Properties - Narrative (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Government assistance, amount	$ 26	$ 25
Property balance	56,024	51,744
Government assistance, unamortized amount	272	272
Amortization expense related to government assistance	$ 10	$ 11
Government Assistance, Income, Increase (Decrease), Statement of Income or Comprehensive Income [Extensible Enumeration]	Property balance	Property balance

Government Assistance, Amortization Expense

No definition available.

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

- Definition

Government Assistance Unamortized Amount

+ References

No definition available.

+ Details

Name:	cp_GovernmentAssistanceUnamortizedAmount
Namespace Prefix:	cp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of increase (decrease) in income from government assistance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483507/832-10-50-3

+ Details

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

- Definition

Indicates line item in statement of income or comprehensive income that includes increase (decrease) in income from government assistance.

+ References

+ Details

Name:	us-gaap_GovernmentAssistanceStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration
Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Amount, after accumulated depreciation and amortization, of property, plant, and equipment and finance lease right-of-use asset.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-SubTopic 20
-Topic 842
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-4

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant