v3.10.0.1
INCOME TAXES INCOME TAXES CARRYFORWARD (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended 24 Months Ended
Mar. 31, 2017
Dec. 31, 2037
Dec. 31, 2035
Dec. 31, 2032
Dec. 31, 2026
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2037
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent 35.00%         21.00% 35.00%  
Deferred Tax Assets, State Taxes           $ 30    
Operating Loss Carryforwards           1,807    
Renewable Energy Tax Credit           83    
State Operating Loss Carryforward           2,447    
Tax Credit Carryforward, Amount           4,367    
Tax Carryforward [Member]                
Tax Credit Carryforward, Ending Expiration Date   Dec. 31, 2037            
Renewable Energy Tax Credit [Member]                
Tax Credit Carryforward Expiration Date, Beginning     2035          
Tax Credit Carryforward, Ending Expiration Date               Dec. 31, 2038
State NOL Carryforwards [Member]                
Tax Credit Carryforward, Ending Expiration Date   Dec. 31, 2037            
State and Local Jurisdiction [Member]                
Tax Credit Carryforward, Ending Expiration Date       Dec. 31, 2033 Dec. 31, 2026      
SCE&G                
Deferred Tax Assets, State Taxes           30    
Operating Loss Carryforwards           1,642    
Renewable Energy Tax Credit           83    
State Operating Loss Carryforward           2,198    
Tax Credit Carryforward, Amount           $ 3,953