Product Warranties (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Product Warranties [Abstract]
Beginning Balance	$ 1,340	$ 1,140
Payments and replacement product	(440)	(272)
Additions to warranty reserve for warranties issued during the period	725	480
Change in the warranty reserve for pre-existing warranties	(1)	(8)
Ending Balance	$ 1,624	$ 1,340
Warranty contract term for the equipment project	18 months from shipment date or 12 months from project startup date