Property and Equipment and Leases Construction in Process (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Construction in-process	$ 36,903	$ 31,910
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Construction in-process	4,209	85
Bridges/tunnels/culverts
Property, Plant and Equipment [Line Items]
Construction in-process	1,000	1,600
Track property
Property, Plant and Equipment [Line Items]
Construction in-process	5,504	12,302
Locomotives and railcars
Property, Plant and Equipment [Line Items]
Construction in-process	18,397	11,786
Other equipment
Property, Plant and Equipment [Line Items]
Construction in-process	$ 7,793	$ 6,137