REVENUE RECOGNITION (Schedule of Changes in Contract Asset and Liability Balances) (Details)	12 Months Ended
	Dec. 31, 2018 USD ($)
Contract assets
Contract assets, January 1, 2018	$ 67,000
Contract assets at beginning of year transferred to accounts receivable	(43,000)
Reversal of contract assets due to changes in transaction price	(24,000)
Contract assets recorded on contracts during the period	36,000
Contract assets, December 31, 2018	36,000
Contract liabilities
Contract liabilities, January 1, 2018	146,000
Recognition of revenue included in beginning of year contract liabilities	(138,000)
Contract liabilities, net of revenue recognized on contracts during the period	263,000
Contract liabilities, December 31, 2018	$ 271,000