Changes in Operations Purchase Price Allocation (Details) (USD $)	12 Months Ended			3 Months Ended	9 Months Ended				12 Months Ended			12 Months Ended	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 28, 2012 RailAmerica [Member]	Sep. 30, 2013 RailAmerica [Member]	Oct. 02, 2012 RailAmerica [Member]	Sep. 02, 2011 AZER [Member]	Dec. 28, 2012 Preliminary allocation of fair values [Member] RailAmerica [Member]	Dec. 31, 2013 Final allocation of fair values [Member] RailAmerica [Member]	Dec. 31, 2012 Final allocation of fair values [Member] RailAmerica [Member]	Dec. 28, 2012 Final allocation of fair values [Member] RailAmerica [Member]	Dec. 31, 2013 Scenario, Forecast [Member] RailAmerica [Member]	Dec. 28, 2012 RailAmerica [Member]
Business Acquisition [Line Items]
Income from equity investment in RailAmerica, net	$ 0	$ 15,557,000	$ 0										$ 15,600,000
Other comprehensive loss from equity investment in RailAmerica	41,182,000	(9,376,000)											(1,984,000)
Reduction in net cash paid for acquisition due to change in cash and cash equivalents				(21,800,000)
Measurement period adjustment to the allocation of fair values to property and equipment					10,700,000
Measurement period adjustment to the allocation of fair values to intangible assets					(29,900,000)
Measurement period adjustment to the allocation of fair values to deferred income tax liabilities, net					(16,000,000)
Measurement period adjustment to the allocation of fair values to noncontrolling interest					(5,000,000)
Measurement period adjustment to the allocation of fair values to all other assets, net					1,300,000
Measurement period adjustment to allocation of fair values to goodwill					(3,100,000)				(3,087,000)	474,115,000
Additional depreciation and amortization expense as a result of the measurement period adjustment to the allocation of fair values												4,000,000
Allocation of Fair Value [Abstract]
Cash and cash equivalents						86,102,000	0	107,922,000			107,922,000
Accounts receivable						104,839,000	3,096,000	91,424,000			90,659,000
Materials and supplies						6,406,000	0	7,325,000			7,325,000
Prepaid expenses and other						15,146,000	2,319,000	14,815,000			15,801,000
Deferred income tax assets						49,074,000	0	49,074,000			56,998,000
Property and equipment						1,579,321,000	90,129,000	1,588,612,000			1,599,282,000
Goodwill	630,462,000	634,953,000	160,277,000			474,115,000	0	474,115,000			471,028,000		474,115,000
Intangible assets, net						451,100,000	0	446,327,000			416,427,000
Other assets						116,000	0	116,000			116,000
Total assets						2,766,219,000	95,544,000	2,779,730,000			2,765,558,000
Accounts payable and accrued expenses						143,790,000	5,212,000	135,117,000			140,160,000
Long-term debt						12,158,000	0	12,010,000			12,010,000
Deferred income tax liabilities, net						542,210,000	0	551,856,000			535,864,000
Other long-term liabilities						20,754,000	0	19,618,000			21,439,000
Noncontrolling interest						5,525,000	0	5,525,000			481,000
Net assets						$ 2,041,782,000	$ 90,332,000	$ 2,055,604,000			$ 2,055,604,000