INCOME TAXES (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
U.S. federal corporate income tax rate	21.00%	35.00%	35.00%
Tax Cuts and Jobs Act of 2017, percent of immediate deductibility of certain capital investments	100.00%
Tax Cuts and Jobs Act of 2017, incomplete accounting, provisional expense, deferred tax assets, executive compensation		$ 1,403
State net operating loss carryforwards	$ 68,436	73,083
Income tax receivables	922	106,980
Interest and penalties recognized as income tax expense (benefit)	(1,477)	420	$ 266
Balance of accrued interest and penalties included in lliability for unrecognized income tax benefits	312	1,789	1,369
Unrecognized income tax benefits that would affect the effective tax rate if recognized	3,481	10,673	9,884
Tax Cuts And Jobs Act Of 2017, decrease to net deferred income tax liability	0	301,567	0
Tax Cuts and Jobs Act of 2017, incomplete accounting, provisional transition tax, foreign repatriation	595	12,301	$ 0
Deferred income tax liability not recognized from undistributed U.S. federal income tax	0
Deferred income tax liability not recognized from undistributed foreign earnings	$ 0
Reclassification of stranded tax effects		(29,629)
Tax Year 2017 [Member]
Operating Loss Carryforwards [Line Items]
Income tax receivables		$ 106,000
Scenario, Plan [Member]
Operating Loss Carryforwards [Line Items]
U.S. federal corporate income tax rate	21.00%
Alabama [Member]
Operating Loss Carryforwards [Line Items]
State net operating loss carryforwards	$ 65,577
Alabama [Member] | State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, valuation allowance	$ 29,183
Alabama [Member] | State [Member] | Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards expiration date	Dec. 31, 2023
Alabama [Member] | State [Member] | Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards expiration date	Dec. 31, 2032
Accounting Standards Update 2018-02 [Member]
Operating Loss Carryforwards [Line Items]
Reclassification of stranded tax effects	$ 29,629