Note 11 - Segments and Geographic Information (Details) - Additional Business Unit Gross Profitability Detail for Products Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Products segment net sales:
Products segment net sales	$ 7,890	$ 4,827	$ 19,508	$ 14,938
Products segment gross profit:
Products segment gross profit	2,558	930	6,154	3,051
Pool and Commercial Products [Member]
Products segment net sales:
Products segment net sales	1,648	1,451	4,743	4,739
Products segment cost of sales:
Products segment cost of sales	1,062	991	3,027	3,312
Products segment gross profit:
Products segment gross profit	586	460	1,716	1,427
Government Products [Member]
Products segment net sales:
Products segment net sales	6,002	707	11,164	2,563
Products segment cost of sales:
Products segment cost of sales	3,945	445	7,470	1,746
Products segment gross profit:
Products segment gross profit	2,057	262	3,694	817
Research and Development Services [Member] | Products Segment [Member]
Products segment net sales:
Products segment net sales	7,666	2,723	15,963	9,044
Products segment cost of sales:
Products segment cost of sales	5,023	2,009	10,532	6,701
Products segment gross profit:
Products segment gross profit	2,643	714	5,431	2,343
Research and Development Services [Member]
Products segment net sales:
Products segment net sales	16	565	56	1,742
Products segment cost of sales:
Products segment cost of sales	16	573	35	1,643
Products segment gross profit:
Products segment gross profit		(8)	21	99
Products Segment [Member]
Products segment net sales:
Products segment net sales	7,666	2,723	15,963	9,044
Products segment gross profit:
Products segment gross profit	$ 2,643	$ 714	$ 5,431	$ 2,343