REVENUE RECOGNITION - Schedule of Changes in Contract Asset and Liability Balances (Details)	3 Months Ended
	Mar. 31, 2018 USD ($)
Contract asset
Contract asset, January 1, 2018	$ 67,000
Contract assets at beginning of year transferred to accounts receivable	(42,000)
Contract assets recorded on contracts during the period	2,000
Contract asset, March 31, 2018	27,000
Contract liability
Contract liability, January 1, 2018	140,000
Recognition of revenue included in beginning of year contract liability	(72,000)
Contract liability, net of revenue recognized on contracts during the period	208,000
Foreign currency translation	2,000
Contract liability, March 31, 2018	$ 278,000