common stock upon any exchange of notes and/or offset any cash payment IAC FinanceCo, Inc., IAC FinanceCo 2, Inc. or IAC FinanceCo 3, Inc. is required to make in excess of the principal amount of the exchanged notes. The Exchangeable Notes Warrants have a dilutive effect on the Company's common stock to the extent that the market price per share of the Company common stock exceeds their respective strike prices.

The following tables presents details of the Exchangeable Notes Hedges and Warrants (shares in millions):



	Number of Shares*	Approximate Equivalent Exchange Price per Share*
2022 Exchangeable Notes Hedge	3.4	$	152.18
2026 Exchangeable Notes Hedge	1.9	$	302.77
2030 Exchangeable Notes Hedge	2.0	$	291.35


	Number of Shares*	Strike Price per Share*
2022 Exchangeable Notes Warrants	3.4	$	229.70
2026 Exchangeable Notes Warrants	1.9	$	457.02
2030 Exchangeable Notes Warrants	2.0	$	457.02

_________________

^*Subject to adjustment upon occurrence of specific events.

IAC Senior Notes

On August 23, 2019, the Company redeemed all outstanding 4.75% Senior Notes for $34.5 million plus a premium of $0.5 million and accrued interest of $0.3 million.

IAC Credit Facility

At December 31, 2019, IAC has a $250 million revolving credit facility (the "IAC Credit Facility"), under which IAC Group, LLC, a subsidiary of the Company is the borrower ("Borrower"), that expires on November 5, 2023. At December 31, 2019 and 2018, there were no outstanding borrowings under the IAC Credit Facility. The annual commitment fee on undrawn funds is based on the consolidated net leverage ratio (as defined in the agreement) most recently reported and is 20 basis points at both December 31, 2019 and 2018. Borrowings under the IAC Credit Facility bear interest, at the Borrower's option, at a base rate or LIBOR, in each case, plus an applicable margin, which is based on the Borrower's consolidated net leverage ratio. The terms of the IAC Credit Facility require that the Borrower maintains a consolidated net leverage ratio of not more than 3.25 to 1.0 before the date on which the Borrower no longer holds majority of the outstanding voting stock of each of ANGI and MTCH ("Trigger Date") and no greater than 2.75 to 1.0 on or after the Trigger Date. The terms of the IAC Credit Facility also restrict our ability to incur additional indebtedness. Borrowings under the IAC Credit Facility are unconditionally guaranteed by certain of our wholly-owned domestic subsidiaries and are also secured by the stock of certain of our domestic and foreign subsidiaries, including the shares of MTCH and ANGI owned by the Borrower.

Long-term debt maturities:



Years Ending December 31,	(In thousands)
2020	$	13,750
2021	13,750
2022	970,000
2023	192,500
2024	400,000
Thereafter	1,950,000
Total	3,540,000
Less: current portion of long-term debt	13,750
Less: unamortized original issue discount	357,887
Less: unamortized debt issuance costs	46,791
Total long-term debt, net	$	3,121,572

SHAREHOLDERS' EQUITY	12 Months Ended
SHAREHOLDERS' EQUITY	Dec. 31, 2019
Stockholders' Equity Note [Abstract]
SHAREHOLDERS' EQUITY	SHAREHOLDERS' EQUITY Description of Common Stock and Class B Convertible Common Stock Except as described herein, shares of IAC common stock and IAC Class B common stock are identical. Each holder of shares of IAC common stock and IAC Class B common stock vote together as a single class with respect to matters that may be submitted to a vote or for the consent of IAC's shareholders generally, including the election of directors. In connection with any such vote, each holder of IAC common stock is entitled to one vote for each share of IAC common stock held and each holder of IAC Class B common stock is entitled to ten votes for each share of IAC Class B common stock held. Notwithstanding the foregoing, the holders of shares of IAC common stock, acting as a single class, are entitled to elect 25% of the total number of IAC's directors, and, in the event that 25% of the total number of directors shall result in a fraction of a director, then the holders of shares of IAC common stock, acting as a single class, are entitled to elect the next higher whole number of IAC's directors. In addition, Delaware law requires that certain matters be approved by the holders of shares of IAC common stock or holders of IAC Class B common stock voting as a separate class. Shares of IAC Class B common stock are convertible into shares of IAC common stock at the option of the holder thereof, at any time, on a share-for-share basis. Such conversion ratio will in all events be equitably preserved in the event of any recapitalization of IAC by means of a stock dividend on, or a stock split or combination of, outstanding shares of IAC common stock or IAC Class B common stock, or in the event of any merger, consolidation or other reorganization of IAC with another corporation. Upon the conversion of shares of IAC Class B common stock into shares of IAC common stock, those shares of IAC Class B common stock will be retired and will not be subject to reissue. Shares of IAC common stock are not convertible into shares of IAC Class B common stock. The holders of shares of IAC common stock and the holders of shares of IAC Class B common stock are entitled to receive, share for share, such dividends as may be declared by IAC's Board of Directors out of funds legally available therefor. In the event of a liquidation, dissolution, distribution of assets or winding-up of IAC, the holders of shares of IAC common stock and the holders of shares of IAC Class B common stock are entitled to receive, share for share, all the assets of IAC available for distribution to its stockholders, after the rights of the holders of any IAC preferred stock have been satisfied. Reserved Common Shares In connection with equity compensation plans, the Exchangeable Notes and warrants, 33.7 million shares of IAC common stock are reserved at December 31, 2019. Exchangeable Notes and Warrants During the years ended December 31, 2019, 2018 and 2017, no warrants were exercised and no Exchangeable Notes were exchanged. See "Note 7—Long-term Debt" for additional information on the Exchangeable Notes Warrants. Common Stock Repurchases There were no common stock repurchases during the year ended December 31, 2019. During the years ended December 31, 2018 and 2017, the Company repurchased 0.5 million and 0.7 million shares of IAC common stock for aggregate consideration, on a trade date basis, of $82.9 million and $50.1 million, respectively. At December 31, 2019, the Company has approximately 8.0 million shares remaining in its share repurchase authorization.

ACCUMULATED OTHER COMPREHENSIVE LOSS

12 Months Ended

Dec. 31, 2019

Equity [Abstract]

ACCUMULATED OTHER COMPREHENSIVE LOSS

The following tables present the components of accumulated other comprehensive (loss) income and items reclassified out of accumulated other comprehensive loss into earnings:



	Year Ended December 31, 2019
	Foreign Currency Translation Adjustment			Unrealized Gains On Available-For-Sale Securities			Accumulated Other Comprehensive Loss
	(In thousands)
Balance at January 1	$	(128,726	)	$	4		$	(128,722	)
Other comprehensive loss	(7,938		)	(4		)	(7,942		)
Net current period other comprehensive loss	(7,938		)	(4		)	(7,942		)
Allocation of accumulated other comprehensive loss related to noncontrolling interests	315			—			315
Balance at December 31	$	(136,349	)	$	—		$	(136,349	)



	Year Ended December 31, 2018
	Foreign Currency Translation Adjustment			Unrealized Gains On Available-For-Sale Securities		Accumulated Other Comprehensive Loss
	(In thousands)
Balance at January 1	$	(103,568	)	$	—	$	(103,568	)
Other comprehensive (loss) income before reclassifications	(25,230		)	4		(25,226		)
Amounts reclassified to earnings	(52		)	—		(52		)
Net current period other comprehensive (loss) income	(25,282		)	4		(25,278		)
Allocation of accumulated other comprehensive loss related to noncontrolling interests	124			—		124
Balance at December 31	$	(128,726	)	$	4	$	(128,722	)



	Year Ended December 31, 2017
	Foreign Currency Translation Adjustment			Unrealized Gains On Available-For-Sale Securities			Accumulated Other Comprehensive (Loss) Income
	(In thousands)
Balance at January 1	$	(170,149	)	$	4,026		$	(166,123	)
Other comprehensive income before reclassifications	65,799			7			65,806
Amounts reclassified to earnings	673			(4,033		)	(3,360		)
Net current period other comprehensive income (loss)	66,472			(4,026		)	62,446
Allocation of accumulated other comprehensive loss related to noncontrolling interests	109			—			109
Balance at December 31	$	(103,568	)	$	—		$	(103,568	)

The amounts reclassified out of foreign currency translation adjustment into earnings for the years ended 2018 and 2017 relate to the liquidation of international subsidiaries. The amount reclassified out of unrealized gains on available-for-sale securities into earnings for the year ended December 31, 2017, include a tax benefit of $3.8 million.

EARNINGS PER SHARE

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

EARNINGS PER SHARE

The following table sets forth the computation of basic and diluted earnings per share attributable to IAC shareholders:



	Years Ended December 31,
	2019						2018						2017
	Basic			Diluted			Basic			Diluted			Basic			Diluted
	(In thousands, except per share data)
Numerator:
Net earnings	$	543,820		$	543,820		$	757,747		$	757,747		$	358,008		$	358,008
Net earnings attributable to noncontrolling interests	(112,689		)	(112,689		)	(130,786		)	(130,786		)	(53,084		)	(53,084		)
Impact from public subsidiaries' dilutive securities^(a)	—			(26,063		)	—			(25,228		)	—			(33,531		)
Net earnings attributable to IAC shareholders	$	431,131		$	405,068		$	626,961		$	601,733		$	304,924		$	271,393

Denominator:
Weighted average basic shares outstanding	84,261			84,261			83,407			83,407			80,089			80,089
Dilutive securities^{(a) (b) (c) (d) (e)}	—			5,782			—			7,915			—			5,221
Denominator for earnings per share—weighted average shares^{(a) (b) (c) (d) (e)}	84,261			90,043			83,407			91,322			80,089			85,310

Earnings per share attributable to IAC shareholders:
Earnings per share	$	5.12		$	4.50		$	7.52		$	6.59		$	3.81		$	3.18

__________________________________________________________________

(a)

IAC has the option to settle certain MTCH and ANGI stock-based awards in its shares. For the years ended December 31, 2019 and 2017, it is more dilutive for MTCH to settle these MTCH equity awards. For the year ended December 31, 2018, it is more dilutive for IAC to settle these MTCH equity awards. For the years ended December 31, 2019, 2018 and 2017, it is more dilutive for IAC to settle these ANGI equity awards.

(b)

If the effect is dilutive, weighted average common shares outstanding include the incremental shares that would be issued upon the assumed exercise of stock options, warrants and subsidiary denominated equity, exchange of the Company's Exchangeable Notes and vesting of restricted stock units ("RSUs"). For the years ended December 31, 2019, 2018 and 2017, 11.1 million, 3.5 million, and 6.9 million potentially dilutive securities, respectively, are excluded from the calculation of diluted earnings per share because their inclusion would have been anti-dilutive.

(c)

Market-based awards and performance-based stock units ("PSUs") are considered contingently issuable shares. Shares issuable upon exercise or vesting of market-based awards and PSUs are included in the denominator for earnings per share if (i) the applicable market or performance condition(s) has been met and (ii) the inclusion of the market-based awards and PSUs is dilutive for the respective reporting periods. For the years ended December 31, 2019, 2018 and 2017, 0.2 million, 0.1 million and 0.1 million shares underlying market-based awards and PSUs were excluded from the calculation of diluted earnings per share because the market or performance conditions had not been met.

(d)

It is the Company's intention to settle the Exchangeable Notes through a combination of cash, equal to the face amount of the notes, and shares; therefore, the Exchangeable Notes are only dilutive for periods during which the average price of IAC common stock exceeds the approximate $152.18, $302.77 and $291.35 per share exchange price per $1,000 principal amount of the 2022 Exchangeable Notes, the 2026 Exchangeable Notes and the 2030 Exchangeable Notes, respectively. The average price of IAC common stock was $223.89 and $167.61 for the years ended December 31, 2019 and 2018, respectively, and the dilutive impact of the 2022 Exchangeable Notes, which is the only series of Exchangeable Notes that is currently dilutive, was 1.1 million and 0.3 million shares, respectively. For the year ended December 31, 2017, the 2022 Exchangeable Notes were anti-dilutive as the average price of IAC common stock was $100.54.

(e)

See "Note 11—Stock-based Compensation" for additional information on equity instruments denominated in the shares of certain subsidiaries.

STOCK-BASED COMPENSATION

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

IAC currently has two active plans under which awards denominated in shares of IAC common stock have been granted. These plans cover stock options to acquire shares of IAC common stock, RSUs, including those that are linked to the achievement of the Company's stock price, known as market-based awards ("MSUs") and those that are linked to the achievement of a performance target, known as performance-based awards ("PSUs"), denominated in shares of IAC common stock, as well as provide for the future grant of these and other equity awards. These plans authorize the Company to grant

awards to its employees, officers, directors and consultants. At December 31, 2019, there are 12.6 million shares available for grant under the plans.

The plans were adopted in 2013 and 2018, have a stated term of ten years, and provide that the exercise price of stock options granted will not be less than the market price of the Company's common stock on the grant date. The plans do not specify grant dates or vesting schedules of awards as those determinations have been delegated to the Compensation and Human Resources Committee of IAC's Board of Directors (the "Committee"). Each grant agreement reflects the vesting schedule for that particular grant as determined by the Committee. Broad-based stock option awards issued to date have generally vested in equal annual installments over a four-year period and RSU awards currently outstanding generally vest in either equal annual installments over a four-year period or cliff-vest after a three-year period, in each case, from the grant date. MSU awards currently outstanding cliff-vest after the market condition has been met either within a three-year or five-year period from the date of grant. PSU awards issued to date cliff-vest after a three-year period from the date of grant.

The amount of stock-based compensation expense recognized in the consolidated statement of operations is net of estimated forfeitures. The forfeiture rate is estimated at the grant date based on historical experience and revised, if necessary, in subsequent periods if actual forfeitures differ from the estimated rate. The expense ultimately recorded is for the awards that vest. At December 31, 2019, there is $272.6 million of unrecognized compensation cost, net of estimated forfeitures, related to all equity-based awards, which is expected to be recognized over a weighted average period of approximately 2.3 years.

The total income tax benefit recognized in the accompanying consolidated statement of operations for the years ended December 31, 2019, 2018 and 2017 related to all stock-based compensation is $189.8 million, $189.0 million and $423.0 million, respectively.

The aggregate income tax benefit recognized related to the exercise of stock options for the years ended December 31, 2019, 2018 and 2017, is $137.2 million, $169.0 million, and $411.6 million, respectively. As the Company is currently in a NOL position, there will be some delay in the timing of the realization of the cash benefit of the income tax deductions related to stock-based compensation because it will be dependent upon the amount and timing of future taxable income and the timing of estimated income tax payments.

IAC Stock Options

Stock options outstanding at December 31, 2019 and changes during the year ended December 31, 2019 are as follows:



	December 31, 2019
	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (In Years)	Aggregate Intrinsic Value
	(Shares and intrinsic value in thousands)
Options outstanding at January 1, 2019	5,814		$	62.97
Granted	—		—
Exercised	(911	)	53.41
Forfeited	(15	)	101.01
Expired	(1	)	124.29
Options outstanding at December 31, 2019	4,887		$	64.63	5.3	$	901,629
Options exercisable	3,851		$	62.83	4.9	$	717,388

The aggregate intrinsic value in the table above represents the difference between IAC's closing stock price on the last trading day of 2019 and the exercise price, multiplied by the number of in-the-money options that would have been exercised had all option holders exercised their options on December 31, 2019. The total intrinsic value of stock options exercised during the years ended December 31, 2019, 2018 and 2017 is $167.4 million, $83.7 million and $164.6 million, respectively.

The following table summarizes the information about stock options outstanding and exercisable at December 31, 2019:



	Options Outstanding				Options Exercisable
Range of Exercise Prices	Outstanding at December 31, 2019	Weighted- Average Remaining Contractual Life in Years	Weighted- Average Exercise Price		Exercisable at December 31, 2019	Weighted- Average Remaining Contractual Life in Years	Weighted- Average Exercise Price
	(Shares in thousands)
$20.01 to $30.00	3	0.1	$	21.60	3	0.1	$	21.60
$30.01 to $40.00	363	1.3	32.39		363	1.3	32.39
$40.01 to $50.00	1,124	5.2	42.96		840	4.8	43.32
$50.01 to $60.00	142	2.2	59.89		141	2.2	59.90
$60.01 to $70.00	916	5.4	65.87		796	5.1	65.97
$70.01 to $80.00	1,755	6.4	75.29		1,206	6.0	74.99
$80.01 to $90.00	500	5.3	84.31		500	5.3	84.31
Greater than $90.01	84	8.2	150.23		2	7.6	104.13
	4,887	5.3	$	64.63	3,851	4.9	$	62.83

There were no stock options granted by the Company during 2019. Less than 0.1 million and approximately 1.2 million stock options were granted by the Company during the years ended December 31, 2018 and 2017, respectively. During 2018, the Company granted market-based stock options that only vest if the price of IAC common stock exceeds the relevant price threshold for a twenty-day consecutive period and the service requirement is met. The market-based vesting condition was achieved in the fourth quarter of 2018. The service requirement provides that this award vests in two installments, the first 50% in 2021 and the second 50% in 2022.

The fair value of stock option awards, with the exception of market-based awards, is estimated on the grant date using the Black-Scholes option pricing model. The Black-Scholes option pricing model incorporates various assumptions, including expected volatility and expected term. During 2018 and 2017, expected stock price volatilities were estimated based on the Company's historical volatility. The risk-free interest rates are based on U.S. Treasuries with comparable terms as the awards, in effect at the grant date. Expected term is based upon the historical exercise behavior of our employees and the dividend yields are based on IAC's historical dividend payments. The following are the weighted average assumptions used in the Black-Scholes option pricing model:



	Years Ended December 31,
	2018		2017
Expected volatility	27	%	29	%
Risk-free interest rate	2.7	%	2.0	%
Expected term	6.2 years		5.2 years
Dividend yield	—	%	—	%

The weighted average fair value of stock options granted during the years ended December 31, 2018 and 2017 are $53.94 and $22.94, respectively.

Cash received from stock option exercises for the years ended December 31, 2019, 2018 and 2017 was $10.7 million, $41.7 million and $82.4 million, respectively.

The Company currently settles all stock options on a net basis. Assuming all stock options outstanding on December 31, 2019 were net settled on that date, the Company would have issued 1.8 million common shares (of which 1.4 million is related to vested stock options and 0.4 million is related to unvested stock options) and would have remitted $450.8 million (of which

$358.7 million is related to vested stock options and $92.1 million is related to unvested stock options) in cash for withholding taxes (assuming a 50% withholding rate).

IAC Restricted Stock Units, Market-based Stock Units and Performance-based Stock Units

RSUs, MSUs and PSUs are awards in the form of phantom shares or units denominated in a hypothetical equivalent number of shares of IAC common stock and with the value of each RSU and PSU equal to the fair value of IAC common stock at the date of grant. The value of each MSU is estimated using a lattice model that incorporates a Monte Carlo simulation of IAC's stock price. Each RSU and PSU grant is subject to service-based vesting, where a specific period of continued employment must pass before an award vests. PSUs also include performance-based vesting, where certain performance targets set at the time of grant must be achieved before an award vests. The vesting of MSUs is tied to the stock price of IAC. For RSU grants, the expense is measured at the grant date as the fair value of IAC common stock and expensed as stock-based compensation over the vesting term. For MSU grants, the expense is measured using a lattice model and expensed as stock-based compensation over the derived service period. For PSU grants, the expense is measured at the grant date as the fair value of IAC common stock and expensed as stock-based compensation over the vesting term if the performance targets are considered probable of being achieved.

Unvested RSUs, MSUs and PSUs outstanding at December 31, 2019 and changes during the year ended December 31, 2019 are as follows:



	RSUs				MSUs			PSUs
	Number of Shares		Weighted Average Grant Date Fair Value		Number of Shares	Weighted Average Grant Date Fair Value		Number of Shares		Weighted Average Grant Date Fair Value
	(Shares in thousands)
Unvested at January 1, 2019	459		$	115.12	—	$	—	113		$	76.00
Granted	63		220.77		159	153.43		—		—
Vested	(304	)	118.25		—	—		—		—
Forfeited	(16	)	194.10		—	—		(113	)	76.00
Unvested at December 31, 2019	202		$	132.37	159	$	153.43	—		$	—

The weighted average fair value of RSUs and PSUs granted during the years ended December 31, 2019, 2018 and 2017 based on market prices of IAC's common stock on the grant date was $220.77, $178.29 and $90.04, respectively. The weighted average fair value of MSUs granted during the year ended December 31, 2019 based on the lattice model was $153.43. There were no MSUs granted or outstanding during the years ended December 31, 2018 and 2017. The total fair value of RSUs and PSUs that vested during the years ended December 31, 2019, 2018 and 2017 was $69.3 million, $8.9 million and $32.5 million, respectively. There were no MSUs that vested during the year ended December 31, 2019.

Equity Instruments Denominated in the Shares of Certain Subsidiaries

Non-publicly-traded Subsidiaries

The following description excludes awards denominated in the shares of the Company's publicly-traded subsidiaries, MTCH and ANGI. MTCH and ANGI stock-based awards are issued pursuant to their respective stock incentive plans.

The Company has granted stock settled stock appreciation rights denominated in the equity of certain non-publicly traded subsidiaries to employees and management of those subsidiaries. These equity awards vest over a period of years or upon the occurrence of certain prescribed events. The value of the stock settled stock appreciation rights is tied to the value of the common stock of these subsidiaries. Accordingly, these interests only have value to the extent the relevant business appreciates in value above the initial value utilized to determine the exercise price. These interests can have significant value in the event of significant appreciation. The fair value of these interest is generally determined by negotiation or arbitration when settled, which will occur at various dates through 2026. These equity awards are settled on a net basis, with the award holder entitled to receive a payment in IAC common shares equal to the intrinsic value of the award at exercise less an amount equal to the

required cash tax withholding payment. The number of IAC common shares ultimately needed to settle these awards may vary significantly from the estimated number below as a result of both movements in our stock price and a determination of fair value of the relevant subsidiary that is different than our estimate. The expense associated with these equity awards is initially measured at fair value at the grant date and is expensed as stock-based compensation over the vesting term. The number of IAC common shares that would be required to settle these interests at current estimated fair values, including vested and unvested interests, at December 31, 2019 is 0.1 million shares. Withholding taxes, which will be paid by the Company on behalf of the employees upon exercise, would have been $20.2 million at December 31, 2019, assuming a 50% withholding rate.

MTCH

MTCH currently settles substantially all equity awards on a net basis. Assuming all MTCH equity awards outstanding on December 31, 2019 were net settled on that date, MTCH would have issued 8.0 million common shares (of which 2.6 million is related to vested shares and 5.4 million is related to unvested shares) and would have remitted $655.9 million (of which $209.5 million is related to vested shares and $446.4 million is related to unvested shares) in cash for withholding taxes (assuming a 50% withholding rate). If MTCH decided to issue a sufficient number of shares to cover the $655.9 million employee withholding tax obligation, 8.0 million additional shares would be issued by MTCH.

Following the completion of the MTCH IPO, certain subsidiary denominated equity awards, including those issued by Tinder, Inc., were settleable, at IAC's election, in shares of IAC common stock or MTCH common stock. Pursuant to the Employee Matters Agreement between IAC and MTCH, to the extent shares of IAC common stock are issued in settlement of these awards, MTCH reimburses IAC for the cost of those shares in cash or by issuing IAC shares of MTCH common stock. In July 2017, Tinder was merged into MTCH and as a result, all Tinder denominated equity awards were converted into MTCH tandem stock options ("Tandem Awards"). All of the MTCH Tandem Awards exercised during 2019, 2018 and 2017 were exercised on a net basis and were settled in IAC common shares; the Company issued 0.2 million, 0.7 million and 2.0 million shares, respectively, of its common stock to settle these awards and MTCH issued 0.6 million, 2.5 million and 11.3 million shares, respectively, of its common stock to IAC as reimbursement. The Company is no longer settling the Tandem Awards in IAC common stock.

During 2017, MTCH also purchased certain fully vested Tandem Awards, and made cash payments of approximately $520 million to cover both the withholding taxes paid on behalf of employees exercising these converted awards and the purchase of certain fully vested awards.

ANGI

In connection with the Combination, previously issued stock appreciation rights related to the common stock of HomeAdvisor (US) were converted into ANGI stock appreciation rights that are settleable, at ANGI's option, on a net basis with ANGI remitting withholding taxes on behalf of the employee or on a gross basis with ANGI issuing a sufficient number of Class A shares to cover the withholding taxes. While these awards can be settled in either Class A shares of ANGI or shares of IAC common stock at IAC's option, these awards are currently being settled in shares of ANGI. If settled in IAC common stock, ANGI reimburses IAC in either cash or through the issuance of Class A shares to IAC. Assuming all of the stock appreciation rights outstanding on December 31, 2019 were net settled on that date, ANGI would have issued 6.8 million shares of ANGI Class A stock and ANGI would have remitted $57.3 million in cash for withholding taxes (assuming a 50% withholding rate). If ANGI decided to issue a sufficient number of shares to cover the $57.3 million employee withholding tax obligation, 6.8 million additional Class A shares would be issued by ANGI. Assuming all other ANGI equity awards outstanding on December 31, 2019 were net settled on that date, including stock options, RSUs and subsidiary denominated equity, ANGI would have issued 5.1 million shares and would have remitted $43.4 million in cash for withholding taxes (assuming a 50% withholding rate).

Prior to the Combination in 2017, the Company issued a number of IAC denominated PSUs to certain ANGI employees. Vesting of the PSUs was contingent upon ANGI's performance for the year ended December 31, 2019. These awards did not vest because the performance conditions were not achieved.

Modification of awards

During 2019, the Company modified certain equity awards and recognized modification charges of $13.1 million.

During 2018, the Company modified certain equity awards and recognized modification charges of $7.9 million. In addition, in connection with the ANGI chief executive officer transition during the fourth quarter of 2018, ANGI accelerated $3.9 million of expense into 2018 from 2019.

In connection with the Combination, the previously issued HomeAdvisor (US) stock appreciation rights were converted into ANGI equity awards resulting in a modification charge of $217.7 million of which $29.0 million, $56.9 million, and $93.4 million were recognized as stock-based compensation expense in the years ended December 31, 2019, 2018, and 2017 respectively, and the remaining charge will be recognized over the vesting period of the modified awards.

During the second quarter of 2017, the Company modified certain HomeAdvisor (US) denominated equity awards and recognized a modification charge of $6.6 million.

During 2014, the Company granted an equity award denominated in shares of a subsidiary of the Company to a non-employee, which was marked to market each reporting period. In the third quarter of 2017, the award was modified and MTCH settled the remaining portion of the award for cash of $33.9 million.

SEGMENT INFORMATION

12 Months Ended

Dec. 31, 2019

Segment Reporting [Abstract]

SEGMENT INFORMATION

The overall concept that IAC employs in determining its operating segments is to present the financial information in a manner consistent with: how the chief operating decision maker views the businesses; how the businesses are organized as to segment management; and the focus of the businesses with regards to the types of services or products offered or the target market. Operating segments are combined for reporting purposes if they meet certain aggregation criteria, which principally relate to the similarity of their economic characteristics or, in the case of the Emerging & Other reportable segment, do not meet the quantitative thresholds that require presentation as separate reportable segments.

