Summary of Inventories (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Inventory, Net [Abstract]
Raw materials	$ 13,876	$ 12,501
Work in process	15,865	12,800
Finished goods	9,848	10,549
Inventory, Gross, Total	39,589	35,850
Less: Progress billings	(1,924)	(4,558)
Total inventories	$ 37,665	$ 31,292