Revenue - Schedule of Disaggregation of Revenue by Type and Product (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of revenue
Total revenue	$ 215,857	$ 201,320
Investment Management Fees
Disaggregation of revenue
Total revenue	169,785	156,836
Investment Management Fees \| Mutual Funds
Disaggregation of revenue
Total revenue	115,173	108,416
Investment Management Fees \| ETF's
Disaggregation of revenue
Total revenue	5,179	5,441
Investment Management Fees \| Separate Accounts and Other Vehicles
Disaggregation of revenue
Total revenue	47,312	42,582
Performance-based Investment Fees \| Mutual Funds
Disaggregation of revenue
Total revenue	2,023	690
Performance-based Investment Fees \| Separate Accounts and Other Vehicles
Disaggregation of revenue
Total revenue	98	(293)
Administration Fees \| Mutual Funds
Disaggregation of revenue
Total revenue	26,334	24,376
Administration Fees \| ETF's
Disaggregation of revenue
Total revenue	744	710
Fund Distribution Fees \| Mutual Funds
Disaggregation of revenue
Total revenue	5,583	5,740
Transfer Agent Fees \| Mutual Funds
Disaggregation of revenue
Total revenue	13,411	13,658
Fund Administration and Distribution Fees
Disaggregation of revenue
Total revenue	$ 46,072	$ 44,484