SUPPLEMENTAL CASH FLOW INFORMATION (Details) $ in Millions	6 Months Ended
Jun. 30, 2015 USD ($)
Supplemental Cash Flow Elements [Abstract]
Acquisition-related contingent consideration liabilities	$ 27.1

Fair Value Of Contingent Consideration At Date Of Acquisition

No definition available.

Name:	iaci_FairValueOfContingentConsiderationAtDateOfAcquisition
Namespace Prefix:	iaci_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration