RESTRUCTURING COSTS - Schedule of Restructuring Accrual (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	$ 0
Provision	1,580
Cash Payments	(665)
Restructuring Accrual, Ending Balance	915
Employee Severance
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	1,234
Cash Payments	(367)
Restructuring Accrual, Ending Balance	867
Facility Closing
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	346
Cash Payments	(298)
Restructuring Accrual, Ending Balance	48
Commercial Industrial
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	602
Cash Payments	(284)
Restructuring Accrual, Ending Balance	318
Commercial Industrial | Employee Severance
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	318
Cash Payments	0
Restructuring Accrual, Ending Balance	318
Commercial Industrial | Facility Closing
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	284
Cash Payments	(284)
Restructuring Accrual, Ending Balance	0
Defense
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	799
Cash Payments	(267)
Restructuring Accrual, Ending Balance	532
Defense | Employee Severance
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	799
Cash Payments	(267)
Restructuring Accrual, Ending Balance	532
Defense | Facility Closing
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	0
Cash Payments	0
Restructuring Accrual, Ending Balance	0
Power
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	179
Cash Payments	(114)
Restructuring Accrual, Ending Balance	65
Power | Employee Severance
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	117
Cash Payments	(100)
Restructuring Accrual, Ending Balance	17
Power | Facility Closing
Restructuring Reserve [Roll Forward]
Restructuring Accrual, Beginning Balance	0
Provision	62
Cash Payments	(14)
Restructuring Accrual, Ending Balance	$ 48