Segment Operating Results Revenues Derived from Clients and Private Equity Funds by Geographical Areas (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Net revenue	[1]	$ 271,055	$ 219,052	$ 510,774	$ 369,471
United States [Member]
Segment Reporting Information [Line Items]
Net revenue	[1]	203,186	142,502	365,008	250,429
Europe And Other [Member]
Segment Reporting Information [Line Items]
Net revenue	[1]	56,927	47,997	128,138	84,785
Latin America [Member]
Segment Reporting Information [Line Items]
Net revenue	[1]	$ 10,942	$ 28,553	$ 17,628	$ 34,257

[1] Excludes Other Revenue and Interest Expense.