Note 3 - Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Restricted cash held as a certificate of deposit | $ 267 | $ 477 |
| Warrant liability | 0 | |
| Fair Value, Inputs, Level 1 [Member] | ||
| Restricted cash held as a certificate of deposit | 267 | 477 |
| Warrant liability | 30,432 | |
| Fair Value, Inputs, Level 2 [Member] | ||
| Restricted cash held as a certificate of deposit | 0 | 0 |
| Warrant liability | 0 | |
| Fair Value, Inputs, Level 3 [Member] | ||
| Restricted cash held as a certificate of deposit | 0 | $ 0 |
| Warrant liability | $ 30,432 |