Inventories - Inventories, net (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Inventories [Line Items]
Total raw materials	$ 3,678	$ 3,253
Total work-in-process	6,054	5,902
Total finished goods	2,158	2,068
Total inventories, net	11,890	11,223
Security Products [Member]
Inventories [Line Items]
Total raw materials	2,608	2,310
Total work-in-process	5,592	5,458
Total finished goods	1,598	1,578
Marine Components [Member]
Inventories [Line Items]
Total raw materials	1,070	943
Total work-in-process	462	444
Total finished goods	$ 560	$ 490