Income Taxes (Narrative) (Details) - CAD ($) $ in Millions |
3 Months Ended | 6 Months Ended |
|---|---|---|
Apr. 30, 2026 |
Apr. 30, 2026 |
|
| Disclosure Of Income Tax [Line Items] | ||
| Additional Income Tax and Interest reassessed | $ 1,799 | |
| Adjustments for current tax of prior periods | $ (288) | |
| Revenu Quebec Agency [member] | 2011 to 2019 taxation years [member] | ||
| Disclosure Of Income Tax [Line Items] | ||
| Additional Income Tax and Interest reassessed | 52 | |
| Canada Revenue Agency Reassessment [member] | 2011 to 2020 taxation years [member] | ||
| Disclosure Of Income Tax [Line Items] | ||
| Additional Income Tax and Interest reassessed | 1,676 | |
| Alberta Tax and Revenue Administration Reassessment [member] | 2011 to 2020 taxation years [member] | ||
| Disclosure Of Income Tax [Line Items] | ||
| Additional Income Tax and Interest reassessed | $ 71 |