XML 69 R55.htm IDEA: XBRL DOCUMENT v3.10.0.1
Product Warranty (Details) - USD ($)
$ in Thousands
9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Product Warranties Disclosures [Abstract]      
Product Warranty Accrual $ 2,032   $ 2,074
Summary of product warranty activity      
Beginning balance 2,074 $ 2,280  
Charges to expense 1,592 845  
Costs incurred (1,634) (810)  
Ending balance $ 2,032 $ 2,315