Income taxes - Provision for Income Taxes and Effective Income Tax Rates (Details) - USD ($) $ in Thousands	3 Months Ended
Jun. 30, 2026	Jun. 30, 2025
Income taxes [Abstract]
Provision for income taxes	$ 0	$ 0
Effective income tax rate	0.00%	0.00%

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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