Loans and Allowance for Credit Losses - Summary of Gross Carrying Amount of Loans Measured at Amortized Cost (Parenthetical) (Detail) - CAD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 28, 2024 |
Oct. 31, 2024 |
Oct. 31, 2023 |
|
| Financial instruments purchased or originated credit-impaired [member] | |||
| Disclosure of credit risk exposure [line items] | |||
| Purchased Credit Impaired Loan | $ 135 | ||
| Financial instruments purchased or originated credit-impaired [member] | HSBC Canada [Member] | |||
| Disclosure of credit risk exposure [line items] | |||
| Purchased Credit Impaired Loan | $ 109 | ||
| Credit risk [member] | |||
| Disclosure of credit risk exposure [line items] | |||
| Percentage of credit impaired loans collateralized fully or partially | 88.00% | 88.00% | |