Commitments and Contingencies (Details)	1 Months Ended		9 Months Ended
	Mar. 31, 2016 mi	May 31, 2007 entity	Sep. 30, 2017 USD ($) claim mi	Aug. 09, 2017	Dec. 30, 2016 USD ($)
Loss Contingencies [Line Items]
Locomotive fleet covered by maintenance program (as a percent)				34.00%	50.00%
Estimated obligation under maintenance program			$ 1,700,000,000		$ 5,000,000,000
Casualty and non catastrophic property deductible			25,000,000
Casualty and catastrophic property deductible			$ 50,000,000
Environmental
Loss Contingencies [Line Items]
Number of miles pertaining to Passaic River tidal reach required to be studied by EPA | mi			17
Pending Litigation
Loss Contingencies [Line Items]
Claims with potential material impact (number of claims) | claim			1
Pending Litigation | Fuel Surcharge Antitrust Litigation
Loss Contingencies [Line Items]
Class action lawsuits filed against U.S.-based Class I railroads, excluding CSXT (number of entities) | entity		3
Pending Litigation | Minimum
Loss Contingencies [Line Items]
Possible loss for certain legal proceedings			$ 2,000,000
Pending Litigation | Maximum
Loss Contingencies [Line Items]
Possible loss for certain legal proceedings			$ 116,000,000
Settled Litigation | Environmental
Loss Contingencies [Line Items]
Number of miles subject to remediation | mi	8
Years required for site cleanup	10 years