v3.10.0.1
INCOME TAXES INCOME TAXES (Details 3) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Investments, Owned, Federal Income Tax Note [Line Items]        
Deferred Income Tax Expense (Benefit) $ (407) $ 286 $ 224  
Deferred Federal Income Tax Expense (Benefit) (352) 323 203  
Deferred Tax Assets, Net [Abstract]        
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities 84 88    
Deferred tax Nuclear Decommissioning 143 141    
Deferred Tax Assets, Financial Instruments 10 15    
Deferred Tax Asset, Unamortized Investment, Tax Credits 7 8    
Deferred Tax Assets, Other 4 6    
Deferred Tax Assets, Net 1,061 1,185    
Deferred Tax Liabilities, Gross [Abstract]        
Deferred Tax Liabilities, Property, Plant and Equipment 1,227 1,220    
Deferred Tax Liabilities, Tax Deferred Expense Compensation and Benefits, Employee Benefits 60 60    
Deferred Tax Liabilities, Asset Retirement Obligation 94 91    
Deferred tax asset unrecovered plant 24 27    
Deferred Tax Liability, Demand Side Management 16 16    
deferred tax liability, prepayments 21 21    
Deferred Tax Liabilities, Other 63 49    
Deferred Tax Liabilities, Gross 2,173 2,446    
Deferred Tax Liabilities, Net, Noncurrent 1,112 1,261    
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]        
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions 8 0 94  
Gross decreases tax positions in prior period 0 (273) 0  
Gross increases current period tax positions 0 21 207  
Unrecognized Tax Benefits, gross of state deduction on federal return and certain operating loss and tax credit carryfowards 106 98 350 $ 49
SCE&G        
Investments, Owned, Federal Income Tax Note [Line Items]        
Deferred Income Tax Expense (Benefit) 398 259 187  
Deferred Federal Income Tax Expense (Benefit) (346) 261 167  
Deferred Tax Assets, Net [Abstract]        
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities 40 42    
Deferred tax Nuclear Decommissioning 135 132    
Deferred Tax Asset, Unamortized Investment, Tax Credits 7 8    
Deferred Tax Assets, Other 5 5    
Deferred Tax Assets, Net 954 1,055    
Deferred Tax Liabilities, Gross [Abstract]        
Deferred Tax Liabilities, Property, Plant and Equipment 1,033 1,035    
Deferred Tax Liabilities, Tax Deferred Expense Compensation and Benefits, Employee Benefits 53 53    
Deferred Tax Liabilities, Asset Retirement Obligation 88 85    
Deferred tax asset unrecovered plant 24 27    
Deferred Tax Liability, Demand Side Management 16 16    
deferred tax liability, prepayments 20 19    
Deferred Tax Liabilities, Other 41 31    
Deferred Tax Liabilities, Gross 1,943 2,228    
Deferred Tax Liabilities, Net, Noncurrent 989 1,173    
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]        
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions 8 0 94  
Gross decreases tax positions in prior period 0 (273) 0  
Gross increases current period tax positions 0 21 207  
Unrecognized Tax Benefits, gross of state deduction on federal return and certain operating loss and tax credit carryfowards $ 106 $ 98 $ 350 $ 49