Note 12 - Segments and Geographic Information (Detail) - Additional Business Unit Gross Profitability Detail for Products-based Business Segment (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Products segment net sales:
Products segment net sales	$ 29,837		$ 25,752		$ 35,129
Products segment gross profit:
Products segment gross profit	6,237		5,171		6,403
Products Segment [Member]
Products segment net sales:
Products segment net sales	19,268		16,189		15,366
Products segment cost of sales:
Products segment cost of sales	14,450		12,540		12,394
Products segment gross profit:
Products segment gross profit	4,818		3,649		2,972
Pool and Commercial Products [Member]
Products segment net sales:
Products segment net sales	14,948		11,911		12,265
Products segment cost of sales:
Products segment cost of sales	10,367		8,560		7,988
Products segment gross profit:
Products segment gross profit	4,581		3,351		4,277
Government Products/ Research and Development Services [Member]
Products segment net sales:
Products segment net sales	4,320		4,278		3,101
Products segment cost of sales:
Products segment cost of sales	4,083		3,980		3,104
Products segment gross profit:
Products segment gross profit	237		298		(3)
Products Segment Overhead [Member]
Products segment cost of sales:
Products segment cost of sales		[1]		[1]	1,302	[1]
Products segment gross profit:
Products segment gross profit		[1]		[1]	$ (1,302)	[1]

[1] Unallocated manufacturing overhead is defined as costs associated with the operation and shut down of the Solon manufacturing facility which was relocated to the Mexico facility; and specific expenses which are not attributable to a specific business unit but rather are calculated on the total products business segment.