Quarterly report pursuant to Section 13 or 15(d)

Business and Summary of Significant Accounting Principles (Revenue Recognition) (Details)

v3.5.0.2
Business and Summary of Significant Accounting Principles (Revenue Recognition) (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Dec. 31, 2015
Public Utilities, General Disclosures [Line Items]          
Revenues $ 233,766 $ 247,528 $ 464,864 $ 478,617  
Receivables 221,787   221,787   $ 208,384
High Cost Support Program [Member]          
Public Utilities, General Disclosures [Line Items]          
Revenues 16,300 $ 16,900 32,500 $ 34,100  
Receivables $ 45,200   $ 45,200