Segment Operating Results - Revenues Derived from Clients and Private Equity Funds by Geographical Areas (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Net Revenues	$ 371,413	$ 349,429	$ 759,697	$ 608,484
United States [Member]
Segment Reporting Information [Line Items]
Net Revenues	274,484	218,945	537,649	392,855
Europe and Other [Member]
Segment Reporting Information [Line Items]
Net Revenues	96,589	120,470	219,500	192,681
Latin America [Member]
Segment Reporting Information [Line Items]
Net Revenues	$ 340	$ 10,014	$ 2,548	$ 22,948