Note 9 - Summary of Option Activity Under Stock Plans (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015
Outstanding (in shares)	1,431,716	1,433,216
Outstanding. (in dollars per share)	$ 4.08	$ 4.08
Outstanding	6 years 73 days	6 years 146 days
Outstanding	$ 7,721,341	$ 6,221,909
Forfeited (in shares)	(1,500)
Forfeited. (in dollars per share)	$ 5.84
Exercisable at March 31, 2015 (in shares)		818,800
Exercisable at March 31, 2015 (in dollars per share)		$ 3.73
Exercisable at March 31, 2015		5 years 292 days
Exercisable at March 31, 2015		$ 4,703,645