Note 9 - Summary of Option Activity Under Stock Plans (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Mar. 31, 2015
Outstanding (in shares)	685,000
Outstanding, weighted average exercise price (in dollars per share)	$ 4.65
Outstanding, weighted average remaining contractual term	5 years 146 days	5 years 255 days
Outstanding, aggregate intrinsic value	$ 630,743		$ 566,323
Granted (in shares)
Granted, weighted average exercise price (in dollars per share)
Exercised (in shares)
Exercised, weighted average exercise price (in dollars per share)
Forfeited (in shares)	(4,500)
Forfeited, weighted average exercise price (in dollars per share)	$ 5.01
Outstanding (in shares)	680,500	685,000
Outstanding, weighted average exercise price (in dollars per share)	$ 4.64	$ 4.65
Exercisable (in shares)	519,750
Exercisable, weighted average exercise price (in dollars per share)	$ 4.31
Exercisable, weighted average remaining contractual term	5 years 73 days
Exercisable, aggregate intrinsic value	$ 582,503