v2.4.0.6

SHAREHOLDERS' EQUITY (Details) (USD $) In Thousands, except Share data, unless otherwise specified | 1 Months Ended | 12 Months Ended | 1 Months Ended | 12 Months Ended | 1 Months Ended | 12 Months Ended | 1 Months Ended | 12 Months Ended | 1 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 31, 2010 | Dec. 31, 2011 | Dec. 31, 2010 | Nov. 30, 2011 Common stock | Dec. 31, 2010 Common stock | Dec. 31, 2011 Common stock vote | Sep. 30, 2011 Common stock Chairman of the Board and Senior Executive of the Company | Dec. 31, 2011 Common stock Chairman of the Board and Senior Executive of the Company | Nov. 30, 2011 Class B convertible common stock | Dec. 31, 2010 Class B convertible common stock | Dec. 31, 2011 Class B convertible common stock vote | Dec. 31, 2010 Class B convertible common stock Celebrate Interactive, Inc. | Sep. 30, 2011 Class B convertible common stock Chairman of the Board and Senior Executive of the Company | Dec. 31, 2010 Class B convertible common stock Chairman of the Board and Senior Executive of the Company | Dec. 31, 2011 Class B convertible common stock Chairman of the Board and Senior Executive of the Company
Shareholders' equity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Votes per share |  |  |  |  |  | 1 |  |  |  |  | 10 |  |  |  |
Percentage of the total number of directors the holders of common stock are entitled to elect |  | 25.00% |  |  |  |  |  |  |  |  |  |  |  |  |
Shares exchanged |  |  |  |  | 4,300,000 |  |  | 1,500,000 |  | 8,500,000 |  | 8,500,000 |  | 4,300,000 | 1,500,000
Number of shares of common stock exchanged for each share of Class B common stock |  |  |  |  |  |  |  |  |  |  |  |  | 1 |  |
Maximum number or shares that may be exchanged |  |  |  |  |  |  | 1,500,000 |  |  |  |  |  |  |  |
Cash payment component of tax-free exchange for substantially all of Liberty's stake in IAC | $ 217,900 |  | $ 217,921 |  |  |  |  |  |  |  |  |  |  |  |
Outstanding shares |  |  |  |  | 84,078,621 | 77,126,881 |  |  |  | 4,289,499 | 5,789,499 |  |  |  | 5,800,000
Percentage of the outstanding total voting power of the Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 42.90%
Cash dividends declared, per share |  |  |  | $ 0.12 |  |  |  |  | $ 0.12 |  |  |  |  |  |
Common stock reserved |  |  |  |  |  | 42,000,000 |  |  |  |  |  |  |  |  |

X
- Definition Aggregate cash dividends declared during the period for each share of common stock outstanding. + References No definition available. + Details
Name: | iaci_CommonStockDividendsPerShareCashDeclared
Namespace Prefix: | iaci_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the percentage of the outstanding total voting interests of the Company. + References No definition available. + Details
Name: | iaci_CommonStockVotingRightsPercentage
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
Name: | iaci_CommonStockVotingRightsPerShare
Namespace Prefix: | iaci_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash outflow during the period, as part of a tax-free exchange, to repurchase shares in the entity from a shareholder. + References No definition available. + Details
Name: | iaci_PaymentsForRepurchaseOfCommonStockInExchangeTransaction
Namespace Prefix: | iaci_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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
- Definition The number of shares exchanged in a tax free transaction with a third-party. + References No definition available. + Details
Name: | iaci_StockExchangeCommonStockSharesExchanged
Namespace Prefix: | iaci_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of common stock shares issued for each share of Class B common stock exchanged. + References No definition available. + Details
Name: | iaci_StockExchangeCommonStockSharesIssuedForEachCommonStockClassBSharesExchanged
Namespace Prefix: | iaci_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the maximum number or shares that may be exchanged. + References No definition available. + Details
Name: | iaci_StockExchangeMaximumNumberOfSharesThatMayBeExchanged
Namespace Prefix: | iaci_
Data Type: | xbrli:sharesItemType
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 Statement of Financial Accounting Standard (FAS) -Number 129 -Paragraph 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: 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
Name: | us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total number of shares of common stock held by shareholders. May be all or portion of the number of common shares authorized. These shares represent the ownership interest of the common shareholders. Shares outstanding equals shares issued minus shares held in treasury and other adjustments, if any. + References Reference 1: 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=6959260&loc=d3e187085-122770 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 AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. 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 04 -Article 3 Reference 6: 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_CommonStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant