v3.19.2
Regulatory Matters - Cost Recovery Clauses (Details) - USD ($)
$ in Millions
Jun. 30, 2019
Feb. 05, 2019
Dec. 31, 2018
ALABAMA POWER CO      
Loss Contingencies [Line Items]      
Rate RSE Refund Liability   $ 75  
ALABAMA POWER CO | Deferred under recovered regulatory clause revenues      
Loss Contingencies [Line Items]      
Rate CNP Compliance $ 0   $ 42
Rate CNP PPA 25   25
Retail Energy Cost Recovery 0   109
ALABAMA POWER CO | Customer accounts receivable      
Loss Contingencies [Line Items]      
Rate CNP Compliance 10   0
Retail Energy Cost Recovery 8   0
ALABAMA POWER CO | Other regulatory liabilities, deferred      
Loss Contingencies [Line Items]      
Natural Disaster Reserve 19   20
GEORGIA POWER CO | Receivables – under recovered fuel clause revenues      
Loss Contingencies [Line Items]      
Fuel Cost Recovery 69   115
MISSISSIPPI POWER CO | Over recovered regulatory clause liabilities      
Loss Contingencies [Line Items]      
Fuel Cost Recovery $ 9   $ 8