Fair value measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Assets: | ||
| Investments in equity | $ 96,966 | $ 82,050 |
| Investments in equity securities recorded at cost | 2,500 | 2,500 |
| Fair value, recurring | ||
| Assets: | ||
| Investments in equity | 94,466 | 79,550 |
| Total assets | 94,466 | 79,550 |
| Level 1 | Fair value, recurring | ||
| Assets: | ||
| Investments in equity | 0 | 0 |
| Total assets | 0 | 0 |
| Level 2 | Fair value, recurring | ||
| Assets: | ||
| Investments in equity | 0 | 0 |
| Total assets | 0 | 0 |
| Level 3 | Fair value, recurring | ||
| Assets: | ||
| Investments in equity | 0 | 0 |
| Total assets | 0 | 0 |
| Investments Measured at Net Asset Value | Fair value, recurring | ||
| Assets: | ||
| Investments in equity | 94,466 | 79,550 |
| Total assets | $ 94,466 | $ 79,550 |