Regulatory Matters - Alabama Power (Details) - ALABAMA POWER CO - Restatement Adjustment $ in Millions |
Apr. 15, 2019
USD ($)
|
|---|---|
| Error Corrections and Prior Period Adjustments Restatement [Line Items] | |
| Capitalized asset retirement costs, net | $ 700 |
| Remaining amounts of regulatory assets for which no return on investment during recovery period is provided | 700 |
| Plant Gorgas Units 8, 9, and 10 | |
| Error Corrections and Prior Period Adjustments Restatement [Line Items] | |
| Net investment costs | 654 |
| Remaining amounts of regulatory assets for which no return on investment during recovery period is provided | $ 654 |