Segment and Geographic Area Information North American & European and Australian Operations (Details) (USD $)	2 Months Ended	3 Months Ended								12 Months Ended
	Sep. 28, 2012	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014 region reportable_segment	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Number of operating regions										11
Number of reportable segments										2
Operating revenues										$ 1,639,012,000	$ 1,568,643,000	$ 874,916,000
Income from operations		113,471,000	123,116,000	110,109,000	74,875,000	94,830,000	101,741,000	107,417,000	76,200,000	421,571,000	380,188,000	190,322,000
Depreciation and amortization										157,081,000	141,644,000	73,405,000
Interest expense										56,162,000	67,894,000	62,845,000
Interest income										1,445,000	3,971,000	3,725,000
Provision for income taxes										107,107,000	46,296,000	46,402,000
Contingent forward sale contract mark-to-market expense	50,100,000									0	0	50,106,000
Income from equity investment in RailAmerica, net										0	0	15,557,000
Expenditures for additions to property & equipment, net of grants from outside parties										305,721,000	215,405,000	192,062,000
North American & European Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues										1,325,830,000	1,243,847,000	585,893,000
Income from operations										330,560,000	284,122,000	115,387,000
Depreciation and amortization										128,986,000	114,542,000	50,156,000
Interest expense										43,722,000	52,740,000	45,996,000
Interest income										1,157,000	3,631,000	3,219,000
Provision for income taxes										83,664,000	24,038,000	28,451,000
Contingent forward sale contract mark-to-market expense												50,106,000
Income from equity investment in RailAmerica, net												15,557,000
Expenditures for additions to property & equipment, net of grants from outside parties										280,657,000	163,545,000	69,636,000
Australian Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues										313,182,000	324,796,000	289,023,000
Income from operations										91,011,000	96,066,000	74,935,000
Depreciation and amortization										28,095,000	27,102,000	23,249,000
Interest expense										12,440,000	15,154,000	16,849,000
Interest income										288,000	340,000	506,000
Provision for income taxes										23,443,000	22,258,000	17,951,000
Contingent forward sale contract mark-to-market expense												0
Income from equity investment in RailAmerica, net												0
Expenditures for additions to property & equipment, net of grants from outside parties										$ 25,064,000	$ 51,860,000	$ 122,426,000