Debt Instrument, Amount of Debt Discount and Increase to Additional Paid in capital

No definition available.

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Period Type:	instant

- Definition

Debt Instrument, Covenant Terms, Interest Coverage Ratio

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Covenant Terms, Leverage Ratio

+ References

No definition available.

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- Definition

Debt Instrument, Covenant Terms, Leverage Ratio Limiting Ability to Pay Dividends, Make Distributions, or Repurchase Stock

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Exchange Price Per Share

+ References

No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Percentage of Exchange Price on Applicable Trading day

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No definition available.

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- Definition

Debt Instrument, Percentage of Product of Last Reported Price

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Period of Consecutive Reported Sale Price of Common Stock

+ References

No definition available.

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- Definition

Debt Instrument, Period of Reported Sale Price of Common Stock

+ References

No definition available.

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- Definition

Dent Instrument, Exchangeable Shares

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No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

Long-term Debt, Maturities, Quarterly Repayments of Principal

+ References

No definition available.

+ Details

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Balance Type:	credit
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- Definition

Long-term Debt, Maturities, Repayments of Principal, Final Payment

+ References

No definition available.

+ Details

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Balance Type:	credit
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- Definition

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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-Subparagraph (SX 210.5-03.8)
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- Definition

Amount of amortization expense attributable to debt issuance costs.

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- Definition

Exercise price per share or per unit of warrants or rights outstanding.

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Number of warrants or rights outstanding.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

The amount by which the convertible debt's if-converted value exceeds its principle amount at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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-Subparagraph (SX 210.5-02.22(a)(1))
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- Definition

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

+ References

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- Definition

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.

+ References

No definition available.

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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

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

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

+ Details

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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- Definition

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

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Balance Type:	credit
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- Definition

The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

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Balance Type:	debit
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- Definition

Number of shares issued which are neither cancelled nor held in the treasury.

+ References

No definition available.

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Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
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- Details

