Note 10 - Activity of Business Segments - Consolidated Net Sales (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Mar. 31, 2019
Net sales	$ 18,154,000	$ 18,154,000	$ 12,304,000
Building Supply [Member] | Operating Segments [Member]
Net sales		7,557,000	6,498,000
Disposable Protective Apparel [Member] | Operating Segments [Member]
Net sales		$ 10,597,000	$ 5,806,000