Segment Information - Segment's Contribution with Respect to Net Revenue, Operating Expenses, Operating Income (Loss) and Total Assets (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Depreciation and amortization of property	$ 30,855	$ 24,580	$ 22,712
Financial Advisory [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of property	5,710	6,739	6,718
Asset Management [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of property	3,250	3,502	3,693
Corporate [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of property	$ 21,895	$ 14,339	$ 12,301