Business Acquisition	9 Months Ended
Business Acquisition	Sep. 30, 2022
Business Combinations [Abstract]
Business Acquisition	Business acquisition Kansas City Southern The Company accounts for its investment in KCS using the equity method of accounting while the U.S. Surface Transportation Board ("STB") considers the Company's application to control KCS. The STB review of CP's proposed control of KCS while KCS is in the voting trust is expected to be completed in the first quarter of 2023. The investment in KCS of $45,964 million as at September 30, 2022 includes $627 million of equity earnings of KCS and foreign currency translation of $3,445 million, offset by dividends of $593 million received in the nine months ended September 30, 2022. Included within the $221 million and $627 million of equity earnings of KCS recognized for the three and nine months ended September 30, 2022 was amortization (net of tax), of the approximately $30 billion basis difference, representing the difference in value between the consideration paid to acquire KCS and the underlying carrying value of the net assets of KCS as at December 14, 2021, immediately prior to the acquisition by CP. The amortization (net of tax), recognized for the three and nine months ended September 30, 2022 was $42 million and $121 million, respectively. The basis difference is related to depreciable property, plant and equipment, intangible assets with definite lives, and long-term debt, and is amortized over the related assets' remaining useful lives, and the remaining terms to maturity of the debt instruments. During the three and nine months ended September 30, 2022, the Company incurred $18 million and $57 million, in acquisition-related costs, respectively, recorded within "Purchased services and other" in the Company's Interim Consolidated Statements of Income. Acquisition-related costs of $12 million and $39 million incurred by KCS during the three and nine months ended September 30, 2022 are included within "Equity earnings of Kansas City Southern" in the Company's Interim Consolidated Statements of Income. During the three and nine months ended September 30, 2021, the Company incurred $98 million and $442 million, respectively, in acquisition-related costs associated with the Original Merger Agreement and Merger Agreement, of which $15 million and $147 million were recorded within "Purchased services and other" and $83 million and $295 million were recorded within "Other expense", respectively, including the amortization of financing fees associated with new credit facilities. Total financing fees paid for a bridge facility associated with the KCS acquisition during the three and nine months ended September 30, 2021 were $nil and $45 million, respectively, presented under "Cash (used in) provided by financing activities" in the Company's Interim Consolidated Statements of Cash Flows. On May 21, 2021, KCS terminated the Original Merger Agreement entered into on March 21, 2021 with CP to enter into a definitive agreement with Canadian National Railway ("CN"). At the same time and in accordance with the terms of the Original Merger Agreement, KCS paid CP a termination fee of $845 million (U.S. $700 million). This amount is reported as "Merger termination fee" in the Company's Interim Consolidated Statements of Income for the nine months ended September 30, 2021. No similar items were received in the same period of 2022. In connection with the Merger Agreement, the Company remitted $1,773 million (U.S. $1,400 million) to KCS on September 15, 2021 in connection with KCS's payment of the CN merger termination fees, recorded within "Investment in KCS" in the Company's Balance Sheets.