The following table presents revenue by reportable segment:



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Revenue:
Match Group	$	2,051,258		$	1,729,850		$	1,330,661
ANGI Homeservices	1,326,205			1,132,241			736,386
Vimeo	196,015			159,641			103,332
Dotdash	167,594			130,991			90,890
Applications	519,459			582,287			577,998
Emerging & Other	496,832			528,250			468,589
Inter-segment elimination	(308		)	(368		)	(617		)
Total	$	4,757,055		$	4,262,892		$	3,307,239

The following table presents the revenue of the Company's segments disaggregated by type of service:



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
Match Group
Direct revenue:
North America	$	1,024,161	$	902,478	$	741,334



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
International	983,013		774,693		539,915
Total Direct revenue	2,007,174		1,677,171		1,281,249
Indirect revenue (principally advertising revenue)	44,084		52,679		49,412
Total Match Group revenue	$	2,051,258	$	1,729,850	$	1,330,661

Supplemental information on Direct revenue
Tinder	$	1,152,045	$	805,316	$	403,216
Other brands	855,129		871,855		878,033
Total Direct revenue	$	2,007,174	$	1,677,171	$	1,281,249

ANGI Homeservices
Marketplace:
Consumer connection revenue	$	913,533	$	704,341	$	521,481
Service professional membership subscription revenue	64,706		66,214		56,135
Other revenue	6,971		3,940		3,798
Total Marketplace revenue	985,210		774,495		581,414
Advertising and other revenue	264,682		287,676		97,483
Total North America revenue	1,249,892		1,062,171		678,897
Consumer connection revenue	59,611		50,913		40,009
Service professional membership subscription revenue	14,231		17,362		16,596
Advertising and other revenue	2,471		1,795		884
Total Europe revenue	76,313		70,070		57,489
Total ANGI Homeservices revenue	$	1,326,205	$	1,132,241	$	736,386

Vimeo
Platform revenue	$	193,736	$	146,665	$	99,650
Hardware revenue	2,279		12,976		3,682
Total Vimeo revenue	$	196,015	$	159,641	$	103,332

Dotdash
Display advertising revenue	$	126,487	$	103,704	$	76,316
Performance marketing revenue	41,107		27,287		14,574
Total Dotdash revenue	$	167,594	$	130,991	$	90,890

Applications
Desktop:
Advertising revenue:
Google advertising revenue	$	291,215	$	426,964	$	480,774
Non-Google advertising revenue	13,162		10,992		6,762
Total advertising revenue	304,377		437,956		487,536
Subscription and other revenue	15,858		20,815		34,613
Total Desktop revenue	320,235		458,771		522,149
Mosaic Group:
Subscription and other revenue	189,878		104,975		27,980
Advertising revenue	9,346		18,541		27,869
Total Mosaic Group revenue	199,224		123,516		55,849
Total Applications revenue	$	519,459	$	582,287	$	577,998



	Years Ended December 31,
	2019		2018		2017
	(In thousands)

Emerging & Other
Advertising revenue:
Google advertising revenue	$	391,709	$	357,752	$	225,576
Non-Google advertising revenue	45,750		66,733		53,911
Total advertising revenue	437,459		424,485		279,487
Other revenue	59,373		103,765		169,497
Test preparation revenue	—		—		19,605
Total Emerging & Other revenue	$	496,832	$	528,250	$	468,589

Revenue by geography is based on where the customer is located. Geographic information about revenue and long-lived assets is presented below:



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
Revenue:
United States	$	3,070,487	$	2,824,928	$	2,323,050
All other countries	1,686,568		1,437,964		984,189
Total	$	4,757,055	$	4,262,892	$	3,307,239



	December 31,
	2019		2018
	(In thousands)
Long-lived assets (excluding goodwill and intangible assets):
United States	$	345,937	$	289,756
All other countries	25,416		29,044
Total	$	371,353	$	318,800

The following tables present operating income (loss) and Adjusted EBITDA by reportable segment:



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Operating income (loss):
Match Group	$	648,531		$	553,294		$	360,517
ANGI Homeservices	38,645			63,906			(149,176		)
Vimeo	(51,921		)	(35,594		)	(27,328		)
Dotdash	29,021			18,778			(15,694		)
Applications	113,569			94,834			130,176
Emerging & Other	(13,012		)	29,964			17,412
Corporate	(183,500		)	(160,043		)	(127,441		)
Total	$	581,333		$	565,139		$	188,466



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Adjusted EBITDA:^(a)
Match Group	$	779,432		$	653,931		$	468,941
ANGI Homeservices	$	202,297		$	247,506		$	37,858
Vimeo	$	(41,790	)	$	(28,045	)	$	(23,607	)
Dotdash	$	39,601		$	21,384		$	(2,763	)
Applications	$	103,551		$	131,837		$	136,757
Emerging & Other	$	(7,756	)	$	36,178		$	25,862
Corporate	$	(88,640	)	$	(74,017	)	$	(67,755	)

_______________________________________________________________________________

(a) The Company's primary financial measure is Adjusted EBITDA, which is defined as operating income excluding: (1) stock-based compensation expense; (2) depreciation; and (3) acquisition-related items consisting of (i) amortization of intangible assets and impairments of goodwill and intangible assets, if applicable, and (ii) gains and losses recognized on changes in the fair value of contingent consideration arrangements. The Company believes this measure is useful for analysts and investors as this measure allows a more meaningful comparison between our performance and that of our competitors. The above items are excluded from our Adjusted EBITDA measure because these items are non-cash in nature. Adjusted EBITDA has certain limitations because it excludes the impact of these expenses.

The following tables reconcile operating income (loss) for the Company's reportable segments and net earnings attributable to IAC shareholders to Adjusted EBITDA:



	Year Ended December 31, 2019
	Operating Income (Loss)			Stock-Based Compensation Expense		Depreciation		Amortization of Intangibles		Acquisition-related Contingent Consideration Fair Value Adjustments			Goodwill Impairment		Adjusted EBITDA
	(In thousands)
Match Group	$	648,531		$	89,724	$	32,450	$	8,727	$	—		$	—	$	779,432
ANGI Homeservices	38,645			$	68,255	$	39,915	$	55,482	$	—		$	—	$	202,297
Vimeo	(51,921		)	$	—	$	478	$	9,653	$	—		$	—	$	(41,790	)
Dotdash	29,021			$	—	$	974	$	9,606	$	—		$	—	$	39,601
Applications	113,569			$	—	$	1,443	$	8,277	$	(19,738	)	$	—	$	103,551
Emerging & Other	(13,012		)	$	—	$	1,088	$	850	$	—		$	3,318	$	(7,756	)
Corporate	(183,500		)	$	82,809	$	12,051	$	—	$	—		$	—	$	(88,640	)
Total	581,333
Interest expense	(153,563		)
Other income, net	66,741
Earnings before income taxes	494,511
Income tax benefit	49,309
Net earnings	543,820
Net earnings attributable to noncontrolling interests	(112,689		)
Net earnings attributable to IAC shareholders	$	431,131



	Year Ended December 31, 2018
	Operating Income (Loss)			Stock-Based Compensation Expense		Depreciation		Amortization of Intangibles		Acquisition-related Contingent Consideration Fair Value Adjustments		Adjusted EBITDA
	(In thousands)
Match Group	$	553,294		$	66,031	$	32,968	$	1,318	$	320	$	653,931
ANGI Homeservices	63,906			$	97,078	$	24,310	$	62,212	$	—	$	247,506
Vimeo	(35,594		)	$	—	$	1,200	$	6,349	$	—	$	(28,045	)
Dotdash	18,778			$	—	$	969	$	1,637	$	—	$	21,384
Applications	94,834			$	—	$	2,601	$	33,266	1,136		$	131,837
Emerging & Other	29,964			$	919	$	1,678	$	3,617	$	—	$	36,178
Corporate	(160,043		)	$	74,392	$	11,634	$	—	$	—	$	(74,017	)
Total	565,139
Interest expense	(109,327		)
Other income, net	305,746
Earnings before income taxes	761,558
Income tax provision	(3,811		)
Net earnings	757,747
Net earnings attributable to noncontrolling interests	(130,786		)
Net earnings attributable to IAC shareholders	$	626,961



	Year Ended December 31, 2017
	Operating Income (Loss)			Stock-Based Compensation Expense		Depreciation		Amortization of Intangibles		Acquisition-related Contingent Consideration Fair Value Adjustments		Adjusted EBITDA
	(In thousands)
Match Group	$	360,517		$	69,090	$	32,613	$	1,468	$	5,253	$	468,941
ANGI Homeservices	(149,176		)	$	149,230	$	14,543	$	23,261	$	—	$	37,858
Vimeo	(27,328		)	$	—	$	1,408	$	2,313	$	—	$	(23,607	)
Dotdash	(15,694		)	$	—	$	2,255	$	10,676	$	—	$	(2,763	)
Applications	130,176			$	—	$	3,863	$	2,170	$	548	$	136,757
Emerging & Other	17,412			$	2,130	$	4,065	$	2,255	$	—	$	25,862
Corporate	(127,441		)	$	44,168	$	15,518	$	—	$	—	$	(67,755	)
Total	188,466
Interest expense	(105,295		)
Other expense, net	(16,213		)
Earnings before income taxes	66,958
Income tax benefit	291,050
Net earnings	358,008
Net earnings attributable to noncontrolling interests	(53,084		)
Net earnings attributable to IAC shareholders	$	304,924

The following table presents capital expenditures by reportable segment:



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
Capital expenditures:
Match Group	$	38,754	$	30,954	$	28,833
ANGI Homeservices	68,804		46,976		26,837
Vimeo	2,801		209		109
Dotdash	—		102		825
Applications	85		111		227
Emerging & Other	345		1,119		852
Corporate	25,863		6,163		17,840
Total	$	136,652	$	85,634	$	75,523

LEASES

12 Months Ended

Dec. 31, 2019

Leases [Abstract]

LEASES

The Company leases land, office space, data center facilities and equipment used in connection with its operations under various operating leases, the majority of which contain escalation clauses.

ROU assets represent the Company’s right to use the underlying assets for the lease term and lease liabilities represent the present value of the Company’s obligation to make payments arising from these leases. ROU assets and related lease liabilities are based on the present value of fixed lease payments over the lease term using the Company's and its publicly-traded subsidiaries' respective incremental borrowing rates on the lease commencement date or January 1, 2019 for leases that commenced prior to that date. The Company combines the lease and non-lease components of lease payments in determining ROU assets and related lease liabilities. If the lease includes one or more options to extend the term of the lease, the renewal option is considered in the lease term if it is reasonably certain the Company will exercise the option(s). Lease expense is recognized on a straight-line basis over the term of the lease. As permitted by ASC 842, leases with an initial term of twelve months or less ("short-term leases") are not recorded on the accompanying consolidated balance sheet.

Variable lease payments consist primarily of common area maintenance, utilities and taxes, which are not included in the recognition of ROU assets and related lease liabilities. The Company’s lease agreements do not contain any material residual value guarantees or material restrictive covenants.



Leases	Balance Sheet Classification	December 31, 2019
		(In thousands)
Assets:
Right-of-use assets	Right-of-use assets, net	$	167,801

Liabilities:
Current lease liabilities	Accrued expenses and other current liabilities	33,118
Long-term lease liabilities	Other long-term liabilities	190,772
Total lease liabilities		$	223,890



Lease Cost	Income Statement Classification	Year Ended December 31, 2019
		(In thousands)
Fixed lease cost	Cost of revenue	$	4,106
Fixed lease cost	Selling and marketing expense	10,641
Fixed lease cost	General and administrative expense	34,639
Fixed lease cost	Product development expense	1,541
Total fixed lease cost^(a)		50,927
Variable lease cost	Cost of revenue	441
Variable lease cost	Selling and marketing expense	1,573
Variable lease cost	General and administrative expense	7,853
Variable lease cost	Product development expense	391
Total variable lease cost		10,258
Net lease cost		$	61,185

_____________________

^(a) Includes approximately $5.3 million of short-term lease cost and $2.1 million of sublease income for the year ended December 31, 2019.

Maturities of lease liabilities as of December 31, 2019 (in thousands)^(b):



Years Ended December 31,
2020	$	43,902
2021	40,567
2022	32,135
2023	28,607
2024	25,594
Thereafter	226,734
Total	397,539
Less: Interest	173,649
Present value of lease liabilities	$	223,890

_____________________

^(b) Lease payments exclude $37.7 million of legally binding minimum lease payments for leases signed but not yet commenced.

The following are the weighted average assumptions used for lease term and discount rate as of December 31, 2019:



Remaining lease term	15.4 years
Discount rate	6.00	%



	Year Ended December 31, 2019
	(In thousands)
Other information:
Right-of-use assets obtained in exchange for lease liabilities	$	66,408
Cash paid for amounts included in the measurement of lease liabilities	$	49,117

COMMITMENTS AND CONTINGENCIES

12 Months Ended

Dec. 31, 2019

Commitments and Contingencies Disclosure [Abstract]

COMMITMENTS AND CONTINGENCIES

Commitments

The Company has entered into certain off-balance sheet commitments that require the future purchase of services ("purchase obligations"). Future payments under noncancelable unconditional purchase obligations as of December 31, 2019 are as follows:



	Amount of Commitment Expiration Per Period
	Less Than 1 Year		1-3 Years		3-5 Years		More Than 5 Years		Total Amounts Committed
	(In thousands)
Purchase obligations	$	119,116	$	81,423	$	—	$	—	$	200,539

Purchase obligations include (i) a $150.0 million three-year cloud computing contract, of which $50.0 million was paid in 2019 and had a related prepaid asset of $40.3 million at December 31, 2019 included in "Other current assets" on the consolidated balance sheet, and two remaining minimum payments of $50.0 million each that are due in 2020 and 2021, (ii) remaining payments of $59.3 million related to a two-year cloud computing contract, which $40.9 million and $18.3 million are estimated to be paid in 2020 and 2021, respectively, (iii) remaining payments of $23.8 million related to advertising

commitments to be made in 2020, and (iv) a remaining payment of $13.1 million related to the purchase of a 50% interest in a corporate aircraft that is expected to be made in 2021.

Contingencies

In the ordinary course of business, the Company is a party to various lawsuits. The Company establishes reserves for specific legal matters when it determines that the likelihood of an unfavorable outcome is probable and the loss is reasonably estimable. Management has also identified certain other legal matters where we believe an unfavorable outcome is not probable and, therefore, no reserve is established. Although management currently believes that resolving claims against us, including claims where an unfavorable outcome is reasonably possible, will not have a material impact on the liquidity, results of operations, or financial condition of the Company, these matters are subject to inherent uncertainties and management's view of these matters may change in the future. The Company also evaluates other contingent matters, including income and non-income tax contingencies, to assess the likelihood of an unfavorable outcome and estimated extent of potential loss. It is possible that an unfavorable outcome of one or more of these lawsuits or other contingencies could have a material impact on the liquidity, results of operations, or financial condition of the Company. See "Note 3—Income Taxes" for additional information related to income tax contingencies.

Tinder Optionholder Litigation against IAC and Match Group

On August 14, 2018, ten then-current and former employees of Match Group, LLC or Tinder, Inc. ("Tinder"), an operating business of Match Group, filed a lawsuit in New York state court against IAC and Match Group. See Sean Rad et al. v. IAC/InterActiveCorp and Match Group, Inc., No. 654038/2018 (Supreme Court, New York County). The complaint alleges that in 2017, the defendants: (i) wrongfully interfered with a contractually established process for the independent valuation of Tinder by certain investment banks, resulting in a substantial undervaluation of Tinder and a consequent underpayment to the plaintiffs upon exercise of their Tinder stock options, and (ii) then wrongfully merged Tinder into Match Group, thereby depriving certain of the plaintiffs of their contractual right to later valuations of Tinder on a stand-alone basis. The complaint asserts claims for breach of contract, breach of the implied covenant of good faith and fair dealing, unjust enrichment, interference with contractual relations (as against Match Group only), and interference with prospective economic advantage, and seeks compensatory damages in the amount of at least $2 billion, as well as punitive damages. On August 31, 2018, four plaintiffs who were still employed by Match Group filed a notice of discontinuance of their claims without prejudice, leaving the six former employees as the remaining plaintiffs.

On October 9, 2018, the defendants filed a motion to dismiss the complaint on various grounds, including that the 2017 valuation of Tinder by the investment banks was an expert determination any challenge to which is both time-barred under applicable law and available only on narrow substantive grounds that the plaintiffs have not pleaded in their complaint; the plaintiffs opposed the motion. On June 13, 2019, the court issued a decision and order (i) granting the motion to dismiss the claims for breach of the implied covenant of good faith and fair dealing and for unjust enrichment, (ii) granting the motion to dismiss the merger-related claim for breach of contract as to two of the remaining six plaintiffs, and (iii) otherwise denying the motion to dismiss. On June 21, 2019, the defendants filed a notice of appeal from the trial court’s partial denial of their motion to dismiss, and the parties thereafter briefed the appeal. On October 29, 2019, the Appellate Division, First Department, issued an order affirming the lower court’s decision. On November 22, 2019, the defendants filed a motion for reargument or, in the alternative, leave to appeal the Appellate Division's order to the New York Court of Appeals; the plaintiffs opposed the motion, which remains pending.

On June 3, 2019, the defendants filed a second motion to dismiss based upon certain provisions of the plaintiffs' agreement with a litigation funding firm; the plaintiffs have opposed the motion, which remains pending. Document discovery in the case is substantially complete, and deposition discovery is underway. On January 30, 2020, the parties participated in a mediation that did not result in resolution of the matter. IAC and Match Group believe that the allegations in this lawsuit are without merit and will continue to defend vigorously against it.

RELATED PARTY TRANSACTIONS

12 Months Ended

Dec. 31, 2019

RELATED PARTY TRANSACTIONS

IAC and MTCH:

IAC and MTCH, in connection with MTCH's IPO, entered into the following agreements:


•	A Master Transaction Agreement, under which MTCH agrees to assume all of the assets and liabilities related to its business and agrees to indemnify IAC against any losses arising out of any breach by MTCH of the Master Transaction Agreement or other IPO related agreements;


•	An Investor Rights Agreement that provides IAC with (i) specified registration and other rights relating to shares of MTCH common stock and (ii) anti-dilution rights with respect to MTCH common stock;


•	An Employee Matters Agreement, which governs the respective rights, responsibilities and obligations of IAC and MTCH after the IPO with respect to a range of compensation (including stock-based compensation) and benefit issues;


•	A Tax Sharing Agreement, which governs the respective rights, responsibilities and obligations of IAC and MTCH with respect to tax liabilities and benefits, entitlement to refunds, preparation of tax returns, tax contests and other tax matters regarding U.S. federal, state, local and foreign income taxes; and

•

A Services Agreement, under which IAC has agreed to provide a range of services to MTCH, including, among others, (i) assistance with certain legal, finance, internal audit, treasury, information technology support, insurance and tax affairs, including assistance with certain public company reporting obligations; (ii) payroll processing services; (iii) tax compliance services; and (iv) such other services as to which IAC and MTCH may agree, and MTCH agrees to provide IAC informational technology services and such other services as to which IAC and MTCH may agree.

During the years ended December 31, 2019, 2018 and 2017, 0.8 million, 3.0 million and 11.9 million shares, respectively, of MTCH common stock were issued to IAC pursuant to the employee matters agreement; 0.7 million, 2.5 million and 11.3 million, respectively, of which were issued as reimbursement for shares of IAC common stock issued in connection with the exercise and settlement of MTCH tandem stock options and equity awards denominated in shares of a subsidiary of MTCH, respectively; and 0.1 million, 0.5 million and 0.6 million, respectively, of which were issued as reimbursement for shares of IAC common stock issued in connection with the exercise and vesting of IAC equity awards held by MTCH employees.

For the years ended December 31, 2019, 2018 and 2017, MTCH was charged $7.9 million, $7.6 million and $9.9 million, respectively, by the Company for services rendered pursuant to a services agreement. Included in these amounts are $5.8 million, $5.2 million and $5.1 million, respectively, for leasing of office space for certain of MTCH's businesses at properties owned by IAC. These amounts were paid in full by MTCH at December 31, 2019, 2018 and 2017, respectively.

At December 31, 2019, MTCH had taxes payable of $0.2 million due to the Company pursuant to the tax sharing agreement. At December 31, 2018, there were no outstanding receivables or payables pursuant to the tax sharing agreement. Refunds made by the Company during 2018 and 2017 pursuant to this agreement were $7.0 million and $10.9 million, respectively. For the year ended December 31, 2019, there were no payments to or refunds from MTCH pursuant to the tax sharing agreement.

In December 2017, certain international subsidiaries of MTCH agreed to sell NOLs that were not expected to be utilized to an IAC subsidiary for $0.9 million.

IAC and ANGI:

IAC and ANGI, in connection with the Combination, entered into the following agreements:


•	A Contribution Agreement under which the Company separated its HomeAdvisor business from its other businesses and caused the HomeAdvisor business to be transferred to ANGI prior to the Combination. Under the Contribution

Agreement, ANGI agrees to indemnify IAC against any losses arising out of any breach by ANGI of the Contribution Agreement;


•	An Investor Rights Agreement that provides IAC with (i) specified registration and other rights relating to shares of ANGI common stock owned by IAC; (ii) anti-dilution rights with respect to ANGI common stock; and (iii) specified board matters with respect to designation of ANGI directors;

•

A Services Agreement, under which IAC has agreed to provide a range of services to ANGI, including, among others, (i) assistance with certain legal, M&A, human resources, finance, risk management, internal audit and treasury functions, health and wellness, information security services and insurance and tax affairs, including assistance with certain public company and unclaimed property reporting obligations; (ii) accounting, controllership and payroll processing services; (iii) investor relations services; (iv) tax compliance services; and (v) such other services as to which IAC and ANGI may agree.


•	A Tax Sharing Agreement, which governs the respective rights, responsibilities and obligations of IAC and ANGI with respect to tax matters, including taxes attributable to ANGI, entitlement to refunds, allocation of tax attributes, preparation of tax returns, certain tax elections, control of tax contests and other tax matters regarding U.S. federal, state, local and foreign income taxes; and

•

An Employee Matters Agreement, which governs the respective rights, responsibilities and obligations of IAC and ANGI after the closing of the Combination with respect to a range of compensation (including stock-based compensation) and benefit issues. Pursuant to this agreement, the Compensation Committee of the IAC Board of Directors has the exclusive authority to determine the treatment of outstanding IAC equity awards in the event of a distribution of ANGI capital stock to IAC stockholders in a transaction intended to qualify as tax-free for U.S. federal income tax purposes. Such authority includes (but is not limited to) the ability to convert all or part of IAC equity awards outstanding immediately prior to the distribution into equity awards denominated in shares of ANGI Class A Common Stock, which ANGI would be obligated to assume and which would be dilutive to ANGI's stockholders.

Additionally, on September 29, 2017, the Company and ANGI entered into two intercompany notes (collectively referred to as "Intercompany Notes") to ANGI as follows: (i) a Payoff Intercompany Note, which provided the funds necessary to repay the outstanding balance under Angie's List's previously existing credit agreement, totaling $61.5 million; and (ii) a Working Capital Intercompany Note, which provided ANGI with $15 million for working capital purposes. These Intercompany Notes were repaid on November 1, 2017, with a portion of the proceeds from the ANGI Term Loan that were received on the same date.

For the years ended December 31, 2019 and 2018, and for the period subsequent to the Combination through December 31, 2017, 0.5 million, 0.9 million and 0.4 million shares, respectively, of ANGI Class B common stock were issued to IAC pursuant to the employee matters agreement as reimbursement for shares of IAC common stock issued in connection with the exercise and vesting of IAC equity awards held by ANGI employees.

On October 10, 2018, IAC was issued 5.1 million shares of Class B common stock of ANGI pursuant to the post-closing adjustment provision of the Angie's List merger agreement.

For the years ended December 31, 2019 and 2018, and for the period subsequent to the Combination through December 31, 2017, ANGI was charged $4.8 million, $5.7 million and $1.7 million, respectively, by the Company for services rendered pursuant to the services agreement. There were no outstanding receivables or payables pursuant to the services agreement as of December 31, 2019. At December 31, 2018, the Company had a $0.1 million outstanding payable to ANGI, pursuant to the services agreement. This amount was deducted from the charges due from ANGI pursuant to the services agreement discussed above during the first quarter of 2019.

At December 31, 2019 and 2018, ANGI had taxes payable of $0.2 million and $12.1 million, respectively, due to the Company pursuant to the tax sharing agreement. During the first quarter of 2019, $11.4 million was paid to the Company pursuant to this agreement.

The Company subleases office space from ANGI and was charged $1.4 million of rent for the year ended December 31, 2019. There were outstanding payables of $0.9 million due to ANGI at December 31, 2019, pursuant to sublease agreements.

IAC and Expedia:

Each of IAC and Expedia has a 50% ownership interest in two aircraft that may be used by both companies. The Company and Expedia purchased an aircraft during the second quarter of 2017 to replace a previously owned aircraft, which was subsequently sold on February 13, 2018. The Company paid $17.4 million (50% of the total purchase price and refurbish costs) for its interest in the new aircraft. In addition, in 2019, the Company and Expedia entered into an agreement to jointly acquire a new corporate aircraft for a total expected cost of $72.3 million (including purchase price and related costs), with each company to bear 50% of such expected cost. The Company paid approximately $23 million in 2019 in connection with our joint entry into the purchase agreement, and the respective share of the balance is due upon delivery of the new aircraft, which is expected to occur in early 2021. Members of the aircraft flight crews are employed by an entity in which each of the Company and Expedia has a 50% ownership interest. The Company and Expedia have agreed to share costs relating to flight crew compensation and benefits pro-rata according to each company's respective usage of the aircraft, for which they are separately billed by the entity described above. The Company and Expedia are related parties since they are under common control, given that Mr. Diller serves as Chairman and Senior Executive of both IAC and Expedia. For the years ended December 31, 2019, 2018 and 2017, total payments made to this entity by the Company were not material.

BENEFIT PLANS	12 Months Ended
BENEFIT PLANS	Dec. 31, 2019
Retirement Benefits [Abstract]
BENEFIT PLANS	BENEFIT PLANS IAC has a retirement savings plan in the United States that qualifies under Section 401(k) of the Internal Revenue Code. Under the IAC/InterActiveCorp Retirement Savings Plan ("the Plan"), participating employees may contribute up to 50% of their pre-tax earnings, but not more than statutory limits. Prior to July 2019, IAC contributed a dollar for each dollar a participant contributed in this plan, with a maximum contribution of 3% of a participant's eligible earnings. In June 2019, the Company approved a change to its matching contribution to 100% of the first 10% of compensation, subject to IRS limits on the Company's matching contribution, that a participant contributes to the Plan. This change is being phased in beginning July 1, 2019 and will be fully implemented by all IAC subsidiaries participating in the Plan no later than January 1, 2020. Matching contributions for the Plan for the years ended December 31, 2019, 2018 and 2017 are $21.0 million, $12.9 million and $11.1 million, respectively. Matching contributions are invested in the same manner as each participant's voluntary contributions in the investment options provided under the Plan. An investment option in the Plan is IAC common stock, but neither participant nor matching contributions are required to be invested in IAC common stock. The increase in matching contributions in 2019 is due primarily to the aforementioned change to the Company's matching contribution. The increase in matching contributions in 2018 is due primarily to an increase in participation in the Plan due to increases in headcount from the Combination and continued corporate growth at ANGI, MTCH, Vimeo and Dotdash. IAC also has or participates in various benefit plans, principally defined contribution plans, for its international employees. IAC's contributions for these plans for the years ended December 31, 2019, 2018 and 2017 are $4.0 million, $3.4 million and $2.5 million, respectively.

CONSOLIDATED FINANCIAL STATEMENT DETAILS

12 Months Ended

Dec. 31, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

CONSOLIDATED FINANCIAL STATEMENT DETAILS



	December 31,
	2019		2018
	(In thousands)
Other current assets:
Prepaid expenses	$	97,609	$	55,586
Capitalized costs to obtain a contract with a customer	71,548		69,817
Capitalized downloadable search toolbar costs, net	21,985		33,365
Income taxes receivable	9,308		10,132
Other	48,917		59,353
Other current assets	$	249,367	$	228,253



	December 31,
	2019			2018
	(In thousands)
Property and equipment, net:
Buildings and leasehold improvements	$	270,509		$	249,026
Capitalized software and computer equipment	268,927			229,083
Furniture and other equipment	93,082			86,694
Land	11,591			11,591
Projects in progress	51,603			29,204
Property and equipment	695,712			605,598
Accumulated depreciation and amortization	(324,359		)	(286,798		)
Property and equipment, net	$	371,353		$	318,800



	December 31,
	2019		2018
	(In thousands)
Accrued expenses and other current liabilities:
Accrued employee compensation and benefits	$	153,705	$	137,583
Accrued advertising expense	91,470		105,520
Other	256,828		191,783
Accrued expenses and other current liabilities	$	502,003	$	434,886



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
Other income (expense), net	$	66,741	$	305,746	$	(16,213	)

Other income, net in 2019 includes: $55.0 million of interest income; a $20.5 million gain related to the sale of our investment in Pinterest; $14.5 million in net upward adjustments related to investments in equity securities without readily determinable fair values; a unrealized reduction of $9.1 million in the estimated fair value of a warrant; a realized loss of $8.2 million related to the sale of Vimeo's hardware business in the first quarter of 2019; and a $1.7 million mark-to-market charge pertaining to a subsidiary denominated equity instrument.

Other income, net in 2018 includes: $26.8 million realized gain on the sale of certain Pinterest shares held by the Company and a $128.8 million unrealized gain to adjust our remaining interest in Pinterest to fair value in accordance with ASU No. 2016-01, which was adopted effective January 1, 2018; $120.6 million in gains related to the sales of Dictionary.com, Electus, Felix and CityGrid; $30.4 million of interest income; and $5.3 million in net foreign currency exchange gains due primarily to the strengthening of the U.S. dollar relative to the British Pound ("GBP") during the year ended December 31, 2019.

Other expense, net in 2017 includes: $16.8 million in net foreign currency exchange losses due primarily to the weakening of the U.S. dollar relative to the GBP; $15.4 million expense related to the extinguishment of the 6.75% MTCH Senior Notes and repricing of the MTCH Term Loan; $13.0 million mark-to-market charge principally pertaining to a subsidiary denominated equity award held by a non-employee; $12.2 million in other-than-temporary impairment charges related to certain investments; $1.2 million expense related to the write-off of deferred financing costs associated with the repayment of the 4.875% Senior Notes; $34.9 million in realized gains related to the sales of certain investments; and $11.4 million of interest income.

Cash and Cash Equivalents and Restricted Cash

The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the consolidated balance sheet to the total amounts shown in the consolidated statement of cash flows:



	December 31, 2019		December 31, 2018		December 31, 2017		December 31, 2016
	(In thousands)
Cash and cash equivalents	$	3,139,295	$	2,131,632	$	1,630,809	$	1,329,187
Restricted cash included in other current assets	654		1,633		2,873		20,464
Restricted cash included in other assets	409		420		—		10,548
Total cash and cash equivalents and restricted cash as shown on the consolidated statement of cash flows	$	3,140,358	$	2,133,685	$	1,633,682	$	1,360,199

Restricted cash at December 31, 2019 primarily consists of a deposit related to corporate credit cards.

