DERIVATIVE FINANCIAL INSTRUMENTS FAIR VALUE ON BALANCE SHEET (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 38	$ 38
Derivative Liability	38	37
Derivative Asset	14	59
Derivative Asset, Fair Value, Gross Asset	14	59
Other Deferred Debits and Other Assets [Member]
Derivative [Line Items]
Derivative Asset	1	1
Other Deferred Credits and Other Liabilities
Derivative [Line Items]
Derivative Liability	22	28
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
Prepayments [Member]
Derivative [Line Items]
Derivative Liability	13
Derivative Asset	12
Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	24	32
Derivative Liability	24	32
Derivative Asset	0	54
Derivative Asset, Fair Value, Gross Asset	0	54
Commodity Contract [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	1	3
Derivative Liability	1	3
Derivative Asset	1	1
Derivative Asset, Fair Value, Gross Asset	1	1
Other Energy Management Contract [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	13	3
Derivative Liability	2	2
Derivative Asset	2	4
Derivative Asset, Fair Value, Gross Asset	13	4
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	22	30
Derivative Asset, Fair Value, Gross Asset	0	0
Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member] \| Derivative Financial Instruments, Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	2	3
Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member] \| Other Deferred Credits and Other Liabilities
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	19	24
Designated as Hedging Instrument [Member] \| Commodity Contract [Member] \| Other Current Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		0
Designated as Hedging Instrument [Member] \| Commodity Contract [Member] \| Other Current Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		1
Designated as Hedging Instrument [Member] \| Commodity Contract [Member] \| Prepayments [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	1	2
Derivative Asset, Fair Value, Gross Asset		0
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	16	8
Derivative Asset, Fair Value, Gross Asset	14	59
Not Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member] \| Derivative Financial Instruments, Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		1
Derivative Asset, Fair Value, Gross Asset		54
Not Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member] \| Other Deferred Credits and Other Liabilities
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	3	4
Not Designated as Hedging Instrument [Member] \| Commodity Contract [Member] \| Other Current Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		1
Not Designated as Hedging Instrument [Member] \| Commodity Contract [Member] \| Prepayments [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	1
Not Designated as Hedging Instrument [Member] \| Other Energy Management Contract [Member] \| Derivative Financial Instruments, Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		2
Not Designated as Hedging Instrument [Member] \| Other Energy Management Contract [Member] \| Other Deferred Debits and Other Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	1	1
Not Designated as Hedging Instrument [Member] \| Other Energy Management Contract [Member] \| Other Current Assets [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		0
Derivative Asset, Fair Value, Gross Asset	1	3
Not Designated as Hedging Instrument [Member] \| Other Energy Management Contract [Member] \| Other Current Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	1
Not Designated as Hedging Instrument [Member] \| Other Energy Management Contract [Member] \| Prepayments [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	12	1
Derivative Asset, Fair Value, Gross Asset	11	0
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 Deferred Credits and Other Liabilities
Derivative [Line Items]
Derivative Liability	10	13
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 \| Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	11	15
Derivative Liability	11	15
Derivative Asset	0	54
Derivative Asset, Fair Value, Gross Asset	0	54
SCE&G \| Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	8	10
SCE&G \| Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member] \| Derivative Financial Instruments, Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	1	1
SCE&G \| Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member] \| Other Deferred Credits and Other Liabilities
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	7	9
SCE&G \| Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	3	5
Derivative Asset, Fair Value, Gross Asset	0	54
SCE&G \| Not Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member] \| Derivative Financial Instruments, Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		1
Derivative Asset, Fair Value, Gross Asset		54
SCE&G \| Not Designated as Hedging Instrument [Member] \| Interest Rate Contract [Member] \| Other Deferred Credits and Other Liabilities
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 3	$ 4

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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