Commitments and contingencies - Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Lessee, Lease, Description [Line Items]
Finance lease, right-of-use-asset amortization	$ 607	$ 607
Other income (expense)	521	534
Operating Lease Costs	288	281
Total lease cost	1,416	1,422
Research and development
Lessee, Lease, Description [Line Items]
Finance lease, right-of-use-asset amortization	607	607
Operating Lease Costs	223	229
Selling, general and administrative
Lessee, Lease, Description [Line Items]
Operating Lease Costs	$ 65	$ 52