Post-Employment Benefits - Summary of Net Remeasurement Gains (Losses) Recognized in OCI (Parenthetical) (Detail) - CAD ($) $ in Millions	12 Months Ended
Oct. 31, 2022	Oct. 31, 2021
Immaterial subsidiaries [member]
Disclosure of defined benefit plans [line items]
Net remeasurement gains (losses) recognized in OCI	$ 0	$ (6)

The decrease (increase) in a net defined benefit liability (asset) resulting from the remeasurement of that net defined benefit liability (asset). [Refer: Net defined benefit liability (asset)]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2021-01-01
-Paragraph 141
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_141_c&doctype=Standard
-URIDate 2021-03-24

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