Post-employment benefit plans - Funded Status of Post-Employment Benefit Plans Cost (Details) - CAD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Disclosure of defined benefit plans [line items]
Post-employment benefit asset (liability)	$ (2,248)	$ (1,738)
Plan asset (deficit)
Disclosure of defined benefit plans [line items]
Post-employment benefit asset (liability)	(3,249)	(2,390)
Plan asset (deficit) \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Present value of post-employment benefit obligations	(20,433)	(26,001)
Fair value of plan assets	23,682	28,391
Plan surplus (deficit)	3,249	2,390
Post-employment benefit asset (liability)	2,248	1,738
Plan asset (deficit) \| FUNDED \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Present value of post-employment benefit obligations	(18,741)	(23,872)
Fair value of plan assets	23,291	27,979
Plan surplus (deficit)	4,550	4,107
Post-employment benefit asset (liability)	3,549	3,455
Plan asset (deficit) \| PARTIALLY FUNDED \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Present value of post-employment benefit obligations	(1,461)	(1,840)
Fair value of plan assets	391	412
Plan surplus (deficit)	(1,070)	(1,428)
Post-employment benefit asset (liability)	(1,070)	(1,428)
Plan asset (deficit) \| UNFUNDED \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Present value of post-employment benefit obligations	(231)	(289)
Fair value of plan assets	0	0
Plan surplus (deficit)	(231)	(289)
Post-employment benefit asset (liability)	(231)	(289)
Effect of asset limit
Disclosure of defined benefit plans [line items]
Post-employment benefit asset (liability)	980	652
Effect of asset limit \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Effect of asset limit	(1,001)	(652)
Effect of asset limit \| FUNDED \| Defined Benefit Plan and OPEB
Disclosure of defined benefit plans [line items]
Effect of asset limit	(1,001)	(652)
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 2022-03-24
-Paragraph 57
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2022-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2022-03-24

+ 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 [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2022-03-24
-Paragraph 140
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2022-en-r&anchor=para_140_a&doctype=Standard
-URIDate 2022-03-24

+ Details

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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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