SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
SUPPLEMENTAL CASH FLOW INFORMATION [Abstract]
Interest paid	$ 120	$ 191
Federal, state, and local income taxes paid, net	5,327	3,588
Income tax receivable applied to long-term taxes payable		1,819
Change in contract receivables	(2,144)	(2,602)
Change in contract liabilities	2,144	2,602
Property, plant, and equipment purchases in accounts payable	$ 2,460	$ 682