Contingencies	9 Months Ended
Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Litigation In the normal course of its operations, the Company becomes involved in various legal actions, including claims relating to injuries and damage to property. The Company maintains provisions it considers to be adequate for such actions. While the final outcome with respect to actions outstanding or pending at September 30, 2023 cannot be predicted with certainty, it is the opinion of management that their resolution will not have a material adverse effect on the Company’s business, financial position, results of operations, or liquidity. However, an unexpected adverse resolution of one or more of these legal actions could have a material adverse effect on the Company's business, financial position, results of operations, or liquidity in a particular quarter or fiscal year. Legal proceedings related to Lac-Mégantic rail accident On July 6, 2013, a train carrying petroleum crude oil operated by Montréal Maine and Atlantic Railway (“MMAR”) or a subsidiary, Montréal Maine & Atlantic Canada Co. (“MMAC” and collectively the “MMA Group”), derailed in Lac-Mégantic, Québec. The derailment occurred on a section of railway owned and operated by the MMA Group and while the MMA Group exclusively controlled the train. Following the derailment, MMAC sought court protection in Canada under the Companies’ Creditors Arrangement Act and MMAR filed for bankruptcy in the U.S. Plans of arrangement were approved in both Canada and the U.S. (the “Plans”), providing for the distribution of approximately $440 million amongst those claiming derailment damages. A number of legal proceedings, set out below, were commenced in Canada and the U.S. against the Company and others: (1)Québec's Minister of Sustainable Development, Environment, Wildlife and Parks ordered various parties, including the Company, to remediate the derailment site (the "Cleanup Order") and served the Company with a Notice of Claim for $95 million for those costs. The Company appealed the Cleanup Order and contested the Notice of Claim with the Administrative Tribunal of Québec. These proceedings are stayed pending determination of the Attorney General of Québec (“AGQ”) action (paragraph 2 below). (2)The AGQ sued the Company in the Québec Superior Court claiming $409 million in damages, which was amended and reduced to $315 million (the “AGQ Action”). The AGQ Action alleges that: (i) the Company was responsible for the petroleum crude oil from its point of origin until its delivery to Irving Oil Ltd.; and (ii) the Company is vicariously liable for the acts and omissions of the MMA Group. (3)A class action in the Québec Superior Court on behalf of persons and entities residing in, owning or leasing property in, operating a business in, or physically present in Lac-Mégantic at the time of the derailment was certified against the Company on May 8, 2015 (the "Class Action"). Other defendants including MMAC and Mr. Thomas Harding ("Harding") were added to the Class Action on January 25, 2017. On November 28, 2019, the plaintiffs' motion to discontinue their action against Harding was granted. The Class Action seeks unquantified damages, including for wrongful death, personal injury, property damage, and economic loss. (4)Eight subrogated insurers sued the Company in the Québec Superior Court claiming approximately $16 million in damages, which was amended and reduced to approximately $15 million (the “Promutuel Action”), and two additional subrogated insurers sued the Company claiming approximately $3 million in damages (the “Royal Action”). Both actions contain similar allegations as the AGQ Action. The actions do not identify the subrogated parties. As such, the extent of any overlap between the damages claimed in these actions and under the Plans is unclear. The Royal Action is stayed pending determination of the consolidated proceedings described below. On December 11, 2017, the AGQ Action, the Class Action and the Promutuel Action were consolidated. The joint liability trial of these consolidated claims commenced on September 21, 2021 with oral arguments ending on June 15, 2022. The Québec Superior Court issued a decision on December 14, 2022 dismissing all claims as against the Company, finding that the Company’s actions were not the direct and immediate cause of the accident and the damages suffered by the plaintiffs. All three plaintiffs filed a declaration of appeal on January 13, 2023. A damages trial will follow after the disposition of all appeals, if necessary. (5)Forty-eight plaintiffs (all individual claims joined in one action) sued the Company, MMAC, and Harding in the Québec Superior Court claiming approximately $5 million in damages for economic loss and pain and suffering, and asserting similar allegations as in the Class Action and the AGQ Action. The majority of the plaintiffs opted-out of the Class Action and all but two are also plaintiffs in litigation against the Company, described in paragraph 7 below. This action is stayed pending determination of the consolidated claims described above. (6)The MMAR U.S. bankruptcy estate representative commenced an action against the Company in November 2014 in the Maine Bankruptcy Court claiming that the Company failed to abide by certain regulations and seeking approximately U.S. $30 million in damages for MMAR’s loss in business value according to a recent expert report filed by the bankruptcy estate. This action asserts that the Company knew or ought to have known that the shipper misclassified the petroleum crude oil and therefore should have refused to transport it. Summary judgment motion was argued and taken under advisement on June 9, 2022, and decision is pending. On May 23, 2023, the case management judge stayed the proceedings pending the outcome of the appeal in the Canadian consolidated claims. (7)The class and mass tort action commenced against the Company in June 2015 in Texas (on behalf of Lac-Mégantic residents and wrongful death representatives) and the wrongful death and personal injury actions commenced against the Company in June 2015 in Illinois and Maine, were all transferred and consolidated in Federal District Court in Maine (the “Maine Actions”). The Maine Actions allege that the Company negligently misclassified and improperly packaged the petroleum crude oil. On the Company’s motion, the Maine Actions were dismissed. The plaintiffs appealed the dismissal decision to the United States First Circuit Court of Appeals, which dismissed the plaintiffs' appeal on June 2, 2021. The plaintiffs further petitioned the United States First Circuit Court of Appeals for a rehearing, which