XML 57 R47.htm IDEA: XBRL DOCUMENT v3.8.0.1
WARRANTY COSTS AND OTHER CONTINGENCIES - Analysis of warranty accruals (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]    
Balance at beginning of period $ 5,373 $ 4,629
Less: Payments made during the period (689) (608)
Add: Warranty provision for the period 981 872
Changes to warranty provision for prior periods 38 51
Balance at March 31 $ 5,703 $ 4,944