REGULATORY MATTERS - MPC Environmental Compliance Overview Plan (Details) - Mississippi Power - USD ($) $ in Millions |
1 Months Ended | 12 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Feb. 14, 2025 |
Feb. 13, 2025 |
Oct. 25, 2024 |
Jul. 31, 2024 |
May 31, 2024 |
Jun. 30, 2023 |
Apr. 30, 2023 |
Jun. 30, 2022 |
Apr. 30, 2022 |
Dec. 31, 2021 |
|
| Public Utilities, General Disclosures [Line Items] | ||||||||||
| Public utilities, approved rate increase (decrease), amount | $ (5) | $ (7) | $ 18 | $ 9 | ||||||
| Requested rate increase (decrease), amount | $ 11 | |||||||||
| Subsequent Event | ||||||||||
| Public Utilities, General Disclosures [Line Items] | ||||||||||
| Requested rate increase (decrease), amount | $ 8 | |||||||||
| Environmental Compliance Overview Plan | ||||||||||
| Public Utilities, General Disclosures [Line Items] | ||||||||||
| Public utilities, approved rate increase (decrease), amount | $ 9 | $ 3 | $ 1 | |||||||
| Environmental Compliance Overview Plan | Subsequent Event | ||||||||||
| Public Utilities, General Disclosures [Line Items] | ||||||||||
| Requested rate increase (decrease), amount | $ 6 | |||||||||