INCOME TAXES (Details) - USD ($)	3 Months Ended								9 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments, Owned, Federal Income Tax Note [Line Items]
Deferred Tax Asset, Deferred Fuel Cost	$ 8,000,000									$ 8,000,000
Income Available to Common Shareholders	98,000,000	$ 149,000,000	$ 99,000,000	$ 400,000,000	$ 105,000,000	$ 144,000,000	$ 96,000,000	$ 193,000,000		$ 746,000,000	$ 538,000,000	$ 471,000,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent					6.00%				6.90%	5.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent										35.00%
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current Federal Tax Expense (Benefit)										$ 382,000,000	38,000,000	161,000,000
Current State and Local Tax Expense (Benefit)										57,000,000	(4,000,000)	17,000,000
Current Income Tax Expense (Benefit)										439,000,000	34,000,000	178,000,000
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred Federal Income Tax Expense (Benefit)										36,000,000	(184,000,000)	(39,000,000)
Deferred State and Local Income Tax Expense (Benefit)										7,000,000	(34,000,000)	(10,000,000)
Deferred Income Tax Expense (Benefit)										43,000,000	(218,000,000)	(49,000,000)
Income Tax Reconciliation, Tax Credits, Investment [Abstract]
Amortization of Amounts Deferred Under State and Local Investment Tax Credits										(1,000,000)	(1,000,000)	(1,000,000)
Investment Tax Credit										(3,000,000)	(4,000,000)	(4,000,000)
Income Tax Expense (Benefit)										393,000,000	248,000,000	223,000,000
Income (Loss) from Continuing Operations before Income Taxes, Domestic										1,139,000,000	786,000,000	694,000,000
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount										399,000,000	275,000,000	243,000,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount										38,000,000	24,000,000	22,000,000
Income Tax Reconciliation, Amortization of State and Local Investment Tax Credits										(6,000,000)	(5,000,000)	(5,000,000)
Income Tax Reconciliation, Allowance for Cost of Equity Funds Used During Construction										(9,000,000)	(11,000,000)	(9,000,000)
Effective Income Tax Rate Reconciliation, Deduction, Dividends, Amount										(10,000,000)	(10,000,000)	(10,000,000)
Amortization of Amounts Deferred under Federal Investment Tax Credits										(2,000,000)	(3,000,000)	(3,000,000)
Section41TaxCredit										(1,000,000)	(3,000,000)	0
Section 45 tax credit										(9,000,000)	(9,000,000)	(5,000,000)
Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent										(18,000,000)	(7,000,000)	(11,000,000)
Income Tax Reconciliation, Sale of Subsidiaries										7,000,000
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount										2,000,000	(3,000,000)	1,000,000
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities	135,000,000				$ 127,000,000					135,000,000	127,000,000
Deferred tax Nuclear Decommissioning	199,000,000				216,000,000					199,000,000	216,000,000
Deferred Tax Assets, Financial Instruments	35,000,000				40,000,000					35,000,000	40,000,000
Deferred Tax Asset, Unamortized Investment, Tax Credits	16,000,000				17,000,000					16,000,000	17,000,000
Deferred Tax Assets, Monetization of Bankruptcy Claims	0				10,000,000					0	10,000,000
Deferred Tax Assets, Other	5,000,000				10,000,000					5,000,000	10,000,000
Deferred Tax Assets, Net	398,000,000				420,000,000					398,000,000	420,000,000
Deferred Tax Liabilities, Property, Plant and Equipment	1,906,000,000				1,928,000,000					1,906,000,000	1,928,000,000
Deferred Tax Liabilities, Tax Deferred Expense Compensation and Benefits, Employee Benefits	96,000,000				107,000,000					96,000,000	107,000,000
Deferred Tax Liabilities, Asset Retirement Obligation	135,000,000				122,000,000					135,000,000	122,000,000
Deferred Tax Liabilities, Deferred Expense Fuel Costs	0				27,000,000					0	27,000,000
Deferred tax asset unrecovered plant	49,000,000				53,000,000					49,000,000	53,000,000
Deferred Tax Liabilities, Derivatives	0				21,000,000					0	21,000,000
Deferred Tax Liability, Demand Side Management	23,000,000				21,000,000					23,000,000	21,000,000
deferred tax liability, prepayments	31,000,000				27,000,000					31,000,000	27,000,000
Deferred Tax Liabilities, Other	65,000,000				45,000,000					65,000,000	45,000,000
Deferred Tax Liabilities, Net	2,305,000,000				2,351,000,000					2,305,000,000	2,351,000,000
Deferred Tax Liabilities, Net, Noncurrent	1,907,000,000				1,931,000,000					1,907,000,000	1,931,000,000
