Note 9 - Activity of Business Segments - Reconciliation of Total Segment Income to Total Consolidated Net Income (Details) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Income	$ 1,430,000	$ 1,146,000	$ 552,000	$ 503,000	$ 693,000	$ 1,522,000	$ 3,128,000	$ 2,718,000
Provision for income taxes	395,000			159,000			974,000	808,000
Operating Segments [Member]
Income	2,955,000			1,875,000			7,546,000	7,380,000
Operating Segments [Member] | Building Supply [Member]
Income	1,973,000			1,386,000			4,456,000	4,968,000
Operating Segments [Member] | Disposable Protective Apparel [Member]
Income	982,000			489,000			3,090,000	2,412,000
Corporate, Non-Segment [Member]
Income	$ 1,130,000			$ 1,213,000			$ 3,444,000	$ 3,854,000