Note 10 - Activity of Business Segments - Consolidated Net Sales (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net sales	$ 30,027,000	$ 30,027,000	$ 12,027,000	$ 73,681,000	$ 35,745,000
Building Supply [Member] | Operating Segments [Member]
Net sales		7,668,000	7,215,000	22,677,000	20,423,000
Disposable Protective Apparel [Member] | Operating Segments [Member]
Net sales		$ 22,359,000	$ 4,812,000	$ 51,004,000	$ 15,322,000