Description of Business and Summary of Significant Accounting Policies (Warranties) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Changes in the product warranty liability      
Balance at the beginning of the period $ 2,032 $ 1,945 $ 1,415
Warranty costs accrued 4,040 3,147 2,458
Warranty claims (3,548) (3,060) (1,928)
Balance at the end of the period $ 2,524 $ 2,032 $ 1,945
Alternate      
Product Warranty      
Product warranty period 3 years    
Minimum      
Product Warranty      
Product warranty period 2 years    
Maximum      
Product Warranty      
Product warranty period 10 years