Share-based compensation - Summary of Stock Option Activity and Related Information (Parenthetical) (Detail) - CAD ($) $ / shares in Units, $ in Millions |
12 Months Ended | |
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Oct. 31, 2022 |
Oct. 31, 2021 |
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Disclosure of terms and conditions of share-based payment arrangement [abstract] | ||
Cash received for options exercised | $ 51 | $ 75 |
Weighted average share price at the date of exercise | $ 134.1 | $ 115.11 |