Income taxes - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Income Tax Examination [Line Items]
Operating loss carryforwards	$ 455.1	$ 328.9
Domestic Tax Jurisdiction
Income Tax Examination [Line Items]
Operating loss carryforwards, subject to expiration	267.7	228.1
Foreign Tax Jurisdiction
Income Tax Examination [Line Items]
Operating loss carryforwards, not subject to expiration	148.6	$ 79.7
Other Tax Authorities
Income Tax Examination [Line Items]
Operating loss carryforwards, subject to expiration	26.8
Operating loss carryforwards, not subject to expiration	$ 12.1