Business Segment Information - Schedule of Business Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net sales:
Total net sales	$ 21,453	$ 20,428
Operating income:
Total operating income	1,434	1,583
Other non-operating income, net	16
Interest expense	(59)	(121)
Income from continuing operations before income taxes	1,391	1,462
Security Products [Member]
Net sales:
Total net sales	18,974	18,195
Operating income:
Total operating income	3,193	3,471
Marine Components [Member]
Net sales:
Total net sales	2,479	2,233
Operating income:
Total operating income	(110)	(250)
Corporate Operating Expense [Member]
Operating income:
Total operating income	$ (1,649)	$ (1,638)