Related party transactions - Summary of Stock Options, Share-based Awards and Shares Held by Key Management Personnel, Directors and Their Close Family Members (Parenthetical) (Detail) $ in Millions |
Oct. 31, 2024
CAD ($)
shares
|
Oct. 31, 2023
CAD ($)
shares
|
|---|---|---|
| Disclosure of transactions between related parties [line items] | ||
| Number of stock options, stock awards and shares held by key management personnel, Directors and their close family members | shares | 79,445 | 32,958 |
| Value of stock options, stock awards and shares held by key management personnel, Directors and their close family members | $ | $ 12 | $ 4 |