Note 1 - Summary of Significant Accounting Policies - Antidilutive Securities (Details) - shares |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Potentially dilutive securities (in shares) | 39,209,042 | 36,905,711 | 73,036,318 | 68,368,140 |
| Share-Based Payment Arrangement, Option [Member] | ||||
| Potentially dilutive securities (in shares) | 36,171,577 | 33,790,121 | 41,223,116 | 38,986,186 |
| Convertible Debt Securities [Member] | ||||
| Potentially dilutive securities (in shares) | 0 | 0 | 26,675,169 | 24,165,796 |
| Warrant [Member] | ||||
| Potentially dilutive securities (in shares) | 3,037,465 | 3,115,590 | 5,138,033 | 5,216,158 |