Investments - Schedule of Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Schedule of Equity Method Investments [Line Items]
Other investments	$ 17,381	$ 13,394
Investments valued under the measurement alternative	109,821	17,091	$ 2,990
Total Investments	649,626	207,747
Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Investments held in trust	276,003	0
Partnerships
Schedule of Equity Method Investments [Line Items]
Equity method investments	240,337	166,106
Total Investments	22,445,159	17,577,766
Partnerships Held by Consolidated VIEs
Schedule of Equity Method Investments [Line Items]
Equity method investments	4,787	9,988
Other Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 1,297	$ 1,168