Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021	Mar. 31, 2020
Goodwill [Line Items]
Other investments (Note 6)	$ 55,418	$ 62,995
Operating lease right of use asset (Note 11)	5,099	6,109	$ 6,109
Other intangible assets and other assets	6,568	5,323
Other assets	128,181	113,082
Shockwave Medical
Goodwill [Line Items]
Fair value of investment	$ 61,096	$ 38,655