Note 8 - Stock-based Compensation - Stock-based Compensation Expense 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 expense | $ 243 | $ 166 | $ 457 | $ 362 |
| Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense | ||||
| Stock-based compensation expense | 71 | 55 | 135 | 132 |
| Location, Statement of Income, Balance [Axis]: us-gaap:SellingGeneralAndAdministrativeExpense | ||||
| Stock-based compensation expense | $ 172 | $ 111 | $ 322 | $ 230 |