COMMITMENTS AND CONTINGENCIES (Fair Value Supply Agreement) (Details) - Commitments - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accrued Expenses And Other Current Liabilities | Supply Agreement Liability, Short-term
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of Period	$ 0	$ 166
Payments	0	(166)
Transfer		0
Transfer to accounts payable	0
Balance, End of Period	0	0
Accrued Expenses And Other Current Liabilities | Supply Agreement Liability, Short-term | Selling, general and administrative
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
(Gain)/loss from change in fair value	0	0
Accrued Expenses And Other Current Liabilities | Above Market Supply Agreement Liability, Short-term
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of Period	2,641	0
Payments	(1,817)	(113)
Transfer		3,273
Transfer to accounts payable	(159)
Balance, End of Period	195	2,641
Accrued Expenses And Other Current Liabilities | Above Market Supply Agreement Liability, Short-term | Selling, general and administrative
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
(Gain)/loss from change in fair value	(470)	(519)
Other Noncurrent Liabilities | Supply Agreement Liability, Long-term
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of Period	0	0
Payments	0	0
Transfer		0
Transfer to accounts payable	0
Balance, End of Period	0	0
Other Noncurrent Liabilities | Supply Agreement Liability, Long-term | Selling, general and administrative
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
(Gain)/loss from change in fair value	0	0
Other Noncurrent Liabilities | Above Market Supply Agreement Liability, Long-term
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of Period	0	2,648
Payments	0	(415)
Transfer		(3,273)
Transfer to accounts payable	0
Balance, End of Period	0	0
Other Noncurrent Liabilities | Above Market Supply Agreement Liability, Long-term | Selling, general and administrative
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
(Gain)/loss from change in fair value	$ 0	$ 1,040