Business and Customers (Details)	12 Months Ended
	Dec. 31, 2012 track_miles railroads	Dec. 31, 2011	Dec. 31, 2010	Oct. 02, 2012 employees
Entity Information [Line Items]
Track miles	14,700
Number of railroads operated	111
Number of Operating Regions	11
Number of employees				4,600
customers served	2,000
Ports we operate	35
Percent of freight revenues from 10 largest customers	25.00%	24.00%	22.00%
GWA North [Member]
Entity Information [Line Items]
Track miles	1,400
RailAmerica [Member]
Entity Information [Line Items]
Percent of freight revenues from 10 largest customers	13.00%