Share-based compensation - Schedule Assumptions used in Determining Fair Value of Stock Options (Details) - Employee stock option - $ / shares |
3 Months Ended | |
|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
|
| Assumptions for Stock Awards Granted [Abstract] | ||
| Share price at grant date, minimum (in USD per share) | $ 29.21 | $ 67.51 |
| Share price at grant date, maximum (in USD per share) | 29.60 | 70.50 |
| Exercise price, minimum (in USD per share) | 29.21 | 67.51 |
| Exercise price, maximum (in USD per share) | $ 29.60 | $ 70.50 |
| Expected volatility, minimum | 53.30% | 59.94% |
| Expected volatility, maximum | 55.78% | 66.17% |
| Expected life (years) | 5 years 6 months | |
| Risk free rate, minimum | 4.14% | 3.93% |
| Risk free rate, maximum | 4.41% | 4.30% |
| Minimum | ||
| Assumptions for Stock Awards Granted [Abstract] | ||
| Expected life (years) | 5 years | |
| Fair value (in USD per share) | $ 15.70 | $ 39.50 |
| Maximum | ||
| Assumptions for Stock Awards Granted [Abstract] | ||
| Expected life (years) | 5 years 6 months | |
| Fair value (in USD per share) | $ 16.21 | $ 40.47 |