GOODWILL AND INTANGIBLE ASSETS (Details 2) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 29,217	$ 29,110
Finite-Lived Intangible Assets, Accumulated Amortization	(14,626)	(14,319)
Finite-Lived Intangible Assets, Net	14,591	14,791
Other intangible assets, net	26,340	26,386
Technical Know How [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	12,989	12,997
Finite-Lived Intangible Assets, Accumulated Amortization	(8,187)	(8,067)
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	9,017	9,026
Finite-Lived Intangible Assets, Accumulated Amortization	(2,316)	(2,204)
Land Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	2,765	2,667
Finite-Lived Intangible Assets, Accumulated Amortization	(406)	(378)
Patents, trade names, drawings, and other [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	4,446	4,420
Finite-Lived Intangible Assets, Accumulated Amortization	(3,717)	(3,670)
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 11,749	$ 11,595