Goodwill, In-Process Research & Development and Other Assets - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Oct. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Goodwill [Line Items]
Goodwill		$ 78,568,000	$ 31,969,000	$ 32,601,000
Accumulated impairment loss, goodwill		0
Gross carrying amount. infinite lived intangible assets, cost		$ 27,000,000.0
Intangible asset, amortized useful life	15 years	15 years
Accumulated impairment losses on IPR&D assets		$ 0
Other Intangible Assets
Goodwill [Line Items]
Intangible asset, amortized useful life		15 years
Impella Cardiosystems AG [Member]
Goodwill [Line Items]
Goodwill		$ 78,600,000	$ 32,000,000.0