Note 4 - Contract Receivables (Details)	6 Months Ended
Jun. 30, 2014
Receivables [Abstract]
Majority Of Unbilled Receivables Will Be Substantially Billed And Collected	1 year

Majority of unbilled receivables will be substantially billed and collected.

No definition available.

Name:	icfi_MajorityOfUnbilledReceivablesWillBeSubstantiallyBilledAndCollected
Namespace Prefix:	icfi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration