Business Description, Basis of Presentation and Significant Accounting Policies Summary of Significant Accounting Policies - Warranties (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary of Significant Accounting Policies - Warranties (Details) [Abstract]
Product Warranty Accrual	$ 385	$ 385	$ 467
Warranty accruals/additions	132	443
Warranty Usage	$ (132)	$ (525)