v2.4.0.6

SHAREHOLDERS' EQUITY (Details 2) (USD $) In Thousands, except Per Share data, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Changes in outstanding warrants |  |  |
Outstanding at the beginning of the period (in shares) | $ 18,297 |  |
Exercised (in shares) | (3,949) | 0 | (11,600)
Outstanding at the end of the period (in shares) | 14,348 | 18,297 |
Outstanding at the beginning of the period (in dollars per share) | $ 28.07 |  |
Exercised (in dollars per share) | $ 26.90 |  |
Outstanding at the end of the period (in dollars per share) | $ 28.40 | $ 28.07 |
Tranche 1 |  |  |
Changes in outstanding warrants |  |  |
Outstanding at the end of the period (in shares) | 9,836 |  |
Outstanding at the end of the period (in dollars per share) | $ 26.86 |  |
Tranche 2 |  |  |
Changes in outstanding warrants |  |  |
Outstanding at the end of the period (in shares) | $ 4,512 |  |
Outstanding at the end of the period (in dollars per share) | $ 31.75 |  |

X
- Definition Represents the weighted average strike price of warrants or rights exercised. + References No definition available. + Details
Name: | iaci_ClassOfWarrantOrRightExercisedWeightedAverageStrikePrice
Namespace Prefix: | iaci_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of warrants or rights exercised during the period. + References No definition available. + Details
Name: | iaci_ClassOfWarrantOrRightNumberExercised
Namespace Prefix: | iaci_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the weighted average strike price of warrants or rights outstanding. + References No definition available. + Details
Name: | iaci_ClassOfWarrantOrRightOutstandingWeightedAverageStrikePrice
Namespace Prefix: | iaci_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Value of warrants and rights outstanding. "Equity warrants and rights outstanding" represents derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. Warrants are often included in a new debt issue to entice investors by a higher return potential. + 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=6881521&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 4 -Section 08 -Paragraph i Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 00-27 -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 Emerging Issues Task Force (EITF) -Number 98-5 -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. + Details
Name: | us-gaap_WarrantsAndRightsOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant