Significant Accounting Policies Property and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
material losses incurred through dispositions from unanticipated or unusual events	$ 0
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life, Minimum	3 years
Property, Plant and Equipment, Maximum Useful Life	30 years
Bridges/tunnels/culverts
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life, Minimum	20 years
Property, Plant and Equipment, Maximum Useful Life	50 years
Track property
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life, Minimum	5 years
Property, Plant and Equipment, Maximum Useful Life	50 years
Computer equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life, Minimum	2 years
Property, Plant and Equipment, Maximum Useful Life	7 years
Locomotives and rail cars
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life, Minimum	5 years
Property, Plant and Equipment, Maximum Useful Life	30 years
Vehicles and mobile equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life, Minimum	5 years
Property, Plant and Equipment, Maximum Useful Life	10 years
Signals and crossing equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life, Minimum	10 years
Property, Plant and Equipment, Maximum Useful Life	30 years
Track equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life, Minimum	5 years
Property, Plant and Equipment, Maximum Useful Life	10 years
Other equipment
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life, Minimum	3 years
Property, Plant and Equipment, Maximum Useful Life	20 years