Investments of Operating Entities and Consolidated Funds - Operating Entities - Variable Interest Entities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Assets	$ 10,943,641	$ 7,828,199
Liabilities	9,699,564	6,659,078
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	9,700,000	8,000,000
Liabilities	661,500	1,300,000
Variable Interest Entity, Nonconsolidated, Comparison of Carrying Amount of Assets and Liabilities to Maximum Loss Exposure	169,100	210,700
Maximum exposure regarding nonconsolidated variable interest entities	$ 241,600	$ 326,000