Income Taxes (Schedule of Deferred Taxes) (Details) - USD ($) $ in Thousands |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Income Taxes [Abstract] | ||
| Federal and state net operating loss carryforwards | $ 22,578 | $ 28,153 |
| Research and development tax credit carryforwards | 2,237 | 2,450 |
| Stock based compensation | 1,665 | 1,561 |
| Other provision and expenses not currently deductible | 4,448 | 2,317 |
| Total deferred tax assets | 30,928 | 34,481 |
| Depreciation and amortization | (507) | (521) |
| Prepaid expenses | (7) | (68) |
| Total deferred liabilities | (514) | (589) |
| Less: valuation allowance | (30,414) | (33,892) |
| Net deferred tax asset |