Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	$ 1,152,646	$ 1,083,871
Not subject to contracts with customers:
Dividend and interest income, net of broker-dealer related interest expense	17,465	16,833
Investment gains (losses)	31,059	(20,538)
Other revenues	556	441
Total revenue not from contract with customer	49,080	(3,264)
Net revenues	1,201,726	1,080,607
Base fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	849,182	817,866
Performance-based fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	66,032	37,246
All-in-management fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	90,808	88,444
12b-1 fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	14,766	16,252
Other distribution fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	97,244	94,324
Shareholder servicing fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	24,188	16,642
JV related revenues
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	6,361	9,334
Other
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	$ 4,065	$ 3,763