Note 9 - Activity of Business Segments - Reconciliation of Total Segment Income to Total Consolidated Net Income (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Income	$ 1,146,000	$ 552,000	$ 693,000	$ 1,522,000	$ 1,698,000	$ 2,215,000
Provision for income taxes	438,000		197,000		579,000	649,000
Operating Segments [Member]
Income	2,851,000		2,138,000		4,591,000	5,505,000
Operating Segments [Member] | Building Supply [Member]
Income	1,527,000		1,915,000		2,483,000	3,582,000
Operating Segments [Member] | Disposable Protective Apparel [Member]
Income	1,324,000		223,000		2,108,000	1,923,000
Corporate, Non-Segment [Member]
Income	$ 1,267,000		$ 1,248,000		$ 2,314,000	$ 2,641,000