Derivative Financial Instruments Contingent Forward Sale Contract (Details) (USD $)	3 Months Ended	12 Months Ended						12 Months Ended
	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Sep. 28, 2012	Jul. 23, 2012 The Carlyle Group [Member] RailAmerica [Member]	Jul. 17, 2012 The Carlyle Group [Member] RailAmerica [Member]	Dec. 31, 2012 The Carlyle Group [Member] RailAmerica [Member] Forward Contracts [Member]	Feb. 12, 2013 Series A-1 Preferred Stock [Member] The Carlyle Group [Member]	Dec. 31, 2012 Series A-1 Preferred Stock [Member] The Carlyle Group [Member] RailAmerica [Member]	Oct. 02, 2012 Series A-1 Preferred Stock [Member] The Carlyle Group [Member] RailAmerica [Member]
Derivative [Line Items]
Proceeds from issuance of stock											$ 350,000,000
Preferred Stock conversion shares						17.1
Optional Preferred Stock Conversion Rate						130.00%
Optional Preferred Stock Conversion Price						$ 76.03			$ 76.03
Preferred Stock conversion price							58.49
Convertible preferred stock coupon rate							4.50%			5.00%
Contingent forward sale contract mark-to-market expense	$ (50,100,000)	$ 50,106,000	$ 0	$ 0				$ 50,100,000
Share Price					$ 66.86