Revenue Recognition - Schedule of Balances of Receivables from Contracts with Customers (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Disaggregation Of Revenue [Line Items]
Receivables from contracts with customers	$ 94,338	$ 86,126
Non-customer receivables	2,584	1,444
Total receivables	96,922	87,570
Mutual Funds
Disaggregation Of Revenue [Line Items]
Receivables from contracts with customers	57,391	55,858
ETF's
Disaggregation Of Revenue [Line Items]
Receivables from contracts with customers	2,603	2,079
Separate Accounts and Other Vehicles
Disaggregation Of Revenue [Line Items]
Receivables from contracts with customers	$ 34,344	$ 28,189