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Income Taxes - Additional Information (Detail) - CAD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Oct. 31, 2025 | Oct. 31, 2024 | Oct. 31, 2023
Disclosure of Income Tax [Line items] |  |  |
Deferred income tax assets loss carryforwards | $ 2,732 | $ 3,024 | $ 3,420
Temporary differences, unused tax losses and unused tax credits for which no deferred tax asset is recognized | 917 | 947 |
Temporary differences associated with repatriation of earnings from investments in subsidiaries, branches and associates and interests in joint arrangements for which deferred tax liabilities have not been recognised | 31,000 | 27,000 |
Less than five years expiry [Member] |  |  |
Disclosure of Income Tax [Line items] |  |  |
Unused tax losses for which no deferred tax asset recognised | 52 | 53 |
2011 - 2018 taxation years [member] |  |  |
Disclosure of Income Tax [Line items] |  |  |
Additional income tax expense and interest | 1,465 |  |
Canada [member] | Tax loss carryforwards [member] |  |  |
Disclosure of Income Tax [Line items] |  |  |
Deferred income tax assets loss carryforwards | 50 | 20 |
United States [member] | Tax loss carryforwards [member] |  |  |
Disclosure of Income Tax [Line items] |  |  |
Deferred income tax assets loss carryforwards | $ 4 | $ 3 |

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- Definition The aggregate amount of temporary differences associated with investments in subsidiaries, branches and associates and interests in joint arrangements, for which deferred tax liabilities have not been recognised as a result of satisfying both of the following conditions: (a) the parent, investor, joint venturer or joint operator is able to control the timing of the reversal of the temporary difference; and (b) it is probable that the temporary difference will not reverse in the foreseeable future. [Refer: Total for all associates [member]; Total for all subsidiaries [member]; Temporary differences [member]; Investments in subsidiaries reported in separate financial statements] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2024-01-01 -Paragraph 81 -Subparagraph f -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2024-en-r&anchor=para_81_f&doctype=Standard -URIDate 2024-03-27 + Details
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