Property and Equipment and Leases Property and Equipment (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Gross Book Value		$ 5,984,538,000	$ 5,863,487,000
Accumulated Depreciation		(1,371,524,000)	(1,206,566,000)
Net Book Value		4,613,014,000	4,656,921,000
Depreciation expense		206,700,000	192,900,000	$ 172,300,000
Australian Operations [Member]
Property, Plant and Equipment [Line Items]
Net Book Value		609,450,000	664,367,000
Asset Impairment Charges	$ (13,000,000)		(5,900,000)
Land and land improvements
Property, Plant and Equipment [Line Items]
Gross Book Value		742,417,000	755,234,000
Accumulated Depreciation		0	0
Net Book Value		742,417,000	755,234,000
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Gross Book Value		245,400,000	257,173,000
Accumulated Depreciation		(74,595,000)	(59,611,000)
Net Book Value		170,805,000	197,562,000
Bridges/tunnels/culverts
Property, Plant and Equipment [Line Items]
Gross Book Value		749,395,000	718,001,000
Accumulated Depreciation		(139,957,000)	(122,380,000)
Net Book Value		609,438,000	595,621,000
Track Property [Member]
Property, Plant and Equipment [Line Items]
Gross Book Value		2,868,568,000	2,792,529,000
Accumulated Depreciation		(641,739,000)	(568,954,000)
Net Book Value		2,226,829,000	2,223,575,000
Total property
Property, Plant and Equipment [Line Items]
Gross Book Value		4,605,780,000	4,522,937,000
Accumulated Depreciation		(856,291,000)	(750,945,000)
Net Book Value		3,749,489,000	3,771,992,000
Computer equipment
Property, Plant and Equipment [Line Items]
Gross Book Value		23,310,000	24,070,000
Accumulated Depreciation		(17,811,000)	(17,852,000)
Net Book Value		5,499,000	6,218,000
Locomotives and railcars
Property, Plant and Equipment [Line Items]
Gross Book Value		1,011,879,000	993,872,000
Accumulated Depreciation		(328,070,000)	(290,796,000)
Net Book Value		683,809,000	703,076,000
Vehicles and mobile equipment
Property, Plant and Equipment [Line Items]
Gross Book Value		81,433,000	77,928,000
Accumulated Depreciation		(56,178,000)	(48,147,000)
Net Book Value		25,255,000	29,781,000
Signals and crossing equipment
Property, Plant and Equipment [Line Items]
Gross Book Value		75,886,000	75,460,000
Accumulated Depreciation		(46,583,000)	(42,079,000)
Net Book Value		29,303,000	33,381,000
Track equipment
Property, Plant and Equipment [Line Items]
Gross Book Value		66,069,000	55,046,000
Accumulated Depreciation		(23,238,000)	(18,873,000)
Net Book Value		42,831,000	36,173,000
Other equipment
Property, Plant and Equipment [Line Items]
Gross Book Value		87,537,000	77,271,000
Accumulated Depreciation		(43,353,000)	(37,874,000)
Net Book Value		44,184,000	39,397,000
Total equipment
Property, Plant and Equipment [Line Items]
Gross Book Value		1,346,114,000	1,303,647,000
Accumulated Depreciation		(515,233,000)	(455,621,000)
Net Book Value		830,881,000	848,026,000
Construction-in-process [Member]
Property, Plant and Equipment [Line Items]
Gross Book Value		32,644,000	36,903,000
Accumulated Depreciation		0	0
Net Book Value		$ 32,644,000	$ 36,903,000