Stock-Based Compensation - Stock-based compensation expense (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
Sep. 30, 2021 |
Sep. 30, 2020 |
|
Stock-Based Compensation | ||||
Stock options | $ 74 | $ 140 | $ 436 | $ 535 |
Restricted stock units | 87 | 165 | 71 | 640 |
Deferred stock units | (131) | 204 | ||
Total | $ 30 | $ 305 | $ 711 | $ 1,175 |