PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 248,034	$ 245,141
Less: accumulated depreciation	83,408	79,387
Property, plant and equipment, net	164,626	165,754
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,239	4,208
Building [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	47,316	45,735
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	181,547	177,841
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,932	$ 17,357