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Employee Compensation - Pension and Other Employee Future Benefits - Additional Information (Detail) - CAD ($) $ in Millions | 12 Months Ended
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Oct. 31, 2025 | Oct. 31, 2024
Disclosure of defined benefit plans [line items] |  |
Estimated Benefit payments | $ 605 |
Increase Decrease In Defined Benefit Plan Assets Recognized In Other Comprehensive Income | 47 |
Other comprehensive loss write down of surplus assets | 62 |
Recognized As Reduction In Employee Compensation Expense [Member] |  |
Disclosure of defined benefit plans [line items] |  |
Defined benefit plans impact of plan amendments expenses | 19 |
Pension Plans [member] |  |
Disclosure of defined benefit plans [line items] |  |
Defined benefit plans impact of plan amendments expenses | 19 |
Pension Plans [member] | Scenario, Forecast [Member] |  |
Disclosure of defined benefit plans [line items] |  |
Estimated Benefit payments | 41 |
Other employee future benefit plans [member] |  |
Disclosure of defined benefit plans [line items] |  |
Defined benefit plans impact of plan amendments expenses |  | $ 84
Other comprehensive loss write down of surplus assets | 0 |
Other employee future benefit plans [member] | Employee Compensation Expense [Member] |  |
Disclosure of defined benefit plans [line items] |  |
Defined benefit plan amendments gain loss | 84 |
Other employee future benefit plans [member] | Scenario, Forecast [Member] |  |
Disclosure of defined benefit plans [line items] |  |
Estimated Benefit payments | $ 23 |

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- Definition The estimate of the expected contributions to be made to a defined benefit plan for the next annual reporting period. [Refer: Defined benefit plans [domain]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 147 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_147_b&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 148 -Subparagraph d -Clause iii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_148_d_iii&doctype=Standard -URIDate 2024-03-27 + Details
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