Commitments and contingencies - Income Statement Information (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Lessee, Lease, Description [Line Items] | ||
| Finance Lease Costs | $ 2,428 | $ 2,428 |
| Operating Lease Costs | 1,156 | 1,129 |
| Total lease cost | 5,647 | 5,675 |
| Research and development | ||
| Lessee, Lease, Description [Line Items] | ||
| Finance Lease Costs | 2,428 | 2,428 |
| Operating Lease Costs | 887 | 877 |
| Total lease cost | 5,647 | 5,675 |
| Other expense | ||
| Lessee, Lease, Description [Line Items] | ||
| Finance Lease Costs | 2,063 | 2,118 |
| Selling, general and administrative | ||
| Lessee, Lease, Description [Line Items] | ||
| Operating Lease Costs | $ 269 | $ 252 |