GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION - Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities			$ 355,808	$ 379,802
Cash flows from investing activities:
Acquisitions, net of cash acquired			(201,026)	(17,513)
Capital expenditures			(76,623)	(39,696)
Proceeds from maturities of marketable debt securities	$ 40,000	$ 5,000	163,500	10,000
Purchases of marketable debt securities			(39,740)	(124,397)
Net proceeds from the sale of businesses and investments			23,373	27,540
Purchases of investments			0	(31,180)
Other, net			(2,156)	9,599
Net cash used in investing activities			(132,672)	(165,647)
Cash flows from financing activities:
Purchase of exchangeable note hedges			(303,428)	0
Proceeds from issuance of warrants			166,520	0
Debt issuance costs			(26,361)	(532)
Purchase of noncontrolling interests			(6,121)	(877)
Distribution to IAC pursuant to the ANGI tax sharing agreement			0
Intercompany			0	0
Other, net			(3,719)	(4,829)
Net cash used in financing activities			796,771	(202,705)
Total cash provided			1,019,907	11,450
Effect of exchange rate changes on cash, cash equivalents, and restricted cash			361	44
Net increase in cash, cash equivalents, and restricted cash			1,020,268	11,494
Cash, cash equivalents, and restricted cash at beginning of period			2,133,685	1,633,682
Cash, cash equivalents, and restricted cash at end of period	3,153,953	1,645,176	3,153,953	1,645,176
Reportable Legal Entities | IAC
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities			(54,883)	(24,698)
Cash flows from investing activities:
Acquisitions, net of cash acquired			0	(4,142)
Capital expenditures			(1,408)	(2,200)
Proceeds from maturities of marketable debt securities			138,500	10,000
Purchases of marketable debt securities			(39,740)	(124,397)
Net proceeds from the sale of businesses and investments			170	408
Purchases of investments				(18,180)
Other, net			0	(5,000)
Net cash used in investing activities			97,522	(143,511)
Cash flows from financing activities:
Purchase of noncontrolling interests			(3,182)	0
Distribution to IAC pursuant to the ANGI tax sharing agreement			11,355
Intercompany			921,515	375,167
Other, net				2,311
Net cash used in financing activities			1,073,186	396,431
Total cash provided			1,115,825	228,222
Effect of exchange rate changes on cash, cash equivalents, and restricted cash			(2)	11
Net increase in cash, cash equivalents, and restricted cash			1,115,823	228,233
Cash, cash equivalents, and restricted cash at beginning of period			1,018,082	585,639
Cash, cash equivalents, and restricted cash at end of period	2,133,905	813,872	2,133,905	813,872
Reportable Legal Entities | Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities			92,299	418,153
Cash flows from investing activities:
Acquisitions, net of cash acquired			(7,215)	0
Capital expenditures			(14,104)	(847)
Proceeds from maturities of marketable debt securities			0	0
Purchases of marketable debt securities			0	0
Net proceeds from the sale of businesses and investments			39	0
Purchases of investments				0
Other, net			(3,270)	3,884
Net cash used in investing activities			(24,550)	3,037
Cash flows from financing activities:
Purchase of noncontrolling interests			0	0
Distribution to IAC pursuant to the ANGI tax sharing agreement			0
Intercompany			(67,749)	(421,190)
Net cash used in financing activities			(67,749)	(421,190)
Net increase in cash, cash equivalents, and restricted cash			0	0
Cash, cash equivalents, and restricted cash at end of period	0	0	0	0
Reportable Legal Entities | Non-Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities			341,838	314,884
Cash flows from investing activities:
Acquisitions, net of cash acquired			(193,811)	(13,371)
Capital expenditures			(61,111)	(36,649)
Proceeds from maturities of marketable debt securities			25,000	0
Purchases of marketable debt securities			0	0
Net proceeds from the sale of businesses and investments			23,164	27,132
Purchases of investments				(13,000)
Other, net			1,114	10,715
Net cash used in investing activities			(205,644)	(25,173)
Cash flows from financing activities:
Debt issuance costs			(26,361)	(532)
Purchase of noncontrolling interests			(2,939)	(877)
Distribution to IAC pursuant to the ANGI tax sharing agreement			(11,355)
Intercompany			(877,212)	(282,514)
Other, net			(3,719)	(7,140)
Net cash used in financing activities			(232,112)	(506,483)
Total cash provided			(95,918)	(216,772)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash			363	33
Net increase in cash, cash equivalents, and restricted cash			(95,555)	(216,739)
Cash, cash equivalents, and restricted cash at beginning of period			1,115,603	1,048,043
Cash, cash equivalents, and restricted cash at end of period	1,020,048	831,304	1,020,048	831,304
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities			(23,446)	(328,537)
Cash flows from investing activities:
Acquisitions, net of cash acquired			0	0
Capital expenditures			0	0
Proceeds from maturities of marketable debt securities			0	0
Purchases of marketable debt securities			0	0
Net proceeds from the sale of businesses and investments			0	0
Purchases of investments				0
Other, net			0	0
Net cash used in investing activities			0	0
Cash flows from financing activities:
Purchase of noncontrolling interests			0	0
