DERIVATIVE FINANCIAL INSTRUMENTS (Details 3) (USD $)	3 Months Ended					3 Months Ended			3 Months Ended						3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Energy Management Contracts [Member]	Dec. 31, 2012 Energy Management Contracts [Member]	Mar. 31, 2013 Interest Rate Contract	Mar. 31, 2012 Interest Rate Contract	Dec. 31, 2012 Interest Rate Contract	Mar. 31, 2013 Commodity Contract	Mar. 31, 2012 Commodity Contract	Sep. 30, 2011 Commodity Contract	Mar. 31, 2013 SCEG	Mar. 31, 2012 SCEG	Dec. 31, 2012 SCEG	Mar. 31, 2013 SCEG Interest Rate Contract	Mar. 31, 2012 SCEG Interest Rate Contract	Dec. 31, 2012 SCEG Interest Rate Contract
Gain (Loss) on Derivatives
Interest Rate Cash Flow Hedge Ineffectiveness is Immaterial	insignificant	insignificant										insignificant	insignificant
Derivative Instruments, Gain (Loss) Deferred in Regulatory Accounts Effective Portion, Net						$ 35,000,000	$ 30,000,000								$ 35,000,000	$ 30,000,000
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)								(1,000,000)	(1,000,000)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	(4,000,000)	(10,000,000)				(2,000,000)	(2,000,000)		(2,000,000)	(8,000,000)
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred						6,000,000			700,000
Gain or (Loss) Deferred in Regulatory Accounts (Effective Portion), classified in interest expense	3,000,000	(4,000,000)				1,000,000	0		(2,000,000)	4,000,000
Derivatives not designated as hedging instruments - gain (loss) recognized in income, classified in gas purchased for resale									0		(1,000,000)	0	(1,000,000)
Derivative, Credit Risk Related Contingent Features [Abstract]
Collateral Already Posted, Aggregate Fair Value	60,600,000		78,300,000	(8,000,000)	(11,000,000)	(53,000,000)		(67,000,000)				22,100,000		35,200,000	22,000,000		35,000,000
Additional collateral required to be posted to counterparties if all underlying contingent features were fully triggered	21,300,000		26,200,000									22,200,000		22,700,000
Aggregate fair value of all derivative instruments with contingent provisions that are in a net liability position	81,900,000		104,500,000									44,300,000		57,900,000
Cashcollateralrequestedfromcounterparty	45,600,000		32,100,000									43,900,000		32,100,000
Derivative, net asset position	45,600,000		32,100,000									43,900,000		32,100,000
LetterofCreditAvailableCommodityDerivatives,assetposition	9,000,000		10,000,000
Commodity Derivative, net asset position	$ 9,000,000		$ 13,000,000