Restricted cash at December 31, 2018 primarily consists of a cash collateralized letter of credit and a deposit related to corporate credit cards.

Restricted cash at December 31, 2017 primarily supports a letter of credit to a supplier, which was released to the Company in the second quarter of 2018.

Restricted cash at December 31, 2016 primarily included funds held in escrow for the redemption and repurchase of IAC Senior Notes and the MyHammer tender offer. In the first quarter of 2018, the Senior Notes were redeemed and repurchased and the funds held in escrow for the MyHammer tender offer were returned to the Company.

Supplemental Disclosure of Non-Cash Transactions:

The Company recorded an acquisition-related contingent consideration liability of $25.5 million during the year ended December 31, 2018, in connection with an acquisition. There were no acquisition-related contingent consideration liabilities recorded for the years ended December 31, 2019 and 2017. See "Note 6—Financial Instruments and Fair Value Measurements" for additional information on contingent consideration arrangements.

On October 19, 2018, ANGI issued 8.6 million shares of its Class A common stock valued at $165.8 million in connection with the acquisition of Handy.

On September 29, 2017, ANGI issued 61.3 million shares of its Class A common stock valued at $763.7 million in connection with the Combination.

Supplemental Disclosure of Cash Flow Information:



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Cash paid (received) during the year for:
Interest	$	96,730		$	90,485		$	92,461
Income tax payments	39,515			45,154			35,598
Income tax refunds	(5,436		)	(33,698		)	(42,025		)

QUARTERLY RESULTS (UNAUDITED)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

QUARTERLY RESULTS (UNAUDITED)



	Quarter Ended March 31^(a)		Quarter Ended June 30 ^(a)		Quarter Ended September 30 ^(a)		Quarter Ended December 31^(a)
	(In thousands, except per share data)
Year Ended December 31, 2019
Revenue	$	1,105,843	$	1,186,658	$	1,246,874	$	1,217,680
Cost of revenue	260,071		276,389		296,385		294,575
Operating income	79,873		154,310		185,852		161,298
Net earnings	112,985		146,791		159,772		124,272
Net earnings attributable to IAC shareholders	88,695		113,467		128,544		100,425
Per share information attributable to IAC shareholders:
Basic earnings per share^(f)	$	1.06	$	1.35	$	1.52	$	1.19
Diluted earnings per share^(f)	$	0.91	$	1.19	$	1.35	$	1.05

	Quarter Ended March 31^(b)		Quarter Ended June 30^(c)		Quarter Ended September 30^(d)		Quarter Ended December 31^(e)
	(In thousands, except per share data)
Year Ended December 31, 2018
Revenue	$	995,075	$	1,059,122	$	1,104,592	$	1,104,103
Cost of revenue	201,962		218,224		237,238		253,722
Operating income	89,950		168,437		172,832		133,920
Net earnings	87,839		280,854		171,577		217,477
Net earnings attributable to IAC shareholders	71,082		218,353		145,774		191,752
Per share information attributable to IAC shareholders:
Basic earnings per share^(f)	$	0.86	$	2.61	$	1.75	$	2.29
Diluted earnings per share^(f)	$	0.71	$	2.32	$	1.49	$	2.04

_______________________________________________________________________________


(a)	The first, second, third and fourth quarters of 2019 include after-tax stock-based compensation expense of $2.2 million, $1.9 million, $1.7 million, and $1.7 million, respectively, related to the modification of previously issued HomeAdvisor equity awards and previously issued Angie's List equity awards, both of which were converted into ANGI Homeservices' equity awards in the Combination.

(b)

The first quarter of 2018 includes after-tax stock-based compensation expense of $14.6 million related to the modification of previously issued HomeAdvisor equity awards and previously issued Angie's List equity awards, both of which were converted into ANGI Homeservices' equity awards in the Combination, and the acceleration of certain converted equity awards resulting from the termination of Angie's List employees in connection with the Combination, as well as after-tax costs of $4.1 million related to the Combination (including $2.8 million of deferred revenue write-offs).


(c)	The second quarter of 2018 includes:

after-tax stock-based compensation expense of $12.8 million related to the modification of previously issued HomeAdvisor equity awards and previously issued Angie's List equity awards, both of which were converted into ANGI Homeservices' equity awards in the Combination, and the acceleration of certain converted equity awards resulting from the termination of Angie's List employees in connection with the Combination, as well as after-tax costs of $2.0 million related to the Combination (including $1.8 million of deferred revenue write-offs).


ii.	after-tax realized and unrealized gains of $133.3 million related to the sale of a certain equity investment.


(d)	The third quarter of 2018 includes after-tax stock-based compensation expense of $12.3 million related to the modification of previously issued HomeAdvisor equity awards and previously issued Angie's List equity awards, both of which were converted into ANGI Homeservices' equity awards in the Combination.


(e)	The fourth quarter of 2018 includes:


i.	after-tax stock-based compensation expense of $14.4 million related to the modification of previously issued HomeAdvisor equity awards and previously issued Angie's List equity awards, both of which were converted into ANGI Homeservices' equity awards in the Combination.


ii.	combined after-tax gains of $92.5 million related to the sales of Dictionary.com, Electus, Felix and CityGrid.


iii.	after-tax impairment charges related to indefinite-lived intangible assets of $21.3 million.

(f)

Quarterly per share amounts may not add to the related annual per share amount because of differences in the average common shares outstanding during each period.

SUBSEQUENT EVENTS SUBSEQUENT EVENTS	12 Months Ended
SUBSEQUENT EVENTS SUBSEQUENT EVENTS	Dec. 31, 2019
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS On January 31, 2020, the Company received 1.4 million shares of Match Group common stock in exchange for the contribution of certain real estate to Match Group. On February 11, 2020, the Company completed the acquisition of Care.com, a leading global platform for finding and managing family care, for approximately $500 million, net of cash acquired. Care.com will be reflected in the consolidated financial statements of the Company from the date of its acquisition. On February 11, 2020, MTCH completed a private offering of $500 million aggregate principal amount of 4.125% Senior Notes due August 1, 2030. The net proceeds from the offering, in the event the Separation is consummated, will be used to fund the cash consideration of $3.00 per MTCH common share that will be payable in connection with the Separation. If the Separation is not consummated, the net proceeds will be used by MTCH for general corporate purposes. On February 13, 2020, the $500 million MTCH Credit Facility was amended to, among other things, increase the available borrowing capacity to $750 million, reduce the interest rate to LIBOR plus 1.375%, and extend its maturity to February 13, 2025. Additionally, the $425 million MTCH Term Loan was amended to reprice the outstanding balance to LIBOR plus 1.75% and extend its maturity to February 13, 2027.

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS

12 Months Ended

Dec. 31, 2019

SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS

Schedule II

IAC/INTERACTIVECORP AND SUBSIDIARIES

VALUATION AND QUALIFYING ACCOUNTS



Description	Balance at Beginning of Period		Charges to Earnings				Charges to Other Accounts				Deductions				Balance at End of Period
	(In thousands)
2019
Allowance for doubtful accounts and revenue reserves	$	18,860	$	65,803		^(a)	$	238			$	(60,175	)	^(b)	$	24,726
Deferred tax valuation allowance	115,853		15,404			^(c)	(1,637		)	^(d)	—				129,620
Other reserves	7,734														7,961
2018
Allowance for doubtful accounts and revenue reserves	$	11,489	$	48,445		^(a)	$	(573	)		$	(40,501	)	^(b)	$	18,860
Deferred tax valuation allowance	132,598		(20,746		)	^(e)	4,001			^(f)	—				115,853
Other reserves	2,544														7,734
2017
Allowance for doubtful accounts and revenue reserves	$	16,405	$	28,930		^(a)	$	(1,006	)		$	(32,840	)	^(b)	$	11,489
Sales returns accrual	80		—				(80		)		—				—
Deferred tax valuation allowance	88,170		38,144			^(g)	6,284			^(h)	—				132,598
Other reserves	2,822														2,544

_________________________________________________________


(a)	Additions to the allowance for doubtful accounts are charged to expense.


(b)	Write-off of fully reserved accounts receivable.


(c)	Amount is primarily related to an increase in foreign NOLs partially offset by a net decrease in unbenefited capital losses.


(d)	Amount is primarily related to currency translation adjustments on foreign NOLs.


(e)	Amount is primarily related to a decrease in foreign tax credits subject to a valuation allowance and the realization of previously unbenefited capital losses, partially offset by an increase in state NOLs and foreign interest deduction carryforwards.


(f)	Amount is primarily related to acquired federal and state NOLs, partially offset by currency translation adjustments on foreign NOLs.


(g)	Amount is due primarily to the establishment of foreign NOLs related to an acquisition.

(h)

Amount is primarily related to acquired state NOLs, acquired foreign tax credits and currency translation adjustments on foreign NOLs.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

Basis of Presentation

The Company prepares its consolidated financial statements in accordance with U.S. generally accepted accounting principles ("GAAP").

Basis of Consolidation and Accounting for Investments in Equity Securities

Accounting for Investments in Equity Securities

Accounting Estimates

reported amounts of assets, liabilities, revenue and expenses and the related disclosure of contingent assets and liabilities. Actual results could differ from these estimates.

Revenue Recognition

•

The Company's disaggregated revenue disclosures are presented in "Note 12—Segment Information."



	Under ASC 606 (as reported)			Under ASC 605			Effect of adoption of ASU No. 2014-09
	(In thousands)
Revenue by segment:
Match Group	$	1,729,850		$	1,729,850		$	—
ANGI Homeservices	1,132,241			1,132,241			—
Vimeo	159,641			160,931			(1,290		)
Dotdash	130,991			130,991			—
Applications	582,287			581,492			795
Emerging & Other	528,250			528,250			—
Inter-segment eliminations	(368		)	(368		)	—
Total	$	4,262,892		$	4,263,387		$	(495	)

Operating costs and expenses by segment:
Match Group	$	1,176,556		$	1,176,556		$	—
ANGI Homeservices	1,068,335			1,073,275			(4,940		)
Vimeo	195,235			196,212			(977		)
Dotdash	112,213			112,213			—
Applications	487,453			484,644			2,809
Emerging & Other	498,286			498,286			—
Corporate	159,675			159,675			—
Total	$	3,697,753		$	3,700,861		$	(3,108	)

Operating income (loss) by segment:
Match Group	$	553,294		$	553,294		$	—
ANGI Homeservices	63,904			58,964			4,940
Vimeo	(35,594		)	(35,281		)	(313		)
Dotdash	18,778			18,778			—
Applications	94,834			96,848			(2,014		)
Emerging & Other	29,964			29,964			—
Corporate	(160,043		)	(160,043		)	—
Total	$	565,137		$	562,524		$	2,613

Net earnings	$	757,747		$	755,741		$	2,006

Transaction Price

Arrangements with Multiple Performance Obligations

Assets Recognized from the Costs to Obtain a Contract with a Customer

Performance Obligations

Match Group

ANGI Homeservices

Vimeo

Dotdash

Applications

Emerging & Other

Bluecrew revenue consists of service revenue, which is generated through staffing workers and recognized as control of the promised services is transferred to our customers.

Accounts Receivables, Net of Allowance for Doubtful Accounts and Revenue Reserves

Deferred Revenue

Cash and Cash Equivalents

Investments in Debt Securities

Certain Risks and Concentrations

$69.1 million at December 31, 2019 and 2018, respectively.

Property and Equipment

Business Combinations

Goodwill and Indefinite-Lived Intangible Assets


•	MTCH's October 1, 2019 market capitalization of $20.0 billion exceeded its carrying value by approximately $19.8 billion and MTCH's strong operating performance.


•	ANGI's October 1, 2019 market capitalization of $3.6 billion exceeded its carrying value by approximately $2.2 billion.

•

The aggregate goodwill balance for the Desktop reporting unit for which the most recent estimate of fair value is less than 10% over its carrying value is approximately $265.1 million.

The 2017 annual assessment of goodwill and indefinite-lived intangible assets did not identify any impairments.

Long-Lived Assets and Intangible Assets with Definite Lives

Fair Value Measurements


•	Level 1: Observable inputs obtained from independent sources, such as quoted market prices for identical assets and liabilities in active markets.

•

Traffic Acquisition Costs

websites. These payments include amounts based on revenue share and other arrangements. The Company expenses these payments in the period incurred as a component of cost of revenue.

Advertising Costs

Legal Costs

Legal costs are expensed as incurred.

Income Taxes

Earnings Per Share

Foreign Currency Translation and Transaction Gains and Losses

Translation gains and losses relating to foreign entities that are liquidated or substantially liquidated are reclassified out of accumulated other comprehensive income (loss) into earnings.

Stock-Based Compensation

Stock-based compensation is measured at the grant date based on the fair value of the award and is generally expensed over the requisite service period.

Redeemable Noncontrolling Interests

Recent Accounting Pronouncements

Accounting Pronouncement adopted by the Company

Adoption of ASU No. 2016-02, Leases (Topic 842)

See "Note 13—Leases" for additional information on the adoption of ASC 842.

Accounting Pronouncement Not Yet Adopted by the Company

ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes

Reclassifications

Certain prior year amounts have been reclassified to conform to the current year presentation.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

Schedule of Estimated Useful Lives of Property and Equipment



Asset Category	Estimated Useful Lives
Buildings and leasehold improvements	3 to 39 Years
Capitalized software and computer equipment	2 to 3 Years
Furniture and other equipment	3 to 12 Years



	December 31,
	2019			2018
	(In thousands)
Property and equipment, net:
Buildings and leasehold improvements	$	270,509		$	249,026
Capitalized software and computer equipment	268,927			229,083
Furniture and other equipment	93,082			86,694
Land	11,591			11,591
Projects in progress	51,603			29,204
Property and equipment	695,712			605,598
Accumulated depreciation and amortization	(324,359		)	(286,798		)
Property and equipment, net	$	371,353		$	318,800

Schedule of Cash, Cash Equivalents, and Restricted Cash



	December 31, 2019		December 31, 2018		December 31, 2017		December 31, 2016
	(In thousands)
Cash and cash equivalents	$	3,139,295	$	2,131,632	$	1,630,809	$	1,329,187
Restricted cash included in other current assets	654		1,633		2,873		20,464
Restricted cash included in other assets	409		420		—		10,548
Total cash and cash equivalents and restricted cash as shown on the consolidated statement of cash flows	$	3,140,358	$	2,133,685	$	1,633,682	$	1,360,199

Schedule of Cash, Cash Equivalents, and Restricted Cash



	December 31, 2019		December 31, 2018		December 31, 2017		December 31, 2016
	(In thousands)
Cash and cash equivalents	$	3,139,295	$	2,131,632	$	1,630,809	$	1,329,187
Restricted cash included in other current assets	654		1,633		2,873		20,464
Restricted cash included in other assets	409		420		—		10,548
Total cash and cash equivalents and restricted cash as shown on the consolidated statement of cash flows	$	3,140,358	$	2,133,685	$	1,633,682	$	1,360,199

INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Schedule of Income before Income Taxes

U.S. and foreign earnings (loss) before income taxes and noncontrolling interests are as follows:



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
U.S.	$	370,073	$	630,417	$	(52,606	)
Foreign	124,438		131,141		119,564
Total	$	494,511	$	761,558	$	66,958

Schedule of Components of Income Tax Expense (Benefit)

The components of the income tax provision (benefit) are as follows:



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Current income tax provision (benefit):
Federal	$	278		$	(2,849	)	$	(31,844	)
State	807			2,569			1,964
Foreign	29,707			38,770			24,108
Current income tax provision (benefit)	30,792			38,490			(5,772		)

Deferred income tax provision (benefit):
Federal	(52,985		)	(21,792		)	(255,477		)
State	(25,128		)	172			(28,364		)
Foreign	(1,988		)	(13,059		)	(1,437		)
Deferred income tax benefit	(80,101		)	(34,679		)	(285,278		)
Income tax (benefit) provision	$	(49,309	)	$	3,811		$	(291,050	)

Schedule of Deferred Tax Assets and Liabilities



	December 31,
	2019			2018
	(In thousands)
Deferred tax assets:
Net operating loss carryforwards	$	340,472		$	291,639
Tax credit carryforwards	117,286			89,397
Stock-based compensation	79,108			82,698
Long-term lease liabilities	52,748			—
Other	71,328			53,631
Total deferred tax assets	660,942			517,365
Less valuation allowance	(129,620		)	(115,853		)
Net deferred tax assets	531,322			401,512

Deferred tax liabilities:
Investment in subsidiaries	(235,920		)	(238,650		)
Intangible assets	(70,830		)	(77,669		)
Right-of-use assets	(39,226		)	—
Investment in Pinterest	—			(22,927		)
Other	(39,680		)	(21,080		)
Total deferred tax liabilities	(385,656		)	(360,326		)
Net deferred tax assets	$	145,666		$	41,186

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of the income tax (benefit) provision to the amounts computed by applying the statutory federal income tax rate to earnings before income taxes is shown as follows:



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Income tax provision at the federal statutory rate of 21% (35% for 2017)	$	103,847		$	159,927		$	23,435
State income taxes, net of effect of federal tax benefit	6,146			16,794			782
Stock-based compensation	(135,179		)	(129,654		)	(358,901		)
Research credits	(33,377		)	(14,276		)	(6,947		)
Realization of certain deferred tax assets	(9,281		)	(13,200		)	(3,133		)
Foreign income taxed at a different statutory tax rate	(3,333		)	(3,206		)	(14,725		)
Deferred tax adjustment for enacted changes in tax laws and rates	890			(7,488		)	705
Non-deductible impairments for certain cost method investments	—			—			2,669
Transition tax	—			(9,190		)	62,667
Withholding taxes	7,304			5,165			562
Other, net	13,674			(1,061		)	1,836
Income tax (benefit) provision	$	(49,309	)	$	3,811		$	(291,050	)

Schedule of Income Tax Contingencies

A reconciliation of the beginning and ending amount of unrecognized tax benefits, including penalties but excluding interest, is as follows:



	December 31,
	2019			2018			2017
	(In thousands)
Balance at January 1	$	48,875		$	36,732		$	38,372
Additions based on tax positions related to the current year	14,000			10,334			2,050
Additions for tax positions of prior years	8,949			4,716			1,994
Reductions for tax positions of prior years	(289		)	(400		)	(3,761		)
Settlements	—			—			—
Expiration of applicable statutes of limitations	(1,302		)	(2,507		)	(1,923		)
Balance at December 31	$	70,233		$	48,875		$	36,732

BUSINESS COMBINATION (Tables)

12 Months Ended

Dec. 31, 2019

Business Combinations [Abstract]

Schedule of Purchase Price

The table below summarizes the purchase price:



	Angie's List
	(In thousands)
Class A common stock	$	763,684
Cash consideration for holders who elected to receive $8.50 in cash per share of Angie's List common stock	1,913
Fair value of vested and pro rata portion of unvested stock options attributable to pre-combination services	11,749
Fair value of the pro rata portion of unvested restricted stock units attributable to pre-combination services	4,038
Total purchase price	$	781,384

Schedule of Preliminary Estimated Fair Value of Assets Acquired and Liabilities Assumed

The table below summarizes the fair values of the assets acquired and liabilities assumed at the date of combination:



	Angie's List
	(In thousands)
Cash and cash equivalents	$	44,270
Other current assets	11,280
Property and equipment	16,341
Goodwill	543,674
Intangible assets	317,300
Total assets	932,865
Deferred revenue	(32,595		)
Other current liabilities	(46,150		)
Long-term debt—related party	(61,498		)
Deferred income taxes	(9,833		)
Other long-term liabilities	(1,405		)
Net assets acquired	$	781,384

Schedule of Preliminary Estimated Fair Value of Intangible Assets Acquired

The fair values of the identifiable intangible assets acquired at the date of combination are as follows:



	Angie's List
	(In thousands)		Weighted-Average Useful Life (Years)
Indefinite-lived trade name and trademarks	$	137,000	Indefinite
Service professionals	90,500		3
Developed technology	63,900		6
Memberships	15,900		3
User base	10,000		1
Total identifiable intangible assets acquired	$	317,300

Schedule of Pro Forma Financial Information



	Year Ended December 31, 2017
	(In thousands, except per share data)
Revenue	$	3,529,600
Net earnings attributable to IAC shareholders	$	364,496
Basic earnings per share attributable to IAC shareholders	$	4.55
Diluted earnings per share attributable to IAC shareholders	$	4.27

GOODWILL AND INTANGIBLE ASSETS (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill and Intangible Assets, Net

Goodwill and intangible assets, net are as follows:



	December 31,
	2019		2018
	(In thousands)
Goodwill	$	2,854,462	$	2,726,859
Intangible assets with indefinite lives	446,495		458,104
Intangible assets with definite lives, net of accumulated amortization	131,979		173,318
Total goodwill and intangible assets, net	$	3,432,936	$	3,358,281

Schedule of Goodwill by Reporting Unit

The following table presents the balance of goodwill by reportable segment, including the changes in the carrying value of goodwill, for the year ended December 31, 2019:



	Balance at December 31, 2018		Additions		(Deductions)			Impairment			Foreign Exchange Translation			Balance at December 31, 2019
	(In thousands)
Match Group	$	1,245,013	$	3,553	$	—		$	—		$	(8,726	)	$	1,239,840
ANGI Homeservices	892,800		18,326		(29,267		)	—			192			882,051
Vimeo	77,152		142,222		—			—			—			219,374
Applications:
Desktop	265,146		—		—			—			—			265,146
Mosaic Group	239,746		—		—			—			(144		)	239,602
Total Applications	504,892		—		—			—			(144		)	504,748
Emerging & Other	7,002		4,765		—			(3,318		)	—			8,449
Total	$	2,726,859	$	168,866	$	(29,267	)	$	(3,318	)	$	(8,678	)	$	2,854,462

The following table presents the balance of goodwill by reportable segment, including the changes in the carrying value of goodwill, for the year ended December 31, 2018:



	Balance at December 31, 2017		Additions		(Deductions)			Transfers In/(Out)			Foreign Exchange Translation			Balance at December 31, 2018
	(In thousands)
Match Group	$	1,247,899	$	11,187	$	—		$	—		$	(14,073	)	$	1,245,013
ANGI Homeservices	768,317		142,768		(14,373		)	—			(3,912		)	892,800
Vimeo	77,303		—		(151		)	—			—			77,152
Applications:
Desktop	265,146		—		—			—			—			265,146
Mosaic Group	182,096		50,784		—			7,323			$	(457	)	239,746
Total Applications	447,242		50,784		—			7,323			(457		)	504,892
Emerging & Other	18,305		3,684		(7,664		)	(7,323		)	—			7,002
Total	$	2,559,066	$	208,423	$	(22,188	)	$	—		$	(18,442	)	$	2,726,859

Schedule of Intangible Assets with Definite Lives

Intangible assets with indefinite lives are trade names and trademarks acquired in various acquisitions. At December 31, 2019 and 2018, intangible assets with definite lives are as follows:



	December 31, 2019
	Gross Carrying Amount		Accumulated Amortization			Net		Weighted-Average Useful Life (Years)
	(In thousands)
Technology	$	154,052	$	(79,358	)	$	74,694	4.6
Service professional relationships	99,651		(76,445		)	23,206		2.9
Customer lists and user base	44,548		(24,488		)	20,060		3.3
Trade names	19,074		(13,068		)	6,006		3.2
Memberships	15,900		(11,940		)	3,960		3.0
Other	13,952		(9,899		)	4,053		3.7
Total	$	347,177	$	(215,198	)	$	131,979	3.8



	December 31, 2018
	Gross Carrying Amount		Accumulated Amortization			Net		Weighted-Average Useful Life (Years)
	(In thousands)
Technology	$	143,303	$	(53,199	)	$	90,104	4.7
Service professional relationships	99,528		(44,674		)	54,854		2.9
Customer lists and user base	30,099		(15,126		)	14,973		2.9
Memberships	15,900		(6,640		)	9,260		3.0
Trade names	12,393		(9,393		)	3,000		3.3
Other	8,500		(7,373		)	1,127		4.8
Total	$	309,723	$	(136,405	)	$	173,318	3.8

Schedule of Expected Amortization of Intangible Assets

At December 31, 2019, amortization of intangible assets with definite lives for each of the next five years and thereafter is estimated to be as follows:



Years Ending December 31,	(In thousands)
2020	$	63,844
2021	27,454
2022	22,781
2023	12,870
2024	1,766
Thereafter	3,264
Total	$	131,979

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of Fair Value of Marketable Securities

At December 31, 2019 and 2018, the fair value of marketable securities are as follows:



	December 31,
	2019		2018
	(In thousands)
Available-for-sale marketable debt securities	$	19,993	$	123,246
Marketable equity security	—		419
Total marketable securities	$	19,993	$	123,665

Schedule of Current Available-for-sale Marketable Securities

At December 31, 2018, current available-for-sale marketable debt securities are as follows:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(In thousands)
Treasury discount notes	$	112,291	$	3	$	(3	)	$	112,291
Commercial paper	10,955		—		—			10,955
Total available-for-sale marketable debt securities	$	123,246	$	3	$	(3	)	$	123,246

At December 31, 2019, current available-for-sale marketable debt securities are as follows:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(In thousands)
Commercial paper	$	19,993	$	—	$	—	$	19,993
Total available-for-sale marketable debt securities	$	19,993	$	—	$	—	$	19,993

Schedule of Proceeds from Maturities and Sales of Current Available-for-sale Marketable Securities

The following table presents the proceeds from maturities of available-for-sale marketable debt securities:



	December 31,
	2019		2018		2017
	(In thousands)
Proceeds from maturities of available-for-sale marketable debt securities	$	163,500	$	333,600	$	114,350

Schedule of Long-term Investments

Long-term investments consist of:



	December 31,
	2019		2018
	(In thousands)
Equity securities without readily determinable fair values	$	353,052	$	235,055
Total long-term investments	$	353,052	$	235,055

Schedule of Realized and Unrealized Gains (Losses) on Investments



	Years Ended December 31,
	2019			2018
	(In thousands)
Upward adjustments (gross unrealized gains)	$	19,698		$	128,986
Downward adjustments including impairments (gross unrealized losses)	(5,193		)	(4,931		)
Total	$	14,505		$	124,055



	Years Ended December 31,
	2019		2018
	(In thousands)
Realized gains, net, for equity securities sold	$	23,076	$	27,874
Unrealized gains, net, on equity securities held	14,505		124,170
Total gains recognized, net, in other income (expense), net	$	37,581	$	152,044

Schedule of Financial Instruments Measured at Fair Value on Recurring Basis

The following tables present the Company's financial instruments that are measured at fair value on a recurring basis:



	December 31, 2019
	Quoted Market Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)			Total Fair Value Measurements
	(In thousands)
Assets:
Cash equivalents:
Money market funds	$	2,164,576	$	—	$	—		$	2,164,576
Treasury discount notes	—		199,896		—			199,896
Time deposits	—		128,075		—			128,075
Commercial paper	—		29,960		—			29,960
Marketable securities:
Commercial paper	—		19,993		—			19,993
Other non-current assets:
Warrant	—		—		8,495			8,495
Total	$	2,164,576	$	377,924	$	8,495		$	2,550,995

Liabilities:
Contingent consideration arrangements	$	—	$	—	$	(6,918	)	$	(6,918	)



	December 31, 2018
	Quoted Market Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)			Total Fair Value Measurements
	(In thousands)
Assets:
Cash equivalents:
Money market funds	$	880,815	$	—	$	—		$	880,815
Treasury discount notes	—		561,733		—			561,733
Commercial paper	—		162,417		—			162,417
Time deposits	—		90,036		—			90,036
Marketable securities:
Treasury discount notes	—		112,291		—			112,291
Commercial paper	—		10,955		—			10,955
Marketable equity security	419		—		—			419
Total	$	881,234	$	937,432	$	—		$	1,818,666

Liabilities:
Contingent consideration arrangements	$	—	$	—	$	(28,631	)	$	(28,631	)

Schedule of Unobservable Inputs in Fair Value Measurement

The following table presents the changes in the Company's financial instruments that are measured at fair value on a recurring basis using significant unobservable inputs (Level 3):



	Years Ended December 31,
	2019						2018
	Warrant			Contingent Consideration Arrangements			Contingent Consideration Arrangements
	(In thousands)
Balance at January 1	$	—		$	(28,631	)	$	(2,647	)
Fair value at date of acquisition	17,618			—			(25,521		)
Total net (losses) gains:
Included in earnings:
Fair value adjustments	(9,123		)	19,739			(1,456		)
Included in other comprehensive (loss) income	—			(14		)	45
Settlements	—			1,988			948
Balance at December 31	$	8,495		$	(6,918	)	$	(28,631	)

Schedule of Carrying Value and the Fair Value of Financial Instruments Measured at Fair Value Only for Disclosure Purposes

The following table presents the carrying value and the fair value of financial instruments measured at fair value only for disclosure purposes:



	December 31, 2019						December 31, 2018
	Carrying Value			Fair Value			Carrying Value			Fair Value
	(In thousands)
Current portion of long-term debt	$	(13,750	)	$	(13,681	)	$	(13,750	)	$	(12,753	)
Long-term debt, net^(a)	(3,121,572		)	(4,136,988		)	(2,245,548		)	(2,460,204		)

_________________

^(a)

At December 31, 2019 and 2018, the carrying value of long-term debt, net includes unamortized original issue discount and debt issuance costs of $404.7 million and $88.9 million, respectively.

