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Securities - Summary of Interest Income Calculated Using Effective Interest Method (Detail) - CAD ($) $ in Millions | 12 Months Ended
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Oct. 31, 2025 | Oct. 31, 2024
Disclosure Of interest, dividend and fee income [Line Items] |  |
Total | $ 7,279 | $ 7,987
FVTPL securities [member] |  |
Disclosure Of interest, dividend and fee income [Line Items] |  |
Total | 143 | 161
FVOCI securities [member] |  |
Disclosure Of interest, dividend and fee income [Line Items] |  |
Total | 4,427 | 3,874
Amortized cost securities [member] |  |
Disclosure Of interest, dividend and fee income [Line Items] |  |
Total | $ 2,709 | $ 3,952

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