Shareholders' equity - Narrative (Details) - $ / shares |
6 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Dec. 31, 2025 |
Sep. 30, 2026 |
May 13, 2026 |
|
| Equity [Abstract] | ||||
| Authorized repurchase amount (in shares) | 21,889,744 | |||
| Remaining authorized repurchase amount (in shares) | 21,889,744 | |||
| Dividend (in dollars per share) | $ 6.25 | $ 6.25 |