Annual report pursuant to Section 13 and 15(d)

Software Impairment (Narrative) (Details)

v3.6.0.2
Software Impairment (Narrative) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Plus software impairment charge $ 0 $ 29,839 $ 0
Wireless, Internet, Video, Local Service, and Long Distance Customer Billing Systems [Member]      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Fair Value of remaining capital expenditures   0  
Plus software impairment charge   20,700  
Internally Developed Machine-To-Machine Billing System [Member]      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Plus software impairment charge   7,100  
User Management Software [Member]      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Plus software impairment charge   $ 1,000