v3.25.0.1
REGULATORY MATTERS - APC Rate CNP New Plant (Details) - Alabama Power
$ in Millions
1 Months Ended 12 Months Ended
Jun. 30, 2023
USD ($)
Dec. 31, 2020
MW
Dec. 01, 2023
USD ($)
Oct. 03, 2022
USD ($)
Public Utilities, General Disclosures [Line Items]        
Increase to annual revenue requirement     $ 91 $ 34
Increase to annual revenue requirement, percentage     1.40% 0.60%
Requested rate increase (decrease), amount $ 78      
Requested rate increase (decrease), percentage 1.10%      
Plant Barry Unit 8        
Public Utilities, General Disclosures [Line Items]        
Approximate Nameplate Capacity (MW) | MW   720