PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	$ 147,984		$ 149,104
Accumulated depreciation	(101,337)		(100,349)
Property, plant and equipment, net	46,647		48,755
Depreciation expense	3,500	$ 3,700
Land [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	2,238		2,234
Buildings and Improvements [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	30,025		30,061
Machinery and Equipment [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	113,202		113,780
Construction in Progress [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	$ 2,519		$ 3,029