Note 9 - Share-based Compensation - Summary of Non-vested Options (Details)	6 Months Ended
	Sep. 30, 2017 $ / shares shares
Nonvested (in shares) | shares	19,500
Nonvested (in dollars per share) | $ / shares	$ 2.93
Granted (in shares) | shares	75,000
Granted (in dollars per share) | $ / shares	$ 1.71
Vested (in shares) | shares	(15,000)
Vested (in dollars per share) | $ / shares	$ 2.73
Forfeited (in shares) | shares
Forfeited (in dollars per share) | $ / shares
Nonvested (in shares) | shares	79,500
Nonvested (in dollars per share) | $ / shares	$ 1.82