Note 15 - Segments and Geographic Information (Details) - Additional Business Unit Gross Profitability Detail for Products Segment (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Products segment net sales:
Products segment net sales	$ 21,533	$ 23,375	$ 20,453
Products segment gross profit:
Products segment gross profit	4,579	3,972	3,825
Pool and Commercial Products [Member]
Products segment net sales:
Products segment net sales	5,966	8,486	6,612
Products segment cost of sales:
Products segment cost of sales	4,148	6,170	4,607
Products segment gross profit:
Products segment gross profit	1,818	2,316	2,005
Government Products/ Research and Development Services [Member]
Products segment net sales:
Products segment net sales	5,720	4,320	4,278
Products segment cost of sales:
Products segment cost of sales	4,445	4,083	3,980
Products segment gross profit:
Products segment gross profit	1,275	237	298
Products Segment [Member]
Products segment net sales:
Products segment net sales	11,686	12,806	10,890
Products segment cost of sales:
Products segment cost of sales	8,593	10,253	8,587
Products segment gross profit:
Products segment gross profit	$ 3,093	$ 2,553	$ 2,303