Note 1 - Summary of Significant Accounting Policies (Details) - Product Warranty Reserve Activity (Approximation [Member], USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Approximation [Member]
Note 1 - Summary of Significant Accounting Policies (Details) - Product Warranty Reserve Activity [Line Items]
Beginning Balance	$ 209,000	$ 253,000
Amounts charged to expense	357,000	184,000
Actual warranty costs paid	(324,000)	(228,000)
Ending Balance	$ 242,000	$ 209,000