Inventories - Components of Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Inventories [Line Items]
Raw material	$ 31,350	$ 45,795
Work in process	921	872
Deferred costs of long-term contracts	604	220
Finished goods	104,137	101,111
Total inventories, gross	137,012	147,998
Inventory reserves	(13,655)	(14,710)
Total inventories, net	$ 123,357	$ 133,288