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, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Consolidated net income	$ 693,000	$ 1,522,000	$ 1,671,000	$ 3,719,000	$ 2,215,000	$ 5,390,000
Provision for income taxes	197,000		347,000		649,000	1,354,000
Operating Segments [Member]
Consolidated net income	2,138,000		3,544,000		5,505,000	9,845,000
Operating Segments [Member] | Building Supply [Member]
Consolidated net income	1,915,000		2,177,000		3,582,000	3,729,000
Operating Segments [Member] | Disposable Protective Apparel [Member]
Consolidated net income	223,000		1,367,000		1,923,000	6,116,000
Corporate, Non-Segment [Member]
Consolidated net income	$ 1,248,000		$ 1,526,000		$ 2,641,000	$ 3,101,000