Post-employment benefit plans - Defined Benefit Plans Recognized in Comprehensive Income (Details) - CAD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Changes in net defined benefit liability (asset) resulting from gain (loss) on remeasurement in other comprehensive income [abstract] | ||
| Cumulative gains recognized directly in equity, January 1 | $ 1,228 | $ 432 |
| Actuarial gains in other comprehensive income | 881 | 984 |
| Increase in the effect of the asset limit in other comprehensive income | (22) | (188) |
| Cumulative gains recognized directly in equity, December 31 | 2,087 | $ 1,228 |
| Cumulative actuarial gain (loss) | 2,729 | |
| Cumulative increase in the effect of the asset limit | $ 642 | |