ACCOUNTS RECEIVABLE (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accounts Receivable, Net [Abstract]
Third-party customers	$ 150,179	$ 168,805
Less: allowance for bad debts and credit notes	(10,203)	(9,902)
Total accounts receivable	$ 139,976	$ 158,903