Commitments and Contingencies (Details)			1 Months Ended		6 Months Ended
	Jun. 01, 2021 USD ($)	Jun. 30, 2018 defendant	Mar. 31, 2016 party mi	May 31, 2007 entity claim	Jun. 30, 2021 USD ($) mi	Jun. 30, 2020 USD ($)
Loss Contingencies [Line Items]
Casualty and catastrophic property deductible						$ 100,000,000
Casualty and non catastrophic property deductible						$ 75,000,000
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
Number of consolidated class action lawsuits | claim				1
Pending Litigation | Environmental
Loss Contingencies [Line Items]
Number of miles pertaining to Passaic River tidal reach required to be studied by EPA | mi					17
Number of miles subject to remediation | mi			8
Number of parties participating in allocation process under study | party			80
Number of parties | defendant		110
Minimum | Pending Litigation
Loss Contingencies [Line Items]
Possible loss for certain legal proceedings					$ 2,000,000
Maximum | Pending Litigation
Loss Contingencies [Line Items]
Possible loss for certain legal proceedings					23,000,000
Total Casualty
Loss Contingencies [Line Items]
Self-insured retention amount, per occurrence (up to)	$ 100,000,000				$ 100,000,000