Equity Incentive Plan (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
Dec. 31, 2017 |
|
| Employee Service Share-based Compensation, Aggregate Disclosures [Abstract] | |||||
| Stock options granted | 0 | ||||
| Compensation expense for stock options | $ 50 | $ 179 | $ 87 | $ 326 | |
| Unamortized cost of options | $ 137 | $ 137 | |||
| Weighted-average period to recognize currently unrecognized compensation expense | 4 months 24 days | ||||
| Options exercisable | 442,083 | 442,083 | 375,417 | ||
| Intrinsic value of exercisable options | $ 0 | $ 0 | |||
| Weighted-average remaining contractual life of the options outstanding | 6 years 8 months 12 days | ||||