RATE AND OTHER REGULATORY MATTERS (Details 3) (USD $)	3 Months Ended		12 Months Ended		24 Months Ended
	Mar. 31, 2013 MW	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Jul. 31, 2012	Jan. 31, 2013	Apr. 30, 2012
Regulatory Liabilities:
MPG enviromental remediatio	28
Public Utilities, Authorized Allowable Return on Common Equity, Percentage		11.00%
Regulatory liabilities	$ 917,000,000	$ 882,000,000	$ 882,000,000
Amount allowed to be recovered through electric rates to offset incremental storm damage costs	0
Annual amount of storm damage costs which can not be offset by amounts recovered through electric rates	2.5
Accrual period of nuclear refueling charges in months	18
Regulatory Noncurrent Asset Amortization Period	30
Deferred Income Tax Charges [Member]
Regulatory Liabilities:
Regulatory liabilities	20,000,000
Asset Retirement Obligation Costs [Member]
Regulatory Liabilities:
Regulatory liabilities	701,000,000	692,000,000	692,000,000
Storm damage reserve
Regulatory Liabilities:
Regulatory liabilities	27,000,000	27,000,000	27,000,000
Monetization bankruptcy claim [Member]
Regulatory Liabilities:
Regulatory liabilities	31,000,000	32,000,000	32,000,000
Deferred gains on interest rate derivatives
Regulatory Liabilities:
Regulatory liabilities	137,000,000	110,000,000	110,000,000
Planned major maintenance [Member]
Regulatory Liabilities:
Regulatory liabilities	1,000,000	0	0
SCEG
Regulatory Liabilities:
MPG enviromental remediatio	28
Undercollected balance fuel							80,600,000
Public Utilities Property Plant and Equipment Identifiable Capital Costs			278,000,000
Capital Cost Related to New Federal Healthcare Etc			1,000,000
Public Utilities, Percent Increase (Decrease) in Retail Electric Rates		4.23%	2.30%	2.40%
Public Utilities, Authorized Allowable Return on Common Equity, Percentage		10.25%
historical average temperature			15
Power generation capacity six coal fired units	730
Demand Side Management Program Costs, Noncurrent	20,600,000	19,600,000	19,600,000	7,000,000		27,200,000
Regulatory liabilities	697,000,000	665,000,000	665,000,000
Amount allowed to be recovered through electric rates to offset incremental storm damage costs	100,000,000
Annual amount of storm damage costs which can not be offset by amounts recovered through electric rates	2,500,000
Accrual period of nuclear refueling charges in months	18
Regulatory Noncurrent Asset Amortization Period	30
Amounts Recovered through Electric Rates to offset Turbine Expense					18,400,000
Defined Benefit Plan, Deferred Debit Attributable to Share of Regulatory Authority		63,000,000	63,000,000
Pension Regulatory Asset Amortization Period			30
Share in Approved Capital Costs			8,000,000
Public Utilities Additional Labor Expenses for Oversight of New Units			132,000,000
SCEG | Deferred Income Tax Charges [Member]
Regulatory Liabilities:
Regulatory liabilities		$ 21,000,000	$ 21,000,000