Summary of Significant Accounting Policies Warranty (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2010
Warranty Accrual [Abstract]      
Product Warranty Accrual $ 152 $ 472 $ 813
Product Warranty Accrual, Preexisting, Increase (Decrease) (242) (63)  
Usage $ (78) $ (278)