XML 63 R53.htm IDEA: XBRL DOCUMENT v3.19.1
Product Warranty (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Product Warranties Disclosures [Abstract]      
Product Warranty Accrual $ 2,021   $ 1,916
Summary of product warranty activity      
Beginning balance 1,916 $ 2,074  
Charges to expense 453 741  
Costs incurred (348) (788)  
Ending balance $ 2,021 $ 2,027