CONCENTRATION OF RISK - Revenues and Accounts Receivable From Our Largest Customers (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Concentration Risk [Line Items]
Accounts Receivable	$ 43,129	$ 52,355
Major Customer A [Member] | Total Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
% of Total Revenue	37.00%	62.00%	63.00%
Major Customer A [Member] | Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Accounts Receivable	$ 14,419	$ 19,588	$ 12,050
Major Customer B [Member] | Total Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
% of Total Revenue	33.00%	24.00%	28.00%
Major Customer B [Member] | Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Accounts Receivable	$ 11,990	$ 17,348	$ 9,128
Major Customer C [Member] | Total Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
% of Total Revenue	10.00%	6.00%	4.00%
Major Customer C [Member] | Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Accounts Receivable	$ 9,071	$ 10,632	$ 1,427