Note 10 - Share-based Compensation - Summary of Non-vested Options (Details)	6 Months Ended
	Sep. 30, 2020 $ / shares shares
Nonvested (in shares) | shares	37,500
Nonvested (in dollars per share) | $ / shares	$ 1.52
Granted (in shares) | shares	130,000
Granted (in dollars per share) | $ / shares	$ 1.20
Vested (in shares) | shares	(5,000)
Vested (in dollars per share) | $ / shares	$ 1.27
Forfeited (in shares) | shares	(37,500)
Forfeited (in dollars per share) | $ / shares	$ 1.52
Nonvested (in shares) | shares	125,000
Nonvested (in dollars per share) | $ / shares	$ 1.19