Note 10 - Equity Incentive Plans - Total Stock-based Compensation Recognized for Options 2 (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Stock-based compensation | $ 1,290 | $ 2,121 | $ 2,772 | $ 4,580 |
| Location, Statement of Income, Balance [Axis]: us-gaap:GeneralAndAdministrativeExpense | ||||
| Stock-based compensation | 644 | 627 | 1,314 | 1,384 |
| Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense | ||||
| Stock-based compensation | $ 646 | $ 1,494 | $ 1,458 | $ 3,196 |