PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 247,777	$ 229,505
Less: accumulated depreciation	74,709	70,990
Property, plant and equipment, net	173,068	158,515
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,110	3,247
Building [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	40,146	33,051
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	173,117	153,682
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 30,404	$ 39,525