Post-employment benefit plans - Funded Status of Post-Employment Benefit Plans Cost (Details) - CAD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Disclosure of defined benefit plans [line items]
Post-employment benefit asset (liability)	$ (2,374)	$ (1,657)
Plan asset (deficit)
Disclosure of defined benefit plans [line items]
Post-employment benefit asset (liability)	(3,370)	(2,429)
Plan asset (deficit) \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Present value of post-employment benefit obligations	(21,188)	(21,669)
Fair value of plan assets	24,558	24,098
Plan surplus (deficit)	3,370	2,429
Post-employment benefit asset (liability)	2,374	1,657
Plan asset (deficit) \| Funded \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Present value of post-employment benefit obligations	(19,558)	(20,004)
Fair value of plan assets	24,123	23,703
Plan surplus (deficit)	4,565	3,699
Post-employment benefit asset (liability)	3,569	2,927
Plan asset (deficit) \| Partially funded \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Present value of post-employment benefit obligations	(1,425)	(1,453)
Fair value of plan assets	435	395
Plan surplus (deficit)	(990)	(1,058)
Post-employment benefit asset (liability)	(990)	(1,058)
Plan asset (deficit) \| Unfunded \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Present value of post-employment benefit obligations	(205)	(212)
Fair value of plan assets	0	0
Plan surplus (deficit)	(205)	(212)
Post-employment benefit asset (liability)	(205)	(212)
Effect of asset limit
Disclosure of defined benefit plans [line items]
Post-employment benefit asset (liability)	960	719
Effect of asset limit \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Effect of asset limit	(996)	(772)
Effect of asset limit \| Funded \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Effect of asset limit	(996)	(772)
Effect of asset limit \| Partially funded \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Effect of asset limit	0	0
Effect of asset limit \| Unfunded \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Effect of asset limit	$ 0	$ 0

Effect of Asset Limit

No definition available.

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- Definition

The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2024-01-01
-Paragraph 57
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2024-03-27

+ Details

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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.

+ Details

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- Definition

The amount of deficit or surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [domain]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2024-01-01
-Paragraph 140
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_140_a&doctype=Standard
-URIDate 2024-03-27

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- Definition

The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]]

+ References

+ Details

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- Definition

The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]]

+ References

+ Details

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