SEGMENT INFORMATION - SCHEDULE OF RECONCILIATION OF ADJUSTED EBITDA TO OPERATING INCOME (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting, Other Significant Reconciling Item
Adjusted EBITDA									$ 485,790	$ 544,076	$ 598,303
Stock-Based Compensation Expense									(105,450)	(59,634)	(53,005)
Depreciation									(62,205)	(61,156)	(58,909)
Amortization of Intangibles									(139,952)	(57,926)	(59,843)
Acquisition-related Contingent Consideration Fair Value Adjustments									15,461	13,367	(343)
Impairment									(14,056)	0	0
Operating income	$ (5,430)	$ 87,130	$ 62,769	$ 35,119	$ 110,372	$ 100,953	$ 95,690	$ 71,712	179,588	378,727	426,203
Equity in earnings (losses) of unconsolidated affiliates									772	(9,697)	(6,615)
Interest expense									(73,636)	(56,314)	(33,596)
Other income (expense), net									36,149	(42,787)	30,309
Earnings from continuing operations before income taxes									142,873	269,929	416,301
Income tax provision									(29,516)	(35,372)	(134,502)
Earnings from continuing operations	(31,417)	65,026	57,885	21,863	67,986	150,261	(17,995)	34,305	113,357	234,557	281,799
Less: earnings from discontinued operations, net of tax	28	17	(153)	125	625	175,730	(868)	(814)	17	174,673	1,926
Net earnings	(31,389)	65,043	57,732	21,988	68,611	325,991	(18,863)	33,491	113,374	409,230	283,725
Net loss attributable to noncontrolling interests									6,098	5,643	2,059
Net earnings attributable to IAC shareholders	(31,849)	$ 65,611	$ 59,305	$ 26,405	$ 70,172	$ 326,812	$ (17,996)	$ 35,885	119,472	414,873	285,784
Operating Segments
Segment Reporting, Other Significant Reconciling Item
Impairment									(14,056)
Operating Segments | Match Group
Segment Reporting, Other Significant Reconciling Item
Adjusted EBITDA									278,667	273,448	271,231
Stock-Based Compensation Expense									(50,083)	(20,851)	(12,228)
Depreciation									(25,983)	(25,547)	(20,202)
Amortization of Intangibles									(20,101)	(11,395)	(17,125)
Acquisition-related Contingent Consideration Fair Value Adjustments									11,056	12,912	(343)
Impairment									0
Operating income									193,556	228,567	221,333
Operating Segments | HomeAdvisor
Segment Reporting, Other Significant Reconciling Item
Adjusted EBITDA									18,529	17,701	15,373
Stock-Based Compensation Expense									(1,649)	(558)	0
Depreciation									(6,593)	(6,520)	(5,174)
Amortization of Intangibles									(3,835)	(9,562)	(9,915)
Acquisition-related Contingent Consideration Fair Value Adjustments									0	0	0
Impairment									0
Operating income									6,452	1,061	284
Operating Segments | Publishing
Segment Reporting, Other Significant Reconciling Item
Adjusted EBITDA									87,788	150,960	161,950
Stock-Based Compensation Expense									0	0	(1)
Depreciation									(9,577)	(11,856)	(14,822)
Amortization of Intangibles									(104,903)	(28,581)	(27,643)
Acquisition-related Contingent Consideration Fair Value Adjustments									0	0	0
Impairment									0
Operating income									(26,692)	110,523	119,484
Operating Segments | Applications
Segment Reporting, Other Significant Reconciling Item
Adjusted EBITDA									184,258	186,192	219,263
Stock-Based Compensation Expense									0	0	(1)
Depreciation									(4,617)	(4,385)	(4,346)
Amortization of Intangibles									(6,264)	(2,521)	0
Acquisition-related Contingent Consideration Fair Value Adjustments									1,768	(326)	0
Impairment									0
Operating income									175,145	178,960	214,916
Operating Segments | Video
Segment Reporting, Other Significant Reconciling Item
Adjusted EBITDA									(38,384)	(39,916)	(21,397)
Stock-Based Compensation Expense									(360)	(647)	(633)
Depreciation									(1,091)	(899)	(1,133)
Amortization of Intangibles									(1,558)	(2,099)	(981)
Acquisition-related Contingent Consideration Fair Value Adjustments									2,637	215	0
Impairment									0
Operating income									(38,756)	(43,346)	(24,144)
Operating Segments | Other
Segment Reporting, Other Significant Reconciling Item
Adjusted EBITDA									10,621	13,134	7,520
Stock-Based Compensation Expense									0	0	29
Depreciation									(2,460)	(1,824)	(3,714)
Amortization of Intangibles									(3,291)	(3,768)	(4,179)
Acquisition-related Contingent Consideration Fair Value Adjustments									0	566	0
Impairment	$ (14,100)								(14,056)
Operating income									(9,186)	8,108	(344)
Corporate
Segment Reporting, Other Significant Reconciling Item
Adjusted EBITDA									(55,689)	(57,443)	(55,637)
Stock-Based Compensation Expense									(53,358)	(37,578)	(40,171)
Depreciation									(11,884)	(10,125)	(9,518)
Amortization of Intangibles									0	0	0
Acquisition-related Contingent Consideration Fair Value Adjustments									0	0	0
Impairment									0
Operating income									$ (120,931)	$ (105,146)	$ (105,326)