Revenue Recognition - Schedule of Disaggregation of Revenue by Type and Product (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Disaggregation of revenue
Total revenue	$ 435,361	$ 351,212	$ 823,350	$ 570,814
Investment Management Fees
Disaggregation of revenue
Total revenue	362,243	282,306	678,612	455,607
Investment Management Fees \| Mutual Funds
Disaggregation of revenue
Total revenue	195,214	175,308	384,324	289,649
Investment Management Fees \| ETF's
Disaggregation of revenue
Total revenue	15,892	9,834	30,920	18,563
Investment Management Fees \| Separate Accounts and Other Vehicles
Disaggregation of revenue
Total revenue	91,102	78,103	177,970	126,096
Performance-based Investment Fees \| Mutual Funds
Disaggregation of revenue
Total revenue	4,134	1,607	8,488	3,798
Performance-based Investment Fees \| Separate Accounts and Other Vehicles
Disaggregation of revenue
Total revenue	55,901	17,454	76,910	17,501
Administration Fees \| Mutual Funds
Disaggregation of revenue
Total revenue	33,906	32,333	66,827	59,178
Administration Fees \| ETF's
Disaggregation of revenue
Total revenue	1,603	1,218	3,086	2,312
Fund Distribution Fees \| Mutual Funds
Disaggregation of revenue
Total revenue	24,270	21,552	47,801	26,899
Fund Distribution Fees \| Separate Accounts and Other Vehicles
Disaggregation of revenue
Total revenue	1,129	1,033	2,387	1,033
Transfer Agent Fees \| Mutual Funds
Disaggregation of revenue
Total revenue	12,210	12,770	24,637	25,785
Fund Administration and Distribution Fees
Disaggregation of revenue
Total revenue	$ 73,118	$ 68,906	$ 144,738	$ 115,207