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INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Deferred tax liabilities — |  |
Deