Income taxes - Net loss before income taxes (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest [Abstract] | ||
| United States | $ (66,042) | $ (25,870) |
| United Kingdom | (248,449) | (220,959) |
| Total | $ (314,491) | $ (246,829) |
| X | ||||||||||
- Definition Amount after tax of income (loss) from continuing operations attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- References No definition available.
|