Fair Value Measurement - Reconciliation of Other Investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Reconciliation Of Other Investments [Roll Forward]
Other investments, beginning balance			$ 17,381
Net gain (loss)			47,774	$ 0
Other investments, ending balance	$ 22,767		22,767
Level 3
Reconciliation Of Other Investments [Roll Forward]
Other investments, beginning balance	20,132	$ 17,703	13,298	13,394
Contributions	204	218	321	246
Distributions	(25)	(1,035)	(381)	(1,477)
Net gain (loss)	2,456	1,276	3,074	5,999
Transfer in			6,455
Transfer out	(6,290)	4,271	(6,290)	4,271
Other investments, ending balance	16,477	13,891	16,477	13,891
Private equity funds
Reconciliation Of Other Investments [Roll Forward]
Other investments, ending balance	8,802		8,802
Private equity funds | Level 3
Reconciliation Of Other Investments [Roll Forward]
Other investments, beginning balance	7,159	6,208	6,254	5,786
Contributions	204	218	293	246
Distributions	(25)	(896)	(179)	(1,264)
Net gain (loss)	1,464	252	2,434	1,014
Transfer in			0
Transfer out	0	0	0	0
Other investments, ending balance	8,802	5,782	8,802	5,782
Direct credit co-investments
Reconciliation Of Other Investments [Roll Forward]
Other investments, ending balance	782		782
Direct credit co-investments | Level 3
Reconciliation Of Other Investments [Roll Forward]
Other investments, beginning balance	783	1,889	985	1,756
Contributions	0	0	0	0
Distributions	0	0	(202)	(74)
Net gain (loss)	(1)	6	(1)	213
Transfer in			0
Transfer out	0	0	0	0
Other investments, ending balance	782	1,895	782	1,895
Direct equity co-investments
Reconciliation Of Other Investments [Roll Forward]
Other investments, ending balance	6,893		6,893
Direct equity co-investments | Level 3
Reconciliation Of Other Investments [Roll Forward]
Other investments, beginning balance	6,068	9,606	6,059	5,852
Contributions	0	0	28	0
Distributions	0	(139)	0	(139)
Net gain (loss)	825	1,018	806	4,772
Transfer in			0
Transfer out	0	4,271	0	4,271
Other investments, ending balance	6,893	$ 6,214	6,893	$ 6,214
Publicly traded equity security | Level 3
Reconciliation Of Other Investments [Roll Forward]
Other investments, beginning balance	6,122		0
Contributions	0		0
Distributions	0		0
Net gain (loss)	168		(165)
Transfer in			6,455
Transfer out	(6,290)		(6,290)
Other investments, ending balance	$ 0		$ 0