Note 15 - Activity of Business Segments - Reconciliation of Total Segment Income to Total Consolidated Net Income (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Consolidated net income	$ 3,000,000	$ 3,625,000
Provision for income taxes	680,000	789,000
Operating Segments [Member]
Consolidated net income	7,347,000	8,420,000
Operating Segments [Member] | Building Supply [Member]
Consolidated net income	3,491,000	3,836,000
Operating Segments [Member] | Disposable Protective Apparel [Member]
Consolidated net income	3,856,000	4,584,000
Corporate, Non-Segment [Member]
Consolidated net income	$ 3,667,000	$ 4,006,000