v2.4.1.9

SHAREHOLDERS' EQUITY (Details)	12 Months Ended
	Dec. 31, 2014 vote	Dec. 31, 2013
Shareholders' equity
Percentage of the total number of directors the holders of common stock are entitled to elect	25.00%iaci_PercentageOfDirectorsElectedByHoldersOfCommonStock
Percentage of the outstanding total voting power of the Company	42.50%iaci_ChairmanandSeniorExecutiveVotingPowerPercentage
Common stock
Shareholders' equity
Votes per each share of stock	1iaci_NumberofVotesforEachShareofCommonStock / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember
Outstanding shares	78,356,057us-gaap_CommonStockSharesOutstanding / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember	76,404,552us-gaap_CommonStockSharesOutstanding / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember
Common stock reserved	22,200,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassAMember
Class B convertible common stock
Shareholders' equity
Votes per each share of stock	10iaci_NumberofVotesforEachShareofCommonStock / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember
Outstanding shares	5,789,499us-gaap_CommonStockSharesOutstanding / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember	5,789,499us-gaap_CommonStockSharesOutstanding / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember
Class B Convertible Common Stock Shares Outstanding Percent	100.00%iaci_ChairmanAndSeniorExecutiveStockOwnershipPercentage / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember
Board of Directors Chairman [Member] | Class B convertible common stock
Shareholders' equity
Outstanding shares	5,800,000us-gaap_CommonStockSharesOutstanding / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis = us-gaap_BoardOfDirectorsChairmanMember / us-gaap_StatementClassOfStockAxis = us-gaap_CommonClassBMember

X

- Definition

Percentage of Outstanding Class B Common Stock Shares Owned by Chairman of the Board and Senior Executive

+ References

No definition available.

+ Details

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Namespace Prefix:	iaci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Percentage of the Company's total voting power held by the Chairman of the Board and Senior Executive

+ References

No definition available.

+ Details

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

X

- Definition

Represents the number of votes the holder of each share of common stock is entitled to.

+ References

No definition available.

+ Details

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Namespace Prefix:	iaci_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Represents the percentage of the total number of directors the holders of common stock are entitled to elect.

+ References

No definition available.

+ Details

Name:	iaci_PercentageOfDirectorsElectedByHoldersOfCommonStock
Namespace Prefix:	iaci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

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

X

- Definition

Aggregate number of common shares reserved for future issuance.

+ 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

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770



Reference 4: 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 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 30

-Article 5

+ Details

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Balance Type:	na
Period Type:	instant

X

- Details

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- Details

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X

- Details

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