Non-Controlling Interests in Consolidated Subsidiaries and Funds (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Noncontrolling Interest [Line Items]
Redeemable non-controlling interests in consolidated subsidiaries and funds	$ 0		$ 0		$ 391,275
Nonredeemable Noncontrolling Interest	270,021		270,021		485,595
Net Income (Loss) Attributable to Noncontrolling Interest	9,232	$ 2,770	(19,843)	$ 7,188
Operating Entities
Noncontrolling Interest [Line Items]
Nonredeemable Noncontrolling Interest	72,569		72,569		11,513
Net Income (Loss) Attributable to Noncontrolling Interest	6,283	(2,126)	9,514	(1,586)
Consolidated Funds
Noncontrolling Interest [Line Items]
Redeemable non-controlling interests in consolidated subsidiaries and funds	0		0		391,275
Nonredeemable Noncontrolling Interest	197,452		197,452		$ 82,807
Net Income (Loss) Attributable to Noncontrolling Interest	$ 2,949	$ 4,896	$ (29,357)	$ 8,774