SHAREHOLDERS' EQUITY (Details 2) (USD $) Share data in Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Changes in outstanding warrants
Class of Warrant or Right, Outstanding	$ 0us-gaap_WarrantsAndRightsOutstanding	$ 0us-gaap_WarrantsAndRightsOutstanding	$ 0us-gaap_WarrantsAndRightsOutstanding
Warrants and Rights Issued	0iaci_WarrantsandRightsIssued	0iaci_WarrantsandRightsIssued	0iaci_WarrantsandRightsIssued
Warrants and Rights Exercised	14.3
Proceeds from Warrant Exercises	284,100,000us-gaap_ProceedsFromWarrantExercises
Common stock	$ 11,700,000us-gaap_CommonStockValue

Represents the number of warrants or rights exercised during the period.

No definition available.

Name:	iaci_ClassOfWarrantOrRightNumberExercised
Namespace Prefix:	iaci_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Warrants and Rights Issued

+ References

No definition available.

+ Details

Name:	iaci_WarrantsandRightsIssued
Namespace Prefix:	iaci_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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

- Definition

Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 30

-Article 5

+ Details

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

- Definition

The cash inflow associated with the amount received from holders exercising their stock warrants.

+ References

No definition available.

+ Details

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

- Definition

Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(i))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph i

-Article 4

+ Details

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