Note 10 - Activity of Business Segments - Consolidated Net Sales (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Net sales	$ 14,475,000	$ 30,027,000	$ 55,442,000	$ 73,681,000
Building Supply [Member] | Operating Segments [Member]
Net sales	10,072,000	7,668,000	28,210,000	22,677,000
Disposable Protective Apparel [Member] | Operating Segments [Member]
Net sales	$ 4,403,000	$ 22,359,000	$ 27,232,000	$ 51,004,000