PROPERTY, PLANT & EQUIPMENT (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	$ 308,215	$ 322,885
Less accumulated depreciation	202,450	208,178
Net property, plant and equipment	105,765	114,707
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	3,590	3,631
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	107,100	107,944
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	195,276	205,331
Property under construction
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	$ 2,249	$ 5,979

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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