Investments - Gains and Losses Recognized in Gain (Loss) on Securities, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Gain (Loss) on Securities [Line Items]
Net Unrealized Gains (Losses)	$ 13,423	$ (24,383)	$ 1,965
Gain (Loss) on Securities, net	13,181	(28,696)	9,532
Investments | Investments—Consolidated Investment Companies
Gain (Loss) on Securities [Line Items]
Net Unrealized Gains (Losses)	8,969	(7,896)	642
Net Realized Gains (Losses)	(1,734)	(7,333)	1,609
Gain (Loss) on Securities, net	7,235	(15,229)	2,251
Investments | Receivables - Affiliates and Other
Gain (Loss) on Securities [Line Items]
Net Unrealized Gains (Losses)	4,454	(16,487)	1,323
Net Realized Gains (Losses)	1,492	3,020	5,958
Gain (Loss) on Securities, net	$ 5,946	$ (13,467)	$ 7,281