REGULATORY MATTERS - APC Accounting Orders and Plant Greene County (Details) $ in Millions |
Dec. 31, 2024
USD ($)
MW
|
Dec. 31, 2023
USD ($)
|
Dec. 31, 2021
MW
|
Dec. 31, 2020
MW
|
|---|---|---|---|---|
| Public Utilities, General Disclosures [Line Items] | ||||
| Other deferred charges and assets | $ | $ 19,599 | $ 19,069 | ||
| Alabama Power | ||||
| Public Utilities, General Disclosures [Line Items] | ||||
| Other deferred charges and assets | $ | $ 5,175 | 5,090 | ||
| Percent ownership | 14.00% | |||
| Alabama Power | Plant Greene County Units 1 and 2 | ||||
| Public Utilities, General Disclosures [Line Items] | ||||
| Percent ownership | 60.00% | |||
| Required fossil-stream generation retirements (in MWs) | MW | 300 | |||
| Mississippi Power | ||||
| Public Utilities, General Disclosures [Line Items] | ||||
| Other deferred charges and assets | $ | $ 841 | $ 887 | ||
| Required fossil-stream generation retirements (in MWs) | MW | 950 | |||
| Mississippi Power | Plant Greene County Units 1 and 2 | ||||
| Public Utilities, General Disclosures [Line Items] | ||||
| Percent ownership | 40.00% | |||
| Required fossil-stream generation retirements (in MWs) | MW | 206 |