Special Charges - Additional Information (Detail) - USD ($)	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Other Income And Expenses [Abstract]
Special charges	$ 0	$ 5,061,000

The charge against earnings in the period, comprised of costs associated with non-recurring activities related to our global branding strategy and other strategic branding decisions, a realignment of our workforce and consolidation of office locations.

No definition available.

Name:	fcn_SpecialChargesAmount
Namespace Prefix:	fcn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration