Note 6 - Inventories (Details) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Raw materials	$ 5,664,000	$ 6,456,000
Work in process	3,610,000	4,143,000
Finished goods	5,481,000	5,799,000
	$ 14,755,000	$ 16,398,000	[1]

[1] The condensed consolidated balance sheet as of December 31, 2015 has been prepared using information from the audited consolidated balance sheet as of that date.