Business and Summary of Significant Accounting Principles (Revenue Recognition) (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
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| Public Utilities, General Disclosures [Line Items] | |||||||||||
| Revenues | $ 232,293 | $ 236,655 | $ 233,766 | $ 231,098 | $ 241,344 | $ 258,573 | $ 247,528 | $ 231,089 | $ 933,812 | $ 978,534 | $ 910,198 |
| Receivables | 219,794 | $ 208,384 | $ 219,794 | 208,384 | |||||||
| Urban High Cost Support Program [Member] | |||||||||||
| Public Utilities, General Disclosures [Line Items] | |||||||||||
| Percentage Phase Down, Decrease in Support Payments, Maximum | 60.00% | ||||||||||
| High Cost Support Program [Member] | |||||||||||
| Public Utilities, General Disclosures [Line Items] | |||||||||||
| Revenues | $ 64,100 | $ 66,200 | $ 66,700 | ||||||||
| Receivables | $ 43,900 | $ 43,900 | |||||||||
| X | ||||||||||
- Definition Percentage Phase Down of 2011 support payments under High Cost program No definition available.
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| X | ||||||||||
- Definition Amounts due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer) for goods or services (including trade receivables) that have been delivered or sold in the normal course of business. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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| X | ||||||||||
- Definition Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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