Note 10 - Activity of Business Segments - Consolidated Net Sales (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net sales	$ 17,806,000	$ 25,500,000	$ 40,967,000	$ 43,654,000
Building Supply [Member] | Operating Segments [Member]
Net sales	9,798,000	7,452,000	18,138,000	15,008,000
Disposable Protective Apparel [Member] | Operating Segments [Member]
Net sales	$ 8,008,000	$ 18,048,000	$ 22,829,000	$ 28,646,000