Net realized and unrealized gains - Schedule of Gross Realized and Unrealized Gains and Losses (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Investments, Debt and Equity Securities [Abstract] | ||||
| Realized gains | $ 323 | $ 42 | $ 325 | $ 598 |
| Realized losses | (21) | (1,714) | (467) | (2,392) |
| Net unrealized investment gains recognized on equity securities still held | 3,124 | 2,399 | 6,470 | 5,574 |
| Realized and unrealized gains and losses | $ 3,426 | $ 727 | $ 6,328 | $ 3,780 |