INCOME TAXES (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Income tax benefit recognition threshold more likely than not				50.00%
Retained earnings	$ 3,204,671		$ 2,795,834	$ 3,204,671	$ 2,795,834		$ 2,895,871
Income tax expense	$ 56,984		$ 53,472	$ 130,530	$ 111,764
Cash tax benefit		$ 13,301
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				2032
Alabama [Member] | Forecast [Member]
Operating Loss Carryforwards [Line Items]
State net operating loss carryforwards						$ 63,267
Net operating loss carryforwards, valuation allowance						$ 29,236