DERIVATIVE FINANCIAL INSTRUMENTS Derivative Financial Instruments Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 18	$ 31
Derivative Asset, Fair Value, Gross Liability	(2)	(1)
Derivative Asset	16	30
Derivative Liability, Fair Value, Gross Liability	246	107
Derivative Liability, Fair Value, Gross Asset	(2)	(1)
Derivative Liability	244	106
Derivative, Collateral, Right to Reclaim Securities	0	(8)
Derivative, Collateral, Right to Reclaim Cash	(147)	(50)
Derivative Liability, Fair Value, Amount Offset Against Collateral	97	48
Derivative, Collateral, Obligation to Return Securities	0	(8)
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	16	22
Other Deferred Debits and Other Assets [Member]
Derivative [Line Items]
Derivative Asset	2	8
Other Current Assets [Member]
Derivative [Line Items]
Derivative Asset	14	22
Derivative Liability		3
Other Current Liabilities [Member]
Derivative [Line Items]
Derivative Liability	54	50
Other Deferred Credits and Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability	190	53
Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		15
Derivative Asset		15
Derivative Liability, Fair Value, Gross Liability	237	87
Derivative Liability	237	87
Derivative, Collateral, Right to Reclaim Securities		(8)
Derivative, Collateral, Right to Reclaim Cash	(147)	(36)
Derivative Liability, Fair Value, Amount Offset Against Collateral	90	43
Derivative, Collateral, Obligation to Return Securities		(8)
Derivative Asset, Fair Value, Amount Offset Against Collateral		7
Commodity Contract [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	9	1
Derivative Asset, Fair Value, Gross Liability	0
Derivative Asset	9	1
Derivative Liability, Fair Value, Gross Liability	0	5
Derivative Liability, Fair Value, Gross Asset	0
Derivative Liability	0	5
Derivative, Collateral, Right to Reclaim Cash		(5)
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	9	1
Other Energy Management Contract [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	9	15
Derivative Asset, Fair Value, Gross Liability	(2)	(1)
Derivative Asset	7	14
Derivative Liability, Fair Value, Gross Liability	9	15
Derivative Liability, Fair Value, Gross Asset	(2)	(1)
Derivative Liability	7	14
Derivative, Collateral, Right to Reclaim Cash		(9)
Derivative Liability, Fair Value, Amount Offset Against Collateral	7	5
Derivative Asset, Fair Value, Amount Offset Against Collateral	7	14
SCEG
Derivative [Line Items]
Derivative Asset		15
Derivative Liability	210	65
SCEG | Other Deferred Debits and Other Assets [Member]
Derivative [Line Items]
Derivative Asset		5
SCEG | Other Current Assets [Member]
Derivative [Line Items]
Derivative Asset		10
SCEG | Other Current Liabilities [Member]
Derivative [Line Items]
Derivative Liability	46	34
SCEG | Other Deferred Credits and Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability	164	31
SCEG | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		15
Derivative Asset		15
Derivative Liability, Fair Value, Gross Liability	210	65
Derivative Liability	210	65
Derivative, Collateral, Right to Reclaim Securities		(8)
Derivative, Collateral, Right to Reclaim Cash	(118)	(13)
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ 92	44
Derivative, Collateral, Obligation to Return Securities		(8)
Derivative Asset, Fair Value, Amount Offset Against Collateral		$ 7