REGULATORY MATTERS - Mississippi Power (Details) - MISSISSIPPI POWER CO - USD ($) $ in Millions |
Jun. 25, 2020 |
Mar. 17, 2020 |
Jun. 30, 2020 |
|---|---|---|---|
| Loss Contingencies [Line Items] | |||
| Increase (decrease) in retail rates | $ 2.0 | $ (16.7) | |
| Decrease in retail rates, percentage | 1.85% | ||
| Base rate case filing, measurement input, average equity ratio | 53.00% | ||
| Base rate case filing, measurement input, maximum equity ratio | 55.00% | ||
| Base rate case filing, measurement input, return on investment | 7.57% | ||
| Regulatory asset, amortization period | 4 years | ||
| Regulatory liability, amortization period | 3 years | ||
| Annual base rate adjustment, increase in depreciation | $ 10.0 | ||
| Annual base rate adjustment, compensation costs excluded | $ 3.9 | ||
| Incremental COVID-19 costs deferred | $ 2.0 |