Inventories - Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Inventory [Line Items]
Total raw materials	$ 2,941	$ 2,661
Total work-in-process	11,771	11,130
Total finished goods	3,636	3,311
Total inventories, net	18,348	17,102
Security Products
Inventory [Line Items]
Total raw materials	2,134	2,001
Total work-in-process	9,138	9,018
Total finished goods	2,582	2,363
Marine Components
Inventory [Line Items]
Total raw materials	807	660
Total work-in-process	2,633	2,112
Total finished goods	$ 1,054	$ 948