v2.4.1.9

GOODWILL AND INTANGIBLE ASSETS (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Balance of goodwill and intangible assets, net
Goodwill	$ 1,754,926,000us-gaap_Goodwill	$ 1,675,323,000us-gaap_Goodwill	$ 1,616,154,000us-gaap_Goodwill
Intangible assets with indefinite lives	405,234,000us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill	376,329,000us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill
Intangible assets with definite lives, net	86,702,000us-gaap_FiniteLivedIntangibleAssetsNet	69,007,000us-gaap_FiniteLivedIntangibleAssetsNet
Total goodwill and intangible assets, net	2,246,862,000us-gaap_IntangibleAssetsNetIncludingGoodwill	2,120,659,000us-gaap_IntangibleAssetsNetIncludingGoodwill
Search & Applications
Goodwill and intangible assets
Goodwill, Impaired, Accumulated Impairment Loss	916,900,000us-gaap_GoodwillImpairedAccumulatedImpairmentLoss / us-gaap_StatementBusinessSegmentsAxis = iaci_SearchAndApplicationsMember	916,900,000us-gaap_GoodwillImpairedAccumulatedImpairmentLoss / us-gaap_StatementBusinessSegmentsAxis = iaci_SearchAndApplicationsMember	916,900,000us-gaap_GoodwillImpairedAccumulatedImpairmentLoss / us-gaap_StatementBusinessSegmentsAxis = iaci_SearchAndApplicationsMember
Balance of goodwill and intangible assets, net
Goodwill	774,822,000us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_SearchAndApplicationsMember	738,062,000us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_SearchAndApplicationsMember	723,650,000us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_SearchAndApplicationsMember
Intangible assets with indefinite lives	211,095,000us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_SearchAndApplicationsMember	195,805,000us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_SearchAndApplicationsMember
Intangible assets with definite lives, net	44,355,000us-gaap_FiniteLivedIntangibleAssetsNet / us-gaap_StatementBusinessSegmentsAxis = iaci_SearchAndApplicationsMember	40,550,000us-gaap_FiniteLivedIntangibleAssetsNet / us-gaap_StatementBusinessSegmentsAxis = iaci_SearchAndApplicationsMember
ShoeBuy
Goodwill and intangible assets
Goodwill, Impaired, Accumulated Impairment Loss	28,000,000us-gaap_GoodwillImpairedAccumulatedImpairmentLoss / us-gaap_StatementBusinessSegmentsAxis = iaci_ShoeBuyMember	28,000,000us-gaap_GoodwillImpairedAccumulatedImpairmentLoss / us-gaap_StatementBusinessSegmentsAxis = iaci_ShoeBuyMember	28,000,000us-gaap_GoodwillImpairedAccumulatedImpairmentLoss / us-gaap_StatementBusinessSegmentsAxis = iaci_ShoeBuyMember
Balance of goodwill and intangible assets, net
Goodwill	21,719,000us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_ShoeBuyMember	21,719,000us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_ShoeBuyMember	21,719,000us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_ShoeBuyMember
Media - Connected Ventures
Goodwill and intangible assets
Goodwill, Impaired, Accumulated Impairment Loss	11,600,000us-gaap_GoodwillImpairedAccumulatedImpairmentLoss / us-gaap_StatementBusinessSegmentsAxis = iaci_ConnectedVenturesMember	11,600,000us-gaap_GoodwillImpairedAccumulatedImpairmentLoss / us-gaap_StatementBusinessSegmentsAxis = iaci_ConnectedVenturesMember	11,600,000us-gaap_GoodwillImpairedAccumulatedImpairmentLoss / us-gaap_StatementBusinessSegmentsAxis = iaci_ConnectedVenturesMember
Balance of goodwill and intangible assets, net
Goodwill	$ 8,267,000us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_ConnectedVenturesMember	$ 8,267,000us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_ConnectedVenturesMember	$ 8,267,000us-gaap_Goodwill / us-gaap_StatementBusinessSegmentsAxis = iaci_ConnectedVenturesMember

X

- Details

Name:	iaci_IntangibleAssetsAndGoodwillAbstract
Namespace Prefix:	iaci_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	iaci_IntangibleAssetsAndGoodwillLineItems
Namespace Prefix:	iaci_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a,h)

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillImpairedAccumulatedImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

Name:	us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Carrying amount of finite-lived intangible assets, indefinite-lived intangible assets and goodwill. Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Intangible assets are assets, not including financial assets, lacking physical substance.

+ References

No definition available.

+ Details

Name:	us-gaap_IntangibleAssetsNetIncludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=iaci_ConnectedVenturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=iaci_SearchAndApplicationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=iaci_ShoeBuyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: