Inventories (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Inventory Disclosure [Abstract]
Raw materials	$ 12,576	$ 13,170
Work in progress	3,469	1,709
Finished goods	4,047	3,254
Supplies	927	804
Total Inventories	21,019	18,937
Inventory reserve	(314)	(264)
Net Inventories	$ 20,705	$ 18,673