Represents the percentage of the total purchase price of an aircraft paid by both the Company and a related party.

No definition available.

Name:	iac_PercentageOfOwnershipInterestHeldEachByEntityAndByRelatedPartyInAnotherEntityEmployingFlightCrew
Namespace Prefix:	iac_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the ownership interest in aircraft and entity employing aircraft flight crew that is held by both the reporting entity and a related party.

+ References

No definition available.

+ Details

Name:	iac_PercentageofOwnershipInterestHeldEachbyEntityandbyRelatedPartyinAircraftEmployingFlightCrew
Namespace Prefix:	iac_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of Total Purchase Price and Refurbish Costs Paid In Related Party Transaction

+ References

No definition available.

+ Details

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Namespace Prefix:	iac_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Stock Received During Period, Shares, Related Party Employee Matters Agreement

+ References

No definition available.

+ Details

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Namespace Prefix:	iac_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Stock Received During Period Shares Related Party Employee Matters Agreement, Reimbursement For Settlement Of Equity Award Denominated in Shares Of Parent

+ References

No definition available.

+ Details

Name:	iac_StockReceivedDuringPeriodSharesRelatedPartyEmployeeMattersAgreementReimbursementForSettlementOfEquityAwardDenominatedinSharesOfParent
Namespace Prefix:	iac_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Stock Received During Period Shares Related Party Employee Matters Agreement, Reimbursement For Settlement Of Equity Award Denominated in Shares Of Subsidiary

+ References

No definition available.

+ Details

Name:	iac_StockReceivedDuringPeriodSharesRelatedPartyEmployeeMattersAgreementReimbursementForSettlementOfEquityAwardDenominatedinSharesOfSubsidiary
Namespace Prefix:	iac_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of aircraft operated by the carrier.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfAircraftOperated
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cash outflow from the acquisition of or improvements to long-lived, physical assets used to produce goods and services and not intended for resale, classified as other.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of any current tax-related balances due to affiliates as of the date of each statement of financial position presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 17
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32809-109319

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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.

+ Details

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(e))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Related Parties
-URI http://asc.fasb.org/extlink&oid=16382449

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07.1(c))
-URI http://asc.fasb.org/extlink&oid=6488393&loc=d3e606610-122999

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_AffiliatedEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=iac_EmployeeMattersAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=us-gaap_ServiceAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=iac_TaxSharingAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_OtherAffiliatesMember
Namespace Prefix:
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RELATED PARTY TRANSACTIONS (Details) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) aircraft shares	Dec. 31, 2015 USD ($)	Dec. 31, 2013 USD ($)
Match Group \| Employee Matters Agreement
Related Party Transaction [Line Items]
Shares received from related party pursuant to employee matters agreement (in shares) \| shares	1.0
Shares received from related party as reimbursement for exercise and settlement of equity awards denominated in shares of subsidiary (in shares) \| shares	0.5
Shares received from related party as reimbursement for exercise and vesting of equity awards denominated in shares of parent (in shares) \| shares	0.4
Match Group \| Services Agreement
Related Party Transaction [Line Items]
Payments received from related parties	$ 11.8	$ 0.7
Match Group \| Tax Sharing Agreement
Related Party Transaction [Line Items]
Amounts due to related party	9.0
Payments received from related parties	$ 19.9
Other Affiliates
Related Party Transaction [Line Items]
Ownership interest held by each of the Company and Expedia in aircraft (as a percent)	50.00%
Number of aircraft operated \| aircraft	2
IAC's total purchase price and refurbish costs in aircraft			$ 25.0
Percentage of total purchase price and refurbish costs paid in related party transaction			50.00%
Ownership interest held by each of the Company and Expedia in an entity employing aircraft flight crew (as a percent)	50.00%