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LEASES - Additional Information (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Lessee, Lease, Description [Line Items] |  |  |
Operating lease obligations | $ 1,490 | $ 1,585 |
Transfer of construction work in progress to lease receivables |  |  | $ 210
Maximum | Real estate |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Remaining terms | 27 years |  |
Maximum | Land |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lessee, lease term | 44 years |  |
Maximum | Communication towers |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lessee, lease term | 17 years |  |
Maximum | Fuel cells |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lessor, lease term, operating lease | 10 years |  |
Alabama Power |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Operating lease obligations | $ 93 | 76 |
Alabama Power | Maximum | Electric generating units |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Operating lease remaining lease term | 16 years |  |
Alabama Power | Minimum | Electric generating units |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Operating lease remaining lease term | 1 year |  |
Georgia Power |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Operating lease obligations | $ 875 | 1,002 |
Variable lease, payment | 42 | 45 | 41
Georgia Power | Purchased power, affiliates |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Variable lease, payment | 21 | 21 | 20
Mississippi Power |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Operating lease obligations | $ 9 | 9 |
Transfer of construction work in progress to lease receivables |  |  | 39
Sales-type lease, lease receivable |  |  | $ 39
Mississippi Power | Maximum | Electric generating units |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lessor, sales-type lease, term of contract | 15 years |  |
Southern Power |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Operating lease obligations | $ 546 | 542 |
Lessor, sales-type lease, term of contract |  |  | 20 years
Sales-type lease, lease receivable |  |  | $ 210
Loss on sales-type leases | $ 0 | 1 | $ 40
Southern Power | Maximum | Electric generating units |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lessor, lease term, operating lease | 23 years |  |
Lessor, sales-type lease, term of contract | 18 years |  |
Southern Company Gas |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Operating lease obligations | $ 51 | 60 |
Southern Company Gas | Maximum |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lessor, remaining term | 19 years |  |
Affiliate | Georgia Power | Electric generating units |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Operating lease obligations | $ 416 | $ 461 |
Traditional Electric Operating Companies | Maximum | Outdoor lighting |  |  |
Lessee, Lease, Description [Line Items] |  |  |
Lessor, lease term, operating lease | 10 years |  |

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