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Fair Value Measurements and Trading-Related Revenue - Summary of Financial Instruments Designated At Fair Value Through Profit Or Loss (Parenthetical) (Detail) - CAD ($) $ in Millions | Oct. 31, 2025 | Oct. 31, 2024
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Fair Value of Financial Instruments Not Carried at Fair Value on the Balance Sheet [line items] |  |
Business and government | $ 380,788 | $ 384,993
Securitization and structured entities' liabilities | 51,562 | 40,164
Amortized cost | 96,610 | 115,188
Financial liabilities at fair value through profit or loss, category [member] |  |
Fair Value of Financial Instruments Not Carried at Fair Value on the Balance Sheet [line items] |  |
Structured note liabilities | 49,093 | 45,222
Metal deposits | 3,973 | 1,807
Embedded options related to structured deposits carried at amortized cost | 1,967 | 1,047
Securitization and structured entities' liabilities | 31,351 | 18,314
Money market deposits | 1,129 | 6,032
At fair value [member] |  |
Fair Value of Financial Instruments Not Carried at Fair Value on the Balance Sheet [line items] |  |
Amortized cost | 90,448 | 106,461
Level 2 of fair value hierarchy [member] | At fair value [member] |  |
Fair Value of Financial Instruments Not Carried at Fair Value on the Balance Sheet [line items] |  |
Amortized cost | 90,448 | 106,389
Level 3 of fair value hierarchy [member] | At fair value [member] |  |
Fair Value of Financial Instruments Not Carried at Fair Value on the Balance Sheet [line items] |  |
Amortized cost | 0 | 72
Financial assets at fair value through profit or loss [member] |  |
Fair Value of Financial Instruments Not Carried at Fair Value on the Balance Sheet [line items] |  |
Residential mortgages loans | 79 | 163
Business and government | 13,231 | 12,431
Financial assets at fair value through other comprehensive income [member] |  |
Fair Value of Financial Instruments Not Carried at Fair Value on the Balance Sheet [line items] |  |
Business and government | $ 14 | $ 61

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