LONG-TERM DEBT (Tables)

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Schedule of Long-term Debt

The following table sets forth the components of the Exchangeable Notes as of December 31, 2019 and 2018 (in thousands):



	2022 Exchangeable Notes		2026 Exchangeable Notes		2030 Exchangeable Notes
December 31, 2019
Liability component:
Principal	$	517,500	$	575,000	$	575,000
Less: unamortized original issue discount	40,768		129,037		181,800
Net carrying value of the liability component	$	476,732	$	445,963	$	393,200

Equity component	$	70,363	$	138,796	$	189,213


	2022 Exchangeable Notes
December 31, 2018
Liability component:
Principal	$	517,500
Less: unamortized original issue discount	54,025
Net carrying value of the liability component	$	463,475

Equity component	$	70,363

The following table sets forth interest expense recognized related to Exchangeable Notes (in thousands):



		Year Ended December 31, 2019
		2022 Exchangeable Notes		2026 Exchangeable Notes		2030 Exchangeable Notes
Contractual interest expense		$	4,528	$	2,963	$	6,772
Amortization of original issue discount		13,256		9,759		7,413
Amortization of debt issuance costs		2,981		758		420
Total interest expense recognized		$	20,765	$	13,480	$	14,605


	Year Ended December 31, 2018
		2022 Exchangeable Notes
Contractual interest expense		$	4,528
Amortization of original issue discount		13,134
Amortization of debt issuance costs		3,489
Total interest expense recognized		$	21,151

The following table presents detail of the exchangeable feature:



	Number of shares of the Company's Common Stock into which each $1,000 of Principal of the Exchangeable Notes is Exchangeable*	Approximate Equivalent Exchange Price per Share*		Exchangeable Date
2022 Exchangeable Notes	6.5713	$	152.18	July 1, 2022
2026 Exchangeable Notes	3.3028	$	302.77	March 15, 2026
2030 Exchangeable Notes	3.4323	$	291.35	October 15, 2029

_________________

^*Subject to adjustment upon the occurrence of specific events.

Long-term debt consists of:



	December 31,
	2019		2018
	(In thousands)
MTCH Debt:
MTCH Term Loan due November 16, 2022	$	425,000	$	425,000
MTCH Credit Facility due December 7, 2023	—		260,000
6.375% Senior Notes due June 1, 2024 (the "6.375% MTCH Senior Notes"); interest payable each June 1 and December 1	400,000		400,000
5.00% Senior Notes due December 15, 2027 (the "5.00% MTCH Senior Notes"); interest payable each June 15 and December 15	450,000		450,000
5.625% Senior Notes due February 15, 2029 (the "5.625% MTCH Senior Notes"); interest payable each February 15 and August 15	350,000		—
Total MTCH long-term debt	1,625,000		1,535,000
Less: unamortized original issue discount	6,282		7,352
Less: unamortized debt issuance costs	15,235		11,737
Total MTCH debt, net	1,603,483		1,515,911

ANGI Debt:
ANGI Term Loan due November 5, 2023	247,500		261,250
Less: current portion of ANGI Term Loan	13,750		13,750
Less: unamortized debt issuance costs	1,804		2,529
Total ANGI debt, net	231,946		244,971

IAC Debt:
0.875% Exchangeable Senior Notes due October 1, 2022 (the "2022 Exchangeable Notes"); interest payable each April 1 and October 1	517,500		517,500
0.875% Exchangeable Senior Notes due June 15, 2026 (the "2026 Exchangeable Notes"); interest payable each June 15 and December 15	575,000		—
2.00% Exchangeable Senior Notes due January 15, 2030 (the "2030 Exchangeable Notes"); interest payable each January 15 and July 15; commencing on January 15, 2020	575,000		—
4.75% Senior Notes due December 15, 2022 (the "4.75% Senior Notes"); interest payable each June 15 and December 15	—		34,489
Total IAC long-term debt	1,667,500		551,989
Less: unamortized original issue discount	351,605		54,025
Less: unamortized debt issuance costs	29,752		13,298
Total IAC debt, net	1,286,143		484,666

Total long-term debt, net	$	3,121,572	$	2,245,548

Schedule of Debt Instrument Redemption

These notes may be redeemed at redemption prices set forth below, together with accrued and unpaid interest thereon to the applicable redemption date, if redeemed during the twelve-month period beginning on June 1 of the years indicated below:



Year	Percentage
2019	104.781	%
2020	103.188	%
2021	101.594	%
2022 and thereafter	100.000	%

Thereafter, these notes may be redeemed at the redemption prices set forth below, together with accrued and unpaid interest thereon to the applicable redemption date, if redeemed during the twelve-month period beginning on December 15 of the years indicated below:



Year	Percentage
2022	102.500	%
2023	101.667	%
2024	100.833	%
2025 and thereafter	100.000	%

Thereafter, these notes may be redeemed at redemption prices set forth in the indenture governing the notes, together with accrued and unpaid interest thereon to the applicable redemption date, if redeemed during the twelve-month period beginning on February 15 of the years indicated below:



Year	Percentage
2024	102.813	%
2025	101.875	%
2026	100.938	%
2027 and thereafter	100.000	%

Schedule of Exchangeable Notes Hedges and Warrants

The following tables presents details of the Exchangeable Notes Hedges and Warrants (shares in millions):



	Number of Shares*	Approximate Equivalent Exchange Price per Share*
2022 Exchangeable Notes Hedge	3.4	$	152.18
2026 Exchangeable Notes Hedge	1.9	$	302.77
2030 Exchangeable Notes Hedge	2.0	$	291.35


	Number of Shares*	Strike Price per Share*
2022 Exchangeable Notes Warrants	3.4	$	229.70
2026 Exchangeable Notes Warrants	1.9	$	457.02
2030 Exchangeable Notes Warrants	2.0	$	457.02

_________________

^*Subject to adjustment upon occurrence of specific events.

Schedule of Aggregate Contractual Maturities of Long-term Debt

Long-term debt maturities:



Years Ending December 31,	(In thousands)
2020	$	13,750
2021	13,750
2022	970,000
2023	192,500
2024	400,000
Thereafter	1,950,000
Total	3,540,000
Less: current portion of long-term debt	13,750
Less: unamortized original issue discount	357,887
Less: unamortized debt issuance costs	46,791
Total long-term debt, net	$	3,121,572

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)

12 Months Ended

Dec. 31, 2019

Equity [Abstract]

Schedule of Accumulated Other Comprehensive Loss

The following tables present the components of accumulated other comprehensive (loss) income and items reclassified out of accumulated other comprehensive loss into earnings:



	Year Ended December 31, 2019
	Foreign Currency Translation Adjustment			Unrealized Gains On Available-For-Sale Securities			Accumulated Other Comprehensive Loss
	(In thousands)
Balance at January 1	$	(128,726	)	$	4		$	(128,722	)
Other comprehensive loss	(7,938		)	(4		)	(7,942		)
Net current period other comprehensive loss	(7,938		)	(4		)	(7,942		)
Allocation of accumulated other comprehensive loss related to noncontrolling interests	315			—			315
Balance at December 31	$	(136,349	)	$	—		$	(136,349	)



	Year Ended December 31, 2018
	Foreign Currency Translation Adjustment			Unrealized Gains On Available-For-Sale Securities		Accumulated Other Comprehensive Loss
	(In thousands)
Balance at January 1	$	(103,568	)	$	—	$	(103,568	)
Other comprehensive (loss) income before reclassifications	(25,230		)	4		(25,226		)
Amounts reclassified to earnings	(52		)	—		(52		)
Net current period other comprehensive (loss) income	(25,282		)	4		(25,278		)
Allocation of accumulated other comprehensive loss related to noncontrolling interests	124			—		124
Balance at December 31	$	(128,726	)	$	4	$	(128,722	)



	Year Ended December 31, 2017
	Foreign Currency Translation Adjustment			Unrealized Gains On Available-For-Sale Securities			Accumulated Other Comprehensive (Loss) Income
	(In thousands)
Balance at January 1	$	(170,149	)	$	4,026		$	(166,123	)
Other comprehensive income before reclassifications	65,799			7			65,806
Amounts reclassified to earnings	673			(4,033		)	(3,360		)
Net current period other comprehensive income (loss)	66,472			(4,026		)	62,446
Allocation of accumulated other comprehensive loss related to noncontrolling interests	109			—			109
Balance at December 31	$	(103,568	)	$	—		$	(103,568	)

EARNINGS PER SHARE (Tables)

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Earnings per Share

The following table sets forth the computation of basic and diluted earnings per share attributable to IAC shareholders:



	Years Ended December 31,
	2019						2018						2017
	Basic			Diluted			Basic			Diluted			Basic			Diluted
	(In thousands, except per share data)
Numerator:
Net earnings	$	543,820		$	543,820		$	757,747		$	757,747		$	358,008		$	358,008
Net earnings attributable to noncontrolling interests	(112,689		)	(112,689		)	(130,786		)	(130,786		)	(53,084		)	(53,084		)
Impact from public subsidiaries' dilutive securities^(a)	—			(26,063		)	—			(25,228		)	—			(33,531		)
Net earnings attributable to IAC shareholders	$	431,131		$	405,068		$	626,961		$	601,733		$	304,924		$	271,393

Denominator:
Weighted average basic shares outstanding	84,261			84,261			83,407			83,407			80,089			80,089
Dilutive securities^{(a) (b) (c) (d) (e)}	—			5,782			—			7,915			—			5,221
Denominator for earnings per share—weighted average shares^{(a) (b) (c) (d) (e)}	84,261			90,043			83,407			91,322			80,089			85,310

Earnings per share attributable to IAC shareholders:
Earnings per share	$	5.12		$	4.50		$	7.52		$	6.59		$	3.81		$	3.18

__________________________________________________________________

(a)

(b)

(c)

(d)

(e)

See "Note 11—Stock-based Compensation" for additional information on equity instruments denominated in the shares of certain subsidiaries.

STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Schedule of Changes in Outstanding Stock Options

Stock options outstanding at December 31, 2019 and changes during the year ended December 31, 2019 are as follows:



	December 31, 2019
	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (In Years)	Aggregate Intrinsic Value
	(Shares and intrinsic value in thousands)
Options outstanding at January 1, 2019	5,814		$	62.97
Granted	—		—
Exercised	(911	)	53.41
Forfeited	(15	)	101.01
Expired	(1	)	124.29
Options outstanding at December 31, 2019	4,887		$	64.63	5.3	$	901,629
Options exercisable	3,851		$	62.83	4.9	$	717,388

Schedule of Information for Stock Options Outstanding and Exercisable

The following table summarizes the information about stock options outstanding and exercisable at December 31, 2019:



	Options Outstanding				Options Exercisable
Range of Exercise Prices	Outstanding at December 31, 2019	Weighted- Average Remaining Contractual Life in Years	Weighted- Average Exercise Price		Exercisable at December 31, 2019	Weighted- Average Remaining Contractual Life in Years	Weighted- Average Exercise Price
	(Shares in thousands)
$20.01 to $30.00	3	0.1	$	21.60	3	0.1	$	21.60
$30.01 to $40.00	363	1.3	32.39		363	1.3	32.39
$40.01 to $50.00	1,124	5.2	42.96		840	4.8	43.32
$50.01 to $60.00	142	2.2	59.89		141	2.2	59.90
$60.01 to $70.00	916	5.4	65.87		796	5.1	65.97
$70.01 to $80.00	1,755	6.4	75.29		1,206	6.0	74.99
$80.01 to $90.00	500	5.3	84.31		500	5.3	84.31
Greater than $90.01	84	8.2	150.23		2	7.6	104.13
	4,887	5.3	$	64.63	3,851	4.9	$	62.83

Schedule of Weighted Average Assumptions

The following are the weighted average assumptions used in the Black-Scholes option pricing model:



	Years Ended December 31,
	2018		2017
Expected volatility	27	%	29	%
Risk-free interest rate	2.7	%	2.0	%
Expected term	6.2 years		5.2 years
Dividend yield	—	%	—	%

Schedule of Outstanding Unvested RSUs and PSUs

Unvested RSUs, MSUs and PSUs outstanding at December 31, 2019 and changes during the year ended December 31, 2019 are as follows:



	RSUs				MSUs			PSUs
	Number of Shares		Weighted Average Grant Date Fair Value		Number of Shares	Weighted Average Grant Date Fair Value		Number of Shares		Weighted Average Grant Date Fair Value
	(Shares in thousands)
Unvested at January 1, 2019	459		$	115.12	—	$	—	113		$	76.00
Granted	63		220.77		159	153.43		—		—
Vested	(304	)	118.25		—	—		—		—
Forfeited	(16	)	194.10		—	—		(113	)	76.00
Unvested at December 31, 2019	202		$	132.37	159	$	153.43	—		$	—

SEGMENT INFORMATION (Tables)

12 Months Ended

Dec. 31, 2019

Segment Reporting [Abstract]

Schedule of Segment Reporting Information

The following table presents revenue by reportable segment:



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Revenue:
Match Group	$	2,051,258		$	1,729,850		$	1,330,661
ANGI Homeservices	1,326,205			1,132,241			736,386
Vimeo	196,015			159,641			103,332
Dotdash	167,594			130,991			90,890
Applications	519,459			582,287			577,998
Emerging & Other	496,832			528,250			468,589
Inter-segment elimination	(308		)	(368		)	(617		)
Total	$	4,757,055		$	4,262,892		$	3,307,239

The following table presents the revenue of the Company's segments disaggregated by type of service:



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
Match Group
Direct revenue:
North America	$	1,024,161	$	902,478	$	741,334



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
International	983,013		774,693		539,915
Total Direct revenue	2,007,174		1,677,171		1,281,249
Indirect revenue (principally advertising revenue)	44,084		52,679		49,412
Total Match Group revenue	$	2,051,258	$	1,729,850	$	1,330,661

Supplemental information on Direct revenue
Tinder	$	1,152,045	$	805,316	$	403,216
Other brands	855,129		871,855		878,033
Total Direct revenue	$	2,007,174	$	1,677,171	$	1,281,249

ANGI Homeservices
Marketplace:
Consumer connection revenue	$	913,533	$	704,341	$	521,481
Service professional membership subscription revenue	64,706		66,214		56,135
Other revenue	6,971		3,940		3,798
Total Marketplace revenue	985,210		774,495		581,414
Advertising and other revenue	264,682		287,676		97,483
Total North America revenue	1,249,892		1,062,171		678,897
Consumer connection revenue	59,611		50,913		40,009
Service professional membership subscription revenue	14,231		17,362		16,596
Advertising and other revenue	2,471		1,795		884
Total Europe revenue	76,313		70,070		57,489
Total ANGI Homeservices revenue	$	1,326,205	$	1,132,241	$	736,386

Vimeo
Platform revenue	$	193,736	$	146,665	$	99,650
Hardware revenue	2,279		12,976		3,682
Total Vimeo revenue	$	196,015	$	159,641	$	103,332

Dotdash
Display advertising revenue	$	126,487	$	103,704	$	76,316
Performance marketing revenue	41,107		27,287		14,574
Total Dotdash revenue	$	167,594	$	130,991	$	90,890

Applications
Desktop:
Advertising revenue:
Google advertising revenue	$	291,215	$	426,964	$	480,774
Non-Google advertising revenue	13,162		10,992		6,762
Total advertising revenue	304,377		437,956		487,536
Subscription and other revenue	15,858		20,815		34,613
Total Desktop revenue	320,235		458,771		522,149
Mosaic Group:
Subscription and other revenue	189,878		104,975		27,980
Advertising revenue	9,346		18,541		27,869
Total Mosaic Group revenue	199,224		123,516		55,849
Total Applications revenue	$	519,459	$	582,287	$	577,998



	Years Ended December 31,
	2019		2018		2017
	(In thousands)

Emerging & Other
Advertising revenue:
Google advertising revenue	$	391,709	$	357,752	$	225,576
Non-Google advertising revenue	45,750		66,733		53,911
Total advertising revenue	437,459		424,485		279,487
Other revenue	59,373		103,765		169,497
Test preparation revenue	—		—		19,605
Total Emerging & Other revenue	$	496,832	$	528,250	$	468,589

Schedule of Revenue by Geographic Areas

Revenue by geography is based on where the customer is located. Geographic information about revenue and long-lived assets is presented below:



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
Revenue:
United States	$	3,070,487	$	2,824,928	$	2,323,050
All other countries	1,686,568		1,437,964		984,189
Total	$	4,757,055	$	4,262,892	$	3,307,239

Schedule of Long-lived Assets by Geographic Areas



	December 31,
	2019		2018
	(In thousands)
Long-lived assets (excluding goodwill and intangible assets):
United States	$	345,937	$	289,756
All other countries	25,416		29,044
Total	$	371,353	$	318,800

Schedule of Reconciliation of Adjusted EBITDA to Operating Income (Loss)

The following tables present operating income (loss) and Adjusted EBITDA by reportable segment:



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Operating income (loss):
Match Group	$	648,531		$	553,294		$	360,517
ANGI Homeservices	38,645			63,906			(149,176		)
Vimeo	(51,921		)	(35,594		)	(27,328		)
Dotdash	29,021			18,778			(15,694		)
Applications	113,569			94,834			130,176
Emerging & Other	(13,012		)	29,964			17,412
Corporate	(183,500		)	(160,043		)	(127,441		)
Total	$	581,333		$	565,139		$	188,466



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Adjusted EBITDA:^(a)
Match Group	$	779,432		$	653,931		$	468,941
ANGI Homeservices	$	202,297		$	247,506		$	37,858
Vimeo	$	(41,790	)	$	(28,045	)	$	(23,607	)
Dotdash	$	39,601		$	21,384		$	(2,763	)
Applications	$	103,551		$	131,837		$	136,757
Emerging & Other	$	(7,756	)	$	36,178		$	25,862
Corporate	$	(88,640	)	$	(74,017	)	$	(67,755	)

_______________________________________________________________________________

The following tables reconcile operating income (loss) for the Company's reportable segments and net earnings attributable to IAC shareholders to Adjusted EBITDA:



	Year Ended December 31, 2019
	Operating Income (Loss)			Stock-Based Compensation Expense		Depreciation		Amortization of Intangibles		Acquisition-related Contingent Consideration Fair Value Adjustments			Goodwill Impairment		Adjusted EBITDA
	(In thousands)
Match Group	$	648,531		$	89,724	$	32,450	$	8,727	$	—		$	—	$	779,432
ANGI Homeservices	38,645			$	68,255	$	39,915	$	55,482	$	—		$	—	$	202,297
Vimeo	(51,921		)	$	—	$	478	$	9,653	$	—		$	—	$	(41,790	)
Dotdash	29,021			$	—	$	974	$	9,606	$	—		$	—	$	39,601
Applications	113,569			$	—	$	1,443	$	8,277	$	(19,738	)	$	—	$	103,551
Emerging & Other	(13,012		)	$	—	$	1,088	$	850	$	—		$	3,318	$	(7,756	)
Corporate	(183,500		)	$	82,809	$	12,051	$	—	$	—		$	—	$	(88,640	)
Total	581,333
Interest expense	(153,563		)
Other income, net	66,741
Earnings before income taxes	494,511
Income tax benefit	49,309
Net earnings	543,820
Net earnings attributable to noncontrolling interests	(112,689		)
Net earnings attributable to IAC shareholders	$	431,131



	Year Ended December 31, 2018
	Operating Income (Loss)			Stock-Based Compensation Expense		Depreciation		Amortization of Intangibles		Acquisition-related Contingent Consideration Fair Value Adjustments		Adjusted EBITDA
	(In thousands)
Match Group	$	553,294		$	66,031	$	32,968	$	1,318	$	320	$	653,931
ANGI Homeservices	63,906			$	97,078	$	24,310	$	62,212	$	—	$	247,506
Vimeo	(35,594		)	$	—	$	1,200	$	6,349	$	—	$	(28,045	)
Dotdash	18,778			$	—	$	969	$	1,637	$	—	$	21,384
Applications	94,834			$	—	$	2,601	$	33,266	1,136		$	131,837
Emerging & Other	29,964			$	919	$	1,678	$	3,617	$	—	$	36,178
Corporate	(160,043		)	$	74,392	$	11,634	$	—	$	—	$	(74,017	)
Total	565,139
Interest expense	(109,327		)
Other income, net	305,746
Earnings before income taxes	761,558
Income tax provision	(3,811		)
Net earnings	757,747
Net earnings attributable to noncontrolling interests	(130,786		)
Net earnings attributable to IAC shareholders	$	626,961



	Year Ended December 31, 2017
	Operating Income (Loss)			Stock-Based Compensation Expense		Depreciation		Amortization of Intangibles		Acquisition-related Contingent Consideration Fair Value Adjustments		Adjusted EBITDA
	(In thousands)
Match Group	$	360,517		$	69,090	$	32,613	$	1,468	$	5,253	$	468,941
ANGI Homeservices	(149,176		)	$	149,230	$	14,543	$	23,261	$	—	$	37,858
Vimeo	(27,328		)	$	—	$	1,408	$	2,313	$	—	$	(23,607	)
Dotdash	(15,694		)	$	—	$	2,255	$	10,676	$	—	$	(2,763	)
Applications	130,176			$	—	$	3,863	$	2,170	$	548	$	136,757
Emerging & Other	17,412			$	2,130	$	4,065	$	2,255	$	—	$	25,862
Corporate	(127,441		)	$	44,168	$	15,518	$	—	$	—	$	(67,755	)
Total	188,466
Interest expense	(105,295		)
Other expense, net	(16,213		)
Earnings before income taxes	66,958
Income tax benefit	291,050
Net earnings	358,008
Net earnings attributable to noncontrolling interests	(53,084		)
Net earnings attributable to IAC shareholders	$	304,924

Schedule of Capital Expenditures by Segment

The following table presents capital expenditures by reportable segment:



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
Capital expenditures:
Match Group	$	38,754	$	30,954	$	28,833
ANGI Homeservices	68,804		46,976		26,837
Vimeo	2,801		209		109
Dotdash	—		102		825
Applications	85		111		227
Emerging & Other	345		1,119		852
Corporate	25,863		6,163		17,840
Total	$	136,652	$	85,634	$	75,523

LEASES (Tables)

12 Months Ended

Dec. 31, 2019

Leases [Abstract]

Schedule of Supplemental Balance Sheet Information of Leases



Leases	Balance Sheet Classification	December 31, 2019
		(In thousands)
Assets:
Right-of-use assets	Right-of-use assets, net	$	167,801

Liabilities:
Current lease liabilities	Accrued expenses and other current liabilities	33,118
Long-term lease liabilities	Other long-term liabilities	190,772
Total lease liabilities		$	223,890

Schedule of Lease Cost and Other Information



	Year Ended December 31, 2019
	(In thousands)
Other information:
Right-of-use assets obtained in exchange for lease liabilities	$	66,408
Cash paid for amounts included in the measurement of lease liabilities	$	49,117



Lease Cost	Income Statement Classification	Year Ended December 31, 2019
		(In thousands)
Fixed lease cost	Cost of revenue	$	4,106
Fixed lease cost	Selling and marketing expense	10,641
Fixed lease cost	General and administrative expense	34,639
Fixed lease cost	Product development expense	1,541
Total fixed lease cost^(a)		50,927
Variable lease cost	Cost of revenue	441
Variable lease cost	Selling and marketing expense	1,573
Variable lease cost	General and administrative expense	7,853
Variable lease cost	Product development expense	391
Total variable lease cost		10,258
Net lease cost		$	61,185

_____________________

^(a) Includes approximately $5.3 million of short-term lease cost and $2.1 million of sublease income for the year ended December 31, 2019.

Schedule of Maturities of Operating Lease Liabilities

Maturities of lease liabilities as of December 31, 2019 (in thousands)^(b):



Years Ended December 31,
2020	$	43,902
2021	40,567
2022	32,135
2023	28,607
2024	25,594
Thereafter	226,734
Total	397,539
Less: Interest	173,649
Present value of lease liabilities	$	223,890

_____________________

^(b) Lease payments exclude $37.7 million of legally binding minimum lease payments for leases signed but not yet commenced.

Schedule of Weighted-Average Lease Term and Discount Rate of Leases

The following are the weighted average assumptions used for lease term and discount rate as of December 31, 2019:



Remaining lease term	15.4 years
Discount rate	6.00	%

COMMITMENTS AND CONTINGENCIES (Tables)

12 Months Ended

Dec. 31, 2019

Commitments and Contingencies Disclosure [Abstract]

Schedule of Commercial Commitments Outstanding

Future payments under noncancelable unconditional purchase obligations as of December 31, 2019 are as follows:



	Amount of Commitment Expiration Per Period
	Less Than 1 Year		1-3 Years		3-5 Years		More Than 5 Years		Total Amounts Committed
	(In thousands)
Purchase obligations	$	119,116	$	81,423	$	—	$	—	$	200,539

CONSOLIDATED FINANCIAL STATEMENT DETAILS (Tables)

12 Months Ended

Dec. 31, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Other Current Assets



	December 31,
	2019		2018
	(In thousands)
Other current assets:
Prepaid expenses	$	97,609	$	55,586
Capitalized costs to obtain a contract with a customer	71,548		69,817
Capitalized downloadable search toolbar costs, net	21,985		33,365
Income taxes receivable	9,308		10,132
Other	48,917		59,353
Other current assets	$	249,367	$	228,253

Schedule of Property and Equipment, Net



Asset Category	Estimated Useful Lives
Buildings and leasehold improvements	3 to 39 Years
Capitalized software and computer equipment	2 to 3 Years
Furniture and other equipment	3 to 12 Years



	December 31,
	2019			2018
	(In thousands)
Property and equipment, net:
Buildings and leasehold improvements	$	270,509		$	249,026
Capitalized software and computer equipment	268,927			229,083
Furniture and other equipment	93,082			86,694
Land	11,591			11,591
Projects in progress	51,603			29,204
Property and equipment	695,712			605,598
Accumulated depreciation and amortization	(324,359		)	(286,798		)
Property and equipment, net	$	371,353		$	318,800

Schedule of Accrued Expenses and Other Current Liabilities



	December 31,
	2019		2018
	(In thousands)
Accrued expenses and other current liabilities:
Accrued employee compensation and benefits	$	153,705	$	137,583
Accrued advertising expense	91,470		105,520
Other	256,828		191,783
Accrued expenses and other current liabilities	$	502,003	$	434,886

Schedule of Other (Expense) Income, Net



	Years Ended December 31,
	2019		2018		2017
	(In thousands)
Other income (expense), net	$	66,741	$	305,746	$	(16,213	)

Schedule of Cash and Cash Equivalents



	December 31, 2019		December 31, 2018		December 31, 2017		December 31, 2016
	(In thousands)
Cash and cash equivalents	$	3,139,295	$	2,131,632	$	1,630,809	$	1,329,187
Restricted cash included in other current assets	654		1,633		2,873		20,464
Restricted cash included in other assets	409		420		—		10,548
Total cash and cash equivalents and restricted cash as shown on the consolidated statement of cash flows	$	3,140,358	$	2,133,685	$	1,633,682	$	1,360,199

Schedule of Restricted Cash



	December 31, 2019		December 31, 2018		December 31, 2017		December 31, 2016
	(In thousands)
Cash and cash equivalents	$	3,139,295	$	2,131,632	$	1,630,809	$	1,329,187
Restricted cash included in other current assets	654		1,633		2,873		20,464
Restricted cash included in other assets	409		420		—		10,548
Total cash and cash equivalents and restricted cash as shown on the consolidated statement of cash flows	$	3,140,358	$	2,133,685	$	1,633,682	$	1,360,199

Schedule of Supplemental Disclosure of Cash Flow Information



	Years Ended December 31,
	2019			2018			2017
	(In thousands)
Cash paid (received) during the year for:
Interest	$	96,730		$	90,485		$	92,461
Income tax payments	39,515			45,154			35,598
Income tax refunds	(5,436		)	(33,698		)	(42,025		)

QUARTERLY RESULTS (UNAUDITED) (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Results



	Quarter Ended March 31^(a)		Quarter Ended June 30 ^(a)		Quarter Ended September 30 ^(a)		Quarter Ended December 31^(a)
	(In thousands, except per share data)
Year Ended December 31, 2019
Revenue	$	1,105,843	$	1,186,658	$	1,246,874	$	1,217,680
Cost of revenue	260,071		276,389		296,385		294,575
Operating income	79,873		154,310		185,852		161,298
Net earnings	112,985		146,791		159,772		124,272
Net earnings attributable to IAC shareholders	88,695		113,467		128,544		100,425
Per share information attributable to IAC shareholders:
Basic earnings per share^(f)	$	1.06	$	1.35	$	1.52	$	1.19
Diluted earnings per share^(f)	$	0.91	$	1.19	$	1.35	$	1.05

	Quarter Ended March 31^(b)		Quarter Ended June 30^(c)		Quarter Ended September 30^(d)		Quarter Ended December 31^(e)
	(In thousands, except per share data)
Year Ended December 31, 2018
Revenue	$	995,075	$	1,059,122	$	1,104,592	$	1,104,103
Cost of revenue	201,962		218,224		237,238		253,722
Operating income	89,950		168,437		172,832		133,920
Net earnings	87,839		280,854		171,577		217,477
Net earnings attributable to IAC shareholders	71,082		218,353		145,774		191,752
Per share information attributable to IAC shareholders:
Basic earnings per share^(f)	$	0.86	$	2.61	$	1.75	$	2.29
Diluted earnings per share^(f)	$	0.71	$	2.32	$	1.49	$	2.04

_______________________________________________________________________________


(a)	The first, second, third and fourth quarters of 2019 include after-tax stock-based compensation expense of $2.2 million, $1.9 million, $1.7 million, and $1.7 million, respectively, related to the modification of previously issued HomeAdvisor equity awards and previously issued Angie's List equity awards, both of which were converted into ANGI Homeservices' equity awards in the Combination.

