Equity Award Plans - Performance-based RSUs (Details) - USD ($) $ in Thousands |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Dec. 31, 2017 |
|
| Additional disclosures | |||
| Stock-based compensation expense | $ 2,389 | $ 2,207 | |
| RSUs | |||
| Additional disclosures | |||
| Number of RSUs outstanding (in shares) | 394,500 | 0 | |
| Performance-based RSU | |||
| Additional disclosures | |||
| Number of RSUs outstanding (in shares) | 394,500 | ||
| Performance-based RSU | Pro Forma | |||
| Additional disclosures | |||
| Stock-based compensation expense | $ 190 | ||
| Unrecognized compensation cost | $ 2,740 | ||
| Weighted-average period for unrecognized compensation cost | 3 years 4 months 10 days | ||