Product Warranties Schedule of Product Liability (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Product warranty accrual, at the beginning of the period	$ 1,229	$ 591	$ 983	$ 605
Warranty expenses accrued	99	436	611	707
Warranty settlements made	(552)	(303)	(818)	(588)
Product warranty accrual, at the end of period	$ 776	$ 724	$ 776	$ 724
Minimum
Product Warranty [Line Items]
Product Liability, Warranty Period			1 year
Maximum
Product Warranty [Line Items]
Product Liability, Warranty Period			3 years