Income taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Taxes [Line Items]
Increase in valuation allowance	$ 9,700,000	$ 21,700,000	$ 32,000,000
Unrecognized tax benefits, uncertainty in income taxes	2,300,000	1,800,000
Income tax expense related to interest and penalties	0	$ 0	$ 0
Domestic Tax Jurisdiction
Income Taxes [Line Items]
Operating loss carryforwards	85,500,000
Operating loss carryforwards subject to expiration	24,200,000
Operating loss carryforwards not subject to expiration	61,300,000
Domestic Tax Jurisdiction | Research Tax Credit Carryforward
Income Taxes [Line Items]
Tax credit carryforward, amount	13,700,000
Foreign Tax Jurisdiction
Income Taxes [Line Items]
Operating loss carryforwards	110,700,000
Foreign Tax Jurisdiction | Research Tax Credit Carryforward
Income Taxes [Line Items]
Tax credit carryforward, amount	1,900,000
State and Local Jurisdiction
Income Taxes [Line Items]
Operating loss carryforwards	5,500,000
State and Local Jurisdiction | Research Tax Credit Carryforward
Income Taxes [Line Items]
Tax credit carryforward, amount	$ 4,700,000