Inventories - Components of Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2013	Dec. 31, 2012
Inventory Disclosure [Abstract]
Raw material	$ 30,095	$ 31,350
Work in process	766	921
Deferred costs of long-term contracts	403	604
Finished goods	88,433	104,137
Inventories, gross	119,697	137,012
Inventory reserves	(13,069)	(13,655)
Inventories, net	$ 106,628	$ 123,357