Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Schedule of Inventory [Line Items]
Raw materials	$ 14,025	$ 15,068
Work in process	13,101	11,569
Finished goods	10,086	9,915
Inventory, Gross, Total	37,212	36,552
Less: Progress billings	(3,919)	(2,706)
Total inventories	$ 33,293	$ 33,846