v3.10.0.1
INCOME TAXES (Details) - USD ($)
3 Months Ended 12 Months Ended
Dec. 31, 2018
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Investments, Owned, Federal Income Tax Note [Line Items]              
Deferred Tax Assets, Operating Loss Carryforwards $ 539,000,000     $ 539,000,000 $ 600,000,000    
Deferred Tax Asset, Legal Settlement net of tax 274,000,000     274,000,000 273,000,000    
Unrecognized Tax Benefits, gross of state deduction on federal return and certain operating loss and tax credit carryfowards 106,000,000     106,000,000 $ 98,000,000 $ 350,000,000 $ 49,000,000
Decrease in Unrecognized Tax Benefits is Reasonably Possible 11,000,000     11,000,000      
Unrecognized Tax Benefits that Would Impact Effective Tax Rate 106,000,000     $ 106,000,000      
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent     35.00% 21.00% 35.00%    
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]              
Current Federal Tax Expense (Benefit)       $ (8,000,000) $ (414,000,000) 36,000,000  
Current State and Local Tax Expense (Benefit)       5,000,000 18,000,000 13,000,000  
Current Income Tax Expense (Benefit)       (3,000,000) (396,000,000) 49,000,000  
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]              
Deferred State and Local Income Tax Expense (Benefit)       (55,000,000) (37,000,000) 21,000,000  
Income Tax Reconciliation, Tax Credits, Investment [Abstract]              
Income Tax Expense (Benefit)       (412,000,000) (112,000,000) 271,000,000  
Income (Loss) from Continuing Operations before Income Taxes, Domestic       (940,000,000) (231,000,000) 866,000,000  
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount       (197,000,000) (81,000,000) 303,000,000  
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount       (37,000,000) (7,000,000) 27,000,000  
Income Tax Reconciliation, Amortization of State and Local Investment Tax Credits       (3,000,000) (5,000,000) (5,000,000)  
Income Tax Reconciliation, Allowance for Cost of Equity Funds Used During Construction       (4,000,000) (8,000,000) (10,000,000)  
Effective Income Tax Rate Reconciliation, Deduction, Dividends, Amount       (2,000,000) (9,000,000) (10,000,000)  
Amortization of Amounts Deferred under Federal Investment Tax Credits       (2,000,000) (2,000,000) (2,000,000)  
Section 45 tax credit       (9,000,000) (8,000,000) (8,000,000)  
Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent       0 (18,000,000) (23,000,000)  
Income Tax Reconcilation, Tax Reform Remeasurement       188,000,000 (30,000,000)    
Income Tax Reconciliation, Sale of Subsidiaries       5,000,000 0 0  
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount       2,000,000 (4,000,000) (1,000,000)  
Deferred tax Nuclear Decommissioning 143,000,000     143,000,000 141,000,000    
Deferred Tax Asset, Remeasurement 0     0 54,000,000    
Deferred Tax Assets, Financial Instruments 10,000,000     10,000,000 15,000,000    
Deferred Tax Asset, Unamortized Investment, Tax Credits 7,000,000     7,000,000 8,000,000    
Deferred Tax Assets, Other 4,000,000     4,000,000 6,000,000    
Deferred Tax Assets, Net 1,061,000,000     1,061,000,000 1,185,000,000    
Deferred Tax Liabilities, Property, Plant and Equipment 1,227,000,000     1,227,000,000 1,220,000,000    
Deferred Tax Liability, Impairment 668,000,000     668,000,000 962,000,000    
Deferred Tax Liabilities, Tax Deferred Expense Compensation and Benefits, Employee Benefits 60,000,000     60,000,000 60,000,000    
Deferred Tax Liabilities, Asset Retirement Obligation 94,000,000     94,000,000 91,000,000    
Deferred tax asset unrecovered plant 24,000,000     24,000,000 27,000,000    
Deferred Tax Liability, Demand Side Management 16,000,000     16,000,000 16,000,000    
deferred tax liability, prepayments 21,000,000     21,000,000 21,000,000    
Deferred Tax Liabilities, Other 63,000,000     63,000,000 49,000,000    
Deferred Tax Liabilities, Net 2,173,000,000     2,173,000,000 2,446,000,000    
Deferred Tax Liabilities, Net, Noncurrent 1,112,000,000     1,112,000,000 1,261,000,000    
Unrecognized tax benefits 38,000,000     38,000,000 19,000,000    
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions       8,000,000 0 94,000,000  
