Revenues And Adjusted Segment EBITDA For Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Segment Reporting Information [Line Items]
Revenues	$ 386,055		$ 413,802		$ 1,177,526		$ 1,176,055
Adjusted Segment EBITDA	79,780	[1]	92,306	[1]	237,937	[1]	240,453	[1]
Corporate Finance / Restructuring
Segment Reporting Information [Line Items]
Revenues	110,217		110,311		336,031		319,461
Adjusted Segment EBITDA	25,029		27,495		81,003		59,173
Forensic and Litigation Consulting
Segment Reporting Information [Line Items]
Revenues	83,366		99,064		260,504		275,345
Adjusted Segment EBITDA	13,211		19,113		42,916		53,016
Economic Consulting
Segment Reporting Information [Line Items]
Revenues	96,375		95,662		295,882		264,401
Adjusted Segment EBITDA	19,087		18,650		56,002		50,635
Technology
Segment Reporting Information [Line Items]
Revenues	50,286		56,972		147,643		165,137
Adjusted Segment EBITDA	15,675		19,619		41,739		58,362
Strategic Communications
Segment Reporting Information [Line Items]
Revenues	45,811		51,793		137,466		151,711
Adjusted Segment EBITDA	$ 6,778		$ 7,429		$ 16,277		$ 19,267

[1] Total Adjusted Segment EBITDA is the total of Adjusted Segment EBITDA for all segments.