Warrants (Fair Value of Warrants) (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| Class of Warrant or Right [Line Items] | ||
| Fair Value | $ 1,374 | $ 4,622 |
| Change in Fair Value of common stock warrant liability | 3,248 | (4,599) |
| 2018 January and February Issuance [Member] | ||
| Class of Warrant or Right [Line Items] | ||
| Fair Value | 1,355 | 3,577 |
| 2017 May issuance [Member] | ||
| Class of Warrant or Right [Line Items] | ||
| Fair Value | $ 19 | $ 1,045 |