Equity investment securities - Narrative (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Investments, Debt and Equity Securities [Abstract] | ||||
| Equity securities sold (in shares) | 256,631 | 0 | 256,631 | 0 |
| Proceeds from sale of equity securities | $ 0.6 | $ 0.6 | ||
| Realized loss from equity securities | $ 0.0 | $ 0.2 | ||
| Realized gain from equity investment securities | $ 0.4 | $ 0.5 | ||