was denied on September 8, 2021. On January 24, 2022, the plaintiffs further appealed to the U.S. Supreme Court on two bankruptcy procedural grounds. On May 31, 2022, the U.S. Supreme Court denied the petition, thereby rejecting the plaintiffs' appeal. (8)The trustee for the wrongful death trust commenced Carmack Amendment claims against the Company in North Dakota Federal Court, seeking to recover approximately U.S. $6 million for damaged rail cars and lost crude oil and reimbursement for the settlement paid by the consignor and the consignee under the Plans (alleged to be U.S. $110 million and U.S. $60 million, respectively). The Court issued an Order on August 6, 2020 granting and denying in parts the parties' summary judgment motions which has been reviewed and confirmed following motions by the parties for clarification and reconsideration. Final briefs of dispositive motions for summary judgment and for reconsideration on tariff applicability were submitted on September 30, 2022. On January 20, 2023, the Court granted in part the Company's summary judgment motion by dismissing all claims for recovery of settlement payments but leaving for trial the determination of the value of the lost crude oil. It also dismissed the Company's motion for reconsideration on tariff applicability. The remaining issues of the value of the lost crude oil and applicability of judgement reduction provisions do not require trial, and have been fully briefed. Decision is pending. At this stage of the proceedings, any potential responsibility and the quantum of potential losses cannot be determined. Nevertheless, the Company denies liability and is vigorously defending these proceedings. Court decision related to Remington Development Corporation legal claim On October 20, 2022, the Court of King’s Bench of Alberta issued a decision in a claim brought by Remington Development Corporation (“Remington”) against the Company and the Province of Alberta (“Alberta”) with respect to an alleged breach of contract by the Company in relation to the sale of certain properties in Calgary. In its decision, the Court found the Company had breached its contract with Remington and Alberta had induced the contract breach. The Court found the Company and Alberta liable for damages of approximately $164 million plus interest and costs, and subject to an adjustment to the acquisition value of the property. In a further decision on August 30, 2023, the Court determined that adjustment and set the total damages at $165 million plus interest and costs. On October 20, 2023, the Court determined the costs payable to Remington, however, the Court has not provided any indication of how the damages, which are currently estimated to total approximately $215 million, should be apportioned between the Company and Alberta. As a result, at this time, the Company cannot reasonably estimate the amount of damages for which it is liable under the ruling of the Court. The Company has filed an appeal of the Court’s decision. 2014 Tax Assessment On April 13, 2022, the SAT issued an assessment to CPKCM, a wholly-owned subsidiary of the Company, for Ps.5,525 million ($424 million) for the fiscal year 2014, which included inflation, interest, and penalties. On July 7, 2022, CPKCM filed with the SAT an administrative challenge (recurso de revocación) against the assessment. On September 26, 2022, the SAT withdrew the administrative challenge. On November 10, 2022, CPKCM filed an administrative lawsuit against the withdrawal of the administrative challenge. As part of the lawsuit, CPKCM asked the Court for an injunction to avoid the collection by the SAT of the 2014 assessment. On December 7, 2022, the Administrative Court admitted the annulment lawsuit filed by CPKCM. On February 10, 2023, the SAT filed its response to the lawsuit. On March 15, 2023, the lawsuit was opened to the evidentiary stage. On September 30, 2023, the evidentiary stage was closed. On October 19, 2023, CPKCM filed their final arguments with the Court. The SAT had until October 23, 2023, to file their final arguments to the Court. A resolution from the Administrative Court is expected by the first quarter of 2024. The decision from the Administrative Court may be appealed by CPKCM or the SAT. Environmental liabilities Environmental remediation accruals, recorded on an undiscounted basis unless a reliable, determinable estimate as to an amount and timing of costs can be established, cover site-specific remediation programs. The accruals for environmental remediation represent the Company’s best estimate of its probable future obligation and include both asserted and unasserted claims, without reduction for anticipated recoveries from third parties. Although the recorded accruals include the Company’s best estimate of all probable costs, the Company’s total environmental remediation costs cannot be predicted with certainty. Accruals for environmental remediation may change from time to time as new information about previously untested sites becomes known, and as environmental laws and regulations evolve and advances are made in environmental remediation technology. The accruals may also vary as the courts decide legal proceedings against outside parties responsible for contamination. These potential charges, which cannot be quantified at this time, may materially affect income in the particular period in which a charge is recognized. Costs related to existing, but as yet unknown, or future contamination will be accrued in the period in which they become probable and reasonably estimable. The expense included in “Purchased services and other” in the Company's Interim Consolidated Statements of Income for the three and nine months ended September 30, 2023 was $2 million and $6 million, respectively (three and nine months ended September 30, 2022 - $1 million and $5 million, respectively). Provisions for environmental remediation costs are recorded in the Company's Interim Consolidated Balance Sheets in “Other long-term liabilities”, except for the current portion, which is recorded in “Accounts payable and accrued liabilities”. The total amount provided as at September 30, 2023 was $231 million (December 31, 2022 - $83 million) including liabilities recognized with the acquisition of KCS. Payments are expected to be made over 10 years through 2032. 2023 Business Interruption Insurance Settlement During the third quarter of 2023, the Company realized gain contingencies of $51 million recorded to "Purchased services and other", as a result of settlements reached with insurers for business interruption losses incurred by the Company related to wildfires and floods in B.C.in 2021.

