Note 10 - Activity of Business Segments - Reconciliation of Total Segment Income to Total Consolidated Net Income (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income	$ 576,000	$ 552,000
Provision for income taxes	146,000	141,000
Operating Segments [Member]
Income	1,995,000	1,740,000
Operating Segments [Member] | Building Supply [Member]
Income	963,000	956,000
Operating Segments [Member] | Disposable Protective Apparel [Member]
Income	1,032,000	784,000
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Income	$ 1,273,000	$ 1,047,000