INCOME TAXES (Reconciliation of Statutory Rate) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal taxes at statutory rate	$ 2,874	$ 2,497	$ (8,873)
State taxes, net of federal benefit	1,245	1,663	(1,414)
Change in valuation allowance	(6,754)	(3,330)	(104,710)
Change in federal and state tax rate	2,322	634	115,545
Percentage depletion	(600)	(656)	(598)
Other	966	(700)	(2,733)
Total income tax expense (benefit)	$ 53	$ 108	$ (2,783)
Effective tax rate	0.40%	0.90%	11.00%

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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