Note 14 - Activity of Business Segments - Consolidated Net Sales and Long-lived Asset Information by Geographic Area (Details) - Reportable Geographical Components [Member] - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Net sales by geographic region
Consolidated sales	$ 46,176,000	$ 44,955,000
Long-lived assets by geographic region
Consolidated long-lived assets	2,646,000	2,907,000
UNITED STATES
Net sales by geographic region
Consolidated sales	45,068,000	43,753,000
Long-lived assets by geographic region
Consolidated long-lived assets	2,338,000	2,564,000
International Member
Net sales by geographic region
Consolidated sales	1,108,000	1,202,000
Long-lived assets by geographic region
Consolidated long-lived assets	$ 308,000	$ 343,000