restructuring and other costs (Details) - CAD ($) $ in Millions |
3 Months Ended | 6 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Dec. 31, 2025 |
|
| restructuring and other costs | ||||||
| Goods and services purchased | $ 73 | $ 46 | $ 143 | $ 86 | ||
| Employee benefits expense | 116 | 87 | 361 | 144 | ||
| Total | 189 | 133 | 504 | 230 | $ 706 | $ 432 |
| Real estate rationalization-related restructuring impairments of property, plant and equipment | 1 | 4 | 4 | |||
| Restructuring | ||||||
| restructuring and other costs | ||||||
| Goods and services purchased | 56 | 42 | 113 | 76 | ||
| Employee benefits expense | 97 | 87 | 212 | 144 | ||
| Total | 153 | 129 | 325 | 220 | ||
| Other | ||||||
| restructuring and other costs | ||||||
| Goods and services purchased | 17 | 4 | 30 | 10 | ||
| Employee benefits expense | 19 | 149 | ||||
| Total | $ 36 | $ 4 | $ 179 | $ 10 | ||