RESTRUCTURING ACTIVITIES - Liabilities Recorded For The Restructuring Plan (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Restructuring Cost and Reserve [Roll Forward]
Beginning balance	$ 1,216
Recognized Restructuring Expense	8,628
Costs Paid or Otherwise Settled	(8,661)
Ending balance	1,183
Severance
Restructuring Cost and Reserve [Roll Forward]
Beginning balance	0
Recognized Restructuring Expense	6,052
Costs Paid or Otherwise Settled	(6,052)
Ending balance	0
Other cash restructuring expenses
Restructuring Cost and Reserve [Roll Forward]
Beginning balance	1,216
Recognized Restructuring Expense	2,576
Costs Paid or Otherwise Settled	(2,609)
Ending balance	$ 1,183