Changes in Operations United States Pinsly (Details) $ in Thousands		3 Months Ended								12 Months Ended
	Jan. 05, 2015 USD ($) employee carload mile locomotive	Dec. 31, 2015 USD ($) employee	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) employee	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Revenues		$ 514,853	$ 546,299	$ 542,219	$ 397,030	$ 415,627	$ 432,543	$ 414,563	$ 376,279
Income from operations		$ 94,631	$ 117,559	$ 99,451	$ 72,620	$ 113,471	$ 123,116	$ 110,109	$ 74,875	$ 384,261	$ 421,571	$ 380,188
Number of employees | employee		7,500								7,500
Pinsly [Member]
Cash consideration	$ 41,300
Revenues										$ 14,500
Income from operations										$ 2,600
Track Miles | mile	137
Number of employees | employee	77
Number of locomotives purchased | locomotive	16
Carloads Shipped Annually | carload	35,000