(b)


(c)	The second quarter of 2018 includes:


ii.	after-tax realized and unrealized gains of $133.3 million related to the sale of a certain equity investment.


(d)	The third quarter of 2018 includes after-tax stock-based compensation expense of $12.3 million related to the modification of previously issued HomeAdvisor equity awards and previously issued Angie's List equity awards, both of which were converted into ANGI Homeservices' equity awards in the Combination.


(e)	The fourth quarter of 2018 includes:


i.	after-tax stock-based compensation expense of $14.4 million related to the modification of previously issued HomeAdvisor equity awards and previously issued Angie's List equity awards, both of which were converted into ANGI Homeservices' equity awards in the Combination.


ii.	combined after-tax gains of $92.5 million related to the sales of Dictionary.com, Electus, Felix and CityGrid.


iii.	after-tax impairment charges related to indefinite-lived intangible assets of $21.3 million.

(f)

Quarterly per share amounts may not add to the related annual per share amount because of differences in the average common shares outstanding during each period.

ORGANIZATION - Narrative (Details)	Dec. 31, 2019
Match Group
Noncontrolling Interest [Line Items]
Ownership interest (as a percent)	80.70%
Voting interest (as a percent)	97.50%
ANGI Homeservices
Noncontrolling Interest [Line Items]
Ownership interest (as a percent)	84.10%
Voting interest (as a percent)	98.10%

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)		3 Months Ended								12 Months Ended
	Jan. 01, 2018 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) arrangement	Jan. 01, 2019 USD ($)	Oct. 01, 2018 USD ($)
Intangible Assets and Goodwill
Amortization of capitalized contract costs										$ 464,600,000	$ 355,300,000
Current capitalized contract costs	$ 53,400,000	$ 71,548,000				$ 69,817,000				71,548,000	69,817,000
Non-current capitalized contract costs	4,700,000	6,200,000				4,500,000				$ 6,200,000	4,500,000
Period of payment due from customers for accounts receivable										30 days
Deferred revenue	332,200,000	398,800,000				361,700,000				$ 398,800,000	361,700,000
Deferred revenue recognized during period										356,400,000	330,200,000
Current deferred revenue		397,490,000				360,015,000				397,490,000	360,015,000
Non-current deferred revenue		1,300,000				1,700,000				$ 1,300,000	1,700,000
Maturity period at purchase (less than)										91 days
Revenue		1,217,680,000	$ 1,246,874,000	$ 1,186,658,000	$ 1,105,843,000	1,104,103,000	$ 1,104,592,000	$ 1,059,122,000	$ 995,075,000	$ 4,757,055,000	4,262,892,000	$ 3,307,239,000
Goodwill		2,854,462,000				2,726,859,000				2,854,462,000	2,726,859,000	2,559,066,000
Intangible assets, net		578,474,000				631,422,000				578,474,000	631,422,000
Accounts receivable, net of allowance and reserves		298,334,000				279,189,000				$ 298,334,000	279,189,000
Estimated weighted-average useful life (in years)										18 months
Property and equipment, net		$ 371,353,000				318,800,000				$ 371,353,000	318,800,000
Excess of goodwill fair value over carrying value (less than) (as a percent)		10.00%								10.00%
Goodwill		$ 265,100,000								$ 265,100,000
Goodwill Impairment										3,318,000	0	0
Indefinite-lived intangible assets		121,200,000								121,200,000
Advertising expense										1,200,000,000	1,200,000,000	1,100,000,000
Gains (losses) reclassified to earnings											52,000	$ 3,360,000
Put and call arrangements exercised \| arrangement												2
Purchase of noncontrolling interests										1	2
Retained earnings		1,689,925,000				1,258,794,000				1,689,925,000	1,258,794,000
Deferred income taxes		21,388,000				23,600,000				21,388,000	23,600,000
Increase (decrease) in deferred revenue										37,614,000	49,468,000	$ 39,154,000
Cumulative effect of adoption of new accounting pronouncement	40,205,000
Unrealized gains, net, on equity securities held										14,505,000	124,170,000
Right-of-use assets, net		167,801,000				0				167,801,000	0
Lease liability		223,890,000								223,890,000
Accounting Standards Update 2014-09
Intangible Assets and Goodwill
Revenue											4,262,892,000
Retained earnings	40,200,000
Accounting Standards Update 2016-02
Intangible Assets and Goodwill
Right-of-use assets, net													$ 154,700,000
Noncontrolling Interests
Intangible Assets and Goodwill
Cumulative effect of adoption of new accounting pronouncement	3,410,000
Foreign Currency Translation Adjustment
Intangible Assets and Goodwill
Gains (losses) reclassified to earnings											52,000	(673,000)
Foreign Currency Translation Adjustment \| Other (Expense) Income, Net
Intangible Assets and Goodwill
Gains (losses) reclassified to earnings										0	(100,000)	700,000
Redeemable Noncontrolling Interest
Intangible Assets and Goodwill
Purchase of noncontrolling interests										11,600,000	4,100,000	$ 6,300,000
Trade Names
Intangible Assets and Goodwill
Impairment charges on indefinite-lived intangible assets						27,700,000
Software and software development costs
Intangible Assets and Goodwill
Property and equipment, net		83,800,000				58,100,000				83,800,000	58,100,000
Google Inc.
Intangible Assets and Goodwill
Accounts receivable, net of allowance and reserves		$ 53,000,000.0				$ 69,100,000				$ 53,000,000.0	$ 69,100,000
Google Inc. \| Revenue \| Customer Concentration Risk
Intangible Assets and Goodwill
Concentration risk (as a percent)										15.00%	19.00%	22.00%
Desktop \| Trade Names
Intangible Assets and Goodwill
Impairment charges on indefinite-lived intangible assets										$ 700,000	$ 27,700,000
College Humor Media \| Trade Names
Intangible Assets and Goodwill
Impairment charges on indefinite-lived intangible assets										$ 6,600,000	$ 1,100,000
Minimum \| Discount Rate
Intangible Assets and Goodwill
Measurement input (as a percent)		0.125				0.125				0.125	0.125
Minimum \| Discount Rate \| Indefinite-lived Intangible Assets
Intangible Assets and Goodwill
Measurement input (as a percent)		0.105				0.105				0.105	0.105
Minimum \| Royalty Rate \| Indefinite-lived Intangible Assets
Intangible Assets and Goodwill
Measurement input (as a percent)		0.01				0.0075				0.01	0.0075
Maximum \| Discount Rate
Intangible Assets and Goodwill
Measurement input (as a percent)						0.15					0.15
Maximum \| Discount Rate \| Indefinite-lived Intangible Assets
Intangible Assets and Goodwill
Measurement input (as a percent)		0.275				0.35				0.275	0.35
Maximum \| Royalty Rate \| Indefinite-lived Intangible Assets
Intangible Assets and Goodwill
Measurement input (as a percent)		0.08				0.08				0.08	0.08
Match Group
Intangible Assets and Goodwill
Goodwill		$ 1,239,840,000				$ 1,245,013,000				$ 1,239,840,000	$ 1,245,013,000	$ 1,247,899,000
Market capitalization														$ 20,000,000,000.0
Amount by which market capitalization exceeds carrying value														19,800,000,000
Match Group \| Operating Segments
Intangible Assets and Goodwill
Revenue										2,051,258,000	1,729,850,000	1,330,661,000
Goodwill Impairment										$ 0
Match Group \| Operating Segments \| Accounting Standards Update 2014-09
Intangible Assets and Goodwill
Revenue											1,729,850,000
Match Group \| Minimum
Intangible Assets and Goodwill
Period of membership subscription										1 month
Match Group \| Maximum
Intangible Assets and Goodwill
Period of membership subscription										6 months
ANGI Homeservices
Intangible Assets and Goodwill
Period of membership subscription										1 year
Goodwill		882,051,000				892,800,000				$ 882,051,000	892,800,000	768,317,000
Market capitalization														3,600,000,000
Amount by which market capitalization exceeds carrying value														$ 2,200,000,000
Goodwill Impairment										0
ANGI Homeservices \| Accounting Standards Update 2014-09
Intangible Assets and Goodwill
Current capitalized contract costs	29,700,000
Non-current capitalized contract costs	4,200,000
Retained earnings	25,900,000
Deferred income taxes	8,000,000.0
ANGI Homeservices \| Noncontrolling Interests \| Accounting Standards Update 2014-09
Intangible Assets and Goodwill
Retained earnings	3,400,000
ANGI Homeservices \| Operating Segments
Intangible Assets and Goodwill
Revenue										1,326,205,000	1,132,241,000	736,386,000
Goodwill Impairment										$ 0
ANGI Homeservices \| Operating Segments \| Accounting Standards Update 2014-09
Intangible Assets and Goodwill
Revenue											1,132,241,000
ANGI Homeservices \| Angie's List
Intangible Assets and Goodwill
Period of membership subscription										1 year
Vimeo \| Operating Segments
Intangible Assets and Goodwill
Revenue										$ 196,015,000	159,641,000	103,332,000
Goodwill Impairment										$ 0
Vimeo \| Operating Segments \| Accounting Standards Update 2014-09
Intangible Assets and Goodwill
Revenue											159,641,000
Vimeo \| Minimum
Intangible Assets and Goodwill
Period of membership subscription										1 month
Vimeo \| Maximum
Intangible Assets and Goodwill
Period of membership subscription										1 year
Publishing and Applications \| Google Inc.
Intangible Assets and Goodwill
Revenue										$ 733,500,000	825,200,000	740,700,000
Applications
Intangible Assets and Goodwill
Goodwill		504,748,000				504,892,000				504,748,000	504,892,000	447,242,000
Goodwill Impairment										0
Applications \| Accounting Standards Update 2014-09
Intangible Assets and Goodwill
Retained earnings	15,500,000
Deferred income taxes	4,900,000
Increase (decrease) in deferred revenue	$ (20,300,000)
Applications \| Desktop
Intangible Assets and Goodwill
Goodwill		265,100,000				28,900,000				265,100,000	28,900,000
Applications \| Operating Segments
Intangible Assets and Goodwill
Revenue										519,459,000	582,287,000	577,998,000
Goodwill Impairment										0
Applications \| Operating Segments \| Accounting Standards Update 2014-09
Intangible Assets and Goodwill
Revenue											582,287,000
Applications \| Operating Segments \| Desktop
Intangible Assets and Goodwill
Revenue										320,235,000	458,771,000	522,149,000
Applications \| Google Inc. \| Revenue \| Customer Concentration Risk
Intangible Assets and Goodwill
Revenue										291,100,000	426,500,000	480,600,000
Applications \| Desktop
Intangible Assets and Goodwill
Goodwill		265,146,000				265,146,000				265,146,000	265,146,000	265,146,000
Goodwill Impairment										0
Applications \| Mosaic Group
Intangible Assets and Goodwill
Goodwill		239,602,000				239,746,000				239,602,000	239,746,000	182,096,000
Goodwill Impairment										0
Applications \| Mosaic Group \| Operating Segments
Intangible Assets and Goodwill
Revenue										$ 199,224,000	123,516,000	55,849,000
Applications \| Minimum \| Desktop
Intangible Assets and Goodwill
Period of membership subscription										1 year
Applications \| Minimum \| Mosaic Group
Intangible Assets and Goodwill
Period of membership subscription										1 year
Applications \| Maximum \| Desktop
Intangible Assets and Goodwill
Period of membership subscription										2 years
Applications \| Maximum \| Mosaic Group
Intangible Assets and Goodwill
Period of membership subscription										2 years
Emerging & Other
Intangible Assets and Goodwill
Goodwill		$ 8,449,000				$ 7,002,000				$ 8,449,000	7,002,000	18,305,000
Emerging & Other \| Operating Segments
Intangible Assets and Goodwill
Revenue										496,832,000	528,250,000	468,589,000
Goodwill Impairment										3,318,000
Emerging & Other \| Operating Segments \| Accounting Standards Update 2014-09
Intangible Assets and Goodwill
Revenue											528,250,000
Emerging & Other \| Google Inc. \| Revenue \| Customer Concentration Risk
Intangible Assets and Goodwill
Revenue										385,900,000	339,000,000.0	203,500,000
Emerging & Other \| College Humor Media
Intangible Assets and Goodwill
Goodwill Impairment										3,318,000
Dotdash \| Operating Segments
Intangible Assets and Goodwill
Revenue										167,594,000	130,991,000	$ 90,890,000
Goodwill Impairment										$ 0
Dotdash \| Operating Segments \| Accounting Standards Update 2014-09
Intangible Assets and Goodwill
Revenue											$ 130,991,000

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2019
Buildings and leasehold improvements \| Minimum
Property and equipment, net:
Estimated useful lives, minimum (in years)	3 years
Buildings and leasehold improvements \| Maximum
Property and equipment, net:
Estimated useful lives, minimum (in years)	39 years
Capitalized software and computer equipment \| Minimum
Property and equipment, net:
Estimated useful lives, minimum (in years)	2 years
Capitalized software and computer equipment \| Maximum
Property and equipment, net:
Estimated useful lives, minimum (in years)	3 years
Furniture and other equipment \| Minimum
Property and equipment, net:
Estimated useful lives, minimum (in years)	3 years
Furniture and other equipment \| Maximum
Property and equipment, net:
Estimated useful lives, minimum (in years)	12 years

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Effect of Adoption of ASU 2014-09 (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 1,217,680	$ 1,246,874	$ 1,186,658	$ 1,105,843	$ 1,104,103	$ 1,104,592	$ 1,059,122	$ 995,075	$ 4,757,055	$ 4,262,892	$ 3,307,239
Operating costs and expenses									4,175,722	3,697,753	3,118,773
Operating income (loss)	161,298	185,852	154,310	79,873	133,920	172,832	168,437	89,950	581,333	565,139	188,466
Net earnings	$ 124,272	$ 159,772	$ 146,791	$ 112,985	$ 217,477	$ 171,577	$ 280,854	$ 87,839	543,820	757,747	358,008
Operating segments \| Match Group
Disaggregation of Revenue [Line Items]
Revenues									2,051,258	1,729,850	1,330,661
Operating income (loss)									648,531	553,294	360,517
Operating segments \| ANGI Homeservices
Disaggregation of Revenue [Line Items]
Revenues									1,326,205	1,132,241	736,386
Operating income (loss)									38,645	63,906	(149,176)
Operating segments \| Vimeo
Disaggregation of Revenue [Line Items]
Revenues									196,015	159,641	103,332
Operating income (loss)									(51,921)	(35,594)	(27,328)
Operating segments \| Dotdash
Disaggregation of Revenue [Line Items]
Revenues									167,594	130,991	90,890
Operating income (loss)									29,021	18,778	(15,694)
Operating segments \| Applications
Disaggregation of Revenue [Line Items]
Revenues									519,459	582,287	577,998
Operating income (loss)									113,569	94,834	130,176
Operating segments \| Emerging & Other
Disaggregation of Revenue [Line Items]
Revenues									496,832	528,250	468,589
Operating income (loss)									(13,012)	29,964	17,412
Inter-segment eliminations
Disaggregation of Revenue [Line Items]
Revenues									(308)	(368)	(617)
Corporate
Disaggregation of Revenue [Line Items]
Operating income (loss)									$ (183,500)	(160,043)	$ (127,441)
Accounting Standards Update 2014-09
Disaggregation of Revenue [Line Items]
Revenues										4,262,892
Operating costs and expenses										3,697,753
Operating income (loss)										565,137
Net earnings										757,747
Accounting Standards Update 2014-09 \| Operating segments \| Match Group
Disaggregation of Revenue [Line Items]
Revenues										1,729,850
Operating costs and expenses										1,176,556
Operating income (loss)										553,294
Accounting Standards Update 2014-09 \| Operating segments \| ANGI Homeservices
Disaggregation of Revenue [Line Items]
Revenues										1,132,241
Operating costs and expenses										1,068,335
Operating income (loss)										63,904
Accounting Standards Update 2014-09 \| Operating segments \| Vimeo
Disaggregation of Revenue [Line Items]
Revenues										159,641
Operating costs and expenses										195,235
Operating income (loss)										(35,594)
Accounting Standards Update 2014-09 \| Operating segments \| Dotdash
Disaggregation of Revenue [Line Items]
Revenues										130,991
Operating costs and expenses										112,213
Operating income (loss)										18,778
Accounting Standards Update 2014-09 \| Operating segments \| Applications
Disaggregation of Revenue [Line Items]
Revenues										582,287
Operating costs and expenses										487,453
Operating income (loss)										94,834
Accounting Standards Update 2014-09 \| Operating segments \| Emerging & Other
Disaggregation of Revenue [Line Items]
Revenues										528,250
Operating costs and expenses										498,286
Operating income (loss)										29,964
Accounting Standards Update 2014-09 \| Inter-segment eliminations
Disaggregation of Revenue [Line Items]
Revenues										(368)
Accounting Standards Update 2014-09 \| Corporate
Disaggregation of Revenue [Line Items]
Operating costs and expenses										159,675
Operating income (loss)										(160,043)
Accounting Standards Update 2014-09 \| Under ASC 605
Disaggregation of Revenue [Line Items]
Revenues										4,263,387
Operating costs and expenses										3,700,861
Operating income (loss)										562,524
Net earnings										755,741
Accounting Standards Update 2014-09 \| Under ASC 605 \| Operating segments \| Match Group
Disaggregation of Revenue [Line Items]
Revenues										1,729,850
Operating costs and expenses										1,176,556
Operating income (loss)										553,294
Accounting Standards Update 2014-09 \| Under ASC 605 \| Operating segments \| ANGI Homeservices
Disaggregation of Revenue [Line Items]
Revenues										1,132,241
Operating costs and expenses										1,073,275
Operating income (loss)										58,964
Accounting Standards Update 2014-09 \| Under ASC 605 \| Operating segments \| Vimeo
Disaggregation of Revenue [Line Items]
Revenues										160,931
Operating costs and expenses										196,212
Operating income (loss)										(35,281)
Accounting Standards Update 2014-09 \| Under ASC 605 \| Operating segments \| Dotdash
Disaggregation of Revenue [Line Items]
Revenues										130,991
Operating costs and expenses										112,213
Operating income (loss)										18,778
Accounting Standards Update 2014-09 \| Under ASC 605 \| Operating segments \| Applications
Disaggregation of Revenue [Line Items]
Revenues										581,492
Operating costs and expenses										484,644
Operating income (loss)										96,848
Accounting Standards Update 2014-09 \| Under ASC 605 \| Operating segments \| Emerging & Other
Disaggregation of Revenue [Line Items]
Revenues										528,250
Operating costs and expenses										498,286
Operating income (loss)										29,964
Accounting Standards Update 2014-09 \| Under ASC 605 \| Inter-segment eliminations
Disaggregation of Revenue [Line Items]
Revenues										(368)
Accounting Standards Update 2014-09 \| Under ASC 605 \| Corporate
Disaggregation of Revenue [Line Items]
Operating costs and expenses										159,675
Operating income (loss)										(160,043)
Accounting Standards Update 2014-09 \| Effect of adoption of ASU No. 2014-09
Disaggregation of Revenue [Line Items]
Revenues										(495)
Operating costs and expenses										(3,108)
Operating income (loss)										2,613
Net earnings										2,006
Accounting Standards Update 2014-09 \| Effect of adoption of ASU No. 2014-09 \| Operating segments \| Match Group
Disaggregation of Revenue [Line Items]
Revenues										0
Operating costs and expenses										0
Operating income (loss)										0
Accounting Standards Update 2014-09 \| Effect of adoption of ASU No. 2014-09 \| Operating segments \| ANGI Homeservices
Disaggregation of Revenue [Line Items]
Revenues										0
Operating costs and expenses										(4,940)
Operating income (loss)										4,940
Accounting Standards Update 2014-09 \| Effect of adoption of ASU No. 2014-09 \| Operating segments \| Vimeo
Disaggregation of Revenue [Line Items]
Revenues										(1,290)
Operating costs and expenses										(977)
Operating income (loss)										(313)
Accounting Standards Update 2014-09 \| Effect of adoption of ASU No. 2014-09 \| Operating segments \| Dotdash
Disaggregation of Revenue [Line Items]
Revenues										0
Operating costs and expenses										0
Operating income (loss)										0
Accounting Standards Update 2014-09 \| Effect of adoption of ASU No. 2014-09 \| Operating segments \| Applications
Disaggregation of Revenue [Line Items]
Revenues										795
Operating costs and expenses										2,809
Operating income (loss)										(2,014)
Accounting Standards Update 2014-09 \| Effect of adoption of ASU No. 2014-09 \| Operating segments \| Emerging & Other
Disaggregation of Revenue [Line Items]
Revenues										0
Operating costs and expenses										0
Operating income (loss)										0
Accounting Standards Update 2014-09 \| Effect of adoption of ASU No. 2014-09 \| Inter-segment eliminations
Disaggregation of Revenue [Line Items]
Revenues										0
Accounting Standards Update 2014-09 \| Effect of adoption of ASU No. 2014-09 \| Corporate
Disaggregation of Revenue [Line Items]
Operating costs and expenses										0
Operating income (loss)										$ 0

INCOME TAXES - Narrative (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
INCOME TAXES - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Income tax benefit related to net operating loss carryforwards		$ 40.8
Income tax benefit related to net operating loss carryforwards recorded as a reduction to goodwill		26.9
Tax credit carryforwards		159.5
Tax credit carryforwards that can be carried forward indefinitely		41.2
Tax credit carryforwards expiring primarily by 2018 and 2037		118.3
Valuation Allowance
Decrease in valuation allowance		13.8
Valuation allowance at end of period		129.6
Income Taxes Paid, Net [Abstract]
Interest on income taxes accrued		4.1	$ 3.4
Income tax penalties accrued		1.1	1.4
Unrecognized tax benefits including tax interest accrued		74.4	52.3
Tax positions for which the ultimate deductibility is highly certain but timing is uncertain		69.2	49.1
Change in unrecognized tax benefits unrelated to Federal income taxes statute of limitations expiring within twelve months of current reporting period		24.5
Tax benefits that would impact effective tax rate		24.3
Reduction in the Transition Tax	$ 9.2
Undistributed foreign earnings with no provision		2.1
Undistributed foreign earnings indefinitely reinvested outside of domestic country		41.8
Undistributed foreign earnings		171.2
Federal Tax Authority
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Net operating loss carryforwards		990.3
Net operating loss carryforwards not subject to expiration		80.2
Net operating loss carryforwards without restrictions		617.5
Interest carryforwards		95.1
State Tax Authority
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Net operating loss carryforwards		827.2
Net operating loss carryforwards without restrictions		457.4
Tax credit carryforwards		2.4
Foreign Tax Authority
Deferred Tax Assets, Operating Loss Carryforwards, Components [Abstract]
Net operating loss carryforwards		436.2
Net operating loss carryforwards not subject to expiration		402.7
Net operating loss carryforwards subject to expiration within 20 years		33.5
Interest carryforwards		46.4
Tax credit carryforwards		48.7
Tax credit carryforwards related to research and development		108.4
Continuing Operations
Income Taxes Paid, Net [Abstract]
Unrecognized tax benefit (expense), net of related deferred taxes		0.5	0.3	$ (0.1)
Deferred taxes for interest on unrecognized tax benefits (continuing operations)		$ 0.2	$ 0.1	$ 0.1

INCOME TAXES - Income before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
U.S.	$ 370,073	$ 630,417	$ (52,606)
Foreign	124,438	131,141	119,564
Earnings (loss) before income taxes	$ 494,511	$ 761,558	$ 66,958

INCOME TAXES - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current income tax provision (benefit):
Federal	$ 278	$ (2,849)	$ (31,844)
State	807	2,569	1,964
Foreign	29,707	38,770	24,108
Current income tax provision (benefit)	30,792	38,490	(5,772)
Deferred income tax provision (benefit):
Federal	(52,985)	(21,792)	(255,477)
State	(25,128)	172	(28,364)
Foreign	(1,988)	(13,059)	(1,437)
Deferred income tax benefit	(80,101)	(34,679)	(285,278)
Income tax (benefit) provision	$ (49,309)	$ 3,811	$ (291,050)

INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 340,472	$ 291,639
Tax credit carryforwards	117,286	89,397
Stock-based compensation	79,108	82,698
Long-term lease liabilities	52,748
Other	71,328	53,631
Total deferred tax assets	660,942	517,365
Less valuation allowance	(129,620)	(115,853)
Net deferred tax assets	531,322	401,512
Deferred tax liabilities:
Investment in subsidiaries	(235,920)	(238,650)
Intangible assets	(70,830)	(77,669)
Right-of-use assets	(39,226)
Investment in Pinterest	0	(22,927)
Other	(39,680)	(21,080)
Total deferred tax liabilities	(385,656)	(360,326)
Net deferred tax assets	$ 145,666	$ 41,186

INCOME TAXES - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax provision at the federal statutory rate of 21% (35% for 2017)	$ 103,847	$ 159,927	$ 23,435
State income taxes, net of effect of federal tax benefit	6,146	16,794	782
Stock-based compensation	(135,179)	(129,654)	(358,901)
Research credits	(33,377)	(14,276)	(6,947)
Realization of certain deferred tax assets	(9,281)	(13,200)	(3,133)
Foreign income taxed at a different statutory tax rate	(3,333)	(3,206)	(14,725)
Deferred tax adjustment for enacted changes in tax laws and rates	890	(7,488)	705
Non-deductible impairments for certain cost method investments			2,669
Transition tax	0	(9,190)	62,667
Withholding taxes	7,304	5,165	562
Other, net	13,674	(1,061)	1,836
Income tax (benefit) provision	$ (49,309)	$ 3,811	$ (291,050)

INCOME TAXES - Income Tax Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns
Balance at beginning of the period	$ 48,875	$ 36,732	$ 38,372
Additions based on tax positions related to the current year	14,000	10,334	2,050
Additions for tax positions of prior years	8,949	4,716	1,994
Reductions for tax positions of prior years	(289)	(400)	(3,761)
Settlements	0	0
Expiration of applicable statutes of limitations	(1,302)	(2,507)	(1,923)
Balance at end of the period	$ 70,233	$ 48,875	$ 36,732

BUSINESS COMBINATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		12 Months Ended
	Sep. 29, 2017	Dec. 31, 2018	Dec. 31, 2017
Angie's List
Business Acquisition [Line Items]
Proportion of voting interests acquired (as a percent)	100.00%
Total purchase price	$ 781,384
Basis of purchase price (shares)	61.3
Share price (USD per share)	$ 12.46
Cash acquisition price	$ 1,900
Cash per share paid to acquiree shareholders who elected payout (USD per share)	$ 8.50
Revenue			$ 58,900
Net earnings (loss)			(21,800)
Modification of Equity Awards
Business Acquisition [Line Items]
Adjustment to increase (decrease) in share-based compensation			77,100
Deferred Revenue Write Off Adjustment
Business Acquisition [Line Items]
Adjustment to decrease in revenues			34,100
Amortization Adjustment
Business Acquisition [Line Items]
Adjustment to decrease in amortization of intangible assets			31,900
One-Time Acquisition-related Costs
Business Acquisition [Line Items]
Severance costs		$ 19,800	28,700
Severance and retention costs			19,800
Write-off due to deferred revenue			$ 7,800

BUSINESS COMBINATION - Purchase Price (Details) - Angie's List $ in Thousands	Sep. 29, 2017 USD ($)
Business Acquisition [Line Items]
Cash consideration for holders who elected to receive $8.50 in cash per share of Angie's List common stock	$ 1,900
Total purchase price	781,384
Common Stock
Business Acquisition [Line Items]
Consideration transferred, equity interests	763,684
Cash consideration for holders who elected to receive $8.50 in cash per share of Angie's List common stock	1,913
Common Stock \| Fair value of vested and pro rata portion of unvested stock options attributable to pre-combination services
Business Acquisition [Line Items]
Consideration transferred, equity interests	11,749
Common Stock \| Fair value of the pro rata portion of unvested restricted stock units attributable to pre-combination services
Business Acquisition [Line Items]
Consideration transferred, equity interests	$ 4,038

BUSINESS COMBINATION - Preliminary Estimated Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Sep. 29, 2017
Business Acquisition [Line Items]
Goodwill	$ 2,854,462	$ 2,726,859	$ 2,559,066
Angie's List
Business Acquisition [Line Items]
Cash and cash equivalents				$ 44,270
Other current assets				11,280
Property and equipment				16,341
Goodwill				543,674
Intangible assets				317,300
Total assets				932,865
Deferred revenue				(32,595)
Other current liabilities				(46,150)
Long-term debt—related party				(61,498)
Deferred income taxes				(9,833)
Other long-term liabilities				(1,405)
Net assets acquired				$ 781,384

