Contingencies	6 Months Ended
Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies 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 June 30, 2016 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 financial position or results of operations. Legal proceedings related to Lac-Mégantic rail accident On July 6, 2013, a train carrying crude oil operated by Montreal Maine and Atlantic Railway (“MMA”) and/or its subsidiary, Montreal Maine and Atlantic Canada Co. (“MMAC”, and collectively with MMA, the “MMA Group”) derailed and exploded in Lac-Mégantic, Quebec on a section of railway line owned by the MMA Group. The previous day CP had interchanged the train to the MMA Group, and after that interchange MMA Group exercised exclusive control over the train. Following this incident, the Minister of Sustainable Development, Environment, Wildlife and Parks of Quebec issued an order directing certain named parties to recover the contaminants and to clean up and decontaminate the derailment site. CP was added as a named party on August 14, 2013 (the “Amended Cleanup Order”). CP has sought an administrative appeal of the Amended Cleanup Order to the Administrative Tribunal of Quebec. The proceedings before the Administrative tribunal have been stayed until September 2016. Directly related to this matter, the Province of Quebec filed a lawsuit against CP before the Quebec Superior Court on July 6, 2015 in which it claims $409 million for the damages sustained by the province as a result of the expenses incurred following the derailment, including costs incurred for the work carried out pursuant to the Amended Cleanup Order. The province alleges that CP had custody or control of the contaminants that were discharged in Lac-Mégantic on July 6, 2013, and that CP was otherwise negligent and therefore is solidarily (joint and severally) liable with the other third parties responsible for the accident. The province’s lawsuit has been stayed until September 12, 2016. Also directly related to the this matter, the Quebec Minister of Sustainable Development and Environment has served a Notice of Claim on July 5, 2016 claiming nearly $95 million in compensation from CP for having to carry out the cleanup measures set out in the Amended Cleanup Order, alleging that CP had refused or neglected to carry out same. These proceedings are duplicative, in whole or in part. A class action lawsuit has also been filed in the Superior Court of Quebec on behalf of a class of persons and entities residing in, owning or leasing property in, operating a business in or physically present in Lac-Mégantic (the “Class Action”). The lawsuit seeks damages caused by the derailment including for wrongful deaths, personal injuries, and property damages. CP was added as a defendant on August 16, 2013. On May 8, 2015, the Superior Court of Quebec authorized the institution of the Class Action as against CP and as against the shipper, Western Petroleum, and the shipper’s parent, World Fuel Services (collectively, the “World Fuel Defendants”). The World Fuel Defendants have since settled. No timetable governing the conduct of this lawsuit has been ordered by the Superior Court of Quebec. On July 4, 2016, CP was served with subrogated insurance claims brought by 8 insurers for a claimed amount of approximately $16 million. On July 11, 2016, CP was served with subrogated insurance claims brought by an additional 2 insurers for a claimed amount of approximately $3 million. These insurers have not identified in their respective lawsuit the identity of the parties to whose claims they are subrogated and thus it is difficult to determine the extent to which these claims overlap with other claims and the extent to which their claim would be satisfied after their proof of claim has been reviewed and distribution is received from the Plans of arrangements referred to below. In the wake of the derailment and ensuing litigation, MMAC filed for bankruptcy in Canada (the “Canadian Proceeding”) and MMA filed for bankruptcy in the United States (the “U.S. Proceeding”). Plans of arrangement have been approved both in the Canadian Proceeding and the U.S. Proceeding (the “Plans”). These Plans provide for the distribution of a fund of approximately $440 million amongst those who claimed loss or damage as a result of the derailment and will release those parties which contributed to the fund from any further liability. The Plans also provide for broadly worded third-party releases and injunctions that prevent actions against settling parties. CP has not participated in the settlement and hence will not benefit from any third-party releases or injunctions. In addition, both Plans contain judgment reduction provisions. Pursuant to these provisions, in the event of a judgment against CP in a case arising from the Lac-Mégantic derailment, CP will receive a credit for the greater of (i) the settlement monies received by the plaintiff(s) for the claim, or (ii) the amount which, but for the third-party non-debtor injunctions, CP would have been entitled to obtain from third parties other than MMA and MMAC through contribution or indemnification. CP may also have rights to judgment reduction, as part of the contribution/indemnification credit, for the fault of MMA and/or MMAC. The provisions of the Plans also provide for a potential re-allocation of of the MMA Group’s liability among plaintiffs and CP, the only non-settling party. An Adversary Proceeding filed by the MMA U.S. bankruptcy trustee against CP, Irving Oil and the World Fuel Defendants accuses CP of failing to ensure that World Fuel Defendants or Irving Oil properly classified the oil lading and of not refusing to ship the oil in DOT-111 tank cars. The trustee has since settled with the World Fuel Defendants and Irving Oil and now maintains that CP misfeasance is based upon the railroad’s failure to abide by a Canadian regulation in North Dakota that supposedly would have caused the originating railroad to refuse to carry the crude oil based upon reason to suspect inaccurate classification. In response to CP’s motion to withdraw the Adversary Proceedings from the bankruptcy reference, the trustee maintained that Canadian law rather than U.S. law controlled, and the Article III court found that if the federal regulations governed, the case was not complex enough to warrant withdrawal. In bankruptcy court CP moved to dismiss for want of personal jurisdiction, but that motion, which was heard on August 18, 2015, has been denied. Motions to dismiss on procedural grounds are pending. The trustee recently withdrew objection to the trial of the Adversary Proceedings to a jury before the Article III district court. There are also a class action and a mass action instituted Texas and wrongful death and personal injury actions instituted in Illinois and Maine. All the various lawsuits have been removed to federal court and have since been consolidated in Maine. These actions generally charge CP with negligence in the misclassification and mis-packaging (that is the use of inappropriate DOT-111 tank cars). Motions to dismiss have been filed and heard regarding jurisdiction and venue. Decisions on CP’s motions and other parties’ cross-motions are pending. CP has received two damage to cargo notices of claims from the shipper of the oil on the derailed train, Western Petroleum. Western Petroleum submitted U.S. and Canadian notices of claims for the same damages and, under the Carmack Amendment (49 U.S.C. Section 11706), seeks to recover for all injuries associated with, and indemnification for the derailment. Both jurisdictions permit a shipper to recover the value of damaged lading against any carrier in the delivery chain, subject to limitations in the carrier’s tariffs. CP’s tariffs significantly restrict shipper damage claim rights. Western Petroleum is part of the World Fuel Services group, and those entities settled with the trustee. On April 12, 2016, Trustee (the “WD Trustee”) of a wrongful death trust (the “WD Trust”), as defined and established under the confirmed Plan, filed an action against CP in federal court in North Dakota seeking to establish Carmack Amendment liability under 49 U.S.C. Section 11706. The WD Trustee asserts the WD Trust was assigned Carmack claim rights by the bankruptcy estate representative. The parties that settled Lac Megantic derailment liability in connection with MMA’s confirmed Plan supposedly gave the bankruptcy estate representative the right to assign Carmack claims. The WD Trustee seeks to recover losses associated with the lost lading (approximately $6 million), as well as settlement amounts the consignor (i.e, the shipper, World Fuel Entities) and the consignee (Irving Oil) paid to the MMA bankruptcy estate to settle all Lac Megantic derailment claims, which are alleged to be $110 million and $60 million respectively. The WD Trustee maintains that Carmack liability extends beyond lading losses to cover all derailment related damages incurred by the World Fuel Services group or Irving Oil. CP disputes this interpretation of damages to lading law and maintains that CP’s tariffs, if applicable, would preclude such a result. At this early stage of the legal proceedings, any potential liability and the quantum of potential loss cannot be determined. Nevertheless, CP denies liability for the MMA derailment and intends to vigorously defend itself in the proceedings described above and in any proceeding that may be commenced in the future. Legal proceedings initiated by Canadian National Railway Company On August 13, 2015, Canadian National Railway Company (“CN”) issued a statement of claim against the Company and an employee. The statement of claim was amended on January 7, 2016 to include an additional employee and an officer of the Company. The principal allegations against the Company are that the Company obtained and benefited from certain confidential CN customer data. CN is seeking damages but has not yet provided evidence to substantiate its damages claim. The Company plans to defend this claim and the amount of loss, if any, to the Company as a result of the claim cannot be reasonably estimated. 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 CP’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 CP’s best estimate of all probable costs, CP’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, are not expected to be material to CP’s financial position, but 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” for the three and six months ended June 30, 2016 was $1 million and $2 million, respectively (three and six months ended June 30, 2015 - $3 million and $6 million, respectively). Provisions for environmental remediation costs are recorded in “Other long-term liabilities”, except for the current portion which is recorded in “Accounts payable and accrued liabilities”. The total amount provided at June 30, 2016 was $86 million (December 31, 2015 - $93 million). Payments are expected to be made over 10 years through 2026.

Contingencies

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 June 30, 2016 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 financial position or results of operations.

Legal proceedings related to Lac-Mégantic rail accident

On July 6, 2013, a train carrying crude oil operated by Montreal Maine and Atlantic Railway (“MMA”) and/or its subsidiary, Montreal Maine and Atlantic Canada Co. (“MMAC”, and collectively with MMA, the “MMA Group”) derailed and exploded in Lac-Mégantic, Quebec on a section of railway line owned by the MMA Group. The previous day CP had interchanged the train to the MMA Group, and after that interchange MMA Group exercised exclusive control over the train.

Following this incident, the Minister of Sustainable Development, Environment, Wildlife and Parks of Quebec issued an order directing certain named parties to recover the contaminants and to clean up and decontaminate the derailment site. CP was added as a named party on August 14, 2013 (the “Amended Cleanup Order”). CP has sought an administrative appeal of the Amended Cleanup Order to the Administrative Tribunal of Quebec. The proceedings before the Administrative tribunal have been stayed until September 2016. Directly related to this matter, the Province of Quebec filed a lawsuit against CP before the Quebec Superior Court on July 6, 2015 in which it claims $409 million for the damages sustained by the province as a result of the expenses incurred following the derailment, including costs incurred for the work carried out pursuant to the Amended Cleanup Order. The province alleges that CP had custody or control of the contaminants that were discharged in Lac-Mégantic on July 6, 2013, and that CP was otherwise negligent and therefore is solidarily (joint and severally) liable with the other third parties responsible for the accident. The province’s lawsuit has been stayed until September 12, 2016. Also directly related to the this matter, the Quebec Minister of Sustainable Development and Environment has served a Notice of Claim on July 5, 2016 claiming nearly $95 million in compensation from CP for having to carry out the cleanup measures set out in the Amended Cleanup Order, alleging that CP had refused or neglected to carry out same. These proceedings are duplicative, in whole or in part.

A class action lawsuit has also been filed in the Superior Court of Quebec on behalf of a class of persons and entities residing in, owning or leasing property in, operating a business in or physically present in Lac-Mégantic (the “Class Action”). The lawsuit seeks damages caused by the derailment including for wrongful deaths, personal injuries, and property damages. CP was added as a defendant on August 16, 2013. On May 8, 2015, the Superior Court of Quebec authorized the institution of the Class Action as against CP and as against the shipper, Western Petroleum, and the shipper’s parent, World Fuel Services (collectively, the “World Fuel Defendants”). The World Fuel Defendants have since settled. No timetable governing the conduct of this lawsuit has been ordered by the Superior Court of Quebec.

On July 4, 2016, CP was served with subrogated insurance claims brought by 8 insurers for a claimed amount of approximately $16 million. On July 11, 2016, CP was served with subrogated insurance claims brought by an additional 2 insurers for a claimed amount of approximately $3 million. These insurers have not identified in their respective lawsuit the identity of the parties to whose claims they are subrogated and thus it is difficult to determine the extent to which these claims overlap with other claims and the extent to which their claim would be satisfied after their proof of claim has been reviewed and distribution is received from the Plans of arrangements referred to below.

In the wake of the derailment and ensuing litigation, MMAC filed for bankruptcy in Canada (the “Canadian Proceeding”) and MMA filed for bankruptcy in the United States (the “U.S. Proceeding”). Plans of arrangement have been approved both in the Canadian Proceeding and the U.S. Proceeding (the “Plans”). These Plans provide for the distribution of a fund of approximately $440 million amongst those who claimed loss or damage as a result of the derailment and will release those parties which contributed to the fund from any further liability. The Plans also provide for broadly worded third-party releases and injunctions that prevent actions against settling parties. CP has not participated in the settlement and hence will not benefit from any third-party releases or injunctions. In addition, both Plans contain judgment reduction provisions. Pursuant to these provisions, in the event of a judgment against CP in a case arising from the Lac-Mégantic derailment, CP will receive a credit for the greater of (i) the settlement monies received by the plaintiff(s) for the claim, or (ii) the amount which, but for the third-party non-debtor injunctions, CP would have been entitled to obtain from third parties other than MMA and MMAC through contribution or indemnification. CP may also have rights to judgment reduction, as part of the contribution/indemnification credit, for the fault of MMA and/or MMAC. The provisions of the Plans also provide for a potential re-allocation of of the MMA Group’s liability among plaintiffs and CP, the only non-settling party.

An Adversary Proceeding filed by the MMA U.S. bankruptcy trustee against CP, Irving Oil and the World Fuel Defendants accuses CP of failing to ensure that World Fuel Defendants or Irving Oil properly classified the oil lading and of not refusing to ship the oil in DOT-111 tank cars. The trustee has since settled with the World Fuel Defendants and Irving Oil and now maintains that CP misfeasance is based upon the railroad’s failure to abide by a Canadian regulation in North Dakota that supposedly would have caused the originating railroad to refuse to carry the crude oil based upon reason to suspect inaccurate classification. In response to CP’s motion to withdraw the Adversary Proceedings from the bankruptcy reference, the trustee maintained that Canadian law rather than U.S. law controlled, and the Article III court found that if the federal regulations governed, the case was not complex enough to warrant withdrawal. In bankruptcy court CP moved to dismiss for want of personal jurisdiction, but that motion, which was heard on August 18, 2015, has been denied. Motions to dismiss on procedural grounds are pending. The trustee recently withdrew objection to the trial of the Adversary Proceedings to a jury before the Article III district court.

There are also a class action and a mass action instituted Texas and wrongful death and personal injury actions instituted in Illinois and Maine. All the various lawsuits have been removed to federal court and have since been consolidated in Maine. These actions generally charge CP with negligence in the misclassification and mis-packaging (that is the use of inappropriate DOT-111 tank cars). Motions to dismiss have been filed and heard regarding jurisdiction and venue. Decisions on CP’s motions and other parties’ cross-motions are pending.

CP has received two damage to cargo notices of claims from the shipper of the oil on the derailed train, Western Petroleum. Western Petroleum submitted U.S. and Canadian notices of claims for the same damages and, under the Carmack Amendment (49 U.S.C. Section 11706), seeks to recover for all injuries associated with, and indemnification for the derailment. Both jurisdictions permit a shipper to recover the value of damaged lading against any carrier in the delivery chain, subject to limitations in the carrier’s tariffs. CP’s tariffs significantly restrict shipper damage claim rights. Western Petroleum is part of the World Fuel Services group, and those entities settled with the trustee.

On April 12, 2016, Trustee (the “WD Trustee”) of a wrongful death trust (the “WD Trust”), as defined and established under the confirmed Plan, filed an action against CP in federal court in North Dakota seeking to establish Carmack Amendment liability under 49 U.S.C. Section 11706. The WD Trustee asserts the WD Trust was assigned Carmack claim rights by the bankruptcy estate representative. The parties that settled Lac Megantic derailment liability in connection with MMA’s confirmed Plan supposedly gave the bankruptcy estate representative the right to assign Carmack claims. The WD Trustee seeks to recover losses associated with the lost lading (approximately $6 million), as well as settlement amounts the consignor (i.e, the shipper, World Fuel Entities) and the consignee (Irving Oil) paid to the MMA bankruptcy estate to settle all Lac Megantic derailment claims, which are alleged to be $110 million and $60 million respectively. The WD Trustee maintains that Carmack liability extends beyond lading losses to cover all derailment related damages incurred by the World Fuel Services group or Irving Oil. CP disputes this interpretation of damages to lading law and maintains that CP’s tariffs, if applicable, would preclude such a result.

At this early stage of the legal proceedings, any potential liability and the quantum of potential loss cannot be determined. Nevertheless, CP denies liability for the MMA derailment and intends to vigorously defend itself in the proceedings described above and in any proceeding that may be commenced in the future.

Legal proceedings initiated by Canadian National Railway Company

On August 13, 2015, Canadian National Railway Company (“CN”) issued a statement of claim against the Company and an employee. The statement of claim was amended on January 7, 2016 to include an additional employee and an officer of the Company. The principal allegations against the Company are that the Company obtained and benefited from certain confidential CN customer data. CN is seeking damages but has not yet provided evidence to substantiate its damages claim. The Company plans to defend this claim and the amount of loss, if any, to the Company as a result of the claim cannot be reasonably estimated.

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 CP’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 CP’s best estimate of all probable costs, CP’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, are not expected to be material to CP’s financial position, but 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” for the three and six months ended June 30, 2016 was $1 million and $2 million, respectively (three and six months ended June 30, 2015 - $3 million and $6 million, respectively). Provisions for environmental remediation costs are recorded in “Other long-term liabilities”, except for the current portion which is recorded in “Accounts payable and accrued liabilities”. The total amount provided at June 30, 2016 was $86 million (December 31, 2015 - $93 million). Payments are expected to be made over 10 years through 2026.