v2.4.1.9

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Search & Applications | Minimum
Deferred revenue
Revenue recognition period	1 year
Search & Applications | Maximum
Deferred revenue
Revenue recognition period	2 years
Dating businesses
Deferred revenue
Deferred revenue	117.9us-gaap_DeferredRevenue / us-gaap_StatementBusinessSegmentsAxis = iaci_DatingMember	$ 116.5us-gaap_DeferredRevenue / us-gaap_StatementBusinessSegmentsAxis = iaci_DatingMember
Dating businesses | Minimum
Deferred revenue
Revenue recognition period	1 month
Dating businesses | Maximum
Deferred revenue
Revenue recognition period	6 months
DailyBurn | Minimum
Deferred revenue
Revenue recognition period	1 month
DailyBurn | Maximum
Deferred revenue
Revenue recognition period	12 months
Media | Minimum
Deferred revenue
Revenue recognition period	1 month
Media | Maximum
Deferred revenue
Revenue recognition period	1 year
HomeAdvisor | Minimum
Deferred revenue
Revenue recognition period	1 month
HomeAdvisor | Maximum
Deferred revenue
Revenue recognition period	1 year

X

- Definition

Represents the period over which deferred revenue is recognized.

+ References

No definition available.

+ Details

Name:	iaci_DeferredRevenueRevenueRecognitionPeriod
Namespace Prefix:	iaci_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 13

-Section A



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 13.A.4(a).Q1 Response)

-URI http://asc.fasb.org/extlink&oid=27012821&loc=d3e214044-122780

+ Details

Name:	us-gaap_DeferredRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

Name:	us-gaap_DeferredRevenueArrangementLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=iaci_DailyBurnMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=iaci_DatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=iaci_HomeAdvisorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=iaci_MediaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=iaci_SearchAndApplicationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: