Revenue Recognition (Contract Balances) (Details) - USD ($) $ in Thousands |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2019 |
Mar. 31, 2018 |
Dec. 31, 2018 |
|
| Revenue Recognition | |||
| Accounts receivable, net | $ 30,316 | $ 33,016 | |
| Allowance for Doubtful Accounts Receivable [Roll Forward] | |||
| Balance at the beginning of the period | 1,529 | ||
| Provision | 8 | $ 71 | |
| Write-offs | (291) | ||
| Balance at the end of the period | $ 1,246 | ||
| Payment term, general requirement for payment | 30 days | ||
| Balance at the beginning of the period | $ 8,699 | ||
| Deferred revenue | 4,593 | ||
| Recognition of deferred revenue | (4,548) | ||
| Balance at the end of the period | $ 8,744 | ||