Note 6 - Preferred Stock - Summary of Warrants Activity (Details) - Series F Preferred Warrants [Member] - $ / shares |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Warrants outstanding and exercisable (in shares) | 31,102 | 32,750 |
| Warrants outstanding and exercisable, exercise price (in dollars per share) | $ 975 | $ 975 |
| Exercised, warrants (in shares) | 575 | (1,648) |
| Exercised, warrants, exercise price (in dollars per share) | $ 975 | $ 975 |
| Exercised, warrants (in shares) | (575) | 1,648 |
| Warrants outstanding and exercisable (in shares) | 30,527 | 31,102 |
| Warrants outstanding and exercisable, exercise price (in dollars per share) | $ 975 | $ 975 |