PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Property, plant and equipment
Property, plant and equipment, gross	$ 184,751	$ 184,304
Accumulated depreciation	(124,327)	(122,279)
Property, plant and equipment, net	60,424	62,025
Land, buildings and improvements
Property, plant and equipment
Property, plant and equipment, gross	83,340	82,201
Machinery, equipment and fixtures
Property, plant and equipment
Property, plant and equipment, gross	78,604	79,176
Office furniture, equipment and vehicles
Property, plant and equipment
Property, plant and equipment, gross	22,631	22,689
Construction in progress
Property, plant and equipment
Property, plant and equipment, gross	$ 176	$ 238