PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, plant and equipment
Property, plant and equipment, gross	$ 184,304	$ 183,786
Accumulated depreciation	(122,279)	(117,912)
Property, plant and equipment, net	62,025	65,874
Depreciation expense	7,000	7,700	$ 7,400
Land, buildings and improvements
Property, plant and equipment
Property, plant and equipment, gross	82,201	83,119
Machinery, equipment and fixtures
Property, plant and equipment
Property, plant and equipment, gross	79,176	78,003
Office furniture, equipment and vehicles
Property, plant and equipment
Property, plant and equipment, gross	22,689	22,265
Construction in progress
Property, plant and equipment
Property, plant and equipment, gross	$ 238	$ 399