INVENTORIES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Significant components of inventory
Raw materials	$ 17,963		$ 17,963		$ 12,365
Finished goods	20,223		20,223		24,724
Materials and supplies					453
Inventory net	38,186		38,186		37,542
Inventory write-downs	500	$ 100	566	$ 209
Inventory Valuation Reserves	$ 4,400		$ 4,400		$ 4,100