Securities - Summary of Securities (Parenthetical) (Detail) - CAD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Oct. 31, 2022 |
Jan. 31, 2023 |
|
| Disclosure of detailed information about financial instruments [line items] | ||
| Debt Securities, Available-for-sale, Amortized Cost | $ 0 | |
| Debt securities [member] | Financial assets at amortised cost, category [member] | ||
| Disclosure of detailed information about financial instruments [line items] | ||
| Realized gain (loss) on disposal of debt securities | $ 1 |