SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Average AFUDC Composite Rates (Details) |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|---|
| Alabama Power | |||
| Capitalized Contract Cost [Line Items] | |||
| Composite rate | 8.10% | 8.10% | 7.90% |
| Georgia Power | |||
| Capitalized Contract Cost [Line Items] | |||
| Composite rate | 7.70% | 7.60% | 7.30% |
| Mississippi Power | |||
| Capitalized Contract Cost [Line Items] | |||
| Composite rate | 0.00% | 0.00% | 5.30% |
| Atlanta Gas Light | |||
| Capitalized Contract Cost [Line Items] | |||
| Composite rate | 7.70% | 7.40% | 7.60% |
| Chattanooga Gas | |||
| Capitalized Contract Cost [Line Items] | |||
| Composite rate | 7.10% | 7.10% | 7.10% |
| Nicor Gas | |||
| Capitalized Contract Cost [Line Items] | |||
| Composite rate | 5.60% | 4.60% | 2.00% |