v2.4.0.6

ORGANIZATION (Details) (USD $) In Thousands, unless otherwise specified | 1 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Dec. 31, 2010 | Dec. 31, 2011 brand item country | Dec. 31, 2010 | Sep. 30, 2011 Meetic Match | Dec. 31, 2011 Meetic Match
ORGANIZATION |  |  |  |  |
Minimum number of brands owned by the company |  | 150 |  |  |
Organization |  |  |  |  |
Number of monthly visits to company websites |  | 1,200,000,000 |  |  |
Number of countries where the company has consumer audiences |  | 30 |  |  |
Ownership stake (as a percent) |  |  |  | 81.00% | 81.00%
Cash payment component of tax-free exchange for substantially all of Liberty's stake in IAC | $ 217,900 |  | $ 217,921 |  |

X
- Details
Name: | iaci_NatureOfBusinessLineItems
Namespace Prefix: | iaci_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of brands owned by the entity. + References No definition available. + Details
Name: | iaci_NumberOfBrands
Namespace Prefix: | iaci_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of monthly visits to company websites. + References No definition available. + Details
Name: | iaci_NumberOfMonthlyVisitsToCompanyWebsite
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 The number of countries in which the entity operates as of balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfCountriesInWhichEntityOperates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 5 -Section H + Details
Name: | us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration