Fair Value Measurements - Schedule of Level Three Investment Reconciliation (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Consolidated Funds’ other investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Transfers in (out) of Level III	$ 0		$ 0
Consolidated Entity Excluding Consolidated Funds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
At beginning of the period	3,000,000.0	$ 3,000,000.0	3,000,000.0	$ 3,000,000.0
Additions (redemptions)	(300,000)	100,000	(300,000)	100,000
Transfers in (out) of Level III	0	0	0	0
Total net fair value gains/losses recognized in net income	0	(100,000)	0	(100,000)
Total Level III financial assets	$ 2,700,000	$ 3,000,000.0	$ 2,700,000	$ 3,000,000.0