Post-Employment Benefits - Summary of Net Remeasurement Gains (Losses) Recognized in OCI (Detail) - CAD ($) $ in Millions	3 Months Ended	9 Months Ended
Jul. 31, 2022	Apr. 30, 2022	Jul. 31, 2021	Jul. 31, 2022	Jul. 31, 2021
Pension plan [member]
Disclosure of defined benefit plans [line items]
Net actuarial gains (losses) on defined benefit obligation	$ (123)	$ 1,176	$ (314)	$ 1,332	$ 420
Net actuarial gains (losses) on plan assets	84	(803)	519	(869)	459
Changes in asset ceiling excluding interest income	1	(1)	(1)		(1)
Net remeasurement gains (losses) recognized in OCI	(38)	372	204	463	878
Other post employment benefit plans [member]
Disclosure of defined benefit plans [line items]
Net actuarial gains (losses) on defined benefit obligation	(6)	65	(18)	74	22
Net remeasurement gains (losses) recognized in OCI	$ (6)	$ 65	$ (18)	$ 74	$ 22

Net actuarial gain (loss) on defined benefit obligation.

No definition available.

Name:	cm_NetActuarialGainLossOnDefinedBenefitObligation
Namespace Prefix:	cm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

Name:	ifrs-full_DisclosureOfDefinedBenefitPlansLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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 2021-01-01
-Paragraph 141
-Subparagraph c
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_141_c_iv&doctype=Standard
-URIDate 2021-03-24

+ Details

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

- 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 2021-01-01
-Paragraph 141
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_141_c&doctype=Standard
-URIDate 2021-03-24

+ Details

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

- 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 2021-01-01
-Paragraph 141
-Subparagraph c
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_141_c_i&doctype=Standard
-URIDate 2021-03-24

+ Details

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

- Details

Name:	cm_DefinedBenefitPlansByNameAxis=cm_PensionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cm_DefinedBenefitPlansByNameAxis=cm_OtherPostEmploymentBenefitPlansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: