Earnings per Share Series A-1 Preferred Stock (Details) (Series A-1 Preferred Stock [Member], The Carlyle Group [Member], USD $)	3 Months Ended
	Mar. 31, 2013	Feb. 13, 2013	Oct. 02, 2012 RailAmerica [Member]	Jul. 17, 2012 RailAmerica [Member]
Series A-1 Preferred Stock [Line Items]
Shares issued			350,000
Issuance price per share			$ 1,000.00
Net proceeds from issuance of stock			$ 349,400,000
Shares issued with conversion of Preferred Stock	5,984,232
Convertible Preferred Stock coupon rate				5.00%
Preferred Stock conversion shares				17.1
Optional Preferred Stock conversion rate				130.00%
Optional Preferred Stock conversion price				$ 76.03
Conversions price of Series A-1 Preferred Stock				58.49
Premium on conversion price				4.50%
Cash paid with conversion of Preferred Stock		$ 2,100,000