Property and Equipment and Leases Property and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 5,012,312,000	$ 4,462,019,000
Accumulated depreciation	(797,249,000)	(673,537,000)
Property and equipment, net	4,215,063,000	3,788,482,000
Depreciation expense	159,100,000	135,000,000	$ 119,200,000
Land and land improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	648,498,000	582,383,000
Accumulated depreciation	0	0
Property and equipment, net	648,498,000	582,383,000
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	238,272,000	126,860,000
Accumulated depreciation	(32,624,000)	(22,719,000)
Property and equipment, net	205,648,000	104,141,000
Bridges/tunnels/culverts
Property, Plant and Equipment [Line Items]
Total property and equipment	662,287,000	636,605,000
Accumulated depreciation	(85,040,000)	(60,771,000)
Property and equipment, net	577,247,000	575,834,000
Track property
Property, Plant and Equipment [Line Items]
Total property and equipment	2,508,100,000	2,350,647,000
Accumulated depreciation	(403,778,000)	(357,969,000)
Property and equipment, net	2,104,322,000	1,992,678,000
Total property
Property, Plant and Equipment [Line Items]
Total property and equipment	4,057,157,000	3,696,495,000
Accumulated depreciation	(521,442,000)	(441,459,000)
Property and equipment, net	3,535,715,000	3,255,036,000
Computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	18,633,000	13,997,000
Accumulated depreciation	(11,709,000)	(8,352,000)
Property and equipment, net	6,924,000	5,645,000
Locomotives and railcars
Property, Plant and Equipment [Line Items]
Total property and equipment	653,077,000	531,948,000
Accumulated depreciation	(173,214,000)	(145,073,000)
Property and equipment, net	479,863,000	386,875,000
Vehicles and mobile equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	65,241,000	54,419,000
Accumulated depreciation	(34,656,000)	(31,209,000)
Property and equipment, net	30,585,000	23,210,000
Signals and crossing equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	69,315,000	65,581,000
Accumulated depreciation	(30,754,000)	(22,408,000)
Property and equipment, net	38,561,000	43,173,000
Track equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	28,440,000	27,073,000
Accumulated depreciation	(11,628,000)	(9,019,000)
Property and equipment, net	16,812,000	18,054,000
Other equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	73,405,000	29,532,000
Accumulated depreciation	(13,846,000)	(16,017,000)
Property and equipment, net	59,559,000	13,515,000
Total equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	908,111,000	722,550,000
Accumulated depreciation	(275,807,000)	(232,078,000)
Property and equipment, net	632,304,000	490,472,000
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	47,044,000	42,974,000
Accumulated depreciation	0	0
Property and equipment, net	$ 47,044,000	$ 42,974,000