CONTINGENCIES - Environmental Remediation (Details) - USD ($) $ in Millions |
Jun. 30, 2020 |
Dec. 31, 2019 |
|---|---|---|
| GEORGIA POWER CO | ||
| Loss Contingencies [Line Items] | ||
| Environmental remediation liability, current and former sites | $ 14 | $ 15 |
| SOUTHERN Co GAS | ||
| Loss Contingencies [Line Items] | ||
| Environmental remediation liability, current and former sites | $ 253 | $ 269 |