Fair Value Measurements - Valuation Methodologies (Details) $ in Thousands	Dec. 31, 2021 USD ($)	Mar. 31, 2021 USD ($)
Schedule of Equity Method Investments [Line Items]
Fair Value	$ 22,767	$ 17,381
Private equity funds
Schedule of Equity Method Investments [Line Items]
Fair Value	8,802
Direct credit co-investments
Schedule of Equity Method Investments [Line Items]
Fair Value	782
Direct equity co-investments
Schedule of Equity Method Investments [Line Items]
Fair Value	$ 6,893
Selected market return | Adjusted net asset value | Minimum | Private equity funds
Schedule of Equity Method Investments [Line Items]
Range of and weighted-average inputs	0.047
Selected market return | Adjusted net asset value | Maximum | Private equity funds
Schedule of Equity Method Investments [Line Items]
Range of and weighted-average inputs	0.061
Selected market return | Adjusted net asset value | Weighted Average | Private equity funds
Schedule of Equity Method Investments [Line Items]
Range of and weighted-average inputs	0.059
Market yield | Discounted cash flow | Minimum | Direct credit co-investments
Schedule of Equity Method Investments [Line Items]
Range of and weighted-average inputs	0.100
Market yield | Discounted cash flow | Maximum | Direct credit co-investments
Schedule of Equity Method Investments [Line Items]
Range of and weighted-average inputs	0.100
Market yield | Discounted cash flow | Weighted Average | Direct credit co-investments
Schedule of Equity Method Investments [Line Items]
Range of and weighted-average inputs	0.100
EBITDA multiple | Market approach | Minimum | Direct equity co-investments
Schedule of Equity Method Investments [Line Items]
Range of and weighted-average inputs	8.00
EBITDA multiple | Market approach | Maximum | Direct equity co-investments
Schedule of Equity Method Investments [Line Items]
Range of and weighted-average inputs	15.25
EBITDA multiple | Market approach | Weighted Average | Direct equity co-investments
Schedule of Equity Method Investments [Line Items]
Range of and weighted-average inputs	11.40
Equity multiple | Market approach | Weighted Average | Direct equity co-investments
Schedule of Equity Method Investments [Line Items]
Range of and weighted-average inputs	1.62