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LEASES - Lease Costs (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Lease cost |  |  |
Operating lease cost | $ 248 | $ 252 | $ 297
Finance lease cost: |  |  |
Amortization of ROU assets | 20 | 24 | 23
Interest on lease obligations | 15 | 14 | 13
Total finance lease cost | 35 | 38 | 36
Short-term lease costs | 37 | 40 | 64
Variable lease cost | 48 | 47 | 125
Sublease income |  |  | (1)
Total lease cost | 368 | 377 | 521
Assets Subject to Power Purchase Agreement |  |  |
Lease cost |  |  |
Operating lease cost | 108 | 112 | 162
Alabama Power |  |  |
Lease cost |  |  |
Operating lease cost | 19 | 16 | 59
Finance lease cost: |  |  |
Amortization of ROU assets | 2 | 2 | 1
Interest on lease obligations | 0 | 0 | 0
Total finance lease cost | 2 | 2 | 1
Short-term lease costs | 15 | 16 | 44
Variable lease cost |  | 0 | 13
Variable lease cost | (1) |  |
Sublease income |  |  | 0
Total lease cost | 35 | 34 | 117
Alabama Power | Assets Subject to Power Purchase Agreement |  |  |
Lease cost |  |  |
Operating lease cost | 5 | 4 | 48
Georgia Power |  |  |
Lease cost |  |  |
Operating lease cost | 190 | 192 | 198
Finance lease cost: |  |  |
Amortization of ROU assets | 23 | 19 | 15
Interest on lease obligations | 15 | 17 | 17
Total finance lease cost | 38 | 36 | 32
Short-term lease costs | 15 | 16 | 13
Variable lease cost | 77 | 74 | 105
Sublease income |  |  | 0
Total lease cost | 320 | 318 | 348
Georgia Power | Assets Subject to Power Purchase Agreement |  |  |
Lease cost |  |  |
Operating lease cost | 168 | 174 | 180
Mississippi Power |  |  |
Lease cost |  |  |
Operating lease cost | 4 | 5 | 5
Finance lease cost: |  |  |
Amortization of ROU assets | 1 | 1 | 1
Interest on lease obligations | 1 | 0 | 1
Total finance lease cost | 2 | 1 | 2
Short-term lease costs | 0 | 0 | 0
Variable lease cost | 0 | 0 | 0
Sublease income |  |  | 0
Total lease cost | 6 | 6 | 7
Southern Power |  |  |
Lease cost |  |  |
Operating lease cost | 27 | 34 | 32
Finance lease cost: |  |  |
Amortization of ROU assets | 0 | 0 | 0
Interest on lease obligations | 0 | 0 | 0
Total finance lease cost | 0 | 0 | 0
Short-term lease costs | 0 | 0 | 0
Variable lease cost | 4 | 4 | 5
Sublease income |  |  | 0
Total lease cost | 31 | 38 | 37
Southern Company Gas |  |  |
Lease cost |  |  |
Operating lease cost | 12 | 12 | 15
Finance lease cost: |  |  |
Amortization of ROU assets | 0 | 0 | 0
Interest on lease obligations | 0 | 0 | 0
Total finance lease cost | 0 | 0 | 0
Short-term lease costs | 0 | 0 | 0
Variable lease cost | 0 | 0 | 0
Sublease income |  |  | 0
Total lease cost | $ 12 | $ 12 | $ 15

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- Definition Amount of interest expense on finance lease liability. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 53 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479589/842-20-55-53 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479041/842-20-45-4 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-4 + Details
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