v3.10.0.1
COMMITMENTS AND CONTINGENCIES (Details)
 3 Months Ended 12 Months Ended
Dec. 31, 2018
USD ($)
Mar. 31, 2018
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Commitments and contingencies          
Legal Expense, net of taxes     $ 118,000,000    
Operating Lease, Payments       $ 10  
Estimate of aggregate amount of subcontractor and vendor liens filed     285,000,000    
Guarantee Settlement Receipts     2,200,000,000    
Impairment loss write off $ 1,372,000,000 $ 4,000,000 1,372,000,000 1,118,000,000  
Monetization Settlement Exceeding Costs Incurred     1,997,000,000    
Asset Retirement Obligation Other Conditional Obligations 359,000,000   359,000,000    
Asset Retirement Obligation $ 577,000,000   577,000,000 568,000,000 $ 558,000,000
Asset Retirement Obligation, Liabilities Incurred     0 0  
Asset Retirement Obligation, Liabilities Settled     (15,000,000) (10,000,000)  
Asset Retirement Obligation, Accretion Expense     25,000,000 25,000,000  
Asset Retirement Obligation, Revision of Estimate     $ (1,000,000) $ (5,000,000)  
Environmental          
Emission Rate Standard For Coal Fired Power Plants Under Clean Air Act 1,400   1,400    
Emission Rate Standard for Natural Gas 1,000   1,000    
Goal For Reduced Carbon Dioxide Emissions From 2005 Levels By 2030 Under Clean Air Act     32.00%    
Number of States affected by CSAPR 28   28    
Nuclear Generation          
Public Utilities Percentage Change in Retail Electric Rates Approved under BLRA       18.00%  
Change in Retail Electric Rates Approved Under BLRA     $ 2,768,000,000   64,400,000
Public Utilities, Requested Rate Increase (Decrease), Amount     31,000,000    
Managing Member or General Partner, Subsequent Distribution Amount     115,000,000    
SCPSC Order Reduction Of Total Fuel Cost Component Of Retail Electric Rates To Reflect Lower Projected Fuel Costs And Eliminate Over-Collection Balances     2,000,000,000    
Contractual Obligation, Due in Next Fiscal Year $ 23.7   23.7 $ 3.6  
SCE&G          
Commitments and contingencies          
Operating Lease, Payments     10 11 12
Estimate of aggregate amount of subcontractor and vendor liens filed     33,000,000    
Guarantee Settlement Receipts     1,200,000,000    
Monetization Settlement Exceeding Costs Incurred     1,098,000,000    
Asset Retirement Obligation Other Conditional Obligations 323,000,000   323,000,000    
Asset Retirement Obligation 541,000,000   541,000,000 529,000,000 522,000,000
Asset Retirement Obligation, Liabilities Incurred     0 0  
Asset Retirement Obligation, Liabilities Settled     (15,000,000) (9,000,000)  
Asset Retirement Obligation, Accretion Expense     23,000,000 23,000,000  
Asset Retirement Obligation, Revision of Estimate     4,000,000 $ (7,000,000)  
Nuclear Insurance          
Maximum Insurance Coverage For Each Nuclear Plant by ANI 450,000,000   450,000,000    
Federal Limit on Public Liability Claims from Nuclear Incident Approximate     14,000,000,000    
Maximum liability assessment per reactor for each nuclear incident     137,700,000    
Maximum yearly assessment per reactor     20,500,000    
Maximum Federal Limit on Public Liability Claims per Reactor for each Nuclear Incident at 2/3     91,800,000    
Maximum Insurance Coverage for Nuclear events 2,750,000,000   2,750,000,000    
NEIL Maximum Insurance Coverage To Nuclear Facility For Property Damage And Outage Costs From Non-Nuclear Event     2,330,000,000    
Maximum prosepective insurance premium per nuclear incident     23,400,000    
Maximum amount of coverage to nuclear facility for property damage and outage costs 2,750,000,000   2,750,000,000    
EMANI Maximum Insurance Coverage for Summer Station Unit 1 For Property Damage And Outage Costs From Non-Nuclear Event     415,000,000    
EMANI Maximum Retrospective Premium Assessment     2,000,000    
Environmental          
Environmental Remediation Expense     9,500,000    
Deferred costs, net of costs previously recovered through rates and insurance settlements included in regulatory assets 23,300,000   23,300,000    
Nuclear Generation          
Asset Retirement Obligation Nuclear Decommissioning 218,000,000   218,000,000    
SCPSC Order Reduction Of Total Fuel Cost Component Of Retail Electric Rates To Reflect Lower Projected Fuel Costs And Eliminate Over-Collection Balances     31,000,000   $ 61,000,000
SCE&G | SCE&G          
Nuclear Insurance          
Maximum yearly assessment per reactor     13,700,000    
Summer Station Unit 2 and Unit 3 [Domain]          
Commitments and contingencies          
Transmission Assets related to BLRA Capital Costs $ 367,000,000   367,000,000    
Estimate of aggregate amount of subcontractor and vendor liens filed     $ 60,000,000    
Jointly Owned Utility Plant, Proportionate Ownership Share 55.00%   55.00%    
Other Regulatory Assets (Liabilities) [Member] | Summer Station Unit 2 and Unit 3 [Domain]          
Commitments and contingencies          
Transmission Assets related to BLRA Capital Costs $ 15,000,000   $ 15,000,000