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Loans and Allowance for Credit Losses - Schedule of impaired loans, including the related allowances (Detail) - CAD ($) $ in Millions | Oct. 31, 2025 | Oct. 31, 2024
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Financial assets impaired [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | $ 6,117 | $ 5,190
Financial assets impaired [member] | Canada [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 2,887 | 2,052
Financial assets impaired [member] | United States [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 3,229 | 3,135
Financial assets impaired [member] | Other countries [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 1 | 3
Residential mortgages [member] | Financial assets impaired [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 891 | 647
Consumer installment and other personal [member] | Financial assets impaired [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 467 | 409
Business and government loans [member] | Financial assets impaired [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 4,759 | 4,134
Allowance on impaired loans [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 974 | 653
Allowance on impaired loans [member] | Canada [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 663 | 461
Allowance on impaired loans [member] | United States [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 311 | 192
Allowance on impaired loans [member] | Residential mortgages [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 12 | 10
Allowance on impaired loans [member] | Consumer installment and other personal [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 160 | 168
Allowance on impaired loans [member] | Business and government loans [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 802 | 475
Gross carrying amount [member] | Financial assets impaired [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 7,091 | 5,843
Gross carrying amount [member] | Financial assets impaired [member] | Canada [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 3,550 | 2,513
Gross carrying amount [member] | Financial assets impaired [member] | United States [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 3,540 | 3,327
Gross carrying amount [member] | Financial assets impaired [member] | Other countries [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 1 | 3
Gross carrying amount [member] | Residential mortgages [member] | Financial assets impaired [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 903 | 657
Gross carrying amount [member] | Consumer installment and other personal [member] | Financial assets impaired [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | 627 | 577
Gross carrying amount [member] | Business and government loans [member] | Financial assets impaired [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Total loans | $ 5,561 | $ 4,609

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