Summary of Significant Accounting Policies - Roll Forward of Receivable Allowance (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 Beginning of Year | $ 3,043 | $ 2,762 | $ 2,120 |
| Charged to Expense | 11,014 | 10,785 | 9,735 |
| Write-Offs and Other | (9,895) | (10,504) | (9,093) |
| Balance End of Year | $ 4,162 | $ 3,043 | $ 2,762 |
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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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