Description of Business and Summary of Significant Accounting Policies (Contract Balances) (Details) - USD ($) $ in Thousands |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Dec. 31, 2017 |
|
| Description of Business and Summary of Significant Accounting Policies | |||
| Accounts receivable, net | $ 26,751 | $ 29,925 | |
| Changes in the allowance for doubtful accounts | |||
| Balance at the beginning of the period | 1,147 | ||
| Provision | 71 | $ 137 | |
| Write-offs | (21) | ||
| Balance at the end of the period | $ 1,197 | ||
| Payment term, general requirement for payment | 30 days | ||
| Changes in deferred revenue | |||
| Balance at the beginning of the period | $ 7,682 | ||
| Deferred revenue | 2,260 | ||
| Recognition of deferred revenue | (2,067) | ||
| Balance at the end of the period | $ 7,875 | ||