Note 6 - Inventories - Inventories (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Raw materials	$ 4,081,000	$ 4,313,000
Work in process	1,609,000	2,535,000
Finished goods	3,774,000	4,146,000
	$ 9,464,000	$ 10,994,000	[1]

[1] The condensed consolidated balance sheet as of December 31, 2016 has been prepared using information from the audited consolidated balance sheet as of that date.