Subsequent Events Freightliner (Details) In Thousands, unless otherwise specified					0 Months Ended		0 Months Ended
	Dec. 31, 2014 employee locomotive	Dec. 31, 2013 locomotive	Dec. 31, 2014 Amended and Restated Credit Agreement [Member] USD ($)	Dec. 31, 2013 Amended and Restated Credit Agreement [Member] USD ($)	Feb. 24, 2015 Freightliner [Member] Subsequent Event [Member]	Feb. 24, 2015 Freightliner [Member] Subsequent Event [Member] locomotive rail_car employee	Feb. 24, 2015 Freightliner [Member] Scenario, Forecast [Member] Subsequent Event [Member] USD ($)	Feb. 24, 2015 Freightliner [Member] Scenario, Forecast [Member] Subsequent Event [Member] GBP (£)	Jun. 30, 2020 Freightliner [Member] Scenario, Forecast [Member] Subsequent Event [Member]	Feb. 24, 2015 Freightliner [Member] Scenario, Forecast [Member] Subsequent Event [Member]	Feb. 24, 2015 Freightliner [Member] Amended and Restated Credit Agreement [Member] Scenario, Forecast [Member] Subsequent Event [Member] USD ($)
Subsequent Event [Line Items]
Business Acquisition, Date of Acquisition Agreement					Feb. 25, 2015
Business Acquisition, Percentage of Voting Interests Acquired									100.00%	95.00%
Cash consideration							$ 755,000	£ 490,000
Noncash or Part Noncash Acquisition, Debt Assumed							13,000	8,500
Business Acquisition, Percentage of Voting Interest Not Acquired										5.00%
Acquisition refinancing of debt			$ 1,584,044	$ 1,583,798							$ 650,000
Leased locomotives	162	100				250
Wagons leased						5,500
Number of employees	5,200					2,500