Stock incentive plan - Options outstanding under company's stock incentive plan (Details) - USD ($) |
9 Months Ended | |
|---|---|---|
Sep. 30, 2020 |
Sep. 30, 2019 |
|
| Options | ||
| Options outstanding, beginning of period | 734 | 734 |
| Granted | 0 | 0 |
| Forfeited | 0 | 0 |
| Exercised | 0 | 0 |
| Options outstanding, end of period | 734 | 734 |
| Options exercisable, end of period | 734 | 734 |
| Weighted Average Exercise Price | ||
| Options outstanding, beginning of period | $ 25.63 | $ 25.63 |
| Granted | 0 | 0 |
| Forfeited | 0 | 0 |
| Exercised | 0 | 0 |
| Options outstanding, end of period | 25.63 | 25.63 |
| Fair Value Per Share | ||
| Options outstanding, beginning of period | 9.76 | 9.76 |
| Granted | 0 | 0 |
| Forfeited | 0 | 0 |
| Exercised | 0 | 0 |
| Options outstanding, end of period | $ 9.76 | $ 9.76 |
| Intrinsic Value Options outstanding | $ 0 | $ 0 |