In the normal course of its operations, the Company becomes involved in various legal actions, including claims relating to injuries and damage to property. The Company maintains provisions it considers to be adequate for such actions. While the final outcome with respect to actions outstanding or pending at September 30, 2023 cannot be predicted with certainty, it is the opinion of management that their resolution will not have a material adverse effect on the Company’s business, financial position, results of operations, or liquidity. However, an unexpected adverse resolution of one or more of these legal actions could have a material adverse effect on the Company's business, financial position, results of operations, or liquidity in a particular quarter or fiscal year.

On July 6, 2013, a train carrying petroleum crude oil operated by Montréal Maine and Atlantic Railway (“MMAR”) or a subsidiary, Montréal Maine & Atlantic Canada Co. (“MMAC” and collectively the “MMA Group”), derailed in Lac-Mégantic, Québec. The derailment occurred on a section of railway owned and operated by the MMA Group and while the MMA Group exclusively controlled the train.

Following the derailment, MMAC sought court protection in Canada under the Companies’ Creditors Arrangement Act and MMAR filed for bankruptcy in the U.S. Plans of arrangement were approved in both Canada and the U.S. (the “Plans”), providing for the distribution of approximately $440 million amongst those claiming derailment damages.

(1)Québec's Minister of Sustainable Development, Environment, Wildlife and Parks ordered various parties, including the Company, to remediate the derailment site (the "Cleanup Order") and served the Company with a Notice of Claim for $95 million for those costs. The Company appealed the Cleanup Order and contested the Notice of Claim with the Administrative Tribunal of Québec. These proceedings are stayed pending determination of the Attorney General of Québec (“AGQ”) action (paragraph 2 below).

