Impairment of assets (Details) - CAD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Disclosure of detailed information about investment property [abstract]
Impairment of assets	$ 8	$ 60	$ 17	$ 73

The amount recognised as a reduction of the carrying amount of an asset or cash-generating unit to its recoverable amount. [Refer: Carrying amount [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2025-01-01
-Paragraph 130
-Subparagraph d
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2025-en-r&anchor=para_130_d_ii&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2025-01-01
-Paragraph 130
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2025-en-r&anchor=para_130_b&doctype=Standard
-URIDate 2025-03-27

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