Business Segment Information - Schedule of Business Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net sales:
Total net sales	$ 26,473	$ 24,209	$ 79,102	$ 69,701
Operating income:
Total operating income	3,432	2,977	10,632	7,354
Interest income	7	5	19	32
Interest expense		(11)		(127)
Income before taxes	3,439	2,971	10,651	7,259
Corporate, Non-Segment
Operating income:
Total operating income	(1,485)	(1,584)	(4,332)	(5,076)
Security Products | Operating Segments
Net sales:
Total net sales	23,237	21,457	69,246	61,258
Operating income:
Total operating income	4,694	4,578	14,235	12,245
Marine Components | Operating Segments
Net sales:
Total net sales	3,236	2,752	9,856	8,443
Operating income:
Total operating income	$ 223	$ (17)	$ 729	$ 185