Other comprehensive income (loss) information - Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - CAD ($) $ in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| AOCI Attributable to Parent, Net of Tax [Roll Forward] | ||
| At beginning of period | $ 22,254 | |
| At end of period | 24,543 | $ 24,999 |
| Accumulated Defined Benefit Plans Adjustment Attributable to Parent | ||
| AOCI Attributable to Parent, Net of Tax [Roll Forward] | ||
| At beginning of period | (14) | (214) |
| Current period change excluding amounts reclassified from accumulated other comprehensive income | (5) | 12 |
| Amounts reclassified from accumulated other comprehensive income | 5 | 10 |
| At end of period | $ (14) | $ (192) |
| X | ||||||||||
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
|
| X | ||||||||||
- Definition Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount after tax of reclassification adjustments of other comprehensive income (loss) attributable to parent. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Details
|