Name:	srt_RangeAxis=srt_MaximumMember
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LONG-TERM DEBT - Narrative (Details)					3 Months Ended		6 Months Ended		12 Months Ended			31 Months Ended
LONG-TERM DEBT - Narrative (Details)	May 21, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($)	Nov. 05, 2018 USD ($)	Oct. 02, 2017 USD ($) $ / shares shares	Jun. 30, 2019 USD ($) $ / shares shares	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) $ / shares shares	Jun. 30, 2018 USD ($)	Nov. 05, 2023 USD ($)	Nov. 05, 2022 USD ($)	Dec. 31, 2018 USD ($)	Nov. 05, 2021 USD ($)	Jun. 03, 2019 USD ($)	Feb. 15, 2019	Dec. 04, 2017	Jun. 01, 2016
Debt Instrument [Line Items]
Outstanding balance of debt instrument					$ 3,581,364,000		$ 3,581,364,000
Net unamortized discount (premium)					379,324,000		379,324,000
IAC
Debt Instrument [Line Items]
Net unamortized discount (premium)		$ 54,025,000			372,629,000		372,629,000				$ 54,025,000
IAC Credit Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity					250,000,000		250,000,000
Borrowings outstanding of credit facility		$ 0			0		$ 0				$ 0
Annual commitment fee on undrawn funds, basis points (as a percent)							0.20%				0.20%
IAC Credit Facility \| Maximum \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum leverage ratio		2.75					3.25
Match Group
Debt Instrument [Line Items]
Net unamortized discount (premium)		$ 7,352,000			6,695,000		$ 6,695,000				$ 7,352,000
Match Group \| MTCH Term Loan due November 16, 2022 \| Maximum \| Revolving Credit Facility
Debt Instrument [Line Items]
Leverage ratio limiting ability to pay dividends, make distributions, or repurchase stock							4.0
Match Group \| MTCH Credit Facility due December 7, 2023 \| Revolving Credit Facility
Debt Instrument [Line Items]
Annual commitment fee on undrawn funds, basis points (as a percent)							0.30%				0.25%
Match Group \| MTCH Credit Facility due December 7, 2023 \| Maximum \| Revolving Credit Facility
Debt Instrument [Line Items]
Leverage ratio limiting ability to pay dividends, make distributions, or repurchase stock							2.0
ANGI Homeservices \| ANGI Homeservices Credit Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 250,000,000
Borrowings outstanding of credit facility		0			$ 0		$ 0				$ 0
Annual commitment fee on undrawn funds, basis points (as a percent)							0.25%				0.25%
Debt instrument term			5 years
Senior Notes \| IAC
Debt Instrument [Line Items]
Outstanding balance of debt instrument				$ 517,500,000
Senior Notes \| 6.375% MTCH Senior Notes \| Maximum
Debt Instrument [Line Items]
Maximum leverage ratio							5.0
Senior Notes \| 0.875% Exchangeable Notes due 2022
Debt Instrument [Line Items]
Stated interest rate (as a percent)				0.875%
Exchange price per share (USD per share) \| $ / shares				$ 152.18
Senior Notes \| 0.875% Exchangeable Notes due 2022 \| IAC
Debt Instrument [Line Items]
Stated interest rate (as a percent)				0.875%	0.875%		0.875%
Outstanding balance of debt instrument		463,500,000			$ 470,200,000		$ 470,200,000				$ 463,500,000
Exchangeable stock (shares) \| shares				6.5713
Exchange price per share (USD per share) \| $ / shares				$ 152.18			$ 152.18
Period of reported sale price of common stock (trading days)				20 days			5 days
Period of consecutive reported sale price of common stock (trading days)				30 days			5 days
Exchange price on applicable trading day (as a percent)				130.00%
Amount of product relative to last reported price (as a percent)				98.00%
Amount of debt discount and increase to additional paid in capital				$ 70,400,000
Outstanding stock (shares) \| shares					3,400,000		3,400,000
Outstanding warrants (shares) \| shares					3,400,000		3,400,000
Exercise price of warrants (USD per share) \| $ / shares					$ 229.70		$ 229.70
If-converted value in excess of principal							$ 222,200,000				105,000,000.0
Interest expense					$ 5,400,000	$ 5,300,000	10,800,000	$ 10,500,000
Amortization of debt discount (premium)					3,400,000	3,300,000	6,800,000	6,500,000
Amortization of debt issuance costs					900,000	$ 800,000	1,700,000	$ 1,700,000
Net unamortized discount (premium)		54,000,000.0			$ 47,300,000		$ 47,300,000				54,000,000.0
Senior Notes \| 0.875% Exchangeable Notes due 2022 \| Maximum \| IAC
Debt Instrument [Line Items]
Stated interest rate (as a percent)					3.88%		3.88%
Senior Notes \| 0.875% Exchangeable Notes due 2022 \| Minimum \| IAC
Debt Instrument [Line Items]
Stated interest rate (as a percent)					0.875%		0.875%
Senior Notes \| 0.875% Exchangeable Notes due 2026 & 2.00% Exchangeable Notes due 2030 \| IAC
Debt Instrument [Line Items]
Period of reported sale price of common stock (trading days)	20 days						5 days
Period of consecutive reported sale price of common stock (trading days)	30 days						5 days
Exchange price on applicable trading day (as a percent)	130.00%
Amount of product relative to last reported price (as a percent)	98.00%
Proceeds from issuance of debt after fees and expenses	$ 1,100,000,000
Exercise price of warrants (USD per share) \| $ / shares					$ 457.02		$ 457.02
Interest expense					$ 4,300,000		$ 4,300,000
Amortization of debt discount (premium)					2,600,000		2,600,000
Amortization of debt issuance costs					$ 200,000		$ 200,000
Net unamortized discount (premium)	$ (136,900,000)
