Commitments and Contingencies - Narrative (Details)		1 Months Ended		12 Months Ended
	Jun. 01, 2018 USD ($)	Mar. 31, 2016 party mi	May 31, 2007 entity	Dec. 31, 2018 USD ($) mi
Operating Leased Assets [Line Items]
Maximum lease term (up to)				50 years
Percentage of annual increase in operating lease payments				2.50%
Number of miles of land and integral equipment leased | mi				137
Additional lease term				50 years
Casualty and catastrophic property deductible				$ 50,000,000
Non-catastrophic property deductible				$ 25,000,000
Fuel Surcharge Antitrust Litigation
Operating Leased Assets [Line Items]
Number of other U.S.-based entities mentioned in class action lawsuit | entity			3
Environmental Litigation
Operating Leased Assets [Line Items]
Number of miles pertaining to Passaic River tidal reach required to be studied by EPA | mi				17
Number of miles under study | mi		8
Number of parties participating in allocation process to assign responsibility for costs under study | party		80
Minimum | Pending Litigation
Operating Leased Assets [Line Items]
Range of possible loss from legal proceedings				$ 3,000,000
Maximum | Pending Litigation
Operating Leased Assets [Line Items]
Range of possible loss from legal proceedings				$ 120,000,000
Casualty Reserves | Minimum
Operating Leased Assets [Line Items]
Self-insured retention amount per occurrence	$ 50,000,000
Casualty Reserves | Maximum
Operating Leased Assets [Line Items]
Self-insured retention amount per occurrence	$ 75,000,000