OTHER SUPPLEMENTAL INFORMATION - Other current assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
OTHER SUPPLEMENTAL INFORMATION
Investment in Richmond County Constructors	$ 2,265	$ 785
Right-of-use lease assets	5,743
Other long-term assets	541	865
Total	$ 8,549	$ 1,650