Stock-based compensation - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)	2,501,341		2,501,341
Restricted stock units - Unvested
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	$ 12.8	$ 0.4	$ 45.0	$ 1.5
Unrecognized compensation cost	$ 35.6		$ 35.6
Unrecognized compensation cost, period for recognition			1 year