v2.4.1.9

BENEFIT PLANS (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] |  |  |
Employee contribution limit per calendar year (as a percent of pre-tax earnings) | 50.00%us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent | 50.00%us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent | 50.00%us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Employer contribution limit per calendar year (as a percent of compensation) | 3.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent | 3.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent | 3.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
UNITED STATES |  |  |
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] |  |  |
Defined Benefit Plan, Contributions by Employer | 7.5 us-gaap_DeferredCompensationArrangementWithIndividualEmployerContribution / us-gaap_StatementGeographicalAxis = country_US | 6.5 us-gaap_DeferredCompensationArrangementWithIndividualEmployerContribution / us-gaap_StatementGeographicalAxis = country_US | 6.5 us-gaap_DeferredCompensationArrangementWithIndividualEmployerContribution / us-gaap_StatementGeographicalAxis = country_US
All Other Countries [Member] |  |  |
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] |  |  |
Defined Benefit Plan, Contributions by Employer | 2.5 us-gaap_DeferredCompensationArrangementWithIndividualEmployerContribution / us-gaap_StatementGeographicalAxis = iaci_AllOtherCountriesMember | 2.9 us-gaap_DeferredCompensationArrangementWithIndividualEmployerContribution / us-gaap_StatementGeographicalAxis = iaci_AllOtherCountriesMember | 2.3 us-gaap_DeferredCompensationArrangementWithIndividualEmployerContribution / us-gaap_StatementGeographicalAxis = iaci_AllOtherCountriesMember

X
- Definition The amount of payment into the fund established for purposes of making future disbursements to the individual in accordance with the terms and understanding of the deferred compensation arrangement. + References No definition available. + Details
Name: | us-gaap_DeferredCompensationArrangementWithIndividualEmployerContribution
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementGeographicalAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=iaci_AllOtherCountriesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |