Fair Value Measurements - Schedule of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Mar. 31, 2023
Financial assets:
Fair value investments	$ 17,175	$ 21,586
Total financial assets	121,165	66,338
Financial liabilities:
Secured financing	12,373	14,228
Total financial liabilities	12,373	14,228
Consolidated VIEs
Financial assets:
Fair value investments	103,990	44,752
Level 1
Financial assets:
Fair value investments	4,802	7,358
Total financial assets	4,802	7,358
Financial liabilities:
Secured financing	0	0
Total financial liabilities	0	0
Level 1 | Consolidated VIEs
Financial assets:
Fair value investments	0	0
Level 2
Financial assets:
Fair value investments	0	0
Total financial assets	0	0
Financial liabilities:
Secured financing	0	0
Total financial liabilities	0	0
Level 2 | Consolidated VIEs
Financial assets:
Fair value investments	0	0
Level 3
Financial assets:
Fair value investments	12,373	14,228
Total financial assets	81,754	35,391
Financial liabilities:
Secured financing	12,373	14,228
Total financial liabilities	12,373	14,228
Level 3 | Consolidated VIEs
Financial assets:
Fair value investments	69,381	21,163
NAV
Financial assets:
Fair value investments	0	0
Total financial assets	34,609	23,589
Financial liabilities:
Secured financing	0	0
Total financial liabilities	0	0
NAV | Consolidated VIEs
Financial assets:
Fair value investments	$ 34,609	$ 23,589