GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION - Statement of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	$ 157,706	$ 83,194
Cash flows from investing activities:
Acquisitions, net of cash acquired	(49,164)	(2,524)
Capital expenditures	(41,821)	(35,133)
Investments in time deposits	0	(87,500)
Proceeds from maturities of time deposits	0	87,500
Proceeds from maturities and sales of marketable debt securities	99,350	32,500
Purchases of marketable debt securities	(24,909)	(79,366)
Purchases of investments	(5,105)	(5,056)
Net proceeds from the sale of businesses and investments	119,697	103,735
Intercompany		0
Other, net	1,076	4,815
Net cash provided by investing activities	99,124	18,971
Cash flows from financing activities:
Purchase of IAC treasury stock	(56,424)	(214,635)
Proceeds from Match Group 2016 Senior Notes offering	0	400,000
Principal payment on Match Group Term Loan	0	(410,000)
Debt issuance costs for Match Group 2016 Senior Notes offering	0	(4,621)
Repurchases of IAC Senior Notes	(31,590)	(61,110)
Proceeds from the exercise of IAC stock options	48,146	10,951
Withholding taxes paid on behalf of IAC net settled stock-based awards	(49,900)	(24,048)
Proceeds from the exercise of Match Group stock options	39,403	8,671
Withholding taxes paid on behalf of Match Group net settled stock-based awards	(28,421)	(6,495)
Purchase of noncontrolling interests	(12,361)	(2,411)
Acquisition-related contingent consideration payments	(3,860)	(2,150)
Decrease (increase) in restricted cash related to bond redemptions	20,141	(30,002)
Funds returned from escrow for MyHammer tender offer	10,604	0
Intercompany	0	0
Other, net	(4,873)	(488)
Net cash used in financing activities	(69,135)	(336,338)
Total cash provided (used)	187,695	(234,173)
Effect of exchange rate changes on cash and cash equivalents	5,418	(1,290)
Net increase (decrease) in cash and cash equivalents	193,113	(235,463)
Cash and cash equivalents at beginning of period	1,329,187	1,481,447
Cash and cash equivalents at end of period	1,522,300	1,245,984
IAC
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	(40,671)	(67,034)
Cash flows from investing activities:
Acquisitions, net of cash acquired	0	0
Capital expenditures	(216)	(299)
Investments in time deposits		0
Proceeds from maturities of time deposits		0
Proceeds from maturities and sales of marketable debt securities	99,350	32,500
Purchases of marketable debt securities	(24,909)	(79,366)
Purchases of investments	0	0
Net proceeds from the sale of businesses and investments	0	10,000
Intercompany		(33,495)
Other, net	0	0
Net cash provided by investing activities	74,225	(70,660)
Cash flows from financing activities:
Purchase of IAC treasury stock	(56,424)	(214,635)
Proceeds from Match Group 2016 Senior Notes offering		0
Principal payment on Match Group Term Loan		0
Debt issuance costs for Match Group 2016 Senior Notes offering		0
Repurchases of IAC Senior Notes	(31,590)	(61,110)
Proceeds from the exercise of IAC stock options	48,146	10,951
Withholding taxes paid on behalf of IAC net settled stock-based awards	(49,900)	(24,048)
Proceeds from the exercise of Match Group stock options	0	0
Withholding taxes paid on behalf of Match Group net settled stock-based awards	0	0
Purchase of noncontrolling interests	0	(1,400)
Acquisition-related contingent consideration payments	0	0
Decrease (increase) in restricted cash related to bond redemptions	20,141	(30,002)
Funds returned from escrow for MyHammer tender offer	0
Intercompany	48,386	65,469
Other, net	251	275
Net cash used in financing activities	(20,990)	(254,500)
Total cash provided (used)	12,564	(392,194)
Effect of exchange rate changes on cash and cash equivalents	36	0
Net increase (decrease) in cash and cash equivalents	12,600	(392,194)
Cash and cash equivalents at beginning of period	552,699	1,073,053
Cash and cash equivalents at end of period	565,299	680,859
Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	77,215	76,888
Cash flows from investing activities:
Acquisitions, net of cash acquired	(2,200)	0
Capital expenditures	(24,043)	(11,256)
Investments in time deposits		0
Proceeds from maturities of time deposits		0
Proceeds from maturities and sales of marketable debt securities	0	0
Purchases of marketable debt securities	0	0
Purchases of investments	0	0
Net proceeds from the sale of businesses and investments	0	0
Intercompany		0
Other, net	120	158
