Note 9 - Share-based Compensation - Summary of Non-vested Options (Details)	3 Months Ended
	Jun. 30, 2018 $ / shares shares
Nonvested (in shares) | shares	120,000
Granted (in shares) | shares
Vested (in shares) | shares
Forfeited (in shares) | shares
Nonvested (in shares) | shares	120,000
Nonvested (in dollars per share) | $ / shares	$ 1.81
Granted (in dollars per share) | $ / shares
Vested (in dollars per share) | $ / shares
Forfeited (in dollars per share) | $ / shares
Nonvested (in dollars per share) | $ / shares	$ 1.81