Note 13 - Stock-based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2022 |
Sep. 30, 2021 |
Sep. 30, 2022 |
Sep. 30, 2021 |
|
| Stock-based compensation expense | $ 701 | $ 1,221 | $ 2,237 | $ 3,482 |
| Cost of Sales [Member] | ||||
| Stock-based compensation expense | 13 | 24 | 48 | 67 |
| Research and Development Expense [Member] | ||||
| Stock-based compensation expense | 139 | 216 | 466 | 597 |
| Selling, General and Administrative Expenses [Member] | ||||
| Stock-based compensation expense | $ 549 | $ 981 | $ 1,723 | $ 2,818 |