Distribution to IAC pursuant to the ANGI tax sharing agreement			0
Intercompany			23,446	328,537
Net cash used in financing activities			23,446	328,537
Net increase in cash, cash equivalents, and restricted cash			0	0
Cash, cash equivalents, and restricted cash at end of period	$ 0	$ 0	0	0
IAC/InterActiveCorp
Cash flows from financing activities:
Proceeds from issuance of debt			1,150,000	0
Purchase of Match Group treasury stock				(7,869)
Proceeds from the exercise of stock options			9,767	27,317
Withholding taxes paid on behalf of employees on net settled stock-based awards			(32,789)	(495)
IAC/InterActiveCorp | Reportable Legal Entities | IAC
Cash flows from financing activities:
Proceeds from issuance of debt			0
Purchase of Match Group treasury stock				(7,869)
Proceeds from the exercise of stock options			9,767	27,317
Withholding taxes paid on behalf of employees on net settled stock-based awards			(32,789)	(495)
IAC/InterActiveCorp | Reportable Legal Entities | Guarantor Subsidiaries
Cash flows from financing activities:
Proceeds from issuance of debt			0
Purchase of Match Group treasury stock
Proceeds from the exercise of stock options			0	0
Withholding taxes paid on behalf of employees on net settled stock-based awards			0	0
IAC/InterActiveCorp | Reportable Legal Entities | Non-Guarantor Subsidiaries
Cash flows from financing activities:
Proceeds from issuance of debt			1,150,000
Purchase of Match Group treasury stock
Proceeds from the exercise of stock options			0	0
Withholding taxes paid on behalf of employees on net settled stock-based awards			0	0
IAC/InterActiveCorp | Eliminations
Cash flows from financing activities:
Proceeds from issuance of debt			0
Purchase of Match Group treasury stock
Proceeds from the exercise of stock options			0	0
Withholding taxes paid on behalf of employees on net settled stock-based awards			0	0
Match Group and ANGI Homeservices
Cash flows from financing activities:
Proceeds from the exercise of stock options			573	2,125
Withholding taxes paid on behalf of employees on net settled stock-based awards			(164,710)	(136,727)
Match Group and ANGI Homeservices | Reportable Legal Entities | IAC
Cash flows from financing activities:
Proceeds from the exercise of stock options			0	0
Withholding taxes paid on behalf of employees on net settled stock-based awards			0	0
Match Group and ANGI Homeservices | Reportable Legal Entities | Guarantor Subsidiaries
Cash flows from financing activities:
Proceeds from the exercise of stock options			0	0
Withholding taxes paid on behalf of employees on net settled stock-based awards			0	0
Match Group and ANGI Homeservices | Reportable Legal Entities | Non-Guarantor Subsidiaries
Cash flows from financing activities:
Proceeds from the exercise of stock options			573	2,125
Withholding taxes paid on behalf of employees on net settled stock-based awards			(164,710)	(136,727)
Match Group and ANGI Homeservices | Eliminations
Cash flows from financing activities:
Proceeds from the exercise of stock options			0	0
Withholding taxes paid on behalf of employees on net settled stock-based awards			0	0
Match Group
Cash flows from financing activities:
Proceeds from issuance of debt			40,000	0
Purchase of exchangeable note hedges			(303,428)
Proceeds from issuance of warrants			166,520
Proceeds from Match Group 2019 Senior Notes offering			350,000	0
Principal payments on debt			(300,000)	0
Purchase of Match Group treasury stock			(76,086)	(73,943)
Match Group | Reportable Legal Entities | IAC
Cash flows from financing activities:
Proceeds from issuance of debt			0
Purchase of exchangeable note hedges			0
Proceeds from issuance of warrants			166,520
Proceeds from Match Group 2019 Senior Notes offering			0
Principal payments on debt			0
Match Group | Reportable Legal Entities | Guarantor Subsidiaries
Cash flows from financing activities:
Proceeds from issuance of debt			0
Purchase of exchangeable note hedges			0
Proceeds from issuance of warrants			0
Proceeds from Match Group 2019 Senior Notes offering			0
Principal payments on debt			0
Match Group | Reportable Legal Entities | Non-Guarantor Subsidiaries
Cash flows from financing activities:
Proceeds from issuance of debt			40,000
Purchase of exchangeable note hedges			(303,428)
Proceeds from issuance of warrants			0
Proceeds from Match Group 2019 Senior Notes offering			350,000
Principal payments on debt			(300,000)
Purchase of Match Group treasury stock			(76,086)	(73,943)
Match Group | Eliminations
Cash flows from financing activities:
Proceeds from issuance of debt			0
Purchase of exchangeable note hedges			0
Proceeds from issuance of warrants			0
Proceeds from Match Group 2019 Senior Notes offering			0
Principal payments on debt			0
ANGI Homeservices
Cash flows from financing activities:
Principal payments on debt			(6,875)	(6,875)
ANGI Homeservices | Reportable Legal Entities | IAC
Cash flows from financing activities:
Principal payments on debt			0	0
ANGI Homeservices | Reportable Legal Entities | Guarantor Subsidiaries
Cash flows from financing activities:
Principal payments on debt			0	0
ANGI Homeservices | Reportable Legal Entities | Non-Guarantor Subsidiaries
Cash flows from financing activities:
Principal payments on debt			(6,875)	(6,875)
ANGI Homeservices | Eliminations
Cash flows from financing activities:
Principal payments on debt			$ 0	$ 0