Note 8 - Equity - Effect of Recording Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Allocated share-based compensation expense	$ 630	$ 659	$ 1,867	$ 1,868
Cost of Sales [Member]
Allocated share-based compensation expense	111	104	236	279
Research and Development Expense [Member]
Allocated share-based compensation expense	66	70	181	198
Sales and Marketing [Member]
Allocated share-based compensation expense	160	264	512	770
General and Administrative Expense [Member]
Allocated share-based compensation expense	$ 294	$ 221	$ 938	$ 621