Note 5 - Share-Based Compensation - Schedule of Share-based Compensation Expense (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Share-Based Payment Arrangement, Expense | $ 200 | $ 500 | $ 900 | $ 1,000 |
| Equity Incentive Plan [Member] | ||||
| Share-Based Payment Arrangement, Expense | 223 | 537 | 855 | 1,022 |
| Equity Incentive Plan [Member] | Research and Development [Member] | ||||
| Share-Based Payment Arrangement, Expense | 46 | 58 | 215 | 117 |
| Equity Incentive Plan [Member] | General and Administrative [Member] | ||||
| Share-Based Payment Arrangement, Expense | $ 177 | $ 479 | $ 640 | $ 905 |