Interest Income and Expense - Details of Interest Income from Financial Assets (Parenthetical) (Detail) - CAD ($) $ in Millions	12 Months Ended
Oct. 31, 2025	Oct. 31, 2024
Expenses by nature [abstract]
Interest expense on lease liabilities	$ 125	$ 119
Insurance finance expense	$ 33	$ 30

The amount of expenses arising from a group of insurance contracts issued, comprising incurred claims (excluding repayments of investment components), other incurred insurance service expenses, amortisation of insurance acquisition cash flows, changes that relate to past service and changes that relate to future service. [Refer: Insurance contracts issued [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 17
-IssueDate 2024-01-01
-Paragraph 80
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=17&code=ifrs-tx-2024-en-r&anchor=para_80_a&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 82
-Subparagraph ab
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_82_ab&doctype=Standard
-URIDate 2024-03-27

Name:	ifrs-full_InsuranceServiceExpensesFromInsuranceContractsIssued
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration