Note 9 - Share-based Compensation - Restricted Stock Units (Details) - Restricted Stock Units (RSUs) [Member]	3 Months Ended
	Jun. 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	850
Granted, weighted average grant price (in dollars per share) | $ / shares	$ 3.03
Vested (in shares) | shares	(2,277)
Vested, weighted average grant price (in dollars per share) | $ / shares	$ 2.29
Forfeited (in shares) | shares	(170)
Forfeited, weighted average grant price (in dollars per share) | $ / shares	$ 2.52
Nonvested restricted stock units (in shares) | shares	12,868
Nonvested restricted stock units, weighted average grant price (in dollars per share) | $ / shares	$ 2.26