PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Property, plant and equipment
Property, plant and equipment, gross	$ 185,696	$ 184,304
Accumulated depreciation	(126,032)	(122,279)
Property, plant and equipment, net	59,664	62,025
Land, buildings and improvements
Property, plant and equipment
Property, plant and equipment, gross	83,821	82,201
Machinery, equipment and fixtures
Property, plant and equipment
Property, plant and equipment, gross	78,951	79,176
Office furniture, equipment and vehicles
Property, plant and equipment
Property, plant and equipment, gross	22,798	22,689
Construction in progress
Property, plant and equipment
Property, plant and equipment, gross	$ 126	$ 238