Post-Employment Benefits - Summary of Net Remeasurement Gains (Losses) Recognized in OCI (Detail) - CAD ($) $ in Millions	3 Months Ended	9 Months Ended
Jul. 31, 2024	Apr. 30, 2024	Jul. 31, 2023	Jul. 31, 2024	Jul. 31, 2023
Pension plan [member]
Disclosure of defined benefit plans [line items]
Net actuarial gains (losses) on defined benefit obligation	$ (294)	$ 267	$ 231	$ (726)	$ (284)
Net actuarial gains (losses) on plan assets	549	(262)	(220)	913	113
Changes in asset ceiling excluding interest income	(2)	1		(2)	(1)
Net remeasurement gains (losses) recognized in OCI	253	6	11	185	(172)
Other post employment benefit plans [member]
Disclosure of defined benefit plans [line items]
Net actuarial gains (losses) on defined benefit obligation	(15)	12	14	(38)	(12)
Net remeasurement gains (losses) recognized in OCI	$ (15)	$ 12	$ 14	$ (38)	$ (12)

Net actuarial gain (loss) on defined benefit obligation.

No definition available.

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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 decrease (increase) in the net defined benefit liability (asset) resulting from the gain (loss) on changes in the effect of limiting a net defined benefit asset to the asset ceiling, excluding amounts included in interest income or expense. [Refer: Interest income (expense); Net defined benefit liability (asset); Increase (decrease) in net defined benefit liability (asset) resulting from interest expense (income)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2023-01-01
-Paragraph 141
-Subparagraph c
-Clause iv
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_141_c_iv&doctype=Standard
-URIDate 2023-03-23

+ Details

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- Definition

The decrease (increase) in a net defined benefit liability (asset) resulting from the remeasurement of that net defined benefit liability (asset). [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 c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_141_c&doctype=Standard
-URIDate 2023-03-23

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- Definition

The decrease (increase) in the net defined benefit liability (asset) resulting from the return on plan assets, excluding amounts included in interest income or expense. The return on plan assets is interest, dividends and other revenue derived from the plan assets, together with realised and unrealised gains or losses on the plan assets, less any costs of managing plan assets and less any tax payable by the plan itself, other than tax included in the actuarial assumptions used to measure the present value of the defined benefit obligation. [Refer: Plan assets [member]; Net defined benefit liability (asset); Actuarial assumptions [member]; Increase (decrease) in net defined benefit liability (asset) resulting from interest expense (income)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2023-01-01
-Paragraph 141
-Subparagraph c
-Clause i
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_141_c_i&doctype=Standard
-URIDate 2023-03-23

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