Revenues Derived from Clients and Private Equity Funds by Geographical Areas (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Segment Reporting Information [Line Items]
Net revenue	$ 648,028	[1]	$ 529,758	[1]	$ 376,541	[1]
UNITED STATES
Segment Reporting Information [Line Items]
Net revenue	452,594	[1]	387,063	[1]	290,693	[1]
Europe And Other
Segment Reporting Information [Line Items]
Net revenue	151,261	[1]	112,049	[1]	60,605	[1]
Latin America
Segment Reporting Information [Line Items]
Net revenue	$ 44,173	[1]	$ 30,646	[1]	$ 25,243	[1]

[1] Excludes Other Revenue and Interest Expense.