Fair Value Measurements (Schedule of Reconciliation of Changes in Fair Value for Level 3 Assets and Liabilities) (Parenthetical) (Details) - CAD ($) $ in Millions |
Jul. 31, 2026 |
Apr. 30, 2026 |
Oct. 31, 2025 |
Jul. 31, 2025 |
Apr. 30, 2025 |
Oct. 31, 2024 |
|---|---|---|---|---|---|---|
| Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items] | ||||||
| Derivative assets | $ 80,055 | $ 82,972 | ||||
| Derivatives | 75,308 | 79,356 | ||||
| Netted derivatives [member] | Level 3 of fair value hierarchy [member] | ||||||
| Disclosure Of Fair Value Measurement Of Assets And Liabilities [Line Items] | ||||||
| Derivative assets | 48 | $ 76 | 11 | $ 49 | $ 32 | $ 30 |
| Derivatives | $ 102 | $ 225 | $ 291 | $ 231 | $ 265 | $ 221 |