Note 15 - 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, 2021	Dec. 31, 2020
Net sales by geographic region
Consolidated sales	$ 68,637,000	$ 102,700,000
Long-lived assets by geographic region
Consolidated long-lived assets	6,064,000	4,353,000
UNITED STATES
Net sales by geographic region
Consolidated sales	65,844,000	90,495,000
Long-lived assets by geographic region
Consolidated long-lived assets	4,623,000	2,787,000
International Member
Net sales by geographic region
Consolidated sales	2,793,000	12,205,000
Long-lived assets by geographic region
Consolidated long-lived assets	$ 1,441,000	$ 1,566,000