Business Segment Information - Schedule of Business Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net sales:
Total net sales	$ 24,209	$ 21,281	$ 69,701	$ 63,856
Operating income:
Total operating income	2,977	1,635	7,354	5,376
Other non-operating income, net	5		32
Interest expense	(11)	(114)	(127)	(345)
Income from continuing operations before income taxes	2,971	1,521	7,259	5,031
Security Products
Net sales:
Total net sales	21,457	18,873	61,258	56,315
Operating income:
Total operating income	4,578	3,758	12,245	10,899
Marine Components
Net sales:
Total net sales	2,752	2,408	8,443	7,541
Operating income:
Total operating income	(17)	(181)	185	(330)
Corporate Operating Expense
Operating income:
Total operating income	$ (1,584)	$ (1,942)	$ (5,076)	$ (5,193)