CONTRACT BALANCES (Changes in Deferred Revenue) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Change in Contract with Customer, Liability [Roll Forward]
Balance, beginning of period	$ 3,469
Less: Recognition of deferred revenue from beginning balance	(2,179)
Add: Net increase in current period contract liabilities	2,184
Balance, end of period	$ 3,474