ACCOUNTING POLICIES (Details 2) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) bank	Dec. 31, 2016 USD ($) bank
Allowance for doubtful accounts
Normal credit term granted to customers	30 days
Allowance for doubtful accounts receivable | $	$ 1,300	$ 1,999
Concentration of credit risk
Number of banks who hold majority of cash and cash equivalents | bank	2	2