Exploration and Evaluation Assets, Net - Summary of Exploration and Valuation Assets, Net (Detail) $ in Millions	9 Months Ended
Sep. 30, 2023 CAD ($)
Disclosure Of Exploration And Evaluation Assets [Line Items]
Beginning Balance	$ 685
Ending Balance	796
E&E Assets
Disclosure Of Exploration And Evaluation Assets [Line Items]
Beginning Balance	685
Acquisitions	31
Additions	80
Ending Balance	$ 796

The amount of exploration and evaluation assets recognised as intangible assets in accordance with the entity's accounting policy. [Refer: Exploration and evaluation assets [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 6
-IssueDate 2023-01-01
-Paragraph 25
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=6&code=ifrs-tx-2023-en-r&anchor=para_25&doctype=Standard
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 38
-IssueDate 2023-01-01
-Paragraph 119
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2023-en-r&anchor=para_119&doctype=Standard
-URIDate 2023-03-23

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant