Stockholders' equity - Summary of Weighted Average Assumptions, Options (Details) - Contingently issuable shares under ESPP	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	4.10%	5.10%
Expected volatility	57.90%	51.90%
Expected life (in years)	1 year 3 months 18 days	1 year 3 months 18 days
Expected dividend yield	0.00%	0.00%