SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) customer	Dec. 31, 2016 USD ($) customer	Dec. 31, 2015 USD ($)
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of year	$ 2,144	$ 2,351	$ 3,169
Provisions for bad debts, included in selling, general and administrative	1,542	2,385	3,179
Uncollectible receivables written off	(707)	(2,592)	(3,997)
Balance at end of year	$ 2,979	$ 2,144	2,351
Concentrations of credit and customer risk
Number of customers accounting for more than 10% of consolidated revenues | customer	0	0
Debt issuance costs
Unamortized Debt issuance Costs	$ 2,900
Agreement Debt Issuance Cost	3,400
Amortization of debt issuance costs	$ 4,031	$ 3,435	$ 576
Customer Concentration Risk
Concentrations of credit and customer risk
Concentration Risk, Percentage			10.60%