REVENUE RECOGNITION - Schedule of Changes in Contract Asset and Liability Balances (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Contract asset
Contract asset, January 1, 2018	$ 67
Contract assets at beginning of year transferred to accounts receivable	(42)
Contract assets recorded on contracts during the period	2
Contract asset, June 30, 2018	27
Contract liability
Contract liability, January 1, 2018	146
Recognition of revenue included in beginning of year contract liability	(124)
Contract liability, net of revenue recognized on contracts during the period	217
Foreign currency translation	1
Contract liability, June 30, 2018	$ 240