Other Long-Term Liabilities - Segmented Asset Retirement Obligations (Details) - CAD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|---|---|
| Disclosure of operating segments [line items] | ||||
| Asset retirement obligations | $ 9,743 | $ 8,607 | $ 7,690 | $ 6,908 |
| North America | ||||
| Disclosure of operating segments [line items] | ||||
| Asset retirement obligations | 4,937 | 4,783 | ||
| North Sea | ||||
| Disclosure of operating segments [line items] | ||||
| Asset retirement obligations | 2,629 | 1,724 | ||
| Offshore Africa | ||||
| Disclosure of operating segments [line items] | ||||
| Asset retirement obligations | 275 | 197 | ||
| Oil Sands Mining and Upgrading | ||||
| Disclosure of operating segments [line items] | ||||
| Asset retirement obligations | 1,901 | 1,902 | ||
| Midstream and Refining | ||||
| Disclosure of operating segments [line items] | ||||
| Asset retirement obligations | $ 1 | $ 1 |