Stock Compensation - Schedule of Employees Participating in Stock-Based Compensation Programs (Details) |
Dec. 31, 2018
employee
|
|---|---|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Number of employees | 4,716 |
| Alabama Power | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Number of employees | 745 |
| Georgia Power | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Number of employees | 822 |
| Mississippi Power | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Number of employees | 164 |
| Southern Power | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Number of employees | 95 |
| Southern Company Gas | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Number of employees | 285 |