Income Taxes (Details) - USD ($) $ in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Income Tax Contingency [Line Items] | ||
| Effective tax (benefit) rate | 14.10% | 21.10% |
| ALABAMA POWER CO | ||
| Income Tax Contingency [Line Items] | ||
| Sale of investment tax credit | $ 39 | |
| GEORGIA POWER CO | ||
| Income Tax Contingency [Line Items] | ||
| Sale of investment tax credit | 91 | |
| Payment for PTCs | $ 83 | |
| Effective tax (benefit) rate | 14.30% | 21.70% |
| SOUTHERN POWER CO | ||
| Income Tax Contingency [Line Items] | ||
| Sale of investment tax credit | $ 49 | |
| Effective tax (benefit) rate | 85.10% | (7.00%) |
| SOUTHERN Co GAS | ||
| Income Tax Contingency [Line Items] | ||
| Effective tax (benefit) rate | 23.50% | 23.70% |