SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
SUPPLEMENTAL CASH FLOW INFORMATION [Abstract]
Interest paid	$ 191	$ 416
Federal, state, and local income taxes paid, net	3,588	1,727
Income tax receivable applied to long-term taxes payable	1,819
Change in contract receivables	(2,602)
Change in contract liabilities	2,602
Property, plant, and equipment purchases in accounts payable	$ 682	$ 183