Note 10 - Activity of Business Segments - Consolidated Net Sales (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net sales	$ 25,500,000	$ 25,500,000	$ 11,415,000	$ 43,654,000	$ 23,718,000
Building Supply [Member] | Operating Segments [Member]
Net sales	7,452,000		6,710,000	15,008,000	13,208,000
Disposable Protective Apparel [Member] | Operating Segments [Member]
Net sales	$ 18,048,000		$ 4,705,000	$ 28,646,000	$ 10,510,000