Note 11 - Stock-based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands |
9 Months Ended | |
---|---|---|
Sep. 30, 2022 |
Sep. 30, 2021 |
|
Share-based compensation expense | $ 857 | $ 951 |
General and Administrative Expense [Member] | ||
Share-based compensation expense | 697 | 798 |
Research and Development Expense [Member] | ||
Share-based compensation expense | $ 160 | $ 153 |