Note 10 - Share-based Compensation - Restricted Stock Units (Details) - Restricted Stock Units (RSUs) [Member]	9 Months Ended
	Dec. 31, 2021 $ / shares shares
Nonvested restricted stock units (in shares) | shares	28,188
Nonvested restricted stock units, weighted average grant price (in dollars per share) | $ / shares	$ 2.38
Granted (in shares) | shares	38,672
Granted, weighted average grant price (in dollars per share) | $ / shares	$ 2.91
Vested (in shares) | shares	(34,751)
Vested, weighted average grant price (in dollars per share) | $ / shares	$ 2.84
Forfeited (in shares) | shares	(2,935)
Forfeited, weighted average grant price (in dollars per share) | $ / shares	$ 2.61
Nonvested restricted stock units (in shares) | shares	29,174
Nonvested restricted stock units, weighted average grant price (in dollars per share) | $ / shares	$ 2.52