Income taxes - Narrative (Details) - CAD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Disclosure of temporary difference, unused tax losses and unused tax credits [line items] | |||
| Applicable statutory tax rate | 26.80% | 26.80% | |
| Deferred tax asset | $ (5,927) | $ (5,108) | $ (4,773) |
| Non-capital tax loss carryforwards | |||
| Disclosure of temporary difference, unused tax losses and unused tax credits [line items] | |||
| Unused tax loss carryforward | 1,636 | 281 | |
| Deferred tax asset | 397 | 73 | $ 36 |
| Unused tax losses for which no deferred tax asset recognised | 4 | 4 | |
| Non-capital Loss Carryforwards With Deferred Tax Asset | |||
| Disclosure of temporary difference, unused tax losses and unused tax credits [line items] | |||
| Unused tax loss carryforward | 1,632 | 277 | |
| Capital loss carryforwards | |||
| Disclosure of temporary difference, unused tax losses and unused tax credits [line items] | |||
| Unused tax loss carryforward | $ 54 | $ 55 | |