Annual report pursuant to Section 13 and 15(d)

Intangible Assets and Goodwill (Finite Lived) (Details)

v3.8.0.1
Intangible Assets and Goodwill (Finite Lived) (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]      
Finite-lived intangible assets, gross $ 138,360 $ 128,267  
Less accumulated amortization 62,663 53,823  
Net other intangible assets 75,697 74,444 $ 69,290
Software license fees      
Finite-Lived Intangible Assets [Line Items]      
Finite-lived intangible assets, gross 87,989 80,839  
Rights to use      
Finite-Lived Intangible Assets [Line Items]      
Finite-lived intangible assets, gross 45,114 45,114  
Customer relationships      
Finite-Lived Intangible Assets [Line Items]      
Finite-lived intangible assets, gross 4,221 1,530  
Right-of-way      
Finite-Lived Intangible Assets [Line Items]      
Finite-lived intangible assets, gross 784 784  
Trade name      
Finite-Lived Intangible Assets [Line Items]      
Finite-lived intangible assets, gross $ 252 $ 0