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions       0 (273,000,000) 0  
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions       0 21,000,000 207,000,000  
Utilities Operating Loss, Impairment, Net of Taxes 870,000,000 $ 3,000,000   53,000,000 690,000,000    
SCE&G              
Investments, Owned, Federal Income Tax Note [Line Items]              
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest       (614,000,000)      
Deferred Tax Assets, Operating Loss Carryforwards 493,000,000     493,000,000 541,000,000    
Deferred Tax Asset, Legal Settlement net of tax 274,000,000     274,000,000 273,000,000    
Unrecognized Tax Benefits, gross of state deduction on federal return and certain operating loss and tax credit carryfowards 106,000,000     106,000,000 98,000,000 350,000,000 $ 49,000,000
Unrecognized Tax Benefits, Income Tax Penalties Expense       0      
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]              
Current Federal Tax Expense (Benefit)       (16,000,000) (410,000,000) 50,000,000  
Current State and Local Tax Expense (Benefit)       0 (18,000,000) 13,000,000  
Current Income Tax Expense (Benefit)       (16,000,000) (428,000,000) 63,000,000  
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]              
Deferred State and Local Income Tax Expense (Benefit)       52,000,000 (2,000,000) 20,000,000  
Income Tax Reconciliation, Tax Credits, Investment [Abstract]              
Income Tax Expense (Benefit)       (416,000,000) (171,000,000) 248,000,000  
Net Income (Loss) Attributable to Noncontrolling Interest       25,000,000 13,000,000 13,000,000  
Income (Loss) from Continuing Operations before Income Taxes, Domestic       (1,005,000,000) (343,000,000) 774,000,000  
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount       (211,000,000) (120,000,000) 271,000,000  
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount       (38,000,000) (8,000,000) 26,000,000  
Income Tax Reconciliation, Amortization of State and Local Investment Tax Credits       (3,000,000) (5,000,000) (5,000,000)  
Income Tax Reconciliation, Allowance for Cost of Equity Funds Used During Construction       (2,000,000) (5,000,000) (9,000,000)  
Amortization of Amounts Deferred under Federal Investment Tax Credits       (2,000,000) (2,000,000) (2,000,000)  
Section 45 tax credit       (9,000,000) (8,000,000) (8,000,000)  
Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent       0 (18,000,000) (23,000,000)  
Income Tax Reconcilation, Tax Reform Remeasurement       176,000,000 1,000,000    
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount       2,000,000 (4,000,000) (2,000,000)  
Deferred tax Nuclear Decommissioning 135,000,000     135,000,000 132,000,000    
Deferred Tax Asset, Remeasurement 0     0 54,000,000    
Deferred Tax Asset, Unamortized Investment, Tax Credits 7,000,000     7,000,000 8,000,000    
Deferred Tax Assets, Other 5,000,000     5,000,000 5,000,000    
Deferred Tax Assets, Net 954,000,000     954,000,000 1,055,000,000    
Deferred Tax Liabilities, Property, Plant and Equipment 1,033,000,000     1,033,000,000 1,035,000,000    
Deferred Tax Liability, Impairment 668,000,000     668,000,000 962,000,000    
Deferred Tax Liabilities, Tax Deferred Expense Compensation and Benefits, Employee Benefits 53,000,000     53,000,000 53,000,000    
Deferred Tax Liabilities, Asset Retirement Obligation 88,000,000     88,000,000 85,000,000    
Deferred tax asset unrecovered plant 24,000,000     24,000,000 27,000,000    
Deferred Tax Liability, Demand Side Management 16,000,000     16,000,000 16,000,000    
deferred tax liability, prepayments 20,000,000     20,000,000 19,000,000    
Deferred Tax Liabilities, Other 41,000,000     41,000,000 31,000,000    
Deferred Tax Liabilities, Net 1,943,000,000     1,943,000,000 2,228,000,000    
Deferred Tax Liabilities, Net, Noncurrent 989,000,000     989,000,000 1,173,000,000    
Unrecognized tax benefits $ 38,000,000     38,000,000 19,000,000    
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions       8,000,000 0 94,000,000  
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions       0 (273,000,000) 0  
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions       0 $ 21,000,000 $ 207,000,000  
Utilities Operating Loss, Impairment, Net of Taxes       $ 46,000,000