v3.26.1
Note 2 - Significant Accounting Policies - Stock Option Valuation Assumptions (Details) - $ / shares
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dividend yield 0.00% 0.00%
Expected life (in years) (Year) 6 years 3 months  
Weighted-average grant date fair value per share (in dollars per share) $ 1.78 $ 2.93
Minimum [Member]    
Expected volatility 81.00% 79.00%
Risk-free interest rate 3.80% 4.10%
Expected life (in years) (Year)   6 years 3 months
Maximum [Member]    
Expected volatility 82.00% 80.00%
Risk-free interest rate 4.00% 4.50%
Expected life (in years) (Year)   10 years