v2.4.0.8

LONG-TERM INVESTMENTS (Details3) (USD $) | 12 Months Ended | 3 Months Ended | 12 Months Ended |  | 7 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2012 Marketable equity security | Dec. 31, 2013 Marketable equity security | Dec. 31, 2012 Marketable equity security | Dec. 31, 2011 Meetic | Aug. 31, 2011 Meetic | Dec. 31, 2012 The Newsweek/Daily Beast Company (United States) | May 31, 2012 The Newsweek/Daily Beast Company (United States) | Sep. 30, 2011 Zhenai
Long-term investments |  |  |  |  |  |  |  |  |  |  |
Percentage of ownership interest acquired |  |  |  |  |  |  |  |  |  |  | 20.00%
Other-than-temporary impairment charge to write-down investment | $ 5,000,000 |  |  |  |  |  |  |  |  |  |
Long-term marketable equity securities |  |  |  |  |  |  |  |  |  |  |
Cost basis |  |  |  | 42,100,000 | 8,800,000 | 42,100,000 |  |  |  |  |
Gross unrealized gains | 4,784,000 | 6,996,000 |  |  | 3,000,000 |  |  |  |  |  |
Gross unrealized losses | 0 | 0 |  |  |  | 10,800,000 |  |  |  |  |
Other than temporary impairment recognized in earnings | 5,268,000 | 8,685,000 |  | 8,700,000 |  |  |  |  |  |  |
Period in unrealized loss position |  | 1 year |  |  |  |  |  |  |  |  |
Percentage fair value less than cost |  | 50.00% |  |  |  |  |  |  |  |  |
Mark to Market Adjustment for Previously Held Equity Method Investment Pre-tax |  |  |  |  |  |  | $ 11,700,000 |  | $ 18,600,000 |  |
Percent ownership |  |  |  |  |  |  |  | 27.00% |  | 50.00% |

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the cost method of accounting. + References No definition available. + Details
Name: | iaci_CostMethodInvestmentOwnershipPercentage
Namespace Prefix: | iaci_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition This item represents the pre-tax non cash charge for the mark-to-market adjustment to fair value of a previously held equity method investment prior to it being consolidated. + References No definition available. + Details
Name: | iaci_MarkToMarketAdjustmentForPreviouslyHeldEquityMethodInvestmentPreTax
Namespace Prefix: | iaci_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The percentage in which the long-term investment was below its cost basis before the Company recorded an other than temporary impairment charge. + References No definition available. + Details
Name: | iaci_OtherThanTemporaryImpairmentLossesMeasurementPercentageFairValueLessThanCost
Namespace Prefix: | iaci_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The time period in which the long-term investment was in an unrealized loss position before the Company recorded an other than temporary impairment charge. + References No definition available. + Details
Name: | iaci_OtherThanTemporaryImpairmentLossesMeasurementPeriodInUnrealizedLossPosition
Namespace Prefix: | iaci_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleEquitySecuritiesAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the cost method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 325 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6872867&loc=d3e40691-111596 + Details
Name: | us-gaap_CostmethodInvestmentsOtherThanTemporaryImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition The amount of other than temporary impairment losses on investments in debt and equity securities categorized as Available-for-sale which have been recognized in earnings during the period. Such impairment losses consist of other than temporary impairments (OTTI) on equity securities, credit losses on investments in debt securities, and when the entity intends to sell an impaired debt security or it is more likely than not that the entity will be required to sell the impaired debt security before recovery of its amortized cost basis. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
Name: | us-gaap_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetAvailableforsaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration