Commitments and Contingencies	9 Months Ended
Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Purchase Commitments CSXT has a commitment under a long-term maintenance program agreement that covers a portion of CSXT’s fleet of locomotives. The program costs are based on the maintenance cycle for each covered locomotive, which is determined by the asset's age and type. Expected future costs may change as required maintenance schedules are revised and locomotives are placed into or removed from service. Under CSXT’s current obligations, the agreement will expire no earlier than 2031. On August 9, 2017, the Company exercised certain rights under the agreement, which resulted in a reduction of the locomotive fleet covered from 50% as of December 30, 2016 to an estimated 34% of locomotives beginning August 2018. As a result, the total remaining payments decreased from approximately $5.0 billion at December 30, 2016 to an estimated $1.7 billion at September 30, 2017. Insurance The Company maintains numerous insurance programs with substantial limits for property damage (which includes business interruption) and third-party liability. A certain amount of risk is retained by the Company on each of the property and liability programs. The Company has a $25 million retention per occurrence for the non-catastrophic property program (such as a derailment) and a $50 million retention per occurrence for the liability and catastrophic property programs (such as hurricanes and floods). While the Company believes its insurance coverage is adequate, future claims could exceed existing insurance coverage or insurance may not continue to be available at commercially reasonable rates. Legal The Company is involved in litigation incidental to its business and is a party to a number of legal actions and claims, various governmental proceedings and private civil lawsuits, including, but not limited to, those related to fuel surcharge practices, tax matters, environmental and hazardous material exposure matters, FELA and labor claims by current or former employees, other personal injury or property claims and disputes and complaints involving certain transportation rates and charges. Some of the legal proceedings include claims for compensatory as well as punitive damages and others are, or are purported to be, class actions. While the final outcome of these matters cannot be reasonably determined, considering, among other things, the legal defenses available and liabilities that have been recorded along with applicable insurance, it is currently the opinion of management that none of these pending items is likely to have a material adverse effect on the Company's financial condition, results of operations or liquidity. An unexpected adverse resolution of one or more of these items, however, could have a material adverse effect on the Company's financial condition, results of operations or liquidity in that particular period. The Company is able to estimate a range of possible loss for certain legal proceedings for which a loss is reasonably possible in excess of reserves established. The Company has estimated this range to be $2 million to $116 million in aggregate at September 30, 2017. This estimated aggregate range is based upon currently available information and is subject to significant judgment and a variety of assumptions. Accordingly, the Company's estimate will change from time to time, and actual losses may vary significantly from the current estimate. NOTE 5. Commitments and Contingencies, continued Fuel Surcharge Antitrust Litigation In May 2007, class action lawsuits were filed against CSXT and three other U.S.-based Class I railroads alleging that the defendants' fuel surcharge practices relating to contract and unregulated traffic resulted from an illegal conspiracy in violation of antitrust laws. In November 2007, the class action lawsuits were consolidated in federal court in the District of Columbia, where they are now pending. The suit seeks treble damages allegedly sustained by purported class members as well as attorneys' fees and other relief. Plaintiffs are expected to allege damages at least equal to the fuel surcharges at issue. In June 2012, the District Court certified the case as a class action. The decision was not a ruling on the merits of plaintiffs' claims, but rather a decision to allow the plaintiffs to seek to prove the case as a class. The defendant railroads petitioned the U.S. Court of Appeals for the D.C. Circuit for permission to appeal the District Court's class certification decision. In August 2013, the D.C. Circuit issued a decision vacating the class certification decision and remanded the case to the District Court to reconsider its class certification decision. On October 10, 2017, the District Court issued an order denying class certification. The District Court had delayed proceedings on the merits of the case pending the outcome of the class certification remand proceedings, and has not yet issued a further schedule in light of the order denying class certification. CSXT believes that its fuel surcharge practices were arrived at and applied lawfully and that the case is without merit. Accordingly, the Company intends to defend itself vigorously. However, penalties for violating antitrust laws can be severe, and resolution of this matter or an unexpected adverse decision on the merits could have a material adverse effect on the Company's financial condition, results of operations or liquidity in that particular period. Environmental CSXT is indemnifying Pharmacia LLC (formerly known as Monsanto Company) for certain liabilities associated with real estate located in Kearny, New Jersey along the Lower Passaic River (the “Property”). The Property, which was formerly owned by Pharmacia, is now owned by CSXT. CSXT's indemnification and defense duties arise with respect to several matters. The U.S. Environmental Protection Agency ("EPA"), using its CERCLA authority, seeks cleanup and removal costs and other damages associated with the presence of hazardous substances in the 17-mile Lower Passaic River Study Area (the "Study Area”). CSXT, on behalf of Pharmacia, and a significant number of other potentially responsible parties are together conducting a Remedial Investigation and Feasibility Study of the Study Area pursuant to an Administrative Settlement Agreement and Order on Consent with the EPA. In March 2016, EPA issued its Record of Decision detailing the agency’s mandated remedial process for the lower 8 miles of the Study Area, which was based on a Focused Feasibility Study. EPA has estimated that it will take the potentially responsible parties approximately ten years to complete the work. At a later date, EPA will select a remedy for the remainder of the Study Area and is expected to again seek the participation of private parties to implement the selected remedy using EPA’s CERCLA authority to compel such participation, if necessary. CSXT is also defending and indemnifying Pharmacia in a cooperative natural resource damages assessment process related to the Property. Based on currently available information, the Company does not believe any indemnification or remediation costs potentially allocable to CSXT with respect to the Property and the Study Area would be material to the Company's financial condition, results of operations or liquidity.

Commitments and Contingencies

Purchase Commitments

CSXT has a commitment under a long-term maintenance program agreement that covers a portion of CSXT’s fleet of locomotives. The program costs are based on the maintenance cycle for each covered locomotive, which is determined by the asset's age and type. Expected future costs may change as required maintenance schedules are revised and locomotives are placed into or removed from service. Under CSXT’s current obligations, the agreement will expire no earlier than 2031. On August 9, 2017, the Company exercised certain rights under the agreement, which resulted in a reduction of the locomotive fleet covered from 50% as of December 30, 2016 to an estimated 34% of locomotives beginning August 2018. As a result, the total remaining payments decreased from approximately $5.0 billion at December 30, 2016 to an estimated $1.7 billion at September 30, 2017.

Insurance

The Company maintains numerous insurance programs with substantial limits for property damage (which includes business interruption) and third-party liability. A certain amount of risk is retained by the Company on each of the property and liability programs. The Company has a $25 million retention per occurrence for the non-catastrophic property program (such as a derailment) and a $50 million retention per occurrence for the liability and catastrophic property programs (such as hurricanes and floods). While the Company believes its insurance coverage is adequate, future claims could exceed existing insurance coverage or insurance may not continue to be available at commercially reasonable rates.

Legal

The Company is involved in litigation incidental to its business and is a party to a number of legal actions and claims, various governmental proceedings and private civil lawsuits, including, but not limited to, those related to fuel surcharge practices, tax matters, environmental and hazardous material exposure matters, FELA and labor claims by current or former employees, other personal injury or property claims and disputes and complaints involving certain transportation rates and charges. Some of the legal proceedings include claims for compensatory as well as punitive damages and others are, or are purported to be, class actions. While the final outcome of these matters cannot be reasonably determined, considering, among other things, the legal defenses available and liabilities that have been recorded along with applicable insurance, it is currently the opinion of management that none of these pending items is likely to have a material adverse effect on the Company's financial condition, results of operations or liquidity. An unexpected adverse resolution of one or more of these items, however, could have a material adverse effect on the Company's financial condition, results of operations or liquidity in that particular period.

The Company is able to estimate a range of possible loss for certain legal proceedings for which a loss is reasonably possible in excess of reserves established. The Company has estimated this range to be $2 million to $116 million in aggregate at September 30, 2017. This estimated aggregate range is based upon currently available information and is subject to significant judgment and a variety of assumptions. Accordingly, the Company's estimate will change from time to time, and actual losses may vary significantly from the current estimate.

NOTE 5. Commitments and Contingencies, continued

Fuel Surcharge Antitrust Litigation

In May 2007, class action lawsuits were filed against CSXT and three other U.S.-based Class I railroads alleging that the defendants' fuel surcharge practices relating to contract and unregulated traffic resulted from an illegal conspiracy in violation of antitrust laws. In November 2007, the class action lawsuits were consolidated in federal court in the District of Columbia, where they are now pending. The suit seeks treble damages allegedly sustained by purported class members as well as attorneys' fees and other relief. Plaintiffs are expected to allege damages at least equal to the fuel surcharges at issue.

In June 2012, the District Court certified the case as a class action. The decision was not a ruling on the merits of plaintiffs' claims, but rather a decision to allow the plaintiffs to seek to prove the case as a class. The defendant railroads petitioned the U.S. Court of Appeals for the D.C. Circuit for permission to appeal the District Court's class certification decision. In August 2013, the D.C. Circuit issued a decision vacating the class certification decision and remanded the case to the District Court to reconsider its class certification decision. On October 10, 2017, the District Court issued an order denying class certification. The District Court had delayed proceedings on the merits of the case pending the outcome of the class certification remand proceedings, and has not yet issued a further schedule in light of the order denying class certification.

CSXT believes that its fuel surcharge practices were arrived at and applied lawfully and that the case is without merit. Accordingly, the Company intends to defend itself vigorously. However, penalties for violating antitrust laws can be severe, and resolution of this matter or an unexpected adverse decision on the merits could have a material adverse effect on the Company's financial condition, results of operations or liquidity in that particular period.

Environmental

CSXT is indemnifying Pharmacia LLC (formerly known as Monsanto Company) for certain liabilities associated with real estate located in Kearny, New Jersey along the Lower Passaic River (the “Property”). The Property, which was formerly owned by Pharmacia, is now owned by CSXT. CSXT's indemnification and defense duties arise with respect to several matters. The U.S. Environmental Protection Agency ("EPA"), using its CERCLA authority, seeks cleanup and removal costs and other damages associated with the presence of hazardous substances in the 17-mile Lower Passaic River Study Area (the "Study Area”). CSXT, on behalf of Pharmacia, and a significant number of other potentially responsible parties are together conducting a Remedial Investigation and Feasibility Study of the Study Area pursuant to an Administrative Settlement Agreement and Order on Consent with the EPA.

In March 2016, EPA issued its Record of Decision detailing the agency’s mandated remedial process for the lower 8 miles of the Study Area, which was based on a Focused Feasibility Study. EPA has estimated that it will take the potentially responsible parties approximately ten years to complete the work. At a later date, EPA will select a remedy for the remainder of the Study Area and is expected to again seek the participation of private parties to implement the selected remedy using EPA’s CERCLA authority to compel such participation, if necessary.

CSXT is also defending and indemnifying Pharmacia in a cooperative natural resource damages assessment process related to the Property. Based on currently available information, the Company does not believe any indemnification or remediation costs potentially allocable to CSXT with respect to the Property and the Study Area would be material to the Company's financial condition, results of operations or liquidity.