BUSINESS COMBINATION - Preliminary Estimated Fair Value of Intangible Assets Acquired (Details) - USD ($) $ in Thousands		12 Months Ended
	Sep. 29, 2017	Dec. 31, 2019
Acquired Intangible Assets [Line Items]
Weighted-Average Useful Life (Years)		18 months
Angie's List
Acquired Intangible Assets [Line Items]
Total identifiable intangible assets acquired	$ 317,300
Angie's List \| Service professionals
Acquired Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 90,500
Weighted-Average Useful Life (Years)	3 years
Angie's List \| Developed technology
Acquired Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 63,900
Weighted-Average Useful Life (Years)	6 years
Angie's List \| Memberships
Acquired Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 15,900
Weighted-Average Useful Life (Years)	3 years
Angie's List \| User base
Acquired Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 10,000
Weighted-Average Useful Life (Years)	1 year
Angie's List \| Indefinite-lived trade name and trademarks
Acquired Intangible Assets [Line Items]
Indefinite-lived trade name and trademarks	$ 137,000

BUSINESS COMBINATION - Pro-Forma Financial Information (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares
Business Acquisition, Pro Forma Information [Abstract]
Revenue \| $	$ 3,529,600
Net earnings (loss) attributable to IAC shareholders \| $	$ 364,496
Basic earnings (loss) per share attributable to ANGI Homeservices Inc. shareholders (USD per share) \| $ / shares	$ 4.55
Diluted earnings (loss) per share attributable to ANGI Homeservices Inc. shareholders (USD per share) \| $ / shares	$ 4.27

GOODWILL AND INTANGIBLE ASSETS - Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 2,854,462	$ 2,726,859	$ 2,559,066
Intangible assets with indefinite lives	446,495	458,104
Intangible assets with definite lives, net of accumulated amortization	131,979	173,318
Total goodwill and intangible assets, net	$ 3,432,936	$ 3,358,281

GOODWILL AND INTANGIBLE ASSETS - Goodwill by Reporting Unit (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018 USD ($) operating_segment reportingunit	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Goodwill
Balance at beginning of period	$ 2,559,066	$ 2,726,859	$ 2,559,066
Additions		168,866	208,423
(Deductions)		(29,267)	(22,188)
Impairment		(3,318)	0	$ 0
Foreign Exchange Translation		(8,678)	(18,442)
Balance at end of period		2,854,462	2,726,859	2,559,066
Match Group
Goodwill
Balance at beginning of period	1,247,899	1,245,013	1,247,899
Additions		3,553	11,187
(Deductions)		0	0
Foreign Exchange Translation		(8,726)	(14,073)
Balance at end of period		1,239,840	1,245,013	1,247,899
ANGI Homeservices
Goodwill
Balance at beginning of period	768,317	892,800	768,317
Additions		18,326	142,768
(Deductions)		(29,267)	(14,373)
Transfers In/(Out)			0
Impairment		0
Foreign Exchange Translation		192	(3,912)
Balance at end of period		882,051	892,800	768,317
Vimeo
Goodwill
Balance at beginning of period	77,303	77,152	77,303
Additions		142,222	0
(Deductions)		0	(151)
Transfers In/(Out)			0
Impairment		0
Foreign Exchange Translation		0	0
Balance at end of period		219,374	77,152	77,303
Applications
Goodwill
Balance at beginning of period	447,242	504,892	447,242
Additions		0	50,784
(Deductions)		0	0
Transfers In/(Out)			7,323
Impairment		0
Foreign Exchange Translation		(144)	(457)
Balance at end of period		504,748	504,892	447,242
Accumulated goodwill impairment loss		529,100
Applications \| Desktop
Goodwill
Balance at beginning of period	265,146	265,146	265,146
Additions		0	0
(Deductions)		0	0
Transfers In/(Out)			0
Impairment		0
Foreign Exchange Translation		0	0
Balance at end of period		265,146	265,146	265,146
Applications \| Mosaic Group
Goodwill
Balance at beginning of period	182,096	239,746	182,096
Additions		0	50,784
(Deductions)		0	0
Transfers In/(Out)			7,323
Impairment		0
Foreign Exchange Translation		(144)
Balance at end of period		239,602	239,746	182,096
Emerging & Other
Goodwill
Balance at beginning of period	$ 18,305	7,002	18,305
Additions		4,765	3,684
(Deductions)		0	(7,664)
Transfers In/(Out)			(7,323)
Balance at end of period		8,449	7,002	$ 18,305
Emerging & Other \| Ask Media Group
Goodwill
Accumulated goodwill impairment loss			399,700
Emerging & Other \| College Humor Media
Goodwill
Impairment		(3,318)
Accumulated goodwill impairment loss		$ 14,900	11,600
Dotdash
Goodwill
Accumulated goodwill impairment loss			$ 198,300
Publishing
Goodwill
Number of operating segments \| operating_segment	1
Number of reporting units \| reportingunit	1

GOODWILL AND INTANGIBLE ASSETS - Intangible Assets with Definite Lives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Intangible assets with definite lives
Gross Carrying Amount	$ 347,177	$ 309,723
Accumulated Amortization	(215,198)	(136,405)
Total	$ 131,979	$ 173,318
Weighted-Average Useful Life (Years)	3 years 9 months 18 days	3 years 9 months 18 days
Technology
Intangible assets with definite lives
Gross Carrying Amount	$ 154,052	$ 143,303
Accumulated Amortization	(79,358)	(53,199)
Total	$ 74,694	$ 90,104
Weighted-Average Useful Life (Years)	4 years 7 months 6 days	4 years 8 months 12 days
Service professional relationships
Intangible assets with definite lives
Gross Carrying Amount	$ 99,651	$ 99,528
Accumulated Amortization	(76,445)	(44,674)
Total	$ 23,206	$ 54,854
Weighted-Average Useful Life (Years)	2 years 10 months 24 days	2 years 10 months 24 days
Customer lists and user base
Intangible assets with definite lives
Gross Carrying Amount	$ 44,548	$ 30,099
Accumulated Amortization	(24,488)	(15,126)
Total	$ 20,060	$ 14,973
Weighted-Average Useful Life (Years)	3 years 3 months 18 days	2 years 10 months 24 days
Trade names
Intangible assets with definite lives
Gross Carrying Amount	$ 19,074	$ 12,393
Accumulated Amortization	(13,068)	(9,393)
Total	$ 6,006	$ 3,000
Weighted-Average Useful Life (Years)	3 years 2 months 12 days	3 years 3 months 18 days
Memberships
Intangible assets with definite lives
Gross Carrying Amount	$ 15,900	$ 15,900
Accumulated Amortization	(11,940)	(6,640)
Total	$ 3,960	$ 9,260
Weighted-Average Useful Life (Years)	3 years	3 years
Other
Intangible assets with definite lives
Gross Carrying Amount	$ 13,952	$ 8,500
Accumulated Amortization	(9,899)	(7,373)
Total	$ 4,053	$ 1,127
Weighted-Average Useful Life (Years)	3 years 8 months 12 days	4 years 9 months 18 days

GOODWILL AND INTANGIBLE ASSETS - Expected Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 63,844
2021	27,454
2022	22,781
2023	12,870
2024	1,766
Thereafter	3,264
Total	$ 131,979	$ 173,318

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Narrative (Details)		12 Months Ended
	Oct. 23, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2019 USD ($)	Feb. 15, 2019 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contractual maturity of current available-for-sale debt securities		1 year
Available-for-sale marketable debt securities in a continuous unrealized loss position for longer than twelve months		$ 0
Gross realized gains (losses) from available-for-sale securities		0	$ 0	$ 0
Upward adjustments to equity securities without readily determinable fair value		19,900,000
Downward adjustments to equity securities without readily determinable fair value		7,000,000.0
Other-than-temporary impairment charges on equity method investments			600,000	2,700,000
Other-than-temporary impairment charges on cost-method investments				$ 9,500,000
Proceeds from sale of cost-method investment	$ 60,200,000
Gain (loss) from sale of cost-method investment	$ 9,100,000
Maximum contingent payment		45,000,000.0
Gross fair value of contingent consideration arrangement		12,500,000
Non-current portion of contingent consideration arrangement liability		6,900,000	26,600,000
Current portion of contingent consideration arrangement liability			2,000,000.0
Face amount of debt instrument			500,000,000
Turo
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity method investments					$ 250,000,000
Pinterest
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Realized gain (loss) on disposal of equity method investments		20,500,000
Contingent Consideration Arrangements
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Settlements		1,988,000	948,000
Match Group
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregate principal amount		1,625,000,000	1,535,000,000
Match Group \| Match Group Senior Notes, 5.625% February 15, 2029 \| Senior Notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Aggregate principal amount		$ 350,000,000	$ 0			$ 350,000,000
Stated interest rate (as a percent)		5.625%	5.625%			5.625%
Discount Rate \| Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input (as a percent)		0.125	0.125
Discount Rate \| Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input (as a percent)			0.15
Discount Rate \| Contingent Consideration Arrangements \| Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input (as a percent)		0.25	0.12
Discount Rate \| Contingent Consideration Arrangements \| Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input (as a percent)			0.25

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Fair Value of Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Available-for-sale marketable debt securities	$ 19,993	$ 123,246
Marketable equity security	0	419
Total marketable securities	$ 19,993	$ 123,665

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Current Available-for-Sale Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 19,993	$ 123,246
Gross Unrealized Gains	0	3
Gross Unrealized Losses	0	(3)
Fair Value	19,993	123,246
Treasury discount notes
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		112,291
Gross Unrealized Gains		3
Gross Unrealized Losses		(3)
Fair Value		112,291
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	19,993	10,955
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 19,993	$ 10,955

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Proceeds from Maturities and Sales of Current Available-for-Sale Marketable Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Proceeds from maturities of available-for-sale marketable debt securities	$ 163,500	$ 333,600	$ 114,350

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Long-Term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Equity securities without readily determinable fair values	$ 353,052	$ 235,055
Total long-term investments	$ 353,052	$ 235,055

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Realized and Unrealized Gains and Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Adjustments to Carrying Value of Equity Securities without Readily Determinable Fair Value [Abstract]
Upward adjustments (gross unrealized gains)	$ 19,698	$ 128,986
Downward adjustments including impairments (gross unrealized losses)	(5,193)	(4,931)
Total	14,505	124,055
Adjustments to Carrying Value of Non-Marketable Equity Securities [Abstract]
Realized gains, net, for equity securities sold	23,076	27,874
Unrealized gains, net, on equity securities held	14,505	124,170
Total gains recognized, net, in other income (expense), net	$ 37,581	$ 152,044

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Financial Instruments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	$ 19,993	$ 123,246
Marketable equity security	0	419
Other non-current assets	133,640	134,924
Total	2,550,995	1,818,666
Contingent consideration arrangements	(6,918)	(28,631)
Quoted Market Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	2,164,576	881,234
Contingent consideration arrangements	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	377,924	937,432
Contingent consideration arrangements	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	8,495	0
Contingent consideration arrangements	(6,918)	(28,631)
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	2,164,576	880,815
Money market funds \| Quoted Market Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	2,164,576	880,815
Money market funds \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	0	0
Money market funds \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	0	0
Treasury discount notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	199,896	561,733
Marketable securities:		112,291
Treasury discount notes \| Quoted Market Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	0	0
Marketable securities:		0
Treasury discount notes \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	199,896	561,733
Marketable securities:		112,291
Treasury discount notes \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	0	0
Marketable securities:		0
Time deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	128,075	90,036
Time deposits \| Quoted Market Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	0	0
Time deposits \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	128,075	90,036
Time deposits \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	0	0
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	29,960	162,417
Marketable securities:	19,993	10,955
Commercial paper \| Quoted Market Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	0	0
Marketable securities:	0	0
Commercial paper \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	29,960	162,417
Marketable securities:	19,993	10,955
Commercial paper \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents:	0	0
Marketable securities:	0	0
Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other non-current assets	8,495
Warrant \| Quoted Market Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other non-current assets	0
Warrant \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other non-current assets	0
Warrant \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other non-current assets	$ 8,495
Marketable equity security
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity security		419
Marketable equity security \| Quoted Market Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity security		419
Marketable equity security \| Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity security		0
Marketable equity security \| Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable equity security		$ 0

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Unobservable Inputs of Fair Value Measurements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Warrant
Warrant
Balance at January 1	$ 0
Fair value at date of acquisition	17,618
Fair value adjustments	(9,123)
Included in other comprehensive (loss) income	0
Settlements	0
Balance at December 31	8,495	$ 0
Contingent Consideration Arrangements
Contingent Consideration Arrangements
Balance at January 1	(28,631)	(2,647)
Fair value at date of acquisition	0	(25,521)
Fair value adjustments	19,739	(1,456)
Included in other comprehensive income (loss)	(14)	45
Settlements	1,988	948
Balance at December 31	$ (6,918)	$ (28,631)

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Carrying Value and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current portion of long-term debt	$ (13,750)	$ (13,750)
Long-term debt, net	(3,121,572)	(2,245,548)
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current portion of long-term debt	(13,750)	(13,750)
Long-term debt, net	(3,121,572)	(2,245,548)
Unamortized original issue discount and debt issuance costs	(404,700)	(88,900)
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current portion of long-term debt	(13,681)	(12,753)
Long-term debt, net	$ (4,136,988)	$ (2,460,204)

LONG-TERM DEBT - Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Aug. 23, 2019	Feb. 15, 2019	Dec. 31, 2018	Dec. 04, 2017	Oct. 02, 2017	Jun. 01, 2016
Debt Instrument [Line Items]
Less: unamortized original issue discount	$ 357,887
Less: Current portion of long-term debt	13,750			$ 13,750
Less: unamortized debt issuance costs	46,791
Long-term debt, net	3,121,572			2,245,548
IAC
Debt Instrument [Line Items]
Long-term debt	1,667,500			551,989
Less: unamortized original issue discount	351,605			54,025
Less: unamortized debt issuance costs	29,752			13,298
Long-term debt, net	1,286,143			484,666
IAC \| Senior Notes \| 0.875% Exchangeable Senior Notes due October 1, 2022 (the 2022 Exchangeable Notes); interest payable each April 1 and October 1
Debt Instrument [Line Items]
Long-term debt	517,500			517,500		$ 517,500
Less: unamortized original issue discount	$ 40,768			$ 54,025
Stated interest rate (as a percent)	0.875%			0.875%
IAC \| Senior Notes \| 0.875% Exchangeable Senior Notes due June 15, 2026 (the 2026 Exchangeable Notes); interest payable each June 15 and December 15
Debt Instrument [Line Items]
Long-term debt	$ 575,000			$ 0
Less: unamortized original issue discount	$ 129,037
Stated interest rate (as a percent)	0.875%			0.875%
IAC \| Senior Notes \| 2.00% Exchangeable Senior Notes due January 15, 2030 (the 2030 Exchangeable Notes); interest payable each January 15 and July 15; commencing on January 15, 2020
Debt Instrument [Line Items]
Long-term debt	$ 575,000			$ 0
Less: unamortized original issue discount	$ 181,800
Stated interest rate (as a percent)	2.00%			2.00%
IAC \| Senior Notes \| 4.75% Senior Notes due December 15, 2022 (the 4.75% Senior Notes); interest payable each June 15 and December 15
Debt Instrument [Line Items]
Long-term debt	$ 0	$ 34,500		$ 34,489
Stated interest rate (as a percent)	4.75%	4.75%		4.75%
Match Group
Debt Instrument [Line Items]
Long-term debt	$ 1,625,000			$ 1,535,000
Less: unamortized original issue discount	6,282			7,352
Less: unamortized debt issuance costs	15,235			11,737
Long-term debt, net	1,603,483			1,515,911
Match Group \| Term Loan \| MTCH Term Loan due November 16, 2022
Debt Instrument [Line Items]
Long-term debt	425,000			425,000
Match Group \| Credit Facility \| MTCH Credit Facility due December 7, 2023
Debt Instrument [Line Items]
Long-term debt	0			260,000
Match Group \| Senior Notes \| 6.375% Senior Notes due June 1, 2024 (the 6.375% MTCH Senior Notes); interest payable each June 1 and December 1
Debt Instrument [Line Items]
Long-term debt	$ 400,000			$ 400,000
Stated interest rate (as a percent)	6.375%			6.375%			6.375%
Match Group \| Senior Notes \| 5.00% Senior Notes due December 15, 2027 (the 5.00% MTCH Senior Notes); interest payable each June 15 and December 15
Debt Instrument [Line Items]
Long-term debt	$ 450,000			$ 450,000
Stated interest rate (as a percent)	5.00%			5.00%	5.00%
Match Group \| Senior Notes \| 5.625% Senior Notes due February 15, 2029 (the 5.625% MTCH Senior Notes); interest payable each February 15 and August 15
Debt Instrument [Line Items]
Long-term debt	$ 350,000		$ 350,000	$ 0
Stated interest rate (as a percent)	5.625%		5.625%	5.625%
ANGI Homeservices
Debt Instrument [Line Items]
Less: Current portion of long-term debt	$ 13,750			$ 13,750
Less: unamortized debt issuance costs	1,804			2,529
Long-term debt, net	231,946			244,971
ANGI Homeservices \| Term Loan \| ANGI Term Loan due November 5, 2023
Debt Instrument [Line Items]
Long-term debt	$ 247,500			$ 261,250

LONG-TERM DEBT - Narrative (Details)						3 Months Ended	12 Months Ended					31 Months Ended
LONG-TERM DEBT - Narrative (Details)	Aug. 23, 2019 USD ($)	May 21, 2019 USD ($)	Dec. 31, 2018 USD ($)	Nov. 05, 2018 USD ($)	Oct. 02, 2017 USD ($)	Sep. 30, 2019	Nov. 05, 2023 USD ($)	Nov. 05, 2022 USD ($)	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2018 USD ($) $ / shares	Dec. 31, 2017 USD ($) $ / shares	Nov. 05, 2021 USD ($)	Feb. 15, 2019 USD ($)	Dec. 07, 2018 USD ($)	Dec. 04, 2017	Nov. 01, 2017 USD ($)	Jun. 01, 2016
Debt Instrument [Line Items]
Long-term debt									$ 3,540,000,000
Face amount of debt instrument			$ 500,000,000							$ 500,000,000
Unamortized discount									357,887,000
Cash, cash equivalents and marketable securities									$ 2,300,000,000
Senior Notes \| 2022 Exchangeable Notes
Debt Instrument [Line Items]
Face amount of debt instrument					$ 517,500,000
Approximate Equivalent Exchange Price per Share \| $ / shares									$ 152.18
Senior Notes \| 2026 Exchangeable Notes
Debt Instrument [Line Items]
Approximate Equivalent Exchange Price per Share \| $ / shares										$ 302.77
Senior Notes \| 2030 Exchangeable Notes
Debt Instrument [Line Items]
Approximate Equivalent Exchange Price per Share \| $ / shares											$ 291.35
Revolving Credit Facility \| IAC Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity									$ 250,000,000
Credit facility, borrowings outstanding			$ 0						$ 0	$ 0
Commitment fee rate (as a percent)									0.20%	0.20%
Revolving Credit Facility \| IAC Credit Facility \| Minimum
Debt Instrument [Line Items]
Maximum leverage ratio (not more than)			1.0						1.0
Revolving Credit Facility \| IAC Credit Facility \| Maximum
Debt Instrument [Line Items]
Maximum leverage ratio (not more than)			2.75						3.25
IAC
Debt Instrument [Line Items]
Unamortized discount			$ 54,025,000						$ 351,605,000	$ 54,025,000
Aggregate principal amount			$ 551,989,000						1,667,500,000	551,989,000
IAC \| Senior Notes
Debt Instrument [Line Items]
Long-term debt									1,700,000,000
Period of reported sale price of common stock					20 days	5 days
Period of consecutive reported sale price of common stock					30 days	5 days
Percentage of exchange price on applicable trading day					130.00%
Percentage of product of last reported price					98.00%
If-converted value in excess of principal									$ 329,600,000	$ 105,000,000.0
IAC \| Senior Notes \| 2022 Exchangeable Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)			0.875%						0.875%	0.875%
Long-term debt			$ 463,475,000						$ 476,732,000	$ 463,475,000
Effective interest rate (as a percent)						4.73%
Approximate Equivalent Exchange Price per Share \| $ / shares									$ 152.18
Unamortized discount			54,025,000						$ 40,768,000	54,025,000
Debt interest expense									20,765,000	21,151,000
Amortization of debt discount (premium)									13,256,000	13,134,000
Amortization of debt issuance costs									2,981,000	3,489,000
Aggregate principal amount			$ 517,500,000		$ 517,500,000				$ 517,500,000	$ 517,500,000
IAC \| Senior Notes \| 4.75% Senior Notes due December 15, 2022 (the 4.75% Senior Notes); interest payable each June 15 and December 15
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.75%		4.75%						4.75%	4.75%
Aggregate principal amount	$ 34,500,000		$ 34,489,000						$ 0	$ 34,489,000
Premium for debt redeemed	500,000
Accrued interest paid	$ 300,000
IAC \| Senior Notes \| Senior Notes, 0.875% due June 15, 2026 & Senior Notes, 2.00% due January 15, 2030]
Debt Instrument [Line Items]
Proceeds from issuance of debt after fees and expenses		$ 1,100,000,000
Unamortized discount		$ (136,900,000)
IAC \| Senior Notes \| 2026 Exchangeable Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)			0.875%						0.875%	0.875%
Long-term debt									$ 445,963,000
Face amount of debt instrument					575,000,000.0
Effective interest rate (as a percent)						5.35%
Approximate Equivalent Exchange Price per Share \| $ / shares									$ 302.77
Unamortized discount									$ 129,037,000
Debt interest expense									13,480,000
Amortization of debt discount (premium)									9,759,000
Amortization of debt issuance costs									758,000
Aggregate principal amount			$ 0						$ 575,000,000	$ 0
IAC \| Senior Notes \| 2030 Exchangeable Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)			2.00%						2.00%	2.00%
Long-term debt									$ 393,200,000
Face amount of debt instrument					$ 575,000,000.0
Effective interest rate (as a percent)						6.59%
Approximate Equivalent Exchange Price per Share \| $ / shares									$ 291.35
Unamortized discount									$ 181,800,000
Debt interest expense									14,605,000
Amortization of debt discount (premium)									7,413,000
Amortization of debt issuance costs									420,000
Aggregate principal amount			$ 0						575,000,000	$ 0
Match Group
Debt Instrument [Line Items]
Unamortized discount			7,352,000						6,282,000	7,352,000
Aggregate principal amount			$ 1,535,000,000						$ 1,625,000,000	$ 1,535,000,000
Match Group \| Senior Notes \| 6.375% Senior Notes due June 1, 2024 (the 6.375% MTCH Senior Notes); interest payable each June 1 and December 1
Debt Instrument [Line Items]
Stated interest rate (as a percent)			6.375%						6.375%	6.375%							6.375%
Aggregate principal amount			$ 400,000,000						$ 400,000,000	$ 400,000,000
Match Group \| Senior Notes \| 6.375% Senior Notes due June 1, 2024 (the 6.375% MTCH Senior Notes); interest payable each June 1 and December 1 \| Minimum
Debt Instrument [Line Items]
Maximum leverage ratio (not more than)									1.0
Match Group \| Senior Notes \| 6.375% Senior Notes due June 1, 2024 (the 6.375% MTCH Senior Notes); interest payable each June 1 and December 1 \| Maximum
Debt Instrument [Line Items]
Maximum leverage ratio (not more than)									5.0
Match Group \| Senior Notes \| 5.00% Senior Notes due December 15, 2027 (the 5.00% MTCH Senior Notes); interest payable each June 15 and December 15
Debt Instrument [Line Items]
Stated interest rate (as a percent)			5.00%						5.00%	5.00%					5.00%
Aggregate principal amount			$ 450,000,000						$ 450,000,000	$ 450,000,000
Match Group \| Senior Notes \| Match Group Senior Notes, 6.75% due December 15, 2020
Debt Instrument [Line Items]
Stated interest rate (as a percent)											6.75%				6.75%
Long-term debt											$ 445,200,000
Match Group \| Senior Notes \| Match Group Senior Notes, 5.625% February 15, 2029
Debt Instrument [Line Items]
Stated interest rate (as a percent)			5.625%						5.625%	5.625%			5.625%
Aggregate principal amount			$ 0						$ 350,000,000	$ 0			$ 350,000,000
Match Group \| Term Loan \| MTCH Term Loan due November 16, 2022
Debt Instrument [Line Items]
Face amount of debt instrument									$ 425,000,000
Effective interest rate (as a percent)			5.09%						4.44%	5.09%
Aggregate principal amount			$ 425,000,000						$ 425,000,000	$ 425,000,000
Match Group \| Term Loan \| MTCH Term Loan due November 16, 2022 \| LIBOR
Debt Instrument [Line Items]
Effective interest rate (as a percent)									2.50%
Match Group \| Credit Facility \| Match Group Credit Facility Due December 7, 2023
Debt Instrument [Line Items]
Long-term debt			$ 260,000,000.0						$ 0	$ 260,000,000.0
Effective interest rate (as a percent)			4.00%							4.00%
Aggregate principal amount			$ 260,000,000						$ 0	$ 260,000,000
Match Group \| Revolving Credit Facility \| MTCH Term Loan due November 16, 2022 \| Minimum
Debt Instrument [Line Items]
Net leverage ratio affecting ability to pay dividends, make distributions, or repurchase stock									1.0
Match Group \| Revolving Credit Facility \| MTCH Term Loan due November 16, 2022 \| Maximum
Debt Instrument [Line Items]
Net leverage ratio affecting ability to pay dividends, make distributions, or repurchase stock									4.0
Match Group \| Revolving Credit Facility \| Match Group Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity														$ 500,000,000
Commitment fee rate (as a percent)									0.25%	0.25%
Match Group \| Revolving Credit Facility \| Match Group Credit Agreement \| Minimum
Debt Instrument [Line Items]
Maximum leverage ratio (not more than)									1.0
Minimum interest coverage ratio (not less than)									1.0
Net leverage ratio affecting ability to pay dividends, make distributions, or repurchase stock									1.0
Match Group \| Revolving Credit Facility \| Match Group Credit Agreement \| Maximum
Debt Instrument [Line Items]
Maximum leverage ratio (not more than)									5.0
Minimum interest coverage ratio (not less than)									2.0
Net leverage ratio affecting ability to pay dividends, make distributions, or repurchase stock									2.0
Match Group \| Revolving Credit Facility \| Match Group Credit Agreement \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)									1.50%
ANGI Homeservices \| Term Loan
Debt Instrument [Line Items]
Face amount of debt instrument																$ 275,000,000
ANGI Homeservices \| Term Loan \| ANGI Term Loan due November 5, 2023
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)									3.25%	4.00%
Aggregate principal amount			$ 261,250,000						$ 247,500,000	$ 261,250,000
ANGI Homeservices \| Term Loan \| ANGI Term Loan due November 5, 2023 \| Minimum
Debt Instrument [Line Items]
Maximum leverage ratio (not more than)									1.0
Minimum interest coverage ratio (not less than)									1.0
Net leverage ratio affecting ability to pay dividends, make distributions, or repurchase stock									1.0
ANGI Homeservices \| Term Loan \| ANGI Term Loan due November 5, 2023 \| Maximum
Debt Instrument [Line Items]
Maximum leverage ratio (not more than)									4.5
Minimum interest coverage ratio (not less than)									2.0
Net leverage ratio affecting ability to pay dividends, make distributions, or repurchase stock									4.25
ANGI Homeservices \| Term Loan \| ANGI Term Loan due November 5, 2023 \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)									1.50%
ANGI Homeservices \| Revolving Credit Facility \| ANGI Homeservices Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 250,000,000
Credit facility, borrowings outstanding									$ 0
Term of debt instrument				5 years
Commitment fee rate (as a percent)									0.25%	0.25%
IAC FinanceCo 2, Inc.& IAC FinanceCo 3, Inc. \| IAC \| Senior Notes \| Senior Notes, 0.875% due June 15, 2026 & Senior Notes, 2.00% due January 15, 2030]
Debt Instrument [Line Items]
Period of reported sale price of common stock		20 days
Period of consecutive reported sale price of common stock		30 days
Redemption rate (as a percent)		100.00%
Percentage of exchange price on applicable trading day		130.00%
Forecast \| ANGI Homeservices \| Term Loan \| ANGI Term Loan due November 5, 2023
Debt Instrument [Line Items]
Quarterly principal repayments							$ 10,300,000	$ 6,900,000				$ 3,400,000
Final principal payment							$ 161,600,000

