PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 251,217	$ 229,505
Less: accumulated depreciation	78,424	70,990
Property, plant and equipment, net	172,793	158,515
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,089	3,247
Building [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	46,768	33,051
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	185,863	153,682
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,497	$ 39,525