Fair value of financial instruments - Summary of Liabilities Designated as at Fair Value Through Profit or Loss (Parenthetical) (Detail) - CAD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Oct. 31, 2024 |
Oct. 31, 2023 |
|
| Disclosure of financial liabilities [line items] | ||
| Fair value gains (losses) previously included in OCI related to financial liabilities derecognized | $ 1,425 | $ 798 |
| Financial liabilities designated as at FVTPL [member] | ||
| Disclosure of financial liabilities [line items] | ||
| Fair value gains (losses) previously included in OCI related to financial liabilities derecognized | 15 | 2 |
| Changes in fair value attributable to changes in credit risk | 1 | 29 |
| Cumulative changes in credit risk | $ 9 | $ 17 |