Consolidated Company-Sponsored Investment Funds - Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Recurring
Variable Interest Entity [Line Items]
Derivatives	$ 14,518	$ 24,712
Derivatives	18,180	13,712
Total liabilities measured at fair value	270,870	261,021
Level 1 | Recurring
Variable Interest Entity [Line Items]
Investments	121,703	136,344
Derivatives	1	1,768
Total assets measured at fair value	268,610	233,633
Derivatives	3,511	162
Total liabilities measured at fair value	3,511	162
Level 2 | Recurring
Variable Interest Entity [Line Items]
Investments	32,104	27,799
Derivatives	14,517	22,944
Total assets measured at fair value	914,300	1,572,448
Derivatives	14,669	13,550
Total liabilities measured at fair value	14,669	13,550
Level 3 | Recurring
Variable Interest Entity [Line Items]
Investments	118	129
Derivatives	0	0
Total assets measured at fair value	118	129
Derivatives	0	0
Total liabilities measured at fair value	252,690	247,309
Company-sponsored investment funds | Recurring
Variable Interest Entity [Line Items]
Total assets measured at fair value	410,851	524,088
Total liabilities measured at fair value	2,531	21,540
Company-sponsored investment funds | Level 1 | Recurring
Variable Interest Entity [Line Items]
Total assets measured at fair value	60,630	131,235
Total liabilities measured at fair value	944	14,932
Company-sponsored investment funds | Level 2 | Recurring
Variable Interest Entity [Line Items]
Total assets measured at fair value	350,221	392,853
Total liabilities measured at fair value	1,587	6,608
Company-sponsored investment funds | Level 3 | Recurring
Variable Interest Entity [Line Items]
Total assets measured at fair value	0	0
Total liabilities measured at fair value	0	0
VIEs
Variable Interest Entity [Line Items]
Derivatives	4,902	7,552
Derivatives	2,531	21,540
VIEs | Recurring
Variable Interest Entity [Line Items]
Investments	286,619	516,536
Derivatives	4,902	7,552
Derivatives	2,531	21,540
VIEs | Level 1 | Recurring
Variable Interest Entity [Line Items]
Investments	49,455	129,706
Derivatives	2,139	1,529
Derivatives	944	14,932
VIEs | Level 2 | Recurring
Variable Interest Entity [Line Items]
Investments	237,164	386,830
Derivatives	2,763	6,023
Derivatives	1,587	6,608
VIEs | Level 3 | Recurring
Variable Interest Entity [Line Items]
Investments	0	0
Derivatives	0	0
Derivatives	0	$ 0
VOEs | Recurring
Variable Interest Entity [Line Items]
Investments	110,555
Derivatives	8,775
VOEs | Level 1 | Recurring
Variable Interest Entity [Line Items]
Investments	9,036
Derivatives	0
VOEs | Level 2 | Recurring
Variable Interest Entity [Line Items]
Investments	101,519
Derivatives	8,775
VOEs | Level 3 | Recurring
Variable Interest Entity [Line Items]
Investments	0
Derivatives	$ 0