Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after accumulated amortization, of debt discount (premium).

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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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