Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 125,037	$ 135,509
Management and advisory fees
Disaggregation of Revenue [Line Items]
Revenues	105,407	85,946
Specialized funds
Disaggregation of Revenue [Line Items]
Revenues	57,716	43,649
Customized separate accounts
Disaggregation of Revenue [Line Items]
Revenues	31,719	28,375
Advisory
Disaggregation of Revenue [Line Items]
Revenues	6,293	6,248
Reporting and other
Disaggregation of Revenue [Line Items]
Revenues	5,557	6,318
Distribution management
Disaggregation of Revenue [Line Items]
Revenues	1,213	496
Fund reimbursement revenue
Disaggregation of Revenue [Line Items]
Revenues	2,909	860
Incentive fees
Disaggregation of Revenue [Line Items]
Revenues	19,630	49,563
Incentive fees | Consolidated Entity Excluding Variable Interest Entities (VIE)
Disaggregation of Revenue [Line Items]
Revenues	19,630	49,524
Incentive fees | Consolidated VIEs
Disaggregation of Revenue [Line Items]
Revenues	0	39
Specialized funds | Consolidated Entity Excluding Variable Interest Entities (VIE)
Disaggregation of Revenue [Line Items]
Revenues	18,386	42,209
Specialized funds | Consolidated VIEs
Disaggregation of Revenue [Line Items]
Revenues	0	39
Customized separate accounts
Disaggregation of Revenue [Line Items]
Revenues	$ 1,244	$ 7,315