Changes in Operations Allocation of Fair Values (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Oct. 02, 2012 RailAmerica [Member]	Dec. 28, 2012 Preliminary allocation of fair values [Member] RailAmerica [Member]	Dec. 28, 2012 Final allocation of fair values [Member] RailAmerica [Member]
Business Acquisition [Line Items]
Cash and cash equivalents			$ 86,102	$ 107,922	$ 107,922
Accounts receivable, net			104,839	91,424	90,659
Materials and supplies			6,406	7,325	7,325
Prepaid expenses and other			15,146	14,815	15,801
Deferred income tax assets, net			49,074	49,074	56,998
Property and equipment			1,579,321	1,588,612	1,599,282
Goodwill	635,531	634,953	474,115	474,115	475,584
Intangible assets, net			451,100	446,327	416,427
Other assets, net			116	116	116
Total assets			2,766,219	2,779,730	2,770,114
Accounts payable and accrued expenses			143,790	135,117	140,160
Long-term debt			12,158	12,010	12,010
Deferred income tax liabilities, net			542,210	551,856	540,420
Other long-term liabilities			20,754	19,618	21,439
Noncontrolling interest			5,525	5,525	481
Net assets			$ 2,041,782	$ 2,055,604	$ 2,055,604