Parent company information - Summary of Parent Company Information - Condensed Statements of Income and Comprehensive Income (Parenthetical) (Detail) - CAD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Oct. 31, 2022 |
Oct. 31, 2021 |
|
| Parent [member] | ||
| Parent company information [line items] | ||
| Dividend income from investments in subsidiaries | $ 11 | $ 5 |