DERIVATIVE FINANCIAL INSTRUMENTS (Details 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Gain (Loss) on Derivatives
Interest Rate Cash Flow Hedge Ineffectiveness is Immaterial	insignificant	insignificant	insignificant	insignificant
Effect of Cash Flow Hedges on Statement of Income
Other Comprehensive Income (Loss), Unrealized Gain (Loss) On Derivatives Arising During Period, Net of Tax	$ (1,000,000)	$ 1,000,000	$ 3,000,000	$ (6,000,000)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	(2,000,000)	(3,000,000)	(7,000,000)	(17,000,000)
Derivative, Credit Risk Related Contingent Features [Abstract]
Collateral Already Posted, Aggregate Fair Value	35,400,000		35,400,000		78,300,000
Additional collateral required to be posted to counterparties if all underlying contingent features were fully triggered					26,200,000
Aggregate fair value of all derivative instruments with contingent provisions that are in a net liability position	35,300,000		35,300,000		104,500,000
Cashcollateralrequestedfromcounterparty	78,600,000		78,600,000		32,100,000
Derivative, net asset position	78,600,000		78,600,000		32,100,000
LetterofCreditAvailableCommodityDerivatives,assetposition	9,000,000		9,000,000		10,000,000
Commodity Derivative, net asset position	10,000,000		10,000,000		13,000,000
Interest Rate Contract
Gain (Loss) on Derivatives
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred			6,200,000
Derivative Instruments, Gain (Loss) Deferred in Regulatory Accounts Effective Portion, Net	19,000,000	23,000,000	115,000,000	51,000,000
Derivative Instruments, Gain (Loss) Reclassified from Deferred Accounts into Income Effective Portion, Net	(1,000,000)	(1,000,000)	(2,000,000)	(2,000,000)
Effect of Cash Flow Hedges on Statement of Income
Other Comprehensive Income (Loss), Unrealized Gain (Loss) On Derivatives Arising During Period, Net of Tax	0	(1,000,000)	4,000,000	(5,000,000)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	(2,000,000)	(2,000,000)	(5,000,000)	(5,000,000)
Commodity Contract
Gain (Loss) on Derivatives
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred			2,000,000
Effect of Cash Flow Hedges on Statement of Income
Other Comprehensive Income (Loss), Unrealized Gain (Loss) On Derivatives Arising During Period, Net of Tax	1,000,000	(2,000,000)	1,000,000	1,000,000
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	0	(1,000,000)	(2,000,000)	(12,000,000)
Derivatives not designated as hedging instruments - gain (loss) recognized in income, classified in gas purchased for resale	0	0	0	(1,000,000)
SCEG
Gain (Loss) on Derivatives
Interest Rate Cash Flow Hedge Ineffectiveness is Immaterial	insignificant	insignificant	insignificant	insignificant
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	0	(1,000,000)
Derivative, Credit Risk Related Contingent Features [Abstract]
Collateral Already Posted, Aggregate Fair Value	3,300,000		3,300,000		35,200,000
Additional collateral required to be posted to counterparties if all underlying contingent features were fully triggered					22,700,000
Aggregate fair value of all derivative instruments with contingent provisions that are in a net liability position	2,600,000		2,600,000		57,900,000
Cashcollateralrequestedfromcounterparty	78,600,000		78,600,000		32,100,000
Derivative, net asset position	78,600,000		78,600,000		32,100,000
SCEG | Interest Rate Contract
Gain (Loss) on Derivatives
Derivative Instruments, Gain (Loss) Deferred in Regulatory Accounts Effective Portion, Net	19,000,000	23,000,000	115,000,000	51,000,000
Derivative Instruments, Gain (Loss) Reclassified from Deferred Accounts into Income Effective Portion, Net	$ (1,000,000)	$ (1,000,000)	$ (2,000,000)	$ (2,000,000)