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LONG-TERM DEBT - Schedule of Long-Term Debt (Details) - USD ($)	Jun. 30, 2018	Dec. 31, 2017	Dec. 04, 2017	Jun. 01, 2016
Debt Instrument [Line Items]
Less: current portion of long-term debt	$ 13,750,000	$ 13,750,000
Long-term debt, net	1,982,271,000	1,979,469,000
Match Group, Inc.
Debt Instrument [Line Items]
Long-term debt	1,275,000,000	1,275,000,000
Less: unamortized original issue discount	8,010,000	8,668,000
Less: unamortized debt issuance costs	12,725,000	13,636,000
Long-term debt, net	1,254,265,000	1,252,696,000
Match Group, Inc. \| Term Loan \| Term Loan due November 16, 2022
Debt Instrument [Line Items]
Long-term debt	425,000,000	425,000,000
Match Group, Inc. \| Senior Notes \| 6.375% Senior Notes due June 1, 2024 (the Match Group 6.375% Senior Notes)
Debt Instrument [Line Items]
Long-term debt	$ 400,000,000	$ 400,000,000
Stated interest rate (as a percent)	6.375%	6.375%		6.375%
Match Group, Inc. \| Senior Notes \| Match Group Senior Notes, 5.00% December 15, 2027
Debt Instrument [Line Items]
Long-term debt	$ 450,000,000	$ 450,000,000	$ 450,000,000
Stated interest rate (as a percent)	5.00%		5.00%
ANGI Homeservices
Debt Instrument [Line Items]
Less: current portion of long-term debt	$ 13,750,000	13,750,000
Less: unamortized debt issuance costs	2,635,000	2,938,000
Long-term debt, net	251,740,000	258,312,000
ANGI Homeservices \| Term Loan \| Term Loan due November 01, 2022
Debt Instrument [Line Items]
Long-term debt	268,125,000	275,000,000
IAC/InterActiveCorp
Debt Instrument [Line Items]
Long-term debt	551,989,000	552,359,000
Less: unamortized original issue discount	60,654,000	67,158,000
Less: unamortized debt issuance costs	15,069,000	16,740,000
Long-term debt, net	476,266,000	468,461,000
IAC/InterActiveCorp \| Senior Notes \| Senior Notes, 0.875% due October 1, 2022
Debt Instrument [Line Items]
Long-term debt	$ 517,500,000	517,500,000
Stated interest rate (as a percent)	0.875%
IAC/InterActiveCorp \| Senior Notes \| Senior Notes, 4.75% Due December 15, 2022
Debt Instrument [Line Items]
Long-term debt	$ 34,489,000	$ 34,859,000
Stated interest rate (as a percent)	4.75%