Quarterly Financial Data (Details 2) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
After-tax gain on sale of assets	$ 800,000	$ 500,000	$ 700,000	$ 1,300,000	$ 600,000	$ 2,000,000	$ 5,200,000	$ 800,000
After-tax impact of RailAmerica integration and acquisition-related costs	600,000	1,300,000	700,000	8,000,000	17,700,000	3,100,000	500,000
After-tax business development and financing costs	700,000		200,000	500,000	9,800,000	400,000	400,000	200,000
After tax impact of depreciation and amortization expense as a result of the finalization of the allocation of fair values to RailAmerica's assets and liabilities		1,300,000
After-tax valuation allowance on foreign tax credits generated in prior years	2,000,000
Contingent forward sale contract mark-to-market expense						50,100,000			0	50,106,000	0
After-tax contract termination expense					800,000
RailAmerica [Member]
After-tax impact of RailAmerica integration and acquisition-related costs					3,500,000
Related to prior fiscal year reported in current fiscal year [Member]
After-tax benefit from extension of the short line tax credit				$ 41,000,000					$ 41,000,000