Senior Notes \| 0.875% Exchangeable Notes due 2026
Debt Instrument [Line Items]
Stated interest rate (as a percent)	0.875%
Exchange price per share (USD per share) \| $ / shares	$ 302.77
Senior Notes \| 0.875% Exchangeable Notes due 2026 \| IAC
Debt Instrument [Line Items]
Stated interest rate (as a percent)	0.875%				0.875%		0.875%
Outstanding balance of debt instrument					$ 437,700,000		$ 437,700,000
Exchangeable stock (shares) \| shares	3.3028
Exchange price per share (USD per share) \| $ / shares	$ 302.77						$ 302.77
Amount of debt discount and increase to additional paid in capital	$ 138,800,000
Outstanding stock (shares) \| shares					1,900,000		1,900,000
Outstanding warrants (shares) \| shares					1,900,000		1,900,000
Face amount of debt instrument					$ 575,000,000.0		$ 575,000,000.0
Net unamortized discount (premium)					$ 137,300,000		$ 137,300,000
Senior Notes \| 0.875% Exchangeable Notes due 2026 \| Maximum \| IAC
Debt Instrument [Line Items]
Stated interest rate (as a percent)					4.98%		4.98%
Senior Notes \| 2.00% Exchangeable Notes due 2030
Debt Instrument [Line Items]
Stated interest rate (as a percent)	2.00%
Exchange price per share (USD per share) \| $ / shares	$ 291.35
Senior Notes \| 2.00% Exchangeable Notes due 2030 \| IAC
Debt Instrument [Line Items]
Stated interest rate (as a percent)	2.00%				2.00%		2.00%
Outstanding balance of debt instrument					$ 386,900,000		$ 386,900,000						$ 75,000,000
Exchangeable stock (shares) \| shares	3.4323
Exchange price per share (USD per share) \| $ / shares	$ 291.35						$ 291.35
Amount of debt discount and increase to additional paid in capital	$ 189,200,000
Outstanding stock (shares) \| shares					2,000,000.0		2,000,000.0
Outstanding warrants (shares) \| shares					2,000,000.0		2,000,000.0
Face amount of debt instrument					$ 575,000,000.0		$ 575,000,000.0
Net unamortized discount (premium)					$ 188,100,000		$ 188,100,000
Senior Notes \| 2.00% Exchangeable Notes due 2030 \| Maximum \| IAC
Debt Instrument [Line Items]
Stated interest rate (as a percent)					6.29%		6.29%
Senior Notes \| 4.75% Senior Notes \| IAC
Debt Instrument [Line Items]
Stated interest rate (as a percent)					4.75%		4.75%
Senior Notes \| Match Group \| 6.375% MTCH Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)					6.375%		6.375%									6.375%
Senior Notes \| Match Group \| 5.00% MTCH Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)					5.00%		5.00%								5.00%
Senior Notes \| Match Group \| 5.625% MTCH Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)					5.625%		5.625%							5.625%
Senior Notes \| IAC FinanceCo 2, Inc.& IAC FinanceCo 3, Inc. \| 0.875% Exchangeable Notes due 2026 & 2.00% Exchangeable Notes due 2030 \| IAC
Debt Instrument [Line Items]
Period of reported sale price of common stock (trading days)	20 days
Period of consecutive reported sale price of common stock (trading days)	30 days
Redemption price (as a percent)	100.00%
Exchange price on applicable trading day (as a percent)	130.00%
Term Loan \| Match Group \| MTCH Term Loan due November 16, 2022
Debt Instrument [Line Items]
Outstanding balance of debt instrument		425,000,000			$ 425,000,000.0		$ 425,000,000.0				$ 425,000,000
Basis spread on variable rate (as a percent)							4.90%				5.09%
Term Loan \| Match Group \| MTCH Term Loan due November 16, 2022 \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)							2.50%
Term Loan \| ANGI Homeservices \| ANGI Term Loan due November 5, 2023
Debt Instrument [Line Items]
Outstanding balance of debt instrument		261,300,000			254,400,000		$ 254,400,000				$ 261,300,000
Basis spread on variable rate (as a percent)							4.00%				4.00%
Term Loan \| ANGI Homeservices \| ANGI Term Loan due November 5, 2023 \| Forecast
Debt Instrument [Line Items]
Quarterly repayments of principal									$ 10,300,000	$ 6,900,000		$ 3,400,000
Final principal payment									$ 161,600,000
Term Loan \| ANGI Homeservices \| ANGI Term Loan due November 5, 2023 \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)							1.50%				1.50%
Term Loan \| ANGI Homeservices \| ANGI Term Loan due November 5, 2023 \| Maximum
Debt Instrument [Line Items]
Maximum leverage ratio							4.5
Leverage ratio limiting ability to pay dividends, make distributions, or repurchase stock							4.25
Term Loan \| ANGI Homeservices \| ANGI Term Loan due November 5, 2023 \| Minimum
Debt Instrument [Line Items]
Minimum interest coverage ratio							2.0
Credit Facility \| Match Group \| MTCH Credit Facility due December 7, 2023
Debt Instrument [Line Items]
Outstanding balance of debt instrument		$ 260,000,000.0									$ 260,000,000.0
Borrowings outstanding of credit facility					$ 0		$ 0
Effective interest rate (as a percent)		4.00%									4.00%
Face amount of debt instrument		$ 500,000,000									$ 500,000,000
Credit Facility \| Match Group \| MTCH Credit Facility due December 7, 2023 \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)											1.50%
Credit Facility \| Match Group \| MTCH Credit Facility due December 7, 2023 \| Maximum
Debt Instrument [Line Items]
Maximum leverage ratio							5.0
Credit Facility \| Match Group \| MTCH Credit Facility due December 7, 2023 \| Minimum
Debt Instrument [Line Items]
Minimum interest coverage ratio							2.0