Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands |
Jun. 30, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Balance Sheets [Abstract] | ||
| Trade receivables, allowance for doubtful accounts | $ 11 | $ 11 |
| Common stock, par value | $ 0.10 | $ 0.10 |
| Common stock, shares authorized | 10,000,000 | 10,000,000 |
| Common stock, shares issued | 3,395,521 | 3,395,521 |
| Common stock, shares outstanding | 3,395,521 | 3,395,521 |