Securities - Summary of Unrealized Gains and Losses on Securities at Fair Value through Other Comprehensive Income (Parenthetical) (Detail) - CAD ($) $ in Millions |
Oct. 31, 2022 |
Oct. 31, 2021 |
|---|---|---|
| Disclosure of financial assets [line items] | ||
| Amortized cost | $ 95,630 | $ 78,180 |
| Allowance for credit losses on debt securities at FVOCI | (19) | (9) |
| Gross unrealized gains on securities measured at FVOCI | 696 | 723 |
| Gross unrealized losses on securities measured at FVOCI | (3,435) | (568) |
| Securities measured at fair value through other comprehensive income [member] | Commercial mortgage-backed securities [member] | ||
| Disclosure of financial assets [line items] | ||
| Amortized cost | 2,846 | 2,603 |
| Gross unrealized gains on securities measured at FVOCI | 1 | 1 |
| Gross unrealized losses on securities measured at FVOCI | 92 | 12 |
| Fair value | 2,755 | 2,592 |
| Held-to-collect securities category [member] | ||
| Disclosure of financial assets [line items] | ||
| Amortized cost | $ 77,127 | $ 67,149 |