Consolidation - Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Noncontrolling interests	$ (96,266)	$ (110,399)	$ (113,718)	$ (124,442)	$ (139,147)	$ (138,965)
VOEs
Variable Interest Entity [Line Items]
Cash and cash equivalents	865		1,153
Investments	19,147		24,669
Other assets	110		295
Notes payable	0		0
Securities purchased payable and other liabilities	(547)		(573)
Noncontrolling interests	(6,451)		(7,879)
Net interests in CIP	13,124		17,665
CLOs
Variable Interest Entity [Line Items]
Cash and cash equivalents	208,056		249,003
Investments	1,978,308		2,106,764
Other assets	33,143		43,993
Notes payable	(1,943,949)		(2,083,314)
Securities purchased payable and other liabilities	(183,520)		(230,141)
Noncontrolling interests	(5,448)		(5,917)
Net interests in CIP	86,590		80,388
GFs
Variable Interest Entity [Line Items]
Cash and cash equivalents	1,509		789
Investments	71,760		58,680
Other assets	1,228		1,157
Notes payable	0		0
Securities purchased payable and other liabilities	(750)		(183)
Noncontrolling interests	(19,265)		(10,389)
Net interests in CIP	$ 54,482		$ 50,054