RATE AND OTHER REGULATORY MATTERS (Details 3) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended		24 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2013 MW	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Jul. 31, 2012	Jan. 31, 2013
Regulatory Liabilities:
MPG enviromental remediatio			27
Regulatory liabilities		$ 882,000,000	$ 976,000,000		$ 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		21,000,000	20,000,000		21,000,000
Asset Retirement Obligation Costs [Member]
Regulatory Liabilities:
Regulatory liabilities		692,000,000	709,000,000		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		32,000,000	30,000,000		32,000,000
Deferred gains on interest rate derivatives
Regulatory Liabilities:
Regulatory liabilities		110,000,000	185,000,000		110,000,000
Planned major maintenance [Member]
Regulatory Liabilities:
Regulatory liabilities		0	4,000,000		0
Other Regulatory Liability [Member]
Regulatory Liabilities:
Regulatory liabilities			1,000,000
SCEG
Regulatory Liabilities:
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%		2.87%	2.30%	2.40%
Public Utilities, Authorized Allowable Return on Common Equity, Percentage		10.25%	11.00%
historical average temperature					15
Power generation capacity six coal fired units			730
Demand Side Management Program Costs, Noncurrent		19,600,000	20,600,000		19,600,000	7,000,000		27,200,000
Regulatory liabilities		665,000,000	753,000,000		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