RESTRUCTURING - Summary of Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 78	$ 144
Operating Segments | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	78	144
Operating Segments | Gain on asset disposal | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	(116)
Operating Segments | Contract Termination Costs | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	39
Operating Segments | Equipment Moving Costs | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	144
Operating Segments | Other Exit Costs | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 11	91
Operating Segments | Severance | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses		$ 53