Investments Of Operating Entities And Consolidated Funds - Operating Entities - Gross And Net Derivative Positions And The Related Offsetting Amount (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Receivable on derivative contracts, at fair value		$ 58,194	$ 62,977
Payable for derivative contracts, at fair value		62,054	60,761
Receivable on derivatives contracts, at fair value [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		80,780	66,217
Derivative Asset, Fair Value, Amount Offset Against Collateral	[1]	22,586	3,240
Receivable on derivative contracts, at fair value		58,194	62,977
Financial Instruments, Owned and Pledged as Collateral, at Fair Value		3,631	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		60	2,911
Derivative asset, net of offset		54,503	60,066
Payable for derivatives contracts, at fair value [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		67,295	64,001
Derivative Liability, Fair Value, Amount Offset Against Collateral	[1]	5,241	3,240
Payable for derivative contracts, at fair value		62,054	60,761
Financial Instruments, Owned and Pledged as Collateral, at Fair Value		3,631	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		2,777	24,020
Derivative Liability, net of offset		$ 55,646	$ 36,741

[1] Includes financial instruments subject to enforceable master netting provisions that are permitted to be offset to the extent an event of default has occurred