Intangible Assets, Other Assets, Net and Goodwill Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012 years	Dec. 31, 2011 years
Gross Carrying Amount	$ 680,648	$ 230,131
Accumulated Amortization	46,465	35,525
Net Assets	634,183	194,606
Weighted Average Amortization Period	41	37
Total intangible assets, net	670,206	230,628
Perpetual track access agreements
Indefinite-lived Intangible Assets	35,891	35,891
Operating license
Indefinite-lived Intangible Assets	132	131
Service agreements
Gross Carrying Amount	37,622	37,622
Accumulated Amortization	12,214	10,881
Net Assets	25,408	26,741
Weighted Average Amortization Period	28	28
Customer contracts and relationships
Gross Carrying Amount	150,532	57,859
Accumulated Amortization	17,421	14,501
Net Assets	133,111	43,358
Weighted Average Amortization Period	35	27
Track access agreements
Gross Carrying Amount	492,494	134,650
Accumulated Amortization	16,830	10,143
Net Assets	$ 475,664	$ 124,507
Weighted Average Amortization Period	44	43