Amount of fund to be distributed to those claiming derailment damages.

No definition available.

Name:	cp_AmountofFundtobeDistributed
Namespace Prefix:	cp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Income Tax Examination, Number of Motions Submitted

+ References

No definition available.

+ Details

Name:	cp_IncomeTaxExaminationNumberOfMotionsSubmitted
Namespace Prefix:	cp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Loss Contingency, Appeals, Number of Bankruptcy Procedural Grounds

+ References

No definition available.

+ Details

Name:	cp_LossContingencyAppealsNumberOfBankruptcyProceduralGrounds
Namespace Prefix:	cp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Loss Contingency, Damages Sought Previously, Value

+ References

No definition available.

+ Details

Name:	cp_LossContingencyDamagesSoughtPreviouslyValue
Namespace Prefix:	cp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Loss Contingency, Number of Opted-Out Plaintiffs Opted-Out

+ References

No definition available.

+ Details

Name:	cp_LossContingencyNumberOfOptedOutPlaintiffsOptedOut
Namespace Prefix:	cp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Loss Contingency, Total Estimated Damages, Value

+ References

No definition available.

+ Details

Name:	cp_LossContingencyTotalEstimatedDamagesValue
Namespace Prefix:	cp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of gain recognized in the period that had been disclosed in prior periods as a contingent gain.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483049/450-30-50-1

+ Details

Name:	us-gaap_FormerGainContingencyRecognizedInCurrentPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Estimated amount of loss resulting from an adverse tax position.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15

+ Details

Name:	us-gaap_IncomeTaxExaminationEstimateOfPossibleLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitment.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermPurchaseCommitmentAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of damages awarded to the plaintiff in the legal matter.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-4

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-9

+ Details

Name:	us-gaap_LossContingencyDamagesAwardedValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

+ References

+ Details

Name:	us-gaap_LossContingencyDamagesSoughtValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of plaintiffs that have filed claims pertaining to a loss contingency.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-4

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-9

+ Details

Name:	us-gaap_LossContingencyNumberOfPlaintiffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of pending claims pertaining to a loss contingency.

+ References

+ Details

Name:	us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_OtherCommitmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_GainContingenciesByNatureAxis=cp_LyttonBCWildfireBCFraserCanyonFloodingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=us-gaap_ForeignCountryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityNameAxis=us-gaap_MexicanTaxAuthorityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxPeriodAxis=us-gaap_TaxYear2014Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=cp_TheWDTrusteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=cp_LacMeganticRailAccidentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=cp_ClaimedLossorDamagesDuetoDerailmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=cp_QuebecMinisterofSustainableDevelopmentandEnvironmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=cp_QuebecAttorneyGeneralMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=cp_InitialInsurerClaimantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=cp_SubrogatedInsuranceClaimMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=cp_AdditionalInsurerClaimantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=cp_PlaintiffMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=cp_MMARMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=cp_DamagesforlossinbusinessvalueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=cp_LadingLossRecoveryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=cp_ReimbursementforsettlementpaidbyconsignorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=cp_ReimbursementforsettlementpaidbyconsigneeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_LitigationCaseAxis=cp_RemingtonDevelopmentCorporationLegalClaimMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=cp_RemingtonDevelopmentCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=cp_BreachOfContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_CapitalAdditionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=cp_OperatingExpendituresMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments and contingencies (Details) $ in Millions, $ in Millions, $ in Millions								12 Months Ended
	Aug. 15, 2024 motion	Jan. 05, 2024 USD ($)	Oct. 20, 2023 CAD ($)	Aug. 30, 2023 CAD ($)	Jan. 13, 2023 plaintiff	Oct. 20, 2022 CAD ($)	Jan. 24, 2022 procedural_ground	Dec. 31, 2024 CAD ($) claim plaintiff	Dec. 31, 2024 USD ($) claim plaintiff	Dec. 31, 2024 MXN ($) claim plaintiff	Sep. 30, 2024 CAD ($)
Lytton B.C wildfire & B.C Fraser canyon flooding
Commitments and Contingencies [Line Items]
Former gain contingency, recognized in current period											$ 51
Foreign Tax Jurisdiction \| Mexican Tax Authority \| Tax Year 2014
Commitments and Contingencies [Line Items]
Income tax examination, estimate of possible loss								$ 448		$ 6,313
Income tax examination, number of motions submitted \| motion	2
WD Trustee
Commitments and Contingencies [Line Items]
Damages awarded, value		$ 3.9
Lac-Megantic Rail Accident
Commitments and Contingencies [Line Items]
Number of plaintiffs \| plaintiff					3
Lac-Megantic Rail Accident \| Claimed damages as a result of derailment
Commitments and Contingencies [Line Items]
Amount to be distributed								440
Lac-Megantic Rail Accident \| Quebec Minister of Sustainable Development, Environment, Wildlife and Parks
Commitments and Contingencies [Line Items]
Value of damages sought								95
Lac-Megantic Rail Accident \| Attorney General of Quebec
Commitments and Contingencies [Line Items]
Value of damages sought								231
Value of damages previously sought								409
Lac-Megantic Rail Accident \| Initial Subrogated Insurers \| Subrogated insurance claim
Commitments and Contingencies [Line Items]
Value of damages sought								14
Value of damages previously sought								$ 16
Number of subrogated insurer claims \| claim								8	8	8
Lac-Megantic Rail Accident \| Additional Subrogated Insurers \| Subrogated insurance claim
Commitments and Contingencies [Line Items]
Value of damages sought								$ 3
Number of subrogated insurer claims \| claim								2	2	2
Lac-Megantic Rail Accident \| Class Action Plaintiffs
Commitments and Contingencies [Line Items]
Value of damages sought								$ 5
Number of plaintiffs \| plaintiff								48	48	48
Number of plaintiffs who opted out \| plaintiff								2	2	2
Number of bankruptcy procedural grounds \| procedural_ground							2
Lac-Megantic Rail Accident \| MMAR Estate Representative \| Damages for loss in business value
Commitments and Contingencies [Line Items]
Value of damages sought									$ 30.0
Lac-Megantic Rail Accident \| WD Trustee \| Damaged railcars and lost crude recovery
Commitments and Contingencies [Line Items]
Value of damages sought									6.0
Lac-Megantic Rail Accident \| WD Trustee \| Reimbursement for settlement paid by consignor
Commitments and Contingencies [Line Items]
Value of damages sought									110.0
Lac-Megantic Rail Accident \| WD Trustee \| Reimbursement for settlement paid by consignee
Commitments and Contingencies [Line Items]
Value of damages sought									$ 60.0
Remington Development Corporation legal claim \| Remington Development Corporation \| Breach of contract
Commitments and Contingencies [Line Items]
Damages awarded, value				$ 165		$ 164
Total estimated damages, value			$ 228
Capital Expenditures
Commitments and Contingencies [Line Items]
Future committed expenditures								$ 2,500
Operating Expenditures
Commitments and Contingencies [Line Items]
Future committed expenditures								$ 3,915