Earnings per Share Series A-1 Preferred Stock (Details) (The Carlyle Group [Member], USD $)				3 Months Ended
	Feb. 13, 2013	Jul. 23, 2012 RailAmerica [Member]	Jul. 17, 2012 RailAmerica [Member]	Mar. 31, 2013 Series A-1 Preferred Stock [Member]	Oct. 02, 2012 Series A-1 Preferred Stock [Member] RailAmerica [Member]	Jul. 17, 2012 Series A-1 Preferred Stock [Member] RailAmerica [Member]
Series A-1 Preferred Stock [Line Items]
Preferred Stock, Shares Issued					350,000
Stated par value per share					$ 1,000.00
Net proceeds from issuance of stock					$ 349,400,000
Stock Issued During Period, Shares, Conversion of Convertible Securities				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
Preferred Stock, Redemption Amount			58.49
Premium on conversion price			4.50%
Cash paid with conversion of preferred stock	$ 2,100,000