Note 5 - Property and Equipment - Property and Equipment (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Buildings	$ 355,000	$ 355,000
Machinery and equipment	10,661,000	10,515,000
Office furniture and equipment	1,092,000	1,074,000
Leasehold improvements	506,000	497,000
	12,614,000	12,441,000
Less accumulated depreciation and amortization	(9,968,000)	(9,534,000)
	$ 2,646,000	$ 2,907,000