Investments - Narrative (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Sep. 30, 2022 USD ($) investment	Jun. 30, 2022 USD ($) investment	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Mar. 31, 2022 USD ($)
Schedule of Equity Method Investments [Line Items]
Proceeds from sale of equity method investments	$ 10,000
Gain on sale of investment	9,783
Distributions from investments	1,406			$ 1,406	$ 12,739
Net gain (loss)				5,352	27,838
Unrealized loss on secured borrowings, fair value adjustment	817		$ 186	94	1,000
Investments valued under the measurement alternative	$ 190,023			190,023		$ 156,100
Private equity funds
Schedule of Equity Method Investments [Line Items]
Investments held | investment	2	2
Technology Drive Platform
Schedule of Equity Method Investments [Line Items]
Investments valued under the measurement alternative		$ 3,000
Online Financial Services Platform
Schedule of Equity Method Investments [Line Items]
Investments valued under the measurement alternative		12,000
Individual Investors And Wealth Management Platform
Schedule of Equity Method Investments [Line Items]
Investments valued under the measurement alternative		5,236
Digital Platform
Schedule of Equity Method Investments [Line Items]
Investments valued under the measurement alternative	$ 3,000			3,000
Cloud-based Treasury And Liquidity Solution For Investment Management Firms
Schedule of Equity Method Investments [Line Items]
Investments valued under the measurement alternative	$ 4,000			$ 4,000
Equity method investments in Partnerships
Schedule of Equity Method Investments [Line Items]
Percent interest in partnerships	1.00%			1.00%
Investment, Held As Collateral
Schedule of Equity Method Investments [Line Items]
Net gain (loss)	$ 817		$ 186	$ 94	$ 1,000
Investment, Measurement Alternative
Schedule of Equity Method Investments [Line Items]
Net gain (loss)		$ 6,687