Net cash provided by investing activities	(26,123)	(11,098)
Cash flows from financing activities:
Purchase of IAC treasury stock	0	0
Proceeds from Match Group 2016 Senior Notes offering		0
Principal payment on Match Group Term Loan		0
Debt issuance costs for Match Group 2016 Senior Notes offering		0
Repurchases of IAC Senior Notes	0	0
Proceeds from the exercise of IAC stock options	0	0
Withholding taxes paid on behalf of IAC net settled stock-based awards	0	0
Proceeds from the exercise of Match Group stock options	0	0
Withholding taxes paid on behalf of Match Group net settled stock-based awards	0	0
Purchase of noncontrolling interests	(11,942)	0
Acquisition-related contingent consideration payments	0	(321)
Decrease (increase) in restricted cash related to bond redemptions	0	0
Funds returned from escrow for MyHammer tender offer	0
Intercompany	(39,150)	(65,469)
Other, net	0	0
Net cash used in financing activities	(51,092)	(65,790)
Total cash provided (used)	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Non-Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	121,162	73,340
Cash flows from investing activities:
Acquisitions, net of cash acquired	(46,964)	(2,524)
Capital expenditures	(17,562)	(23,578)
Investments in time deposits		(87,500)
Proceeds from maturities of time deposits		87,500
Proceeds from maturities and sales of marketable debt securities	0	0
Purchases of marketable debt securities	0	0
Purchases of investments	(5,105)	(5,056)
Net proceeds from the sale of businesses and investments	119,697	93,735
Intercompany		0
Other, net	956	4,657
Net cash provided by investing activities	51,022	67,234
Cash flows from financing activities:
Purchase of IAC treasury stock	0	0
Proceeds from Match Group 2016 Senior Notes offering		400,000
Principal payment on Match Group Term Loan		(410,000)
Debt issuance costs for Match Group 2016 Senior Notes offering		(4,621)
Repurchases of IAC Senior Notes	0	0
Proceeds from the exercise of IAC stock options	0	0
Withholding taxes paid on behalf of IAC net settled stock-based awards	0	0
Proceeds from the exercise of Match Group stock options	39,403	8,671
Withholding taxes paid on behalf of Match Group net settled stock-based awards	(28,421)	(6,495)
Purchase of noncontrolling interests	(419)	(1,011)
Acquisition-related contingent consideration payments	(3,860)	(1,829)
Decrease (increase) in restricted cash related to bond redemptions	0	0
Funds returned from escrow for MyHammer tender offer	10,604
Intercompany	(9,236)	33,495
Other, net	(5,124)	(763)
Net cash used in financing activities	2,947	17,447
Total cash provided (used)	175,131	158,021
Effect of exchange rate changes on cash and cash equivalents	5,382	(1,290)
Net increase (decrease) in cash and cash equivalents	180,513	156,731
Cash and cash equivalents at beginning of period	776,488	408,394
Cash and cash equivalents at end of period	957,001	565,125
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities		0
Cash flows from investing activities:
Acquisitions, net of cash acquired		0
Capital expenditures		0
Investments in time deposits		0
Proceeds from maturities of time deposits		0
Proceeds from maturities and sales of marketable debt securities		0
Purchases of marketable debt securities		0
Purchases of investments		0
Net proceeds from the sale of businesses and investments		0
Intercompany		33,495
Other, net		0
Net cash provided by investing activities		33,495
Cash flows from financing activities:
Purchase of IAC treasury stock		0
Proceeds from Match Group 2016 Senior Notes offering		0
Principal payment on Match Group Term Loan		0
Debt issuance costs for Match Group 2016 Senior Notes offering		0
Repurchases of IAC Senior Notes		0
Proceeds from the exercise of IAC stock options		0
Withholding taxes paid on behalf of IAC net settled stock-based awards		0
Proceeds from the exercise of Match Group stock options		0
Withholding taxes paid on behalf of Match Group net settled stock-based awards		0
Purchase of noncontrolling interests		0
Acquisition-related contingent consideration payments		0
Decrease (increase) in restricted cash related to bond redemptions		0
Intercompany		(33,495)
Other, net		0
Net cash used in financing activities		(33,495)
Total cash provided (used)		0
Effect of exchange rate changes on cash and cash equivalents		0
Net increase (decrease) in cash and cash equivalents		0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0	$ 0