Note 3 - Inventories (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Inventory Abnormal Production Costs	$ 0	$ 0	$ 0	$ 250,000
Non Inventoriable Fixed Costs	$ 158,000	$ 35,000	$ 258,000	$ 176,000