Revenue Recognition - Schedule of Disaggregation of Revenue by Type and Product (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation Of Revenue [Line Items]
Total revenue	$ 225,628	$ 209,688	$ 661,106	$ 615,234
Investment Management Fees
Disaggregation Of Revenue [Line Items]
Total revenue	177,809	163,953	520,757	480,199
Investment Management Fees | Mutual Funds
Disaggregation Of Revenue [Line Items]
Total revenue	119,936	112,816	351,659	330,921
Investment Management Fees | ETF's
Disaggregation Of Revenue [Line Items]
Total revenue	6,355	5,200	17,049	15,901
Investment Management Fees | Separate Accounts and Other Vehicles
Disaggregation Of Revenue [Line Items]
Total revenue	49,483	44,736	145,856	129,971
Performance-based Investment Fees | Mutual Funds
Disaggregation Of Revenue [Line Items]
Total revenue	1,924	1,087	5,896	3,489
Performance-based Investment Fees | Separate Accounts and Other Vehicles
Disaggregation Of Revenue [Line Items]
Total revenue	111	114	297	(83)
Administration Fees | Mutual Funds
Disaggregation Of Revenue [Line Items]
Total revenue	27,666	25,644	80,775	74,947
Administration Fees | ETF's
Disaggregation Of Revenue [Line Items]
Total revenue	897	725	2,413	2,159
Fund Distribution Fees | Mutual Funds
Disaggregation Of Revenue [Line Items]
Total revenue	5,641	5,648	16,773	16,978
Transfer Agent Fees | Mutual Funds
Disaggregation Of Revenue [Line Items]
Total revenue	13,615	13,718	40,388	40,951
Fund Administration and Distribution Fees
Disaggregation Of Revenue [Line Items]
Total revenue	$ 47,819	$ 45,735	$ 140,349	$ 135,035