WARRANTY COSTS AND OTHER CONTINGENCIES (Tables)
 3 Months Ended
Mar. 31, 2018
WARRANTY COSTS AND OTHER CONTINGENCIES  
Schedule of analysis of warranty accruals
(in thousands)   2018     2017  
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