RESTRUCTURING - Summary of Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring expenses, net	$ 324	$ 217	$ 402	$ 361
Operating Segments | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses, net	324	217	402	361
Operating Segments | Gain on asset disposal | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses, net	(519)		(636)
Operating Segments | Contract Termination Costs | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses, net	4		43
Operating Segments | Equipment Moving Costs | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses, net	82		227
Operating Segments | Other Exit Costs | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses, net	45	35	56	126
Operating Segments | Severance | NobelClad
Restructuring Cost and Reserve [Line Items]
Restructuring expenses, net	$ 712	$ 182	$ 712	$ 235