Inventories (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Inventory Disclosure [Abstract]
Raw materials	$ 33,694		$ 28,592
Work in process	2,249		2,286
Finished goods	2,099		1,841
Inventory, gross	38,042		32,719
Less: Allowance for excess and obsolete inventories	(802)	(735)	(579)	(804)	(537)	(363)
Total, net	$ 37,240		$ 32,140