Property and Equipment and Leases Property and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Gross Book Value	$ 5,479,665,000	$ 5,012,312,000
Accumulated Depreciation	(976,346,000)	(797,249,000)
Net Book Value	4,503,319,000	4,215,063,000
Depreciation expense	172,300,000	159,100,000	$ 135,000,000
Land and land improvements
Property, Plant and Equipment [Line Items]
Gross Book Value	735,054,000	648,498,000
Accumulated Depreciation	0	0
Net Book Value	735,054,000	648,498,000
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Gross Book Value	214,980,000	238,272,000
Accumulated Depreciation	(43,431,000)	(32,624,000)
Net Book Value	171,549,000	205,648,000
Bridges/tunnels/culverts
Property, Plant and Equipment [Line Items]
Gross Book Value	692,324,000	662,287,000
Accumulated Depreciation	(103,521,000)	(85,040,000)
Net Book Value	588,803,000	577,247,000
Track property
Property, Plant and Equipment [Line Items]
Gross Book Value	2,639,961,000	2,508,100,000
Accumulated Depreciation	(477,366,000)	(403,778,000)
Net Book Value	2,162,595,000	2,104,322,000
Total property
Property, Plant and Equipment [Line Items]
Gross Book Value	4,282,319,000	4,057,157,000
Accumulated Depreciation	(624,318,000)	(521,442,000)
Net Book Value	3,658,001,000	3,535,715,000
Computer equipment
Property, Plant and Equipment [Line Items]
Gross Book Value	20,449,000	18,633,000
Accumulated Depreciation	(14,927,000)	(11,709,000)
Net Book Value	5,522,000	6,924,000
Locomotives and railcars
Property, Plant and Equipment [Line Items]
Gross Book Value	893,911,000	653,077,000
Accumulated Depreciation	(217,704,000)	(173,214,000)
Net Book Value	676,207,000	479,863,000
Vehicles and mobile equipment
Property, Plant and Equipment [Line Items]
Gross Book Value	72,388,000	65,241,000
Accumulated Depreciation	(41,257,000)	(34,656,000)
Net Book Value	31,131,000	30,585,000
Signals and crossing equipment
Property, Plant and Equipment [Line Items]
Gross Book Value	72,210,000	69,315,000
Accumulated Depreciation	(37,632,000)	(30,754,000)
Net Book Value	34,578,000	38,561,000
Track equipment
Property, Plant and Equipment [Line Items]
Gross Book Value	48,931,000	28,440,000
Accumulated Depreciation	(15,663,000)	(11,628,000)
Net Book Value	33,268,000	16,812,000
Other equipment
Property, Plant and Equipment [Line Items]
Gross Book Value	57,547,000	73,405,000
Accumulated Depreciation	(24,845,000)	(13,846,000)
Net Book Value	32,702,000	59,559,000
Total equipment
Property, Plant and Equipment [Line Items]
Gross Book Value	1,165,436,000	908,111,000
Accumulated Depreciation	(352,028,000)	(275,807,000)
Net Book Value	813,408,000	632,304,000
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Gross Book Value	31,910,000	47,044,000
Accumulated Depreciation	0	0
Net Book Value	$ 31,910,000	$ 47,044,000