v3.25.2
Note 9 - Share-based Compensation - Summary of Option Activity Under Stock Plans (Details) - USD ($)
 12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Outstanding (in shares) 297,000 253,000  
Outstanding, weighted average exercise price (in dollars per share) $ 2.47 $ 2.88  
Outstanding, weighted average remaining contractual term (Year) 6 years 8 months 12 days 7 years 1 month 6 days 7 years 6 months
Outstanding, aggregate intrinsic value $ 0 $ 0 $ 0
Granted (in shares) 50,000 50,000  
Granted, weighted average exercise price (in dollars per share) $ 0.78 $ 0.79  
Expired (in shares) (25,000) (6,000)  
Expired, weighted average exercise price (in dollars per share) $ 2.57 $ 5.56  
Granted, weighted average exercise price (in dollars per share) $ 0.78 $ 0.79  
Outstanding (in shares) 322,000 297,000 253,000
Outstanding, weighted average exercise price (in dollars per share) $ 2.2 $ 2.47 $ 2.88
Exercisable (in shares) 222,000    
Exercisable, weighted average exercise price (in dollars per share) $ 2.64    
Exercisable, weighted average remaining contractual term (Year) 5 years 9 months 18 days    
Exercisable, aggregate intrinsic value $ 0    
Vested and expected to vest (in shares) 316,216    
Vested and expected to vest, weighted average exercise price (in dollars per share) $ 2.22    
Vested and expected to vest, weighted average remaining contractual term (Year) 6 years 8 months 12 days    
Vested and expected to vest, aggregate intrinsic value $ 0