Post-employment benefit plans - Service Cost (Details) - CAD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disclosure of defined benefit plans [line items]
DC pension	$ (31)	$ (29)	$ (74)	$ (68)
Capitalized benefit plans cost	17	13	33	26
Total post-employment benefit plans service cost	(48)	(48)	(108)	(106)
DB pension
Disclosure of defined benefit plans [line items]
Current service cost	(33)	(32)	(66)	(64)
OPEBs
Disclosure of defined benefit plans [line items]
Current service cost	$ (1)	$ 0	$ (1)	$ 0

Post-Employment Benefit Expense, Benefit Plans, Service Cost Capitalized

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- Definition

Post-Employment Benefit Expense, Benefit Plans, Service Cost, Net

+ References

No definition available.

+ Details

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- Definition

The increase (decrease) in the net defined benefit liability (asset) resulting from employee service in the current period. [Refer: Net defined benefit liability (asset)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2023-01-01
-Paragraph 141
-Subparagraph a
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-URIDate 2023-03-23

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- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

+ References

No definition available.

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- Definition

The amount of post-employment benefit expense relating to defined contribution plans. Defined contribution plans are post-employment benefit plans under which an entity pays fixed contributions into a separate entity (a fund) and will have no legal or constructive obligation to pay further contributions if the fund does not hold sufficient assets to pay all employee benefits relating to employee service in the current and prior periods.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2023-01-01
-Paragraph 53
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_53&doctype=Standard
-URIDate 2023-03-23

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