Note 14 - Stock Based Compensation - Summary of Stock Option Activity (Details) - $ / shares
12 Months Ended
Jan. 13, 2020
Mar. 31, 2022
Mar. 31, 2021
Outstanding, beginning of year (in shares) (in shares)   300,000 300,000
Outstanding, beginning of year, weighted average exercise price (in dollars per share) (in dollars per share)   $ 0.20 $ 0.20
Issued (in shares) (in shares) 300,000 0 0
Issued, weighted average exercise price (in dollars per share) (in dollars per share) $ 0.20 $ 0 $ 0
Exercised (in shares) (in shares)   0 0
Exercised, weighted average exercise price (in dollars per share) (in dollars per share)   $ 0 $ 0
Expired (in shares) (in shares)   0 0
Expired, weighted average exercise price (in dollars per share) (in dollars per share)   $ 0 $ 0
Cancelled (in shares) (in shares)   (300,000)  
Cancelled, weighted average exercise price (in dollars per share) (in dollars per share)   $ 0.20  
Outstanding, end of period (in shares) (in shares)   0 300,000
Outstanding, beginning of year, weighted average exercise price (in dollars per share) (in dollars per share)   $ 0 $ 0.20
Exercisable, end of period (in shares) (in shares)   0 150,000
Exercisable, end of period (in dollars per share) (in dollars per share)   $ 0 $ 0.20