INCOME TAXES (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
U.S. federal corporate income tax rate	21.00%	21.00%	21.00%
State net operating loss carryforwards	$ 67,756	$ 67,354
Interest and penalties recognized as income tax expense (benefit)	36	(11)	$ (1,477)
Balance of accrued interest and penalties included in liability for unrecognized income tax benefits	336	301	312
Unrecognized income tax benefits that would affect the effective tax rate if recognized	$ 6,641	5,292	$ 3,481
Income tax benefit recognition threshold more likely than not	50.00%
Other Accounts And Notes Receivable [Member]
Operating Loss Carryforwards [Line Items]
Income tax receivables	$ 5,314
Other Current Assets [Member]
Operating Loss Carryforwards [Line Items]
Income tax receivables	938	$ 299
Alabama [Member]
Operating Loss Carryforwards [Line Items]
State net operating loss carryforwards	64,307
Alabama [Member] | State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, valuation allowance	$ 29,236
Alabama [Member] | State [Member] | Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards expiration year	2023
Alabama [Member] | State [Member] | Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards expiration year	2029