| Cover Page - USD ($) | 12 Months Ended | ||
| Dec. 31, 2019 | Apr. 20, 2020 | Jun. 30, 2019 | |
| Document Information [Line Items] | |||
| Document Type | 10-K/A | ||
| Document Fiscal Period Focus | FY | ||
| Current Fiscal Year End Date | --12-31 | ||
| Document Fiscal Year Focus | 2019 | ||
| Document Period End Date | Dec. 31, 2019 | ||
| Amendment Flag | true | ||
| Amendment Description | Canadian Pacific Railway Limited, a corporation incorporated under the Canada Business Corporations Act (the “Company”), qualifies as a foreign private issuer in the U.S. for purposes of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Although as a foreign private issuer the Company is not required to do so, the Company currently continues to file annual reports on Form 10-K, quarterly reports on Form 10-Q, and current reports on Form 8-K with the Securities and Exchange Commission (“SEC”) instead of filing the reports available to foreign private issuers. The Company prepares and files a management proxy circular and related material under Canadian requirements. As the Company’s management proxy circular is not filed pursuant to Regulation 14A, the Company may not incorporate by reference information required by Part III of its Form 10-K from its management proxy circular. The Company filed its Annual Report on Form 10-K for the fiscal year ended December 31, 2019 (“2019 Form 10-K”) on February 20, 2020. In reliance upon and as permitted by Instruction G(3) to Form 10-K, the Company is filing this Amendment No. 1 on Form 10-K/A in order to include in the 2019 Form 10-K the Part III information not previously included in the 2019 Form 10-K. No attempt has been made in this Amendment No. 1 on Form 10-K/A to modify or update the other disclosures presented in the 2019 Form 10-K. This Amendment No. 1 on Form 10-K/A does not reflect events occurring after the filing of the 2019 Form 10-K. Accordingly, this Amendment No. 1 on Form 10-K/A should be read in conjunction with the 2019 Form 10-K and the Company’s other filings with the SEC. In this Amendment No. 1 on Form 10-K/A, we also refer to Canadian Pacific Railway Limited as “Canadian Pacific,” “we,” “us,” “our,” “our corporation,” or “the corporation.” References to “GAAP” mean generally accepted accounting principles in the United States. All references to our websites and to our Canadian management proxy circular filed with the SEC on March 19, 2020 as Exhibit 99.1 to our Current Report on Form 8-K (the “Circular”) contained herein do not constitute incorporation by reference of information contained on such websites and the Circular and such information should not be considered part of this document. | ||
| Document Annual Report | true | ||
| Document Transition Report | false | ||
| Entity Registrant Name | CANADIAN PACIFIC RAILWAY LTD/CN | ||
| Entity File Number | 001-01342 | ||
| Entity Central Index Key | 0000016875 | ||
| Entity Tax Identification Number | 98-0355078 | ||
| Entity Address, Address Line One | 7550 Ogden Dale Road S.E. | ||
| Entity Address, City or Town | Calgary | ||
| Entity Address, State or Province | AB | ||
| Entity Incorporation, State or Country Code | Z4 | ||
| Entity Address, Postal Zip Code | T2C 4X9 | ||
| City Area Code | (403) | ||
| Local Phone Number | 319-7000 | ||
| Entity Well-known Seasoned Issuer | Yes | ||
| Entity Voluntary Filers | No | ||
| Entity Current Reporting Status | Yes | ||
| Entity Interactive Data Current | Yes | ||
| Entity Filer Category | Large Accelerated Filer | ||
| Entity Small Business | false | ||
| Entity Emerging Growth Company | false | ||
| Entity Shell Company | false | ||
| Entity Public Float | $ 32,712,064,612 | ||
| Entity Common Stock, Shares Outstanding | 135,631,754 | ||
| Common Shares, without par value | |||
| Document Information [Line Items] | |||
| Title of 12(b) Security | Common Shares, without par value, of Canadian Pacific Railway Limited | ||
| Trading Symbol | CP | ||
| Security Exchange Name | NYSE | ||
| Perpetual 4% Consolidated Debenture Stock | |||
| Document Information [Line Items] | |||
| Title of 12(b) Security | Perpetual 4% Consolidated Debenture Stock of Canadian Pacific Railway Company | ||
| Trading Symbol | CP/40 | ||
| Security Exchange Name | NYSE |