Unrecognized Tax Benefits	49,000,000				16,000,000					49,000,000	16,000,000	3,000,000
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions										2,000,000
SCE&G
Investments, Owned, Federal Income Tax Note [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	8,000,000									8,000,000
Deferred Tax Asset, Deferred Fuel Cost	7,000,000									7,000,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	17,000,000									17,000,000
Increase in Unrecognized Tax Benefits is Reasonably Possible	7,000,000									$ 7,000,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent										35.00%
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current Federal Tax Expense (Benefit)										$ 208,000,000	39,000,000	146,000,000
Current State and Local Tax Expense (Benefit)										32,000,000	(6,000,000)	13,000,000
Current Income Tax Expense (Benefit)										240,000,000	33,000,000	159,000,000
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred Federal Income Tax Expense (Benefit)										(3,000,000)	(157,000,000)	(25,000,000)
Deferred State and Local Income Tax Expense (Benefit)										(3,000,000)	(32,000,000)	(9,000,000)
Deferred Income Tax Expense (Benefit)										(6,000,000)	(189,000,000)	(34,000,000)
Income Tax Reconciliation, Tax Credits, Investment [Abstract]
Amortization of Amounts Deferred Under State and Local Investment Tax Credits										(1,000,000)	(1,000,000)	(1,000,000)
Investment Tax Credit										(3,000,000)	(4,000,000)	(4,000,000)
Income Tax Expense (Benefit)										231,000,000	218,000,000	189,000,000
Net Income (Loss) Attributable to Noncontrolling Interest										14,000,000	12,000,000	11,000,000
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount										249,000,000	237,000,000	203,000,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount										24,000,000	21,000,000	18,000,000
Income Tax Reconciliation, Amortization of State and Local Investment Tax Credits										(6,000,000)	(5,000,000)	(5,000,000)
Income Tax Reconciliation, Allowance for Cost of Equity Funds Used During Construction										(9,000,000)	(10,000,000)	(9,000,000)
Amortization of Amounts Deferred under Federal Investment Tax Credits										(2,000,000)	(3,000,000)	(3,000,000)
Section 45 tax credit										(9,000,000)	(9,000,000)	(5,000,000)
Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent										(18,000,000)	(7,000,000)	(11,000,000)
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount										1,000,000	(3,000,000)	1,000,000
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities	52,000,000				47,000,000					52,000,000	47,000,000
Deferred tax Nuclear Decommissioning	187,000,000				205,000,000					187,000,000	205,000,000
Deferred Tax Assets, Financial Instruments	2,000,000									2,000,000
Deferred Tax Asset, Unamortized Investment, Tax Credits	16,000,000				17,000,000					16,000,000	17,000,000
Deferred Tax Assets, Other	2,000,000				6,000,000					2,000,000	6,000,000
Deferred Tax Assets, Net	266,000,000				275,000,000					266,000,000	275,000,000
Deferred Tax Liabilities, Property, Plant and Equipment	1,644,000,000				1,623,000,000					1,644,000,000	1,623,000,000
Deferred Tax Liabilities, Tax Deferred Expense Compensation and Benefits, Employee Benefits	85,000,000				91,000,000					85,000,000	91,000,000
Deferred Tax Liabilities, Asset Retirement Obligation	127,000,000				115,000,000					127,000,000	115,000,000
Deferred Tax Liabilities, Deferred Expense Fuel Costs	0				27,000,000					0	27,000,000
Deferred tax asset unrecovered plant	49,000,000				53,000,000					49,000,000	53,000,000
Deferred Tax Liabilities, Derivatives	0				21,000,000					0	21,000,000
Deferred Tax Liability, Demand Side Management	23,000,000				21,000,000					23,000,000	21,000,000
deferred tax liability, prepayments	29,000,000				25,000,000					29,000,000	25,000,000
Deferred Tax Liabilities, Other	41,000,000				23,000,000					41,000,000	23,000,000
Deferred Tax Liabilities, Net	1,998,000,000				1,999,000,000					1,998,000,000	1,999,000,000
Deferred Tax Liabilities, Net, Noncurrent	1,732,000,000				1,724,000,000					1,732,000,000	1,724,000,000
Unrecognized Tax Benefits	$ 49,000,000				$ 16,000,000					49,000,000	16,000,000	3,000,000	$ 0
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions										33,000,000	0	0
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions										(2,000,000)	0	0
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions										$ 2,000,000	$ 13,000,000	$ 3,000,000