v2.4.1.9

STOCK-BASED COMPENSATION (Details 2) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2012
Information about stock options outstanding and exercisable
Common stock		$ 11,700us-gaap_CommonStockValue
Options Outstanding (in shares)	6,520us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions
Weighted-Average Remaining Contractual Life (in years)	6 years
Weighted-Average Exercise Price (in dollars per share)	$ 41.19us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1
Options Exercisable (in shares)	3,647us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions
Weighted Average Remaining Contractual Life (in years)	4 years 8 months 12 days
Weighted-Average Exercise Price (in dollars per share)	$ 33.50us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1
$10.01 to $20.00
Information about stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 10.01us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeOneMember
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 20us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeOneMember
Options Outstanding (in shares)	431us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeOneMember
Weighted-Average Remaining Contractual Life (in years)	4 years 6 months
Weighted-Average Exercise Price (in dollars per share)	$ 17.91us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeOneMember
Options Exercisable (in shares)	431us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeOneMember
Weighted Average Remaining Contractual Life (in years)	4 years 6 months
Weighted-Average Exercise Price (in dollars per share)	$ 17.91us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeOneMember
$20.01 to $30.00
Information about stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 20.01us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeTwoMember
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 30us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeTwoMember
Options Outstanding (in shares)	905us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeTwoMember
Weighted-Average Remaining Contractual Life (in years)	4 years 3 months 18 days
Weighted-Average Exercise Price (in dollars per share)	$ 22.14us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeTwoMember
Options Exercisable (in shares)	905us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeTwoMember
Weighted Average Remaining Contractual Life (in years)	4 years 3 months 18 days
Weighted-Average Exercise Price (in dollars per share)	$ 22.14us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeTwoMember
$30.01 to $40.00
Information about stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 30.01us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeThreeMember
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 40us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeThreeMember
Options Outstanding (in shares)	1,148us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeThreeMember
Weighted-Average Remaining Contractual Life (in years)	6 years 3 months 18 days
Weighted-Average Exercise Price (in dollars per share)	$ 31.84us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeThreeMember
Options Exercisable (in shares)	749us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeThreeMember
Weighted Average Remaining Contractual Life (in years)	6 years 2 months 12 days
Weighted-Average Exercise Price (in dollars per share)	$ 31.60us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeThreeMember
$40.01 to $50.00
Information about stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 40.01us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFourMember
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 50us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFourMember
Options Outstanding (in shares)	2,913us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFourMember
Weighted-Average Remaining Contractual Life (in years)	5 years 8 months 12 days
Weighted-Average Exercise Price (in dollars per share)	$ 45.16us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFourMember
Options Exercisable (in shares)	1,426us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFourMember
Weighted Average Remaining Contractual Life (in years)	4 years
Weighted-Average Exercise Price (in dollars per share)	$ 44.05us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFourMember
$50.01 to $60.00
Information about stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	$ 50.01us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFiveMember
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 60.00us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFiveMember
Options Outstanding (in shares)	381us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFiveMember
Weighted-Average Remaining Contractual Life (in years)	7 years 3 months 18 days
Weighted-Average Exercise Price (in dollars per share)	$ 58.51us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFiveMember
Options Exercisable (in shares)	136us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFiveMember
Weighted Average Remaining Contractual Life (in years)	7 years 3 months 18 days
Weighted-Average Exercise Price (in dollars per share)	$ 58.44us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeFiveMember
$60.01 to $70.00
Information about stock options outstanding and exercisable
Options Outstanding (in shares)	492us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeSixMember
Weighted-Average Remaining Contractual Life (in years)	9 years 3 months 18 days
Weighted-Average Exercise Price (in dollars per share)	$ 66.14us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeSixMember
Options Exercisable (in shares)	0us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeSixMember
Weighted Average Remaining Contractual Life (in years)	0 months
Weighted-Average Exercise Price (in dollars per share)	$ 0.00us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeSixMember
$70.01 to $80.00
Information about stock options outstanding and exercisable
Options Outstanding (in shares)	250us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeSevenMember
Weighted-Average Remaining Contractual Life (in years)	9 years 3 months 18 days
Weighted-Average Exercise Price (in dollars per share)	$ 71.55us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeSevenMember
Options Exercisable (in shares)	0us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeSevenMember
Weighted Average Remaining Contractual Life (in years)	0 months
Weighted-Average Exercise Price (in dollars per share)	$ 0.00us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1 / us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis = iaci_ExercisePriceRangeSevenMember

X

- Definition

Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section S99

-Paragraph 1

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- Definition

Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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Weighted average remaining contractual term of exercisable stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

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The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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