Employee benefit plan - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Retirement Benefits [Abstract]
Defined contribution plan, vest percentage	100.00%
Company contributions to 401 (k) plan	$ 0.4	$ 0.3	$ 0.3

Percentage of employer's matching contributions to a defined contribution plan that vests in a given year.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration