Business and Geographic Segments - Business Segment Information (Detail) (USD $) In Thousands, 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
Net sales:
Total net sales	$ 19,300	$ 21,300	$ 22,200	$ 20,400	$ 18,700	$ 20,100	$ 21,100	$ 19,900	$ 83,196	$ 79,815	$ 76,138
Operating income (loss):
Total operating income		1,600	2,200	1,600	1,400	700	2,400	1,900	5,418	6,412	5,884
Other non-operating income, net										358	336
Interest expense									(479)	(722)	(914)
Income from continuing operations before income taxes									4,939	6,048	5,306
Depreciation and amortization									5,772	6,778	7,676
Total capital expenditure									4,477	3,195	2,120
Security Products [Member]
Net sales:
Total net sales									73,715	71,397	68,005
Operating income (loss):
Total operating income									14,143	14,361	13,066
Depreciation and amortization									2,618	2,976	3,383
Total capital expenditure									2,029	1,714	692
Marine Components [Member]
Net sales:
Total net sales									9,481	8,418	8,133
Operating income (loss):
Total operating income									(819)	(1,223)	(1,432)
Depreciation and amortization									687	907	1,099
Total capital expenditure									713	112	264
Corporate [Member]
Operating income (loss):
Total operating income									(7,906)	(6,726)	(5,750)
Depreciation and amortization									63	42	3
Total capital expenditure									14	36	141
Furniture Components [Member]
Operating income (loss):
Depreciation and amortization									2,404	2,853	3,191
Total capital expenditure									$ 1,721	$ 1,333	$ 1,023