ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
ACCRUED EXPENSES [Abstract]
Sales commissions	$ 2,600	$ 2,609
Subcontracting labor	1,520	1,550
Salaries, bonuses and related benefits	13,479	18,275
Warranty accrual	1,116	1,078
Other	8,503	8,778
Accrued expenses	27,218	$ 32,290
Activity and liability balances related to restructuring costs [Roll Forward]
Liability, beginning balance	0
New charges	947
Cash payment and other settlements	(63)
Liability, ending balance	884
Severance Costs [Member]
Activity and liability balances related to restructuring costs [Roll Forward]
Liability, beginning balance	0
New charges	207
Cash payment and other settlements	(63)
Liability, ending balance	144
Other Restructuring Costs [Member]
Activity and liability balances related to restructuring costs [Roll Forward]
Liability, beginning balance	0
New charges	740
Cash payment and other settlements	0
Liability, ending balance	$ 740