DERIVATIVE FINANCIAL INSTRUMENTS (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013 MMBTU		Dec. 31, 2012 MMBTU
Derivative [Line Items]
Derivative Cash Flow Hedge, Nonmonetary Notional Amount	23,086,250		25,427,000
Derivative not designated as hedging, notional amount	22,086,863	[1]	22,873,275	[2]
Derivative, Nonmonetary Notional Amount	45,173,113	[1]	48,300,275	[2]
Nonmonetary Notional Amount of Basis Swap, Price Risk Derivative Instruments Not Designated as Hedging Instruments	1,365,752		3,500,000
Aggregate notional amount of interest rate swaps designated as cash flow hedge (in dollars)	$ 663.8		$ 1,100.0
Gas Distribution
Derivative [Line Items]
Derivative Cash Flow Hedge, Nonmonetary Notional Amount	0		0
Derivative not designated as hedging, notional amount	6,680,000		5,170,000
Derivative, Nonmonetary Notional Amount	6,680,000		5,170,000
Retail Gas Marketing
Derivative [Line Items]
Derivative Cash Flow Hedge, Nonmonetary Notional Amount	6,924,000		6,490,000
Derivative not designated as hedging, notional amount			0
Derivative, Nonmonetary Notional Amount	7,124,000		6,490,000
Energy Marketing
Derivative [Line Items]
Derivative Cash Flow Hedge, Nonmonetary Notional Amount	16,162,250		18,937,000
Derivative not designated as hedging, notional amount	15,206,863	[1]	17,703,275	[2]
Derivative, Nonmonetary Notional Amount	31,369,113	[1]	36,640,275	[2]
SCEG
Derivative [Line Items]
Aggregate notional amount of interest rate swaps designated as cash flow hedge (in dollars)	$ 571.4		$ 971.4

[1] (a) Includes an aggregate 1,365,752 MMBTU related to basis swap contracts in Energy Marketing.

[2] (b) Includes an aggregate 3,500,000 MMBTU related to basis swap contracts in Energy Marketing.