Receivables and Allowance for Doubtful Receivables (Allowance for Doubtful Receivables Rollforward) (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
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Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
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| Allowance for Doubtful Accounts Receivable [Roll Forward] | |||
| Balance at beginning of year | $ 4,407 | $ 3,630 | $ 4,542 |
| Charged to costs and expenses | 5,800 | 8,516 | 6,359 |
| Charged to other accounts | 0 | 0 | 0 |
| Write-offs net of recoveries | 6,215 | 7,739 | 7,271 |
| Balance at end of year | $ 3,992 | $ 4,407 | $ 3,630 |
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- Definition Amount of allowance for doubtful accounts increase which was not charged to operations. Specifics of where it was charged is discussed in narrative to the footnote. No definition available.
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- Definition For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- Definition Amount of direct write-downs of accounts receivable charged against the allowance. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of expense related to write-down of receivables to the amount expected to be collected. Includes, but is not limited to, accounts receivable and notes receivable. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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