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Loans and Allowance for Credit Losses - Summary of Key Economic Variables Used to Estimate Allowance on Performing Loans During Forecast Period (Detail) | Oct. 31, 2025 | Oct. 31, 2024
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Upside Scenarios [member] | Canada [member] | First 12 months [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 3.60% | 4.60%
Corporate BBB | 1.20% | 1.30%
Unemployment rates | 6.00% | 5.30%
Housing Price Index | 3.90% | 5.90%
Upside Scenarios [member] | Canada [member] | Remaining horizon [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 2.80% | 2.60%
Corporate BBB | 1.80% | 1.80%
Unemployment rates | 5.50% | 4.80%
Housing Price Index | 5.80% | 5.40%
Upside Scenarios [member] | United States [member] | First 12 months [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 4.50% | 4.30%
Corporate BBB | 0.80% | 0.90%
Unemployment rates | 3.60% | 3.40%
Housing Price Index | 3.70% | 5.90%
Upside Scenarios [member] | United States [member] | Remaining horizon [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 2.40% | 2.40%
Corporate BBB | 1.50% | 1.60%
Unemployment rates | 3.10% | 3.00%
Housing Price Index | 3.90% | 4.00%
Base Scenarios [member] | Canada [member] | First 12 months [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 1.10% | 1.80%
Corporate BBB | 1.70% | 1.90%
Unemployment rates | 7.10% | 7.00%
Housing Price Index | (0.40%) | 1.60%
Base Scenarios [member] | Canada [member] | Remaining horizon [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 2.10% | 1.90%
Corporate BBB | 2.00% | 2.00%
Unemployment rates | 6.40% | 6.80%
Housing Price Index | 3.40% | 3.00%
Base Scenarios [member] | United States [member] | First 12 months [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 1.70% | 1.90%
Corporate BBB | 1.50% | 1.60%
Unemployment rates | 4.50% | 4.70%
Housing Price Index | 0.70% | 2.80%
Base Scenarios [member] | United States [member] | Remaining horizon [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 1.80% | 1.90%
Corporate BBB | 1.90% | 2.00%
Unemployment rates | 4.40% | 4.40%
Housing Price Index | 2.40% | 2.60%
Downside Scenarios [member] | Canada [member] | First 12 months [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | (2.70%) | (2.30%)
Corporate BBB | 3.40% | 3.60%
Unemployment rates | 9.40% | 8.80%
Housing Price Index | (10.50%) | (10.90%)
Downside Scenarios [member] | Canada [member] | Remaining horizon [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 1.60% | 1.30%
Corporate BBB | 3.00% | 3.00%
Unemployment rates | 9.60% | 9.40%
Housing Price Index | (0.70%) | (1.00%)
Downside Scenarios [member] | United States [member] | First 12 months [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | (2.30%) | (2.10%)
Corporate BBB | 3.50% | 3.40%
Unemployment rates | 6.80% | 6.70%
Housing Price Index | (11.60%) | (9.60%)
Downside Scenarios [member] | United States [member] | Remaining horizon [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 1.40% | 1.40%
Corporate BBB | 3.00% | 3.10%
Unemployment rates | 7.50% | 7.30%
Housing Price Index | (1.10%) | (1.00%)
Severe Downside Scenario [member] | Canada [member] | First 12 months [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | (4.00%) | (3.60%)
Corporate BBB | 4.20% | 4.20%
Unemployment rates | 9.90% | 9.80%
Housing Price Index | (19.40%) | (19.00%)
Severe Downside Scenario [member] | Canada [member] | Remaining horizon [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 1.20% | 1.20%
Corporate BBB | 3.50% | 3.50%
Unemployment rates | 10.50% | 10.50%
Housing Price Index | (5.00%) | (5.00%)
Severe Downside Scenario [member] | United States [member] | First 12 months [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | (3.50%) | (3.40%)
Corporate BBB | 4.60% | 4.60%
Unemployment rates | 7.50% | 7.60%
Housing Price Index | (20.00%) | (19.30%)
Severe Downside Scenario [member] | United States [member] | Remaining horizon [member] |  |
Disclosure of detailed information about financial instruments [line items] |  |
Real GDP growth rates | 1.30% | 1.30%
Corporate BBB | 3.60% | 3.60%
Unemployment rates | 8.40% | 8.40%
Housing Price Index | (4.30%) | (4.30%)

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