Common stock and additional paid-in capital - Valuation Assumptions In Stock Option Pricing Model (Details) - Stock options	12 Months Ended
	Dec. 31, 2023 USD ($)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Risk free interest rate, minimum	3.45%
Risk free interest rate, maximum	3.59%
Expected life of options	6 years
Expected dividend yield	$ 0
Expected stock price volatility, minimum	57.81%
Expected stock price volatility, maximum	58.65%
Expected forfeiture rate	0.19%