(2)The AGQ sued the Company in the Québec Superior Court claiming $409 million in damages, which was amended and reduced to $315 million (the “AGQ Action”). The AGQ Action alleges that: (i) the Company was responsible for the petroleum crude oil from its point of origin until its delivery to Irving Oil Ltd.; and (ii) the Company is vicariously liable for the acts and omissions of the MMA Group.

(3)A class action in the Québec Superior Court on behalf of persons and entities residing in, owning or leasing property in, operating a business in, or physically present in Lac-Mégantic at the time of the derailment was certified against the Company on May 8, 2015 (the "Class Action"). Other defendants including MMAC and Mr. Thomas Harding ("Harding") were added to the Class Action on January 25, 2017. On November 28, 2019, the plaintiffs' motion to discontinue their action against Harding was granted. The Class Action seeks unquantified damages, including for wrongful death, personal injury, property damage, and economic loss.

(4)Eight subrogated insurers sued the Company in the Québec Superior Court claiming approximately $16 million in damages, which was amended and reduced to approximately $15 million (the “Promutuel Action”), and two additional subrogated insurers sued the Company claiming approximately $3 million in damages (the “Royal Action”). Both actions contain similar allegations as the AGQ Action. The actions do not identify the subrogated parties. As such, the extent of any overlap between the damages claimed in these actions and under the Plans is unclear. The Royal Action is stayed pending determination of the consolidated proceedings described below.

On December 11, 2017, the AGQ Action, the Class Action and the Promutuel Action were consolidated. The joint liability trial of these consolidated claims commenced on September 21, 2021 with oral arguments ending on June 15, 2022. The Québec Superior Court issued a decision on December 14, 2022 dismissing all claims as against the Company, finding that the Company’s actions were not the direct and immediate cause of the accident and the damages suffered by the plaintiffs. All three plaintiffs filed a declaration of appeal on January 13, 2023. A damages trial will follow after the disposition of all appeals, if necessary.

(5)Forty-eight plaintiffs (all individual claims joined in one action) sued the Company, MMAC, and Harding in the Québec Superior Court claiming approximately $5 million in damages for economic loss and pain and suffering, and asserting similar allegations as in the Class Action and the AGQ Action. The majority of the plaintiffs opted-out of the Class Action and all but two are also plaintiffs in litigation against the Company, described in paragraph 7 below. This action is stayed pending determination of the consolidated claims described above.

(6)The MMAR U.S. bankruptcy estate representative commenced an action against the Company in November 2014 in the Maine Bankruptcy Court claiming that the Company failed to abide by certain regulations and seeking approximately U.S. $30 million in damages for MMAR’s loss in business value according to a recent expert report filed by the bankruptcy estate. This action asserts that the Company knew or ought to have known that the shipper misclassified the petroleum crude oil and therefore should have refused to transport it. Summary judgment motion was argued and taken under advisement on June 9, 2022, and decision is pending. On May 23, 2023, the case management judge stayed the proceedings pending the outcome of the appeal in the Canadian consolidated claims.

(7)The class and mass tort action commenced against the Company in June 2015 in Texas (on behalf of Lac-Mégantic residents and wrongful death representatives) and the wrongful death and personal injury actions commenced against the Company in June 2015 in Illinois and Maine, were all transferred and consolidated in Federal District Court in Maine (the “Maine Actions”). The Maine Actions allege that the Company negligently misclassified and improperly packaged the petroleum crude oil. On the Company’s motion, the Maine Actions were dismissed. The plaintiffs appealed the dismissal decision to the United States First Circuit Court of Appeals, which dismissed the plaintiffs' appeal on June 2, 2021. The

plaintiffs further petitioned the United States First Circuit Court of Appeals for a rehearing, which was denied on September 8, 2021. On January 24, 2022, the plaintiffs further appealed to the U.S. Supreme Court on two bankruptcy procedural grounds. On May 31, 2022, the U.S. Supreme Court denied the petition, thereby rejecting the plaintiffs' appeal.

