INCOME TAXES (Income Tax Expense Included in Income Statements) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current Tax Expense
Federal	$ (13,000)	$ 0	$ 0
State	0	0	0
Total Current Income Tax Expense	(13,000)	0	0
Deferred Income Tax Expense
Federal	53,000	98,000	60,000
Federal Investment Tax Credits	(6,000)	(6,000)	(6,000)
State	9,000	9,000	5,000
Total Deferred Income Tax Expense	56,000	101,000	59,000
Total Federal and State Income Tax Expense	$ 42,982	$ 100,763	$ 59,376