Special Charges By Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Special Charges [Line Items]
Special charges	$ 400	$ 26,782	$ 427	$ 26,782	$ 29,600
Corporate Finance / Restructuring
Special Charges [Line Items]
Special charges		10,561	68	10,561
Forensic and Litigation Consulting
Special Charges [Line Items]
Special charges		7,808	173	7,808
Economic Consulting
Special Charges [Line Items]
Special charges		818	(4)	818
Technology
Special Charges [Line Items]
Special charges		2,966	14	2,966
Strategic Communications
Special Charges [Line Items]
Special charges		4,511	64	4,511
Total Reportable Segments
Special Charges [Line Items]
Special charges		26,664	315	26,664
Unallocated Corporate
Special Charges [Line Items]
Special charges		$ 118	$ 112	$ 118