Intangible Assets and Goodwill Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Gross Carrying Amount	$ 1,650,210	$ 1,774,277
Accumulated Amortization	(220,128)	(207,359)
Intangible Assets, Net	$ 1,430,082	$ 1,566,918
Weighted Average Amortization Period (in Years)	47 years	46 years
Total intangible assets, net	$ 1,430,197	$ 1,567,038
Operating license
Non-amortizable intangible assets	115	120
Customer contracts and relationships [Member]
Gross Carrying Amount	740,020	796,354
Accumulated Amortization	(129,833)	(100,621)
Intangible Assets, Net	$ 610,187	$ 695,733
Weighted Average Amortization Period (in Years)	24 years	24 years
Operational Network Rights [Member]
Gross Carrying Amount	$ 466,906	$ 495,088
Accumulated Amortization	(18,262)	(13,260)
Intangible Assets, Net	$ 448,644	$ 481,828
Weighted Average Amortization Period (in Years)	92 years	92 years
Track access agreements [Member]
Gross Carrying Amount	$ 428,617	$ 467,098
Accumulated Amortization	(68,944)	(91,059)
Intangible Assets, Net	$ 359,673	$ 376,039
Weighted Average Amortization Period (in Years)	44 years	41 years
Trade names/trademarks [Member]
Gross Carrying Amount	$ 12,368	$ 13,296
Accumulated Amortization	(1,164)	(919)
Intangible Assets, Net	$ 11,204	$ 12,377
Weighted Average Amortization Period (in Years)	40 years	40 years
Favorable operating leases [Member]
Gross Carrying Amount	$ 2,299	$ 2,441
Accumulated Amortization	(1,925)	(1,500)
Intangible Assets, Net	$ 374	$ 941
Weighted Average Amortization Period (in Years)	5 years	5 years
Intangible Assets, Gross Carrying Value [Member] | Track access agreements [Member]
Finite-Lived Intangible Assets, Period Increase (Decrease)	$ (33,700)
Intangible Assets, Accumulated Amortization [Member] | Track access agreements [Member]
Finite-Lived Intangible Assets, Period Increase (Decrease)	$ 33,700