Note 9 - Share-based Compensation - Restricted Stock Units (Details) - Restricted Stock Units (RSUs) [Member]	6 Months Ended
	Sep. 30, 2022 $ / shares shares
Nonvested restricted stock units (in shares) | shares	14,465
Nonvested restricted stock units, weighted average grant price (in dollars per share) | $ / shares	$ 2.22
Granted (in shares) | shares	66,423
Granted, weighted average grant price (in dollars per share) | $ / shares	$ 3.13
Vested (in shares) | shares	(8,312)
Vested, weighted average grant price (in dollars per share) | $ / shares	$ 2.35
Forfeited (in shares) | shares	(680)
Forfeited, weighted average grant price (in dollars per share) | $ / shares	$ 2.82
Nonvested restricted stock units (in shares) | shares	71,896
Nonvested restricted stock units, weighted average grant price (in dollars per share) | $ / shares	$ 3.04