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LEASES - Additional Information (Details) $ in Millions |  |  | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2024 USD ($) agreement | Jun. 27, 2024 agreement | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($)
Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease obligations | $ 1,453 |  | $ 1,453 | $ 1,490 |
Maximum | Real estate |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Remaining terms |  |  | 20 years |  |
Maximum | Land |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Lessee, lease term |  |  | 44 years |  |
Maximum | Communication towers |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Lessee, lease term |  |  | 16 years |  |
Maximum | Fuel cells |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Lessor, lease term, operating lease | 9 years |  | 9 years |  |
Alabama Power |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease obligations | $ 90 |  | $ 90 | 93 |
Alabama Power | Maximum | Electric generating units |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease remaining lease term | 15 years |  | 15 years |  |
Alabama Power | Minimum | Electric generating units |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease remaining lease term | 3 years |  | 3 years |  |
Georgia Power |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Requested number of affiliate power purchase agreements to be certified | agreement | 2 | 5 |  |  |
Lease not yet commenced, term | 10 years |  | 10 years |  |
Lease not yet commenced amount | $ 83 |  | $ 83 |  |
Operating lease obligations | $ 1,328 |  | 1,328 | 875 |
Variable lease, payment |  |  | 45 | 42 | $ 45
Georgia Power | Purchased power, affiliates |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Variable lease, payment |  |  | $ 22 | 21 | $ 21
Georgia Power | Maximum | Outdoor lighting |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Lessor, lease term, operating lease | 15 years |  | 15 years |  |
Mississippi Power |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease obligations | $ 8 |  | $ 8 | 9 |
Mississippi Power | Maximum | Electric generating units |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Lessor, sales-type lease, term of contract | 14 years |  | 14 years |  |
Southern Power |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease obligations | $ 540 |  | $ 540 | 546 |
Southern Power | Maximum | Electric generating units |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Lessor, lease term, operating lease | 22 years |  | 22 years |  |
Lessor, sales-type lease, term of contract | 17 years |  | 17 years |  |
Southern Company Gas |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Lease not yet commenced, term | 11 years 6 months |  | 11 years 6 months |  |
Lease not yet commenced amount | $ 105 |  | $ 105 |  |
Operating lease obligations | 41 |  | $ 41 | 51 |
Southern Company Gas | Maximum |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Lessor, remaining term |  |  | 18 years |  |
Affiliate | Georgia Power | Electric generating units |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease obligations | $ 893 |  | $ 893 | $ 416 |
Traditional Electric Operating Companies | Maximum | Outdoor lighting |  |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |  |
Lessor, lease term, operating lease | 10 years |  | 10 years |  |

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