Non-controlling Interests (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]
Non-redeemable non-controlling interests	$ 0	$ 18	$ 0	$ 92
Redeemable non-controlling interests:
Total non-controlling interest in net income	81	4,145	(4,550)	22,018
Redeemable non-controlling interest	56,990		56,990		$ 325,561
Other
Noncontrolling Interest [Line Items]
Non-redeemable non-controlling interests	0	18	0	92
Company-sponsored investment funds
Noncontrolling Interest [Line Items]
Non-redeemable non-controlling interests	0	0	0	0
Redeemable non-controlling interests:
Consolidated company-sponsored investment funds	81	$ 4,127	(4,550)	$ 21,926
Redeemable non-controlling interest	$ 56,990		$ 56,990		$ 325,561