Note 12 - Commitments and Contingencies (Details Textual) - USD ($) |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2019 |
Sep. 30, 2018 |
Sep. 30, 2019 |
Sep. 30, 2018 |
|
| Gain (Loss) Related to Litigation Settlement, Total | $ 635,000 | $ 635,000 | ||
| Litigation Settlement, Amount Awarded from Other Party | $ 443,000 | |||