XML 88 R78.htm IDEA: XBRL DOCUMENT v3.25.2

Income Taxes - Additional Information (Detail) - CAD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Jul. 31, 2024	Jul. 31, 2025	Jul. 31, 2025
Disclosure Of Income Taxes [Line Items]
Maximum range of estimated consolidated effective tax rate		1.00%	1.00%
2019 Taxation Year [Member]
Disclosure Of Income Taxes [Line Items]
Additional income tax by denying the tax deductibility			$ 1,918
Organization For Economic Cooperation And Development Pillar Two Tax Regime [Member]
Disclosure Of Income Taxes [Line Items]
Global minimum tax percentage	15.00%

X

- Definition

Line items represent concepts included in income taxes.

+ References

No definition available.

+ Details

Name:	cm_DisclosureOfIncomeTaxesLineItems
Namespace Prefix:	cm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Global minimum tax percentage.

+ References

No definition available.

+ Details

Name:	cm_GlobalMinimumTaxPercentage
Namespace Prefix:	cm_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Maximum range of estimated consolidated effective tax rate.

+ References

No definition available.

+ Details

Name:	cm_MaximumRangeOfEstimatedConsolidatedEffectiveTaxRate
Namespace Prefix:	cm_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Potential additional income tax on dividend received deduction.

+ References

No definition available.

+ Details

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

X

- Details

Name:	cm_TaxYearAxis=cm_TwoThousandAndNineteenTaxationYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	cm_StatutoryActAxis=cm_OrganizationForEconomicCooperationAndDevelopmentPillarTwoTaxRegimeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: