v3.26.1
Note 6 - Stock-Based Compensation - Option Assumptions (Details)
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
The 2017 Employee Stock Purchase Plan [Member]    
Expected volatility   98.00%
Minimum [Member] | The 2017 Employee Stock Purchase Plan [Member]    
Expected term (in years) (Year) 6 months 6 months
Expected volatility 71.70%  
Risk-free interest rate 3.60% 4.10%
Maximum [Member] | The 2017 Employee Stock Purchase Plan [Member]    
Expected term (in years) (Year) 1 year 1 year
Expected volatility 86.60%  
Risk-free interest rate 3.70% 4.30%
Time-based and Performance Options [Member] | Minimum [Member]    
Expected term (in years) (Year) 5 years 1 month 6 days 5 years
Expected volatility 93.00% 93.00%
Risk-free interest rate 3.70% 4.10%
Time-based and Performance Options [Member] | Maximum [Member]    
Expected term (in years) (Year) 6 years 3 months 18 days 6 years 10 months 24 days
Expected volatility 95.00% 100.00%
Risk-free interest rate 3.80% 4.60%
Performance-based and Market-based Options [Member]    
Expected volatility   90.00%
Performance-based and Market-based Options [Member] | Minimum [Member]    
Expected term (in years) (Year)   5 years 6 months
Risk-free interest rate   4.40%
Performance-based and Market-based Options [Member] | Maximum [Member]    
Expected term (in years) (Year)   8 years 10 months 24 days
Risk-free interest rate   4.60%