Inventories - Additional Information (Detail) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Disclosure of inventories [line items]
Cost of inventories recognized as expense during period	$ 42,800	$ 39,100
Refined Products
Disclosure of inventories [line items]
Inventory write-downs	$ 0	86
Crude Oil
Disclosure of inventories [line items]
Inventory write-downs		$ 3

The amount of expense recognised related to the write-down of inventories to net realisable value. [Refer: Inventories]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 2
-IssueDate 2024-01-01
-Paragraph 36
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=2&code=ifrs-tx-2024-en-r&anchor=para_36_e&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 98
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_98_a&doctype=Standard
-URIDate 2024-03-27

Name:	ifrs-full_InventoryWritedown2011
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration