Note 10 - Activity of Business Segments - Reconciliation of Total Segment Income to Total Consolidated Net Income (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Consolidated net income	$ 8,107,000	$ 437,000	$ 19,668,000	$ 2,665,000
Provision for income taxes	2,490,000	110,000	3,284,000	592,000
Operating Segments [Member]
Consolidated net income	12,187,000	1,849,000	27,756,000	5,959,000
Operating Segments [Member] | Building Supply [Member]
Consolidated net income	1,307,000	1,010,000	4,023,000	2,819,000
Operating Segments [Member] | Disposable Protective Apparel [Member]
Consolidated net income	10,880,000	839,000	23,733,000	3,140,000
Corporate, Non-Segment [Member]
Consolidated net income	$ 1,590,000	$ 1,302,000	$ 4,804,000	$ 2,702,000