Stockholders' equity - Summary of Weighted Average Assumptions, Options (Details) - Stock options	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	4.50%	4.50%
Expected volatility	69.70%	69.70%
Expected life (in years)	1 year 7 months 6 days	1 year 7 months 6 days
Expected dividend yield	0.00%	0.00%