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Stockholders' equity - Stock Options Valuation Assumptions (Details) - Employee Stock Option
12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected dividend yield 0.00% 0.00% 0.00%
Expected volatility, minimum 54.00% 47.00% 39.00%
Expected volatility, maximum 62.00% 48.00% 48.00%
Risk-free interest rate, minimum 1.54% 0.43% 0.27%
Risk-free interest rate, maximum 4.31% 0.94% 1.42%
Expected average life of options 4 years 6 months 4 years 6 months 4 years 6 months