Redeemable Non-Controlling Interests in Consolidated Subsidiaries and Funds (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Noncontrolling Interest [Line Items]
Redeemable non-controlling interests in consolidated subsidiaries and funds	$ 315,123		$ 315,123		$ 186,911
Net income (loss) attributable to redeemable non-controlling interests in consolidated subsidiaries and funds	(16,705)	$ 3,916	(21,002)	$ 6,636
Operating Entities
Noncontrolling Interest [Line Items]
Redeemable non-controlling interests in consolidated subsidiaries and funds	7,208		7,208		10,906
Net income (loss) attributable to redeemable non-controlling interests in consolidated subsidiaries and funds	1,525	3,174	1,447	4,092
Consolidated Funds
Noncontrolling Interest [Line Items]
Redeemable non-controlling interests in consolidated subsidiaries and funds	307,915		307,915		$ 176,005
Net income (loss) attributable to redeemable non-controlling interests in consolidated subsidiaries and funds	$ (18,230)	$ 742	$ (22,449)	$ 2,544