(8)The trustee for the wrongful death trust commenced Carmack Amendment claims against the Company in North Dakota Federal Court, seeking to recover approximately U.S. $6 million for damaged rail cars and lost crude oil and reimbursement for the settlement paid by the consignor and the consignee under the Plans (alleged to be U.S. $110 million and U.S. $60 million, respectively). The Court issued an Order on August 6, 2020 granting and denying in parts the parties' summary judgment motions which has been reviewed and confirmed following motions by the parties for clarification and reconsideration. Final briefs of dispositive motions for summary judgment and for reconsideration on tariff applicability were submitted on September 30, 2022. On January 20, 2023, the Court granted in part the Company's summary judgment motion by dismissing all claims for recovery of settlement payments but leaving for trial the determination of the value of the lost crude oil. It also dismissed the Company's motion for reconsideration on tariff applicability. The remaining issues of the value of the lost crude oil and applicability of judgement reduction provisions do not require trial, and have been fully briefed. Decision is pending.

On October 20, 2022, the Court of King’s Bench of Alberta issued a decision in a claim brought by Remington Development Corporation (“Remington”) against the Company and the Province of Alberta (“Alberta”) with respect to an alleged breach of contract by the Company in relation to the sale of certain properties in Calgary. In its decision, the Court found the Company had breached its contract with Remington and Alberta had induced the contract breach. The Court found the Company and Alberta liable for damages of approximately $164 million plus interest and costs, and subject to an adjustment to the acquisition value of the property. In a further decision on August 30, 2023, the Court determined that adjustment and set the total damages at $165 million plus interest and costs. On October 20, 2023, the Court determined the costs payable to Remington, however, the Court has not provided any indication of how the damages, which are currently estimated to total approximately $215 million, should be apportioned between the Company and Alberta. As a result, at this time, the Company cannot reasonably estimate the amount of damages for which it is liable under the ruling of the Court. The Company has filed an appeal of the Court’s decision.

On April 13, 2022, the SAT issued an assessment to CPKCM, a wholly-owned subsidiary of the Company, for Ps.5,525 million ($424 million) for the fiscal year 2014, which included inflation, interest, and penalties. On July 7, 2022, CPKCM filed with the SAT an administrative challenge (recurso de revocación) against the assessment. On September 26, 2022, the SAT withdrew the administrative challenge. On November 10, 2022, CPKCM filed an administrative lawsuit against the withdrawal of the administrative challenge. As part of the lawsuit, CPKCM asked the Court for an injunction to avoid the collection by the SAT of the 2014 assessment. On December 7, 2022, the Administrative Court admitted the annulment lawsuit filed by CPKCM. On February 10, 2023, the SAT filed its response to the lawsuit. On March 15, 2023, the lawsuit was opened to the evidentiary stage. On September 30, 2023, the evidentiary stage was closed. On October 19, 2023, CPKCM filed their final arguments with the Court. The SAT had until October 23, 2023, to file their final arguments to the Court. A resolution from the Administrative Court is expected by the first quarter of 2024. The decision from the Administrative Court may be appealed by CPKCM or the SAT.

The accruals for environmental remediation represent the Company’s best estimate of its probable future obligation and include both asserted and unasserted claims, without reduction for anticipated recoveries from third parties. Although the recorded accruals include the Company’s best estimate of all probable costs, the Company’s total environmental remediation costs cannot be predicted with certainty. Accruals for environmental remediation may change from time to time as new information about previously untested sites becomes known, and as environmental laws and regulations evolve and advances are made in environmental remediation technology. The accruals may also vary as the courts decide legal proceedings against outside parties responsible for contamination. These potential charges, which cannot be quantified at this time, may materially affect income in the particular period in which a charge is recognized. Costs related to existing, but as yet unknown, or future contamination will be accrued in the period in which they become probable and reasonably estimable.

The expense included in “Purchased services and other” in the Company's Interim Consolidated Statements of Income for the three and nine months ended September 30, 2023 was $2 million and $6 million, respectively (three and nine months ended September 30, 2022 - $1 million and $5 million, respectively). Provisions for environmental remediation costs are recorded in the Company's Interim Consolidated Balance Sheets in “Other long-term liabilities”, except for the current portion, which is recorded in “Accounts payable and accrued liabilities”. The total amount provided as at September 30, 2023 was $231 million (December 31, 2022 - $83 million) including liabilities recognized with the acquisition of KCS. Payments are expected to be made over 10 years through 2032.