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, 2023	Dec. 31, 2022
Revenues	$ 61,232,000	$ 61,981,000
Consolidated long-lived assets	5,587,000	5,742,000
UNITED STATES
Revenues	60,882,000	60,489,000
Consolidated long-lived assets	4,340,000	4,380,000
International Member
Revenues	350,000	1,492,000
Consolidated long-lived assets	$ 1,247,000	$ 1,362,000