Business and Customers (Details)	12 Months Ended
	Dec. 31, 2015 mile employee region port reportable_segment provinces customer state railroad	Dec. 31, 2014	Dec. 31, 2013
Number of railroads operated | railroad	120
Number of operating regions | region	11
Number of employees | employee	7,500
Customers served | customer	2,800
Number of reportable segments | reportable_segment	3
Ports operated | port	40
Customer Concentration Risk [Member]
10 largest customers % of revenues	22.00%	24.00%	24.00%
United States [Member]
Number of States in which Entity Operates | state	41
Canada [Member]
Number of Provinces in which Entity Operates | provinces	4
North American [Member]
Short Line and Regional Freight Railroad | port	113
Track miles | mile	13,000
Australia [Member]
Track miles | mile	1,400
North American Operations [Member]
Number of operating regions | provinces	9