Income taxes - Income Tax Expense Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Loss before income taxes	$ (41,519)	$ (59,685)
Basic income tax rate	26.50%	26.50%
Computed income tax recovery	$ (11,003)	$ (15,817)
Accounting charges not deductible for tax purposes		4
Non-deductible share-based compensation	1,637	4,663
Other permanent differences	21
Tax benefits of current period losses and other tax assets, subject to full valuation allowance	8,074	10,945
Valuation allowance for prior year adjustment	136
Foreign income tax rate difference	1,114
Other	$ 21	$ 205
Canada Federal
Basic income tax rate	38.00%	38.00%
Federal tax abatement and general tax reduction (as a percent)	15.00%	15.00%
Additional provincial tax (as a percent)	11.50%	11.50%