Segment Operating Results Revenues Derived from Clients and Private Equity Funds by Geographical Areas (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Segment Reporting Information [Line Items]
Net revenue	$ 920,110	[1]	$ 762,565	[1]	$ 648,028	[1]
United States [Member]
Segment Reporting Information [Line Items]
Net revenue	608,631	[1]	532,615	[1]	452,594	[1]
Europe And Other [Member]
Segment Reporting Information [Line Items]
Net revenue	248,815	[1]	145,267	[1]	151,261	[1]
Latin America [Member]
Segment Reporting Information [Line Items]
Net revenue	$ 62,664	[1]	$ 84,683	[1]	$ 44,173	[1]

[1] Excludes Other Revenue and Interest Expense.