RESTRUCTURING CHARGES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 3,436	$ 0	$ 3,436	$ 0
Minimum
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected future cost (approximate)	25,000		25,000
Projected annual operating expense reduction (approximate)	65,000
Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected future cost (approximate)	35,000		$ 35,000
Projected annual operating expense reduction (approximate)	90,000
Employee Severance and Professional Service Fees
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 3,436