Consolidated Company-Sponsored Investment Funds - Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives - VIEs	$ 24,428	$ 24,712
Derivatives	10,722	13,712
Total liabilities measured at fair value	262,244	261,021
Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	123,880	136,344
Derivatives - VIEs	2,945	1,768
Total assets measured at fair value	298,017	233,633
Derivatives	10	162
Total liabilities measured at fair value	10	162
Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	25,077	27,799
Derivatives - VIEs	21,483	22,944
Total assets measured at fair value	974,494	1,572,448
Derivatives	10,712	13,550
Total liabilities measured at fair value	10,712	13,550
Level 3 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	122	129
Derivatives - VIEs	0	0
Total assets measured at fair value	122	129
Derivatives	0	0
Total liabilities measured at fair value	251,522	247,309
Company-sponsored investment funds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	321,716	524,088
Total liabilities measured at fair value	3,741	21,540
Company-sponsored investment funds | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	73,229	131,235
Total liabilities measured at fair value	1,192	14,932
Company-sponsored investment funds | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	248,487	392,853
Total liabilities measured at fair value	2,549	6,608
Company-sponsored investment funds | Level 3 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Total liabilities measured at fair value	0	0
VIEs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives - VIEs	1,911	7,552
Derivatives	3,741	21,540
VIEs | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	297,386	516,536
Derivatives - VIEs	1,911	7,552
Derivatives	3,741	21,540
VIEs | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	50,467	129,706
Derivatives - VIEs	343	1,529
Derivatives	1,192	14,932
VIEs | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	246,919	386,830
Derivatives - VIEs	1,568	6,023
Derivatives	2,549	6,608
VIEs | Level 3 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	0	0
Derivatives - VIEs	0	0
Derivatives	0	$ 0
VOEs | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	22,419
VOEs | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	22,419
VOEs | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	0
VOEs | Level 3 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments - VIEs	$ 0