Income Taxes Income from Continuing Operations before taxes (Details) (USD $)	3 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Contingent forward sale contract mark-to-market expense	$ (50,100,000)	$ 50,106,000	$ 0	$ 0
Provision for income taxes		46,402,000	38,531,000	30,164,000
Provision For Income Tax As A Percentage Of Income From Continuing Operations Other Than Mark-to-Market Expense		34.80%	24.40%
United States income from continuing operations before taxes		5,716,000	98,050,000	89,132,000
Foreign income form continuing operations before taxes		77,680,000	59,974,000	19,701,000
Total		83,396,000	158,024,000	108,833,000
Provision for United States income taxes applicable to undistributed foreign earnings		0
Undistributed Foreign Earnings		251,400,000
RailAmerica [Member] | The Carlyle Group [Member] | Forward Contracts [Member]
Contingent forward sale contract mark-to-market expense		$ 50,100,000