LONG-TERM DEBT - Debt Instrument Redemption (Details) - Senior Notes	12 Months Ended
	Dec. 31, 2019
6.375% Senior Notes due June 1, 2024 (the 6.375% MTCH Senior Notes); interest payable each June 1 and December 1 \| Period One
Debt Instrument [Line Items]
Redemption rate (as a percent)	104.781%
6.375% Senior Notes due June 1, 2024 (the 6.375% MTCH Senior Notes); interest payable each June 1 and December 1 \| Period Two
Debt Instrument [Line Items]
Redemption rate (as a percent)	103.188%
6.375% Senior Notes due June 1, 2024 (the 6.375% MTCH Senior Notes); interest payable each June 1 and December 1 \| Period Three
Debt Instrument [Line Items]
Redemption rate (as a percent)	101.594%
6.375% Senior Notes due June 1, 2024 (the 6.375% MTCH Senior Notes); interest payable each June 1 and December 1 \| Period Four
Debt Instrument [Line Items]
Redemption rate (as a percent)	100.00%
5.00% Senior Notes due December 15, 2027 (the 5.00% MTCH Senior Notes); interest payable each June 15 and December 15 \| Period One
Debt Instrument [Line Items]
Redemption rate (as a percent)	102.50%
5.00% Senior Notes due December 15, 2027 (the 5.00% MTCH Senior Notes); interest payable each June 15 and December 15 \| Period Two
Debt Instrument [Line Items]
Redemption rate (as a percent)	101.667%
5.00% Senior Notes due December 15, 2027 (the 5.00% MTCH Senior Notes); interest payable each June 15 and December 15 \| Period Three
Debt Instrument [Line Items]
Redemption rate (as a percent)	100.833%
5.00% Senior Notes due December 15, 2027 (the 5.00% MTCH Senior Notes); interest payable each June 15 and December 15 \| Period Four
Debt Instrument [Line Items]
Redemption rate (as a percent)	100.00%
5.625% Senior Notes due February 15, 2029 (the 5.625% MTCH Senior Notes); interest payable each February 15 and August 15 \| Period One
Debt Instrument [Line Items]
Redemption rate (as a percent)	102.813%
5.625% Senior Notes due February 15, 2029 (the 5.625% MTCH Senior Notes); interest payable each February 15 and August 15 \| Period Two
Debt Instrument [Line Items]
Redemption rate (as a percent)	101.875%
5.625% Senior Notes due February 15, 2029 (the 5.625% MTCH Senior Notes); interest payable each February 15 and August 15 \| Period Three
Debt Instrument [Line Items]
Redemption rate (as a percent)	100.938%
5.625% Senior Notes due February 15, 2029 (the 5.625% MTCH Senior Notes); interest payable each February 15 and August 15 \| Period Four
Debt Instrument [Line Items]
Redemption rate (as a percent)	100.00%

LONG-TERM DEBT - Exchangeable Notes (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 02, 2017
Components of Exchangeable Notes [Abstract]
Less: unamortized original issue discount	$ 357,887
Net carrying value of the liability component	$ 3,540,000
Senior Notes \| 2022 Exchangeable Notes
Details of Exchangeable Feature [Abstract]
Approximate Equivalent Exchange Price per Share (USD per share)	$ 152.18
Senior Notes \| 2026 Exchangeable Notes
Details of Exchangeable Feature [Abstract]
Approximate Equivalent Exchange Price per Share (USD per share)		$ 302.77
Senior Notes \| 2030 Exchangeable Notes
Details of Exchangeable Feature [Abstract]
Approximate Equivalent Exchange Price per Share (USD per share)			$ 291.35
IAC
Components of Exchangeable Notes [Abstract]
Principal	$ 1,667,500	$ 551,989
Less: unamortized original issue discount	351,605	54,025
IAC \| Senior Notes
Components of Exchangeable Notes [Abstract]
Net carrying value of the liability component	$ 1,700,000
IAC \| Senior Notes \| 2022 Exchangeable Notes
Details of Exchangeable Feature [Abstract]
Number of shares of the Company's Common Stock into which each $1,000 of Principal of the Exchangeable Notes is Exchangeable (shares)	6.5713
Approximate Equivalent Exchange Price per Share (USD per share)	$ 152.18
Components of Exchangeable Notes [Abstract]
Principal	$ 517,500	517,500		$ 517,500
Less: unamortized original issue discount	40,768	54,025
Net carrying value of the liability component	476,732	463,475
Equity component	70,363	70,363
Interest Expense on Exchangeable Notes [Abstract]
Contractual interest expense	4,528	4,528
Amortization of original issue discount	13,256	13,134
Amortization of debt issuance costs	2,981	3,489
Total interest expense recognized	$ 20,765	21,151
IAC \| Senior Notes \| 2022 Exchangeable Notes \| Exchangeable Notes Hedge
Interest Expense on Exchangeable Notes [Abstract]
Class of warrant outstanding (shares)	3,400,000
Exercise price of warrants (USD per share)	$ 152.18
IAC \| Senior Notes \| 2022 Exchangeable Notes \| Exchangeable Notes Warrants
Interest Expense on Exchangeable Notes [Abstract]
Class of warrant outstanding (shares)	3,400,000
Exercise price of warrants (USD per share)	$ 229.70
IAC \| Senior Notes \| 2026 Exchangeable Notes
Details of Exchangeable Feature [Abstract]
Number of shares of the Company's Common Stock into which each $1,000 of Principal of the Exchangeable Notes is Exchangeable (shares)	3.3028
Approximate Equivalent Exchange Price per Share (USD per share)	$ 302.77
Components of Exchangeable Notes [Abstract]
Principal	$ 575,000	0
Less: unamortized original issue discount	129,037
Net carrying value of the liability component	445,963
Equity component	138,796
Interest Expense on Exchangeable Notes [Abstract]
Contractual interest expense	2,963
Amortization of original issue discount	9,759
Amortization of debt issuance costs	758
Total interest expense recognized	$ 13,480
IAC \| Senior Notes \| 2026 Exchangeable Notes \| Exchangeable Notes Hedge
Interest Expense on Exchangeable Notes [Abstract]
Class of warrant outstanding (shares)	1,900,000
Exercise price of warrants (USD per share)	$ 302.77
IAC \| Senior Notes \| 2026 Exchangeable Notes \| Exchangeable Notes Warrants
Interest Expense on Exchangeable Notes [Abstract]
Class of warrant outstanding (shares)	1,900,000
Exercise price of warrants (USD per share)	$ 457.02
IAC \| Senior Notes \| 2030 Exchangeable Notes
Details of Exchangeable Feature [Abstract]
Number of shares of the Company's Common Stock into which each $1,000 of Principal of the Exchangeable Notes is Exchangeable (shares)	3.4323
Approximate Equivalent Exchange Price per Share (USD per share)	$ 291.35
Components of Exchangeable Notes [Abstract]
Principal	$ 575,000	$ 0
Less: unamortized original issue discount	181,800
Net carrying value of the liability component	393,200
Equity component	189,213
Interest Expense on Exchangeable Notes [Abstract]
Contractual interest expense	6,772
Amortization of original issue discount	7,413
Amortization of debt issuance costs	420
Total interest expense recognized	$ 14,605
IAC \| Senior Notes \| 2030 Exchangeable Notes \| Exchangeable Notes Hedge
Interest Expense on Exchangeable Notes [Abstract]
Class of warrant outstanding (shares)	2,000,000.0
Exercise price of warrants (USD per share)	$ 291.35
IAC \| Senior Notes \| 2030 Exchangeable Notes \| Exchangeable Notes Warrants
Interest Expense on Exchangeable Notes [Abstract]
Class of warrant outstanding (shares)	2,000,000.0
Exercise price of warrants (USD per share)	$ 457.02

LONG-TERM DEBT - Aggregate Contractual Maturities of Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
2020	$ 13,750
2021	13,750
2022	970,000
2023	192,500
2024	400,000
Thereafter	1,950,000
Total long-term debt	3,540,000
Less: Current portion of long-term debt	13,750	$ 13,750
Less: unamortized original issue discount	357,887
Less: unamortized debt issuance costs	46,791
Long-term debt, net	$ 3,121,572	$ 2,245,548

SHAREHOLDERS' EQUITY - Narrative (Details) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) vote warrant exchangeable_note shares	Dec. 31, 2018 USD ($) warrant exchangeable_note shares	Dec. 31, 2017 USD ($) shares
Class of Stock
Directors elected (as a percent)	25.00%
Warrants exercised during period \| warrant	0	0
Exchangeable notes exchanged during period \| exchangeable_note	0	0
Trade date fair value of shares acquired during period \| $	$ 274,302	$ 82,891	$ 50,121
Stock authorized for repurchase (shares)	8.0
Class B Convertible Common Stock
Class of Stock
Number of votes \| vote	10
Common Stock
Class of Stock
Number of votes \| vote	1
Common stock reserved (shares)	33.7
Treasury stock acquired during period (shares)	0.0	0.5	0.7
Trade date fair value of shares acquired during period \| $		$ 82,900	$ 50,100

ACCUMULATED OTHER COMPREHENSIVE LOSS - Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Loss
Balance at beginning of period	$ 3,551,801	$ 2,946,823	$ 2,010,670
Other comprehensive (loss) income before reclassifications	(7,942)	(25,226)	65,806
Amounts reclassified to earnings		(52)	(3,360)
Other comprehensive loss	(7,942)	(25,278)	62,446
Allocation of accumulated other comprehensive loss related to noncontrolling interests	(315)	(124)	(109)
Balance at end of period	3,898,318	3,551,801	2,946,823
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Loss
Balance at beginning of period	(128,726)	(103,568)	(170,149)
Other comprehensive (loss) income before reclassifications	(7,938)	(25,230)	65,799
Amounts reclassified to earnings		(52)	673
Other comprehensive loss	(7,938)	(25,282)	66,472
Allocation of accumulated other comprehensive loss related to noncontrolling interests	(315)	(124)	(109)
Balance at end of period	(136,349)	(128,726)	(103,568)
Unrealized Gains On Available-For-Sale Securities
Accumulated Other Comprehensive Loss
Balance at beginning of period	4	0	4,026
Other comprehensive (loss) income before reclassifications	(4)	4	7
Amounts reclassified to earnings		0	(4,033)
Other comprehensive loss	(4)	4	(4,026)
Allocation of accumulated other comprehensive loss related to noncontrolling interests	0	0	0
Balance at end of period	0	4	0
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Loss
Balance at beginning of period	(128,722)	(103,568)	(166,123)
Balance at end of period	$ (136,349)	$ (128,722)	$ (103,568)

ACCUMULATED OTHER COMPREHENSIVE LOSS - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Equity [Abstract]
Tax (benefit) provision related to unrealized gains/losses on available-for-sale securities	$ 3.8

EARNINGS PER SHARE - Summary (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net earnings									$ 543,820	$ 757,747	$ 358,008
Net earnings attributable to noncontrolling interests									(112,689)	(130,786)	(53,084)
Impact from public subsidiaries' dilutive securities									(26,063)	(25,228)	(33,531)
Net earnings (loss) attributable to IAC shareholders	$ 100,425	$ 128,544	$ 113,467	$ 88,695	$ 191,752	$ 145,774	$ 218,353	$ 71,082	431,131	626,961	304,924
Net earnings attributable to IAC shareholders									$ 405,068	$ 601,733	$ 271,393
Weighted average basic shares outstanding (shares)									84,261	83,407	80,089
Dilutive securities including subsidiary denominated equity, stock options and RSUs (shares)									5,782	7,915	5,221
Weighted average diluted shares outstanding (shares)									90,043	91,322	85,310
Earnings (loss) per share attributable to IAC shareholders: Basic
Basic earnings (loss) per share (USD per share)	$ 1.19	$ 1.52	$ 1.35	$ 1.06	$ 2.29	$ 1.75	$ 2.61	$ 0.86	$ 5.12	$ 7.52	$ 3.81
Earnings (loss) per share attributable to IAC shareholders: Diluted
Diluted earnings (loss) per share (USD per share)	$ 1.05	$ 1.35	$ 1.19	$ 0.91	$ 2.04	$ 1.49	$ 2.32	$ 0.71	4.50	6.59	$ 3.18
Anti-dilutive weighted average common shares
Potentially dilutive securities excluded from calculation of diluted earnings per share (shares)											100
Average stock price during period									$ 223.89	$ 167.61	$ 100.54
RSUs
Anti-dilutive weighted average common shares
Potentially dilutive securities excluded from calculation of diluted earnings per share (shares)									11,100	3,500	6,900
PSUs
Anti-dilutive weighted average common shares
Potentially dilutive securities excluded from calculation of diluted earnings per share (shares)									200	100
0.875% Exchangeable Senior Notes due October 1, 2022 (the 2022 Exchangeable Notes); interest payable each April 1 and October 1 \| Senior Notes
Anti-dilutive weighted average common shares
Potentially dilutive securities excluded from calculation of diluted earnings per share (shares)									1,100	300
Approximate Equivalent Exchange Price per Share (USD per share)									$ 152.18
2026 Exchangeable Notes \| Senior Notes
Anti-dilutive weighted average common shares
Approximate Equivalent Exchange Price per Share (USD per share)										$ 302.77
2030 Exchangeable Notes \| Senior Notes
Anti-dilutive weighted average common shares
Approximate Equivalent Exchange Price per Share (USD per share)											$ 291.35

STOCK-BASED COMPENSATION - Narrative (Details) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017 USD ($)	Dec. 31, 2019 USD ($) installment plan $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award
Number of active stock-based compensation plans \| plan		2
Shares available for grant (shares) \| shares		12,600
Unrecognized compensation cost, net of estimated forfeitures		$ 272,600
Weighted-average period over which cost is expected to be recognized		2 years 3 months 18 days
Income tax benefit		$ 49,309	$ (3,811)	$ 291,050
Intrinsic value of stock options exercised		$ 167,400	$ 83,700	$ 164,600
Stock options granted in period (shares) \| shares		0
Weighted average grant date fair value of stock options granted (USD per share) \| $ / shares			$ 53.94	$ 22.94
Number of shares required to settle vested and unvested interests at fair value (shares) \| shares		100
Cash required to settle vested and unvested interests at fair value		$ 20,200
Withholding rate (as a percent)		50.00%
Incremental compensation cost	$ 6,600
2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award
Stated term (in years)					10 years
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period		4 years
Income tax benefit		$ 189,800	$ 189,000	$ 423,000
Expected volatility (as a percent)			27.00%	29.00%
Risk-free interest rate (as a percent)			2.70%	2.00%
Expected term			6 years 2 months 12 days	5 years 2 months 12 days
Stock options granted in period (shares) \| shares		0	100	1,200
Consecutive days of price over threshold for vesting requirement			20 days
Number of installments \| installment		2
Cash received from stock option exercises		$ 10,700	$ 41,700	$ 82,400
Employee Stock Options, Net Settled
Share-based Compensation Arrangement by Share-based Payment Award
Income tax benefit		$ (137,200)	$ (169,000)	$ (411,600)
Market-Based Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Withholding rate (as a percent)		50.00%
Stock issued in conversion (shares) \| shares		1,800
Excess tax benefit attributable to stock-based compensation		$ 450,800
Market-Based Stock Options - Vested
Share-based Compensation Arrangement by Share-based Payment Award
Stock issued in conversion (shares) \| shares		1,400
Excess tax benefit attributable to stock-based compensation		$ 358,700
Market-Based Stock Options - Unvested
Share-based Compensation Arrangement by Share-based Payment Award
Stock issued in conversion (shares) \| shares		400
Excess tax benefit attributable to stock-based compensation		$ 92,100
RSUs and PSUs
Share-based Compensation Arrangement by Share-based Payment Award
Weighted average grant date fair value of RSUs and PSUs granted (USD per share) \| $ / shares		$ 220.77	$ 178.29	$ 90.04
Fair value of RSUs and PSUs that vested during the period		$ 69,300	$ 8,900	$ 32,500
RSUs
Share-based Compensation Arrangement by Share-based Payment Award
Weighted average grant date fair value of RSUs and PSUs granted (USD per share) \| $ / shares		$ 220.77
PSUs
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period		3 years
Weighted average grant date fair value of RSUs and PSUs granted (USD per share) \| $ / shares		$ 0
MSUs
Share-based Compensation Arrangement by Share-based Payment Award
Weighted average grant date fair value of RSUs and PSUs granted (USD per share) \| $ / shares		$ 153.43	$ 0	$ 0.00
Fair value of RSUs and PSUs that vested during the period		$ 0
Vesting period one \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting rights rate (as a percent)		50.00%
Vesting period one \| RSUs
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting rights rate (as a percent)		33.00%
Vesting period two \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting rights rate (as a percent)		50.00%
Vesting period two \| RSUs
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting rights rate (as a percent)		33.00%
Vesting period three \| RSUs
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting rights rate (as a percent)		33.00%
IAC
Share-based Compensation Arrangement by Share-based Payment Award
Common stock issued (shares) \| shares		200	700	2,000
Match Group
Share-based Compensation Arrangement by Share-based Payment Award
Common stock issued (shares) \| shares		600	2,500	11,300
Cash payments made to cover withholding taxes and exercise of awards				$ 520,000
Vested equity awards settled in cash	$ 33,900
Match Group \| Market Based Awards
Share-based Compensation Arrangement by Share-based Payment Award
Withholding rate (as a percent)		50.00%
Stock issued in conversion (shares) \| shares		8,000
Excess tax benefit attributable to stock-based compensation		$ 655,900
Match Group \| Market Based Awards - Vested
Share-based Compensation Arrangement by Share-based Payment Award
Stock issued in conversion (shares) \| shares		2,600
Excess tax benefit attributable to stock-based compensation		$ 209,500
Match Group \| Market Based Awards - Unvested
Share-based Compensation Arrangement by Share-based Payment Award
Stock issued in conversion (shares) \| shares		5,400
Excess tax benefit attributable to stock-based compensation		$ 446,400
ANGI Homeservices
Share-based Compensation Arrangement by Share-based Payment Award
Cash required to settle vested and unvested interests at fair value		$ 57,300
Withholding rate (as a percent)		50.00%
Common stock issued (shares) \| shares		6,800
Cash withholding obligation		$ 43,400
Cash withholding obligation equivalent (shares) \| shares		5,100
Incremental compensation cost		$ 13,100	$ 7,900
Incremental compensation cost from modification recognized in year of modification		3,900
ANGI Homeservices \| Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award
Incremental compensation cost		217,700
Incremental compensation cost from modification recognized in year of modification		$ 29,000	$ 56,900	$ 93,400
Maximum \| RSUs
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period		4 years
Maximum \| MSUs
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period		5 years
Minimum \| RSUs
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period		3 years
Minimum \| MSUs
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period		3 years

STOCK-BASED COMPENSATION - Changes in Outstanding Stock Options (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Number of Shares
Balance at beginning of period (shares) \| shares	5,814
Granted (shares) \| shares	0
Exercised (shares) \| shares	(911)
Forfeited (shares) \| shares	(15)
Expired (shares) \| shares	(1)
Balance at end of period (shares) \| shares	4,887
Options exercisable (shares) \| shares	3,851
Weighted Average Exercise Price
Balance at beginning of period (USD per share) \| $ / shares	$ 62.97
Granted (USD per share) \| $ / shares	0
Exercised (USD per share) \| $ / shares	53.41
Forfeited (USD per share) \| $ / shares	101.01
Expired (USD per share) \| $ / shares	124.29
Balance at end of period (USD per share) \| $ / shares	64.63
Options exercisable (USD per share) \| $ / shares	$ 62.83
Weighted Average Remaining Contractual Term (In Years)
Remaining term at end of period	5 years 3 months 18 days
Term of options exercisable	4 years 10 months 24 days
Aggregate Intrinsic Value
Balance at end of period \| $	$ 901,629
Options exercisable \| $	$ 717,388

STOCK-BASED COMPENSATION - Stock Options Outstanding and Exercisable (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Options Outstanding
Options outstanding (shares) \| shares	4,887
Weighted- Average Remaining Contractual Life in Years	5 years 3 months 18 days
Weighted-average exercise price (USD per share)	$ 64.63
Options Exercisable
Options exercisable (shares) \| shares	3,851
Weighted- Average Remaining Contractual Life in Years	4 years 10 months 24 days
Weighted-average exercise price (USD per share)	$ 62.83
$20.01 to $30.00
Options Outstanding
Options outstanding (shares) \| shares	3
Weighted- Average Remaining Contractual Life in Years	3 days
Weighted-average exercise price (USD per share)	$ 21.60
Options Exercisable
Options exercisable (shares) \| shares	3
Weighted- Average Remaining Contractual Life in Years	3 days
Weighted-average exercise price (USD per share)	$ 21.60
$30.01 to $40.00
Options Outstanding
Options outstanding (shares) \| shares	363
Weighted- Average Remaining Contractual Life in Years	1 year 3 months 18 days
Weighted-average exercise price (USD per share)	$ 32.39
Options Exercisable
Options exercisable (shares) \| shares	363
Weighted- Average Remaining Contractual Life in Years	1 year 3 months 18 days
Weighted-average exercise price (USD per share)	$ 32.39
$40.01 to $50.00
Options Outstanding
Options outstanding (shares) \| shares	1,124
Weighted- Average Remaining Contractual Life in Years	5 years 2 months 12 days
Weighted-average exercise price (USD per share)	$ 42.96
Options Exercisable
Options exercisable (shares) \| shares	840
Weighted- Average Remaining Contractual Life in Years	4 years 9 months 18 days
Weighted-average exercise price (USD per share)	$ 43.32
$50.01 to $60.00
Options Outstanding
Options outstanding (shares) \| shares	142
Weighted- Average Remaining Contractual Life in Years	2 years 2 months 12 days
Weighted-average exercise price (USD per share)	$ 59.89
Options Exercisable
Options exercisable (shares) \| shares	141
Weighted- Average Remaining Contractual Life in Years	2 years 2 months 12 days
Weighted-average exercise price (USD per share)	$ 59.90
$60.01 to $70.00
Options Outstanding
Options outstanding (shares) \| shares	916
Weighted- Average Remaining Contractual Life in Years	5 years 4 months 24 days
Weighted-average exercise price (USD per share)	$ 65.87
Options Exercisable
Options exercisable (shares) \| shares	796
Weighted- Average Remaining Contractual Life in Years	5 years 1 month 6 days
Weighted-average exercise price (USD per share)	$ 65.97
$70.01 to $80.00
Options Outstanding
Options outstanding (shares) \| shares	1,755
Weighted- Average Remaining Contractual Life in Years	6 years 4 months 24 days
Weighted-average exercise price (USD per share)	$ 75.29
Options Exercisable
Options exercisable (shares) \| shares	1,206
Weighted- Average Remaining Contractual Life in Years	6 years
Weighted-average exercise price (USD per share)	$ 74.99
$80.01 to $90.00
Options Outstanding
Options outstanding (shares) \| shares	500
Weighted- Average Remaining Contractual Life in Years	5 years 3 months 18 days
Weighted-average exercise price (USD per share)	$ 84.31
Options Exercisable
Options exercisable (shares) \| shares	500
Weighted- Average Remaining Contractual Life in Years	5 years 3 months 18 days
Weighted-average exercise price (USD per share)	$ 84.31
Greater than $90.01
Options Outstanding
Options outstanding (shares) \| shares	84
Weighted- Average Remaining Contractual Life in Years	8 years 2 months 12 days
Weighted-average exercise price (USD per share)	$ 150.23
Options Exercisable
Options exercisable (shares) \| shares	2
Weighted- Average Remaining Contractual Life in Years	7 years 7 months 6 days
Weighted-average exercise price (USD per share)	$ 104.13
Minimum \| $20.01 to $30.00
Options Exercisable
Exercise price range, lower limit (USD per share)	20.01
Minimum \| $30.01 to $40.00
Options Exercisable
Exercise price range, lower limit (USD per share)	30.01
Minimum \| $40.01 to $50.00
Options Exercisable
Exercise price range, lower limit (USD per share)	40.01
Minimum \| $50.01 to $60.00
Options Exercisable
Exercise price range, lower limit (USD per share)	50.01
Minimum \| $60.01 to $70.00
Options Exercisable
Exercise price range, lower limit (USD per share)	60.01
Minimum \| $70.01 to $80.00
Options Exercisable
Exercise price range, lower limit (USD per share)	70.01
Minimum \| $80.01 to $90.00
Options Exercisable
Exercise price range, lower limit (USD per share)	80.01
Minimum \| Greater than $90.01
Options Exercisable
Exercise price range, lower limit (USD per share)	90.01
Maximum \| $20.01 to $30.00
Options Exercisable
Exercise price range, upper limit (USD per share)	30
Maximum \| $30.01 to $40.00
Options Exercisable
Exercise price range, upper limit (USD per share)	40
Maximum \| $40.01 to $50.00
Options Exercisable
Exercise price range, upper limit (USD per share)	50
Maximum \| $50.01 to $60.00
Options Exercisable
Exercise price range, upper limit (USD per share)	60.00
Maximum \| $60.01 to $70.00
Options Exercisable
Exercise price range, upper limit (USD per share)	70.00
Maximum \| $70.01 to $80.00
Options Exercisable
Exercise price range, upper limit (USD per share)	80.00
Maximum \| $80.01 to $90.00
Options Exercisable
Exercise price range, upper limit (USD per share)	$ 90.00

STOCK-BASED COMPENSATION - Weighted-Average Assumptions (Details) - Stock Options	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award
Expected volatility (as a percent)	27.00%	29.00%
Risk-free interest rate (as a percent)	2.70%	2.00%
Expected term	6 years 2 months 12 days	5 years 2 months 12 days
Dividend yield (as a percent)	0.00%	0.00%

STOCK-BASED COMPENSATION - Outstanding and Unvested RSUs and PSUs (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
RSUs
Number of Shares
Balance at beginning of the period (shares)	459
Granted (shares)	63
Vested (shares)	(304)
Forfeited (shares)	(16)
Balance at end of the period (shares)	202	459
Weighted Average Grant Date Fair Value
Balance at beginning of the period (USD per share)	$ 115.12
Granted (USD per share)	220.77
Vested (USD per share)	118.25
Forfeited (USD per share)	194.10
Balance at end of the period (USD per share)	$ 132.37	$ 115.12
MSUs
Number of Shares
Balance at beginning of the period (shares)	0
Granted (shares)	159
Vested (shares)	0
Balance at end of the period (shares)	159	0
Weighted Average Grant Date Fair Value
Balance at beginning of the period (USD per share)	$ 0
Granted (USD per share)	153.43	$ 0	$ 0.00
Vested (USD per share)	0
Balance at end of the period (USD per share)	$ 153.43	$ 0
PSUs
Number of Shares
Balance at beginning of the period (shares)	113
Granted (shares)	0
Vested (shares)	0
Forfeited (shares)	(113)
Balance at end of the period (shares)	0	113
Weighted Average Grant Date Fair Value
Balance at beginning of the period (USD per share)	$ 76.00
Granted (USD per share)	0
Vested (USD per share)	0
Forfeited (USD per share)	76.00
Balance at end of the period (USD per share)	$ 0	$ 76.00
Vesting period	3 years

SEGMENT INFORMATION - Segment Reporting Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenue	$ 1,217,680	$ 1,246,874	$ 1,186,658	$ 1,105,843	$ 1,104,103	$ 1,104,592	$ 1,059,122	$ 995,075	$ 4,757,055	$ 4,262,892	$ 3,307,239
Operating Segments \| Match Group
Segment Reporting Information [Line Items]
Revenue									2,051,258	1,729,850	1,330,661
Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue									1,326,205	1,132,241	736,386
Operating Segments \| Vimeo
Segment Reporting Information [Line Items]
Revenue									196,015	159,641	103,332
Operating Segments \| Dotdash
Segment Reporting Information [Line Items]
Revenue									167,594	130,991	90,890
Operating Segments \| Applications
Segment Reporting Information [Line Items]
Revenue									519,459	582,287	577,998
Operating Segments \| Emerging & Other
Segment Reporting Information [Line Items]
Revenue									496,832	528,250	468,589
Inter-segment elimination
Segment Reporting Information [Line Items]
Revenue									$ (308)	$ (368)	$ (617)

