SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
SUPPLEMENTAL CASH FLOW INFORMATION [Abstract]
Interest paid	$ 19	$ 72
Federal, state, and local income taxes paid, net		3,476
Change in contract receivables	2,195	817
Change in contract liabilities	(2,195)	(817)
Property, plant, and equipment purchases in accounts payable	$ 1,308	$ 520