Fair value of financial instrument - Summary of Quantitative Information About Fair Value Measurements Using Significant Unobservable Inputs (Level 3 Instruments) (Parenthetical) (Detail) - Level 3 [member] - CAD ($) $ / shares in Units, $ in Millions |
Oct. 31, 2022 |
Oct. 31, 2021 |
|---|---|---|
| Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items] | ||
| Fair value inputs application on par value | $ 100 | |
| Discounted cash flow [member] | Liquidity discounts [member] | Private equities hedge fund investments and related equity derivatives [member] | ||
| Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items] | ||
| Fair value of securities with liquidity discount inputs | $ 373 | $ 385 |