Quarterly Financial Data (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly Financial Data [Line Items]
Net sales	$ 20,674	$ 34,484	$ 34,115	$ 24,248	$ 18,694	$ 31,586	$ 33,218	$ 24,697	$ 113,521	$ 108,195	$ 108,600
Gross profit	2,596	5,688	5,609	3,409	2,123	5,706	6,302	3,898	17,302	18,029	19,615
Net earnings (loss)	$ (1,480)	$ 307	$ 504	$ (1,345)	$ (1,439)	$ 612	$ 980	$ (1,039)	$ (2,014)	$ (886)	$ 152
Net earnings (loss) per share - diluted	$ (0.32)	$ 0.07	$ 0.11	$ (0.30)	$ (0.32)	$ 0.13	$ 0.21	$ (0.23)	$ (0.44)	$ (0.20)	$ 0.03