DERIVATIVE FINANCIAL INSTRUMENTS OFFSETTING ASSETS AND LIABILITIES (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	$ 3
Derivative Liability	38	$ 37
Derivative, Fair Value, Net	27
Derivative Asset, Fair Value, Gross Liability	(11)	0
Derivative Assets, Gross Amounts Not Offset in the Statement of Financial Position - Financial Instruments	0	0
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Liability, Fair Value, Gross Asset	(11)	(1)
Derivative Liabilities, Net Amount	3	8
Derivative Liability, Fair Value, Gross Liability	38	38
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position - Financial Instruments	0	0
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position - Cash Collateral Posted	24	(29)
Derivative Assets, Net Amount	3	59
Derivative Asset	14	59
Other Deferred Debits and Other Assets [Member]
Derivative [Line Items]
Derivative Asset	1	1
Other Current Assets [Member]
Derivative [Line Items]
Derivative Liability		2
Derivative Asset	1	58
Other Current Liabilities [Member]
Derivative [Line Items]
Derivative Liability	3	7
Other Deferred Credits and Other Liabilities
Derivative [Line Items]
Derivative Liability	22	28
Prepayments [Member]
Derivative [Line Items]
Derivative Liability	13
Derivative Asset	12
SCE&G
Derivative [Line Items]
Derivative Liability	11	15
Derivative Asset	0	54
SCE&G | Other Deferred Debits and Other Assets [Member]
Derivative [Line Items]
Derivative Asset	0	0
SCE&G | Other Current Assets [Member]
Derivative [Line Items]
Derivative Asset		54
SCE&G | Other Current Liabilities [Member]
Derivative [Line Items]
Derivative Liability	1	2
SCE&G | Other Deferred Credits and Other Liabilities
Derivative [Line Items]
Derivative Liability	10	13
Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Liability	24	32
Derivative Assets, Gross Amounts Not Offset in the Statement of Financial Position - Financial Instruments	0	0
Derivative Liabilities, Net Amount	0	4
Derivative Liability, Fair Value, Gross Liability	24	32
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position - Financial Instruments		0
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position - Cash Collateral Posted	24	(28)
Derivative Assets, Net Amount	0	54
Derivative Asset	0	54
Interest Rate Contract [Member] | SCE&G
Derivative [Line Items]
Derivative Liability	11	15
Derivative Assets, Gross Amounts Not Offset in the Statement of Financial Position - Financial Instruments	0	0
Derivative Liabilities, Net Amount	0	15
Derivative Liability, Fair Value, Gross Liability	11	15
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position - Financial Instruments	0	0
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position - Cash Collateral Posted		0
Derivative Assets, Net Amount	0	54
Derivative Asset	0	54
Commodity Contract [Member]
Derivative [Line Items]
Derivative Liability	1	3
Derivative Liabilities, Net Amount	1	3
Derivative Liability, Fair Value, Gross Liability	1	3
Derivative Assets, Net Amount	1	1
Derivative Asset	1	1
Other Energy Management Contract [Member]
Derivative [Line Items]
Derivative Liability	2	2
Derivative Asset, Fair Value, Gross Liability	(11)	0
Derivative Liability, Fair Value, Gross Asset	(11)	(1)
Derivative Liabilities, Net Amount	2	1
Derivative Liability, Fair Value, Gross Liability	13	3
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position - Cash Collateral Posted	0	(1)
Derivative Assets, Net Amount	2	4
Derivative Asset	2	$ 4
Other Energy Management Contract [Member] | SCE&G
Derivative [Line Items]
Derivative Liabilities, Gross Amounts Not Offset in the Statement of Financial Position - Cash Collateral Posted	$ (11)