Inventories - Inventories (Detail) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Components Of Inventory [Line Items]
Raw materials	$ 15,726,000	$ 16,219,000
Work in process	4,623,000	4,161,000
Finished goods	4,819,000	4,494,000
Gross inventory	25,168,000	24,874,000
Less: allowances	(3,066,000)	(2,275,000)
Inventories, net	$ 22,102,000	$ 22,599,000