Note 2 - Inventories - Components of Inventory (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Mar. 31, 2017
Raw materials		$ 326	$ 347
Work in process		2,504	2,323
Finished goods (1)	[1]	6,335	5,173
Supplies		150	129
Inventories, net		$ 9,315	$ 7,972

[1] Net of reserve for obsolescence of $3,000 at September 30, 2017 and March 31, 2017, respectively.