Condensed Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accumulated depreciation (in dollars)	$ 105,011	$ 98,595
Fair value of other assets (in dollars)	$ 46,124	$ 5,984
Treasury stock shares	177,631	169,649
Class A
Common stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock shares authorized	1,000,000,000	1,000,000,000
Common stock shares issued	39,532,614	38,379,858
Common stock shares outstanding	39,354,983	38,210,209
Class B
Common stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock shares authorized	175,000,000	175,000,000
Common stock shares issued	0	0
Common stock shares outstanding	0	0
Class C
Common stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock shares authorized	90,000,000	90,000,000
Common stock shares issued	20,976,598	20,976,598
Common stock shares outstanding	19,810,707	20,976,598
Class D
Common stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock shares authorized	175,000,000	175,000,000
Common stock shares issued	79,610,490	79,610,490
Common stock shares outstanding	79,610,490	79,610,490