Note 10 - Activity of Business Segments - Reconciliation of Total Segment Income to Total Consolidated Net Income (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Consolidated net income	$ 550,000	$ 507,000
Provision for income taxes	222,000	226,000
Operating Segments [Member]
Consolidated net income	2,016,000	1,802,000
Operating Segments [Member] | Building Supply [Member]
Consolidated net income	962,000	1,012,000
Operating Segments [Member] | Disposable Protective Apparel [Member]
Consolidated net income	458,000	335,000
Operating Segments [Member] | Infection Control [Member]
Consolidated net income	596,000	455,000
Corporate, Non-Segment [Member]
Consolidated net income	$ 1,244,000	$ 1,069,000