Note 2 - Risks and Uncertainties (Details Textual) - USD ($) $ in Thousands |
3 Months Ended | |||
|---|---|---|---|---|
Mar. 31, 2020 |
Mar. 31, 2019 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Retained Earnings (Accumulated Deficit), Ending Balance | $ (59,042) | $ (56,617) | ||
| Net Income (Loss) Attributable to Parent, Total | (2,425) | $ (3,252) | ||
| Net Cash Provided by (Used in) Operating Activities, Total | (2,978) | (3,134) | ||
| Cash, Cash Equivalents, and Short-term Investments, Total | 3,300 | |||
| Marketable Securities, Total | 9,300 | |||
| Working Capital | 13,200 | |||
| Working Capital | $ 13,323 | $ 13,906 | $ 7,617 | $ 17,025 |