Regulatory Matters - Mississippi Power (Details) - USD ($) $ in Millions |
Jan. 01, 2019 |
Jul. 09, 2019 |
|---|---|---|
| MISSISSIPPI POWER CO | Subsequent Event | ||
| Loss Contingencies [Line Items] | ||
| Proportionate ownership share | 50.00% | |
| Total estimated cost | $ 66.0 | |
| MISSISSIPPI POWER CO | Subsequent Event | Ash Pond Closure | ||
| Loss Contingencies [Line Items] | ||
| Total estimated cost | 17.0 | |
| MISSISSIPPI POWER CO | MRA Revenue | ||
| Loss Contingencies [Line Items] | ||
| Decrease in base rate under cost based electric tariff | $ 3.7 | |
| Mississippi Power And Gulf Power | Subsequent Event | ||
| Loss Contingencies [Line Items] | ||
| Total estimated cost | $ 125.0 |