Note 10 - Activity of Business Segments - Reconciliation of Total Segment Income to Total Consolidated Net Income (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Consolidated net income	$ 6,220,000	$ 1,010,000	$ 11,561,000	$ 2,228,000
Provision for income taxes	1,822,000	238,000	794,000	481,000
Operating Segments [Member]
Consolidated net income	9,707,000	1,778,000	15,570,000	4,110,000
Operating Segments [Member] | Building Supply [Member]
Consolidated net income	1,307,000	900,000	2,716,000	1,809,000
Operating Segments [Member] | Disposable Protective Apparel [Member]
Consolidated net income	8,400,000	878,000	12,854,000	2,301,000
Corporate, Non-Segment [Member]
Consolidated net income	$ 1,665,000	$ 530,000	$ 3,215,000	$ 1,401,000