ACCOUNTS RECEIVABLE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Third-party customers	$ 187,937	$ 176,628
Less: allowance for bad debts and credit notes	(9,598)	(9,201)
Total accounts receivable	178,339	167,427
Provision for Doubtful Accounts	$ 3,600	$ 2,100	$ 4,200