DERIVATIVE FINANCIAL INSTRUMENTS (Details 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Effect of Fair Value Hedges on Statement of Income
Reduction to interest expense for combined amount of gains on fair value hedges, losses on hedged fixed rate debt, and amortization of deferred gain on previously terminated swaps		$ 900,000		$ 4,900,000
Effect of Cash Flow Hedges on Statement of Income
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	(3,000,000)	(2,000,000)	(17,000,000)	(8,000,000)
Gain or (Loss) Deferred in Regulatory Accounts (Effective Portion), classified in interest expense	1,000,000	(33,000,000)	(6,000,000)	(46,000,000)
Derivative, Credit Risk Related Contingent Features [Abstract]
Collateral Already Posted, Aggregate Fair Value	89,100,000		89,100,000		140,300,000
Additional collateral required to be posted to counterparties if all underlying contingent features were fully triggered	28,300,000		28,300,000		50,700,000
Aggregate fair value of all derivative instruments with contingent provisions that are in a net liability position	117,400,000		117,400,000		191,000,000
Cashcollateralrequestedfromcounterparty	45,800,000		45,800,000		1,100,000
Derivative, net asset position	45,800,000		45,800,000		1,100,000
LetterofCreditAvailableCommodityDerivatives,assetposition	10,000,000		10,000,000		12,000,000
Commodity Derivative, net asset position	12,000,000		12,000,000		27,000,000
Commodity contracts
Effect of Cash Flow Hedges on Statement of Income
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	(1,000,000)	(1,000,000)	(12,000,000)	(5,000,000)
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	600,000
Gain or (Loss) Deferred in Regulatory Accounts (Effective Portion), classified in interest expense	(2,000,000)	5,000,000	1,000,000	7,000,000
Derivatives not designated as hedging instruments - gain (loss) recognized in income, classified in gas purchased for resale	0	0	(1,000,000)	(1,000,000)
Interest Rate Contract
Gain (Loss) on Derivatives
Derivative Instruments, Gain (Loss) Deferred in Regulatory Accounts Effective Portion, Net	23,000,000	(63,000,000)	51,000,000	(72,000,000)
Effect of Cash Flow Hedges on Statement of Income
Gain or (Loss) Deferred in Regulatory Accounts (Effective Portion), classified in interest expense	(1,000,000)	(1,000,000)	(2,000,000)	(2,000,000)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	(2,000,000)	(1,000,000)	(5,000,000)	(3,000,000)
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	6,000,000
Gain or (Loss) Deferred in Regulatory Accounts (Effective Portion), classified in interest expense	(1,000,000)	(28,000,000)	(5,000,000)	(39,000,000)
SCE&G
Effect of Cash Flow Hedges on Statement of Income
Derivatives not designated as hedging instruments - gain (loss) recognized in income, classified in gas purchased for resale	0	0	(1,000,000)	(1,000,000)
Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness		0.8		1.1
Derivative, Credit Risk Related Contingent Features [Abstract]
Collateral Already Posted, Aggregate Fair Value	42,700,000		42,700,000		45,000,000
Additional collateral required to be posted to counterparties if all underlying contingent features were fully triggered	28,000,000		28,000,000		31,700,000
Aggregate fair value of all derivative instruments with contingent provisions that are in a net liability position	70,700,000		70,700,000		76,700,000
Cashcollateralrequestedfromcounterparty	45,800,000		45,800,000		1,100,000
Derivative, net asset position	45,800,000		45,800,000		1,100,000
SCE&G | Interest Rate Contract
Gain (Loss) on Derivatives
Derivative Instruments, Gain (Loss) Deferred in Regulatory Accounts Effective Portion, Net	23,000,000	(63,000,000)	51,000,000	(72,000,000)
Effect of Cash Flow Hedges on Statement of Income
Gain or (Loss) Deferred in Regulatory Accounts (Effective Portion), classified in interest expense	$ (1,000,000)	$ (1,000,000)	$ (2,000,000)	$ (2,000,000)