Financial instruments and risk management (Details) - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Financial Instruments And Risk Management | |||
| Fuel increase operating cost | $ 0.01 | ||
| Fuel sensitivity analysis, increase in operating costs due to reasonably possible increase in price per gallon | $ 3,400 | $ 3,227 | $ 3,719 |
| Fuel decrease operating cost | $ 0.01 | ||
| Fuel sensitivity analysis, increase in operating costs due to reasonably possible decrease in price per gallon | $ (3,400) | $ (3,227) | $ (3,719) |