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, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Consolidated net income	$ 503,000	$ 693,000	$ 1,522,000	$ 766,000	$ 1,671,000	$ 3,719,000	$ 2,718,000	$ 6,156,000
Provision for income taxes	159,000			196,000			808,000	1,550,000
Operating Segments [Member]
Consolidated net income	1,875,000			2,135,000			7,380,000	11,980,000
Operating Segments [Member] | Building Supply [Member]
Consolidated net income	1,386,000			1,901,000			4,968,000	5,629,000
Operating Segments [Member] | Disposable Protective Apparel [Member]
Consolidated net income	489,000			234,000			2,412,000	6,351,000
Corporate, Non-Segment [Member]
Consolidated net income	$ 1,213,000			$ 1,173,000			$ 3,854,000	$ 4,274,000