SEGMENT INFORMATION - Revenue Disaggregated by Service (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 1,217,680	$ 1,246,874	$ 1,186,658	$ 1,105,843	$ 1,104,103	$ 1,104,592	$ 1,059,122	$ 995,075	$ 4,757,055	$ 4,262,892	$ 3,307,239
Operating Segments \| Match Group
Segment Reporting Information [Line Items]
Revenues									2,051,258	1,729,850	1,330,661
Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									1,326,205	1,132,241	736,386
Operating Segments \| Vimeo
Segment Reporting Information [Line Items]
Revenues									196,015	159,641	103,332
Operating Segments \| Dotdash
Segment Reporting Information [Line Items]
Revenues									167,594	130,991	90,890
Operating Segments \| Applications
Segment Reporting Information [Line Items]
Revenues									519,459	582,287	577,998
Operating Segments \| Applications \| Mosaic Group
Segment Reporting Information [Line Items]
Revenues									199,224	123,516	55,849
Operating Segments \| Emerging & Other
Segment Reporting Information [Line Items]
Revenues									496,832	528,250	468,589
North America \| Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									1,249,892	1,062,171	678,897
Europe \| Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									76,313	70,070	57,489
Direct \| Operating Segments \| Match Group
Segment Reporting Information [Line Items]
Revenues									2,007,174	1,677,171	1,281,249
Direct \| Operating Segments \| Match Group \| Tinder
Segment Reporting Information [Line Items]
Revenues									1,152,045	805,316	403,216
Direct \| Operating Segments \| Match Group \| Other brands
Segment Reporting Information [Line Items]
Revenues									855,129	871,855	878,033
Direct \| North America \| Operating Segments \| Match Group
Segment Reporting Information [Line Items]
Revenues									1,024,161	902,478	741,334
Direct \| International \| Operating Segments \| Match Group
Segment Reporting Information [Line Items]
Revenues									983,013	774,693	539,915
Indirect \| Operating Segments \| Match Group
Segment Reporting Information [Line Items]
Revenues									44,084	52,679	49,412
Marketplace \| North America \| Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									985,210	774,495	581,414
Consumer connection revenue \| North America \| Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									913,533	704,341	521,481
Service professional membership subscription revenue \| North America \| Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									64,706	66,214	56,135
Other revenue \| North America \| Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									6,971	3,940	3,798
Advertising and other revenue \| North America \| Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									264,682	287,676	97,483
Advertising and other revenue \| Europe \| Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									2,471	1,795	884
Consumer connection revenue \| Europe \| Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									59,611	50,913	40,009
Service professional membership subscription revenue \| Europe \| Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Revenues									14,231	17,362	16,596
Platform revenue \| Operating Segments \| Vimeo
Segment Reporting Information [Line Items]
Revenues									193,736	146,665	99,650
Hardware revenue \| Operating Segments \| Vimeo
Segment Reporting Information [Line Items]
Revenues									2,279	12,976	3,682
Advertising \| Operating Segments \| Dotdash
Segment Reporting Information [Line Items]
Revenues									126,487	103,704	76,316
Advertising \| Operating Segments \| Applications \| Mosaic Group
Segment Reporting Information [Line Items]
Revenues									9,346	18,541	27,869
Advertising \| Operating Segments \| Emerging & Other
Segment Reporting Information [Line Items]
Revenues									437,459	424,485	279,487
Google advertising revenue \| Operating Segments \| Emerging & Other
Segment Reporting Information [Line Items]
Revenues									391,709	357,752	225,576
Non-Google advertising revenue \| Operating Segments \| Emerging & Other
Segment Reporting Information [Line Items]
Revenues									45,750	66,733	53,911
Affiliate Commerce Commission \| Operating Segments \| Dotdash
Segment Reporting Information [Line Items]
Revenues									41,107	27,287	14,574
Other revenue \| Operating Segments \| Emerging & Other
Segment Reporting Information [Line Items]
Revenues									59,373	103,765	169,497
Desktop \| Operating Segments \| Applications
Segment Reporting Information [Line Items]
Revenues									320,235	458,771	522,149
Advertising \| Operating Segments \| Applications
Segment Reporting Information [Line Items]
Revenues									304,377	437,956	487,536
Google advertising revenue \| Operating Segments \| Applications
Segment Reporting Information [Line Items]
Revenues									291,215	426,964	480,774
Non-Google advertising revenue \| Operating Segments \| Applications
Segment Reporting Information [Line Items]
Revenues									13,162	10,992	6,762
Subscription and other revenue \| Operating Segments \| Applications
Segment Reporting Information [Line Items]
Revenues									15,858	20,815	34,613
Subscription and other revenue \| Operating Segments \| Applications \| Mosaic Group
Segment Reporting Information [Line Items]
Revenues									189,878	104,975	27,980
Test preparation revenue \| Operating Segments \| Emerging & Other
Segment Reporting Information [Line Items]
Revenues									$ 0	$ 0	$ 19,605

SEGMENT INFORMATION - Revenue and Long-Lived Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue and Long-lived Assets by Geography
Revenue:	$ 4,757,055	$ 4,262,892	$ 3,307,239
Long-lived assets (excluding goodwill and intangible assets)	371,353	318,800
United States
Revenue and Long-lived Assets by Geography
Revenue:	3,070,487	2,824,928	2,323,050
Long-lived assets (excluding goodwill and intangible assets)	345,937	289,756
All other countries
Revenue and Long-lived Assets by Geography
Revenue:	1,686,568	1,437,964	$ 984,189
Long-lived assets (excluding goodwill and intangible assets)	$ 25,416	$ 29,044

SEGMENT INFORMATION - Reconciliation of Adjusted EBITDA to Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Other Significant Reconciling Item
Operating income	$ 161,298	$ 185,852	$ 154,310	$ 79,873	$ 133,920	$ 172,832	$ 168,437	$ 89,950	$ 581,333	$ 565,139	$ 188,466
Stock-Based Compensation Expense									240,788	238,420	264,618
Depreciation									88,399	75,360	74,265
Amortization of intangibles									92,595	108,399	42,143
Goodwill Impairment									3,318	0	0
Interest expense									(153,563)	(109,327)	(105,295)
Other expense, net									66,741	305,746	(16,213)
Earnings before income taxes									494,511	761,558	66,958
Income tax benefit									49,309	(3,811)	291,050
Net earnings	124,272	159,772	146,791	112,985	217,477	171,577	280,854	87,839	543,820	757,747	358,008
Net earnings attributable to noncontrolling interests									(112,689)	(130,786)	(53,084)
Net earnings attributable to IAC shareholders	$ 100,425	$ 128,544	$ 113,467	$ 88,695	$ 191,752	$ 145,774	$ 218,353	$ 71,082	431,131	626,961	304,924
ANGI Homeservices
Segment Reporting, Other Significant Reconciling Item
Goodwill Impairment									0
Applications
Segment Reporting, Other Significant Reconciling Item
Goodwill Impairment									0
Operating Segments \| Match Group
Segment Reporting, Other Significant Reconciling Item
Operating income									648,531	553,294	360,517
Stock-Based Compensation Expense									89,724	66,031	69,090
Depreciation									32,450	32,968	32,613
Amortization of intangibles									8,727	1,318	1,468
Acquisition-related Contingent Consideration Fair Value Adjustments									0	320	5,253
Goodwill Impairment									0
Adjusted EBITDA									779,432	653,931	468,941
Operating Segments \| ANGI Homeservices
Segment Reporting, Other Significant Reconciling Item
Operating income									38,645	63,906	(149,176)
Stock-Based Compensation Expense									68,255	97,078	149,230
Depreciation									39,915	24,310	14,543
Amortization of intangibles									55,482	62,212	23,261
Acquisition-related Contingent Consideration Fair Value Adjustments									0	0	0
Goodwill Impairment									0
Adjusted EBITDA									202,297	247,506	37,858
Operating Segments \| Vimeo
Segment Reporting, Other Significant Reconciling Item
Operating income									(51,921)	(35,594)	(27,328)
Stock-Based Compensation Expense									0	0	0
Depreciation									478	1,200	1,408
Amortization of intangibles									9,653	6,349	2,313
Acquisition-related Contingent Consideration Fair Value Adjustments									0	0	0
Goodwill Impairment									0
Adjusted EBITDA									(41,790)	(28,045)	(23,607)
Operating Segments \| Dotdash
Segment Reporting, Other Significant Reconciling Item
Operating income									29,021	18,778	(15,694)
Stock-Based Compensation Expense									0	0	0
Depreciation									974	969	2,255
Amortization of intangibles									9,606	1,637	10,676
Acquisition-related Contingent Consideration Fair Value Adjustments									0	0	0
Goodwill Impairment									0
Adjusted EBITDA									39,601	21,384	(2,763)
Operating Segments \| Applications
Segment Reporting, Other Significant Reconciling Item
Operating income									113,569	94,834	130,176
Stock-Based Compensation Expense									0	0	0
Depreciation									1,443	2,601	3,863
Amortization of intangibles									8,277	33,266	2,170
Acquisition-related Contingent Consideration Fair Value Adjustments									(19,738)	1,136	548
Goodwill Impairment									0
Adjusted EBITDA									103,551	131,837	136,757
Operating Segments \| Emerging & Other
Segment Reporting, Other Significant Reconciling Item
Operating income									(13,012)	29,964	17,412
Stock-Based Compensation Expense									0	919	2,130
Depreciation									1,088	1,678	4,065
Amortization of intangibles									850	3,617	2,255
Acquisition-related Contingent Consideration Fair Value Adjustments									0	0	0
Goodwill Impairment									3,318
Adjusted EBITDA									(7,756)	36,178	25,862
Corporate
Segment Reporting, Other Significant Reconciling Item
Operating income									(183,500)	(160,043)	(127,441)
Stock-Based Compensation Expense									82,809	74,392	44,168
Depreciation									12,051	11,634	15,518
Amortization of intangibles									0	0	0
Acquisition-related Contingent Consideration Fair Value Adjustments									0	0	0
Goodwill Impairment									0
Adjusted EBITDA									$ (88,640)	$ (74,017)	$ (67,755)

SEGMENT INFORMATION - Capital Expenditures by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Capital expenditures:	$ 136,652	$ 85,634	$ 75,523
Operating Segments \| Match Group
Segment Reporting Information [Line Items]
Capital expenditures:	38,754	30,954	28,833
Operating Segments \| ANGI Homeservices
Segment Reporting Information [Line Items]
Capital expenditures:	68,804	46,976	26,837
Operating Segments \| Vimeo
Segment Reporting Information [Line Items]
Capital expenditures:	2,801	209	109
Operating Segments \| Dotdash
Segment Reporting Information [Line Items]
Capital expenditures:		102	825
Operating Segments \| Applications
Segment Reporting Information [Line Items]
Capital expenditures:	85	111	227
Operating Segments \| Emerging & Other
Segment Reporting Information [Line Items]
Capital expenditures:	345	1,119	852
Corporate
Segment Reporting Information [Line Items]
Capital expenditures:	$ 25,863	$ 6,163	$ 17,840

LEASES - Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets:
Right-of-use assets, net	$ 167,801	$ 0
Liabilities:
Current lease liabilities	33,118
Long-term lease liabilities	190,772
Total lease liabilities	$ 223,890

LEASES - Lease Cost (Details)
$ in Thousands

12 Months Ended

Dec. 31, 2019

USD ($)

Lessee, Lease, Description [Line Items]

Operating lease cost

$ 50,927

Variable lease cost

10,258

Lease cost

61,185

Short-term lease cost

$ 5,300

Schedule of Restricted Cash



	December 31, 2019		December 31, 2018		December 31, 2017		December 31, 2016
	(In thousands)
Cash and cash equivalents	$	3,139,295	$	2,131,632	$	1,630,809	$	1,329,187
Restricted cash included in other current assets	654		1,633		2,873		20,464
Restricted cash included in other assets	409		420		—		10,548
Total cash and cash equivalents and restricted cash as shown on the consolidated statement of cash flows	$	3,140,358	$	2,133,685	$	1,633,682	$	1,360,199

Sublease income

$ 2,100

Cost of sales

Lessee, Lease, Description [Line Items]

Operating lease cost

4,106

Variable lease cost

441

Selling and marketing expense

Lessee, Lease, Description [Line Items]

Operating lease cost

10,641

Variable lease cost

1,573

General and administrative expense

Lessee, Lease, Description [Line Items]

Operating lease cost

34,639

Variable lease cost

7,853

Product development expense

Lessee, Lease, Description [Line Items]

Operating lease cost

1,541

Variable lease cost

$ 391

LEASES - Operating Lease Liabilities Maturities (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Leases [Abstract]
2020	$ 43,902
2021	40,567
2022	32,135
2023	28,607
2024	25,594
Thereafter	226,734
Total	397,539
Less: Interest	173,649
Present value of lease liabilities	223,890
Lease payments for leases signed but not yet commenced	$ 37,700

LEASES - Weighted-Average Remaining Term and Discount Rate (Details)	Dec. 31, 2019
Leases [Abstract]
Remaining lease term	15 years 4 months 24 days
Discount rate (as a percent)	6.00%

LEASES - Other Information (Details) $ in Thousands	12 Months Ended
LEASES - Other Information (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Leases [Abstract]
Right-of-use assets obtained in exchange for lease liabilities	$ 66,408
Cash paid for amounts included in the measurement of lease liabilities	$ 49,117

COMMITMENTS AND CONTINGENCIES - Commercial Commitments Outstanding (Details) - Purchase obligations $ in Thousands	Dec. 31, 2019 USD ($)
Other Commitments
Less Than 1 Year	$ 119,116
1-3 Years	81,423
3-5 Years	0
More Than 5 Years	0
Total Amounts Committed	$ 200,539

COMMITMENTS AND CONTINGENCIES - Narrative (Details)				12 Months Ended
COMMITMENTS AND CONTINGENCIES - Narrative (Details)	Jun. 13, 2019 plaintiff	Aug. 31, 2018 plaintiff	Aug. 14, 2018 USD ($) plaintiff	Dec. 31, 2019 USD ($) minimum_payment
Loss Contingencies [Line Items]
Loss contingency accrual				$ 0
Tinder Optionholder Litigation
Loss Contingencies [Line Items]
Number of plaintiffs \| plaintiff		6	10
Number of plaintiffs who filed a discontinuance of claims \| plaintiff	2	4
Tinder Optionholder Litigation \| Pending Litigation
Loss Contingencies [Line Items]
Damages sought			$ 2,000,000,000
Purchase Commitment - Three Year Cloud Computing
Loss Contingencies [Line Items]
Purchase obligations				150,000,000.0
Payments of commercial commitments				50,000,000.0
Prepaid asset				$ 40,300,000
Number of remaining minimum payments \| minimum_payment				2
Commercial commitments due in the next two years				$ 50,000,000.0
Purchase Commitment - Two Year Cloud Computing
Loss Contingencies [Line Items]
Commercial commitments due in the next two years				59,300,000
Commercial commitments due in the next twelve months				40,900,000
Commercial commitments due in Year Two				18,300,000
Purchase Commitments - Advertising
Loss Contingencies [Line Items]
Commercial commitments due in the next twelve months				23,800,000
Purchase obligations
Loss Contingencies [Line Items]
Purchase obligations				200,539,000
Commercial commitments due in the next twelve months				119,116,000
Commercial commitments due between Year One and Year Three				$ 81,423,000
Expedia \| Corporate Aircraft Purchase
Loss Contingencies [Line Items]
Proportion of total purchase price and refurbish costs paid in related party transaction (as a percent)				50.00%
Expedia \| Corporate Aircraft Purchase \| Purchase obligations
Loss Contingencies [Line Items]
Commercial commitments due between Year One and Year Three				$ 13,100,000

RELATED PARTY TRANSACTIONS - Narrative (Details) shares in Millions		1 Months Ended	3 Months Ended	12 Months Ended
	Oct. 10, 2018 shares	Dec. 31, 2017 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) aircraft shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($) shares	Sep. 29, 2017 USD ($) intercompany_note
Match Group \| Employee Matters Agreement
Related Party Transaction [Line Items]
Shares received from related party pursuant to employee matters agreement (in shares) \| shares				0.8	3.0	11.9
Shares received from related party as reimbursement for exercise and settlement of equity awards denominated in shares of subsidiary (in shares) \| shares				0.7	2.5	11.3
Shares received from related party as reimbursement for exercise and vesting of equity awards denominated in shares of parent (in shares) \| shares				0.1	0.5	0.6
Match Group \| Services Agreement
Related Party Transaction [Line Items]
Payments received from related parties				$ 7,900,000	$ 7,600,000	$ 9,900,000
Match Group \| Leased Office Space
Related Party Transaction [Line Items]
Expenses from transactions with related parties				5,800,000	5,200,000	5,100,000
Match Group \| Tax Sharing Agreement
Related Party Transaction [Line Items]
Payments received from related parties				0	7,000,000.0	$ 10,900,000
Due from related parties				$ 200,000	$ 0
Match Group \| Net Operating Loss Sold
Related Party Transaction [Line Items]
Expenses from transactions with related parties		$ 900,000
ANGI Homeservices \| Employee Matters Agreement
Related Party Transaction [Line Items]
Shares received from related party pursuant to employee matters agreement (in shares) \| shares				0.5	0.9	0.4
ANGI Homeservices \| Services Agreement
Related Party Transaction [Line Items]
Payments received from related parties				$ 4,800,000	$ 5,700,000	$ 1,700,000
Due to related parties				0	100,000
ANGI Homeservices \| Tax Sharing Agreement
Related Party Transaction [Line Items]
Current notes receivable due from related party				200,000	$ 12,100,000
Payments received from related party tax expense			$ 11,400,000
ANGI Homeservices \| Intercompany Notes
Related Party Transaction [Line Items]
Number of related party debt instruments \| intercompany_note							2
ANGI Homeservices \| Payoff Intercompany Note
Related Party Transaction [Line Items]
Current notes receivable due from related party							$ 61,500,000
ANGI Homeservices \| Working Capital Intercompany Note
Related Party Transaction [Line Items]
Current notes receivable due from related party							$ 15,000,000
ANGI Homeservices \| Sublease Agreement
Related Party Transaction [Line Items]
Due to related parties				900,000
Related party costs				$ 1,400,000
Other Affiliates
Related Party Transaction [Line Items]
Ownership interest held by each of the Company and Expedia in aircraft (as a percent)				50.00%
Number of aircraft operated \| aircraft				2
IAC's total purchase price and refurbish costs in aircraft				$ 17,400,000
Proportion of total purchase price and refurbish costs paid in related party transaction (as a percent)				50.00%
Ownership interest held by each of the Company and Expedia in an entity employing aircraft flight crew (as a percent)				50.00%
Expedia \| Corporate Aircraft Purchase
Related Party Transaction [Line Items]
Expenses from transactions with related parties				$ 23,000,000
Proportion of total purchase price and refurbish costs paid in related party transaction (as a percent)				50.00%
Expected costs from transactions with related party				$ 72,300,000
Class B Common Stock \| ANGI Homeservices \| Angie's List Merger Agreement
Related Party Transaction [Line Items]
Stock received from related party (shares) \| shares	5.1

BENEFIT PLANS - Narrative (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
BENEFIT PLANS - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Contribution Plan Disclosure
Employee contribution limit per calendar year (up to) (as a percent of pre-tax earnings)			50.00%
Employer contribution limit per calendar year (as a percent of compensation)	10.00%	3.00%
Employer contribution per dollar employee contributes up to contribution limit	100.00%
United States
Defined Contribution Plan Disclosure
Defined contribution plan contributions			$ 21.0	$ 12.9	$ 11.1
Foreign Plan
Defined Contribution Plan Disclosure
Defined contribution plan contributions			$ 4.0	$ 3.4	$ 2.5

CONSOLIDATED FINANCIAL STATEMENT DETAILS - Narrative (Details) - USD ($) shares in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 19, 2018	Dec. 04, 2017	Sep. 29, 2017
Additional consolidated financial statement details
Unrealized gains, net, on equity securities held			$ 14,505,000	$ 124,170,000
Upward adjustments to equity securities without readily determinable fair value			19,900,000
Fair value of contingent consideration at date of acquisition			$ 0	$ 25,500,000	$ 0
Match Group
Additional consolidated financial statement details
Common stock issued (shares)		2,500	600	2,500	11,300
ANGI Homeservices
Additional consolidated financial statement details
Common stock issued (shares)			6,800
Senior Notes \| 4.875% Senior Notes due November 30, 2018 (the 4.875% Senior Notes); interest payable each May 30 and November 30
Additional consolidated financial statement details
Stated interest rate (as a percent)					4.875%
Senior Notes \| Match Group \| 6.75% Senior Notes due December 15, 2022 (the Match Group 6.75% Senior Notes); interest payable each June 15 and December 15
Additional consolidated financial statement details
Stated interest rate (as a percent)					6.75%		6.75%
Other Income (Expense)
Additional consolidated financial statement details
Interest income			$ 55,000,000.0	$ 30,400,000	$ 11,400,000
Upward adjustments to equity securities without readily determinable fair value			14,500,000
Mark-to-market charge pertaining to subsidiary denominated equity instrument			1,700,000
Realized foreign currency transaction gain (loss)				5,300,000
Foreign currency exchange gain (loss)					(16,800,000)
Gain (loss) on mark-to-market adjustment					(13,000,000.0)
Gain on sale of long-term investments					34,900,000
Other Income (Expense) \| Senior Notes \| 4.875% Senior Notes due November 30, 2018 (the 4.875% Senior Notes); interest payable each May 30 and November 30
Additional consolidated financial statement details
Write-off of proportionate share of original issue discount and deferred financing costs					(1,200,000)
Other Income (Expense) \| Senior Notes \| Match Group \| 6.75% Senior Notes due December 15, 2022 (the Match Group 6.75% Senior Notes); interest payable each June 15 and December 15
Additional consolidated financial statement details
Expense related to extinguishment of debt					(15,400,000)
Dictionary.com, Electus, Felix, and CityGrid \| Other Income (Expense)
Additional consolidated financial statement details
Gain (loss) on sale of business				120,600,000
Pinterest \| Other Income (Expense)
Additional consolidated financial statement details
Gain (loss) on sale of business				26,800,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| Dictionary.com, Electus, Felix, and CityGrid
Additional consolidated financial statement details
Gain (loss) on sale of business		$ 92,500,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| Dictionary.com, Electus, Felix, and CityGrid \| Other Income (Expense)
Additional consolidated financial statement details
Gain (loss) on sale of business	$ (8,200,000)
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| Pinterest \| Other Income (Expense)
Additional consolidated financial statement details
Gain (loss) on sale of business			(20,500,000)
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| ASKfm \| Other Income (Expense)
Additional consolidated financial statement details
Gain on other-than-temporary impairment charges					$ (12,200,000)
Pinterest \| Other Income (Expense)
Additional consolidated financial statement details
Unrealized gains, net, on equity securities held				$ 128,800,000
Unrealized reduction in estimated fair value of warrants			$ 9,100,000
Common Stock
Additional consolidated financial statement details
Common stock issued (shares)		262,303	263,230	262,303
Common stock		$ 262,000	$ 263,000	$ 262,000
Common Stock \| ANGI Homeservices
Additional consolidated financial statement details
Common stock issued (shares)						8,600		61,300
Common stock						$ 165,800,000		$ 763,700,000

CONSOLIDATED FINANCIAL STATEMENT DETAILS - Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2018
Other current assets:
Prepaid expenses	$ 97,609	$ 55,586
Capitalized costs to obtain a contract with a customer	71,548	69,817	$ 53,400
Capitalized downloadable search toolbar costs, net	21,985	33,365
Income taxes receivable	9,308	10,132
Other	48,917	59,353
Other current assets	$ 249,367	$ 228,253

CONSOLIDATED FINANCIAL STATEMENT DETAILS - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property and equipment, net:
Property and equipment, gross	$ 695,712	$ 605,598
Accumulated depreciation and amortization	(324,359)	(286,798)
Property and equipment, net	371,353	318,800
Buildings and leasehold improvements
Property and equipment, net:
Property and equipment, gross	270,509	249,026
Capitalized software and computer equipment
Property and equipment, net:
Property and equipment, gross	268,927	229,083
Furniture and other equipment
Property and equipment, net:
Property and equipment, gross	93,082	86,694
Land
Property and equipment, net:
Property and equipment, gross	11,591	11,591
Projects in progress
Property and equipment, net:
Property and equipment, gross	$ 51,603	$ 29,204

CONSOLIDATED FINANCIAL STATEMENT DETAILS - Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued expenses and other current liabilities:
Accrued employee compensation and benefits	$ 153,705	$ 137,583
Accrued advertising expense	91,470	105,520
Other	256,828	191,783
Accrued expenses and other current liabilities	$ 502,003	$ 434,886

CONSOLIDATED FINANCIAL STATEMENT DETAILS - Other Income (Expense), Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other income (expense), net:
Other income (expense), net	$ 66,741	$ 305,746	$ (16,213)

CONSOLIDATED FINANCIAL STATEMENT DETAILS - Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 3,139,295	$ 2,131,632	$ 1,630,809	$ 1,329,187
Restricted cash included in other current assets	654	1,633	2,873	20,464
Restricted cash included in other assets	409	420	0	10,548
Total cash and cash equivalents and restricted cash as shown on the consolidated statement of cash flows	$ 3,140,358	$ 2,133,685	$ 1,633,682	$ 1,360,199

CONSOLIDATED FINANCIAL STATEMENT DETAILS - Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash paid (received) during the year for:
Interest	$ 96,730	$ 90,485	$ 92,461
Income tax payments	39,515	45,154	35,598
Income tax refunds	$ (5,436)	$ (33,698)	$ (42,025)

QUARTERLY RESULTS (UNAUDITED) - Summary (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Data [Abstract]
Revenue	$ 1,217,680	$ 1,246,874	$ 1,186,658	$ 1,105,843	$ 1,104,103	$ 1,104,592	$ 1,059,122	$ 995,075	$ 4,757,055	$ 4,262,892	$ 3,307,239
Cost of revenue	294,575	296,385	276,389	260,071	253,722	237,238	218,224	201,962	1,127,420	911,146	651,008
Operating income	161,298	185,852	154,310	79,873	133,920	172,832	168,437	89,950	581,333	565,139	188,466
Net earnings	124,272	159,772	146,791	112,985	217,477	171,577	280,854	87,839	543,820	757,747	358,008
Net earnings attributable to IAC shareholders	$ 100,425	$ 128,544	$ 113,467	$ 88,695	$ 191,752	$ 145,774	$ 218,353	$ 71,082	$ 431,131	$ 626,961	$ 304,924
Per share information attributable to IAC shareholders:
Basic earnings per share (USD per share)	$ 1.19	$ 1.52	$ 1.35	$ 1.06	$ 2.29	$ 1.75	$ 2.61	$ 0.86	$ 5.12	$ 7.52	$ 3.81
Diluted earnings per share (USD per share)	$ 1.05	$ 1.35	$ 1.19	$ 0.91	$ 2.04	$ 1.49	$ 2.32	$ 0.71	$ 4.50	$ 6.59	$ 3.18
Stock-based compensation expense									$ 240,788	$ 238,420	$ 264,618
Impairment of intangible assets					$ 21,300
Dictionary.com, Electus, Felix, and CityGrid \| Disposal Group, Disposed of by Sale, Not Discontinued Operations
Per share information attributable to IAC shareholders:
Gain on sale of business					92,500
HomeAdvisor
Per share information attributable to IAC shareholders:
Stock-based compensation expense	$ 1,700	$ 1,700	$ 1,900	$ 2,200	$ 14,400	$ 12,300	$ 12,800	$ 14,600
After-tax costs							2,000	4,100
Write-off due to deferred revenue							1,800	$ 2,800
Gain (loss) on sale of equity investments							$ 133,300

SUBSEQUENT EVENTS - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions				12 Months Ended
	Feb. 13, 2020	Feb. 11, 2020	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 07, 2018
Subsequent Event [Line Items]
Face amount of debt instrument					$ 500,000,000
Match Group Credit Agreement \| Match Group \| Revolving Credit Facility
Subsequent Event [Line Items]
Maximum borrowing capacity						$ 500,000,000
Term Loan \| MTCH Term Loan due November 16, 2022 \| Match Group
Subsequent Event [Line Items]
Face amount of debt instrument				$ 425,000,000
LIBOR \| Match Group Credit Agreement \| Match Group \| Revolving Credit Facility
Subsequent Event [Line Items]
Basis spread on variable rate (as a percent)				1.50%
Subsequent Event \| Match Group Credit Agreement \| Match Group \| Revolving Credit Facility
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 750,000,000
Subsequent Event \| Senior Notes \| Match Group Senior Notes, 4.125% August 1, 2030 \| Match Group
Subsequent Event [Line Items]
Face amount of debt instrument		$ 500,000,000
Stated interest rate (as a percent)		4.125%
Subsequent Event \| LIBOR \| Match Group Credit Agreement \| Match Group \| Revolving Credit Facility
Subsequent Event [Line Items]
Basis spread on variable rate (as a percent)	1.375%
Subsequent Event \| LIBOR \| Term Loan \| MTCH Term Loan due November 16, 2022 \| Match Group
Subsequent Event [Line Items]
Basis spread on variable rate (as a percent)	1.75%
Subsequent Event \| Subsidiaries
Subsequent Event [Line Items]
Stock received from related party (shares)			1.4
Subsequent Event \| Match Group
Subsequent Event [Line Items]
Cash per share paid to related party's shareholders who elected payout (USD per share)		$ 3.00
Subsequent Event \| Care.com
Subsequent Event [Line Items]
Total purchase price		$ 500,000,000

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts and revenue reserves
Movement in Valuation Allowances and Reserves
Balance at beginning of period	$ 18,860	$ 11,489	$ 16,405
Charges to Earnings	65,803	48,445	28,930
Charges to Other Accounts	238	(573)	(1,006)
Deductions	(60,175)	(40,501)	(32,840)
Balance at end of period	24,726	18,860	11,489
Sales returns accrual
Movement in Valuation Allowances and Reserves
Balance at beginning of period		0	80
Charges to Earnings			0
Charges to Other Accounts			(80)
Deductions			0
Balance at end of period			0
Deferred tax valuation allowance
Movement in Valuation Allowances and Reserves
Balance at beginning of period	115,853	132,598	88,170
Charges to Earnings	15,404	(20,746)	38,144
Charges to Other Accounts	(1,637)	4,001	6,284
Deductions	0	0	0
Balance at end of period	129,620	115,853	132,598
Other reserves
Movement in Valuation Allowances and Reserves
Balance at beginning of period	7,734	2,544	2,822
Balance at end of period	$ 7,961	$ 7,734	$ 2,544

Label	Element	Value
Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 36,795,000
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 36,795,000