Inventories (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Inventory Disclosure [Abstract]
Raw materials	$ 28,592	$ 28,155
Work in process	2,286	2,757
Finished goods	1,841	2,065
Inventory, gross	32,719	32,977
Less: Allowance for excess and obsolete inventories	(579)	(363)	(300)	(350)
Total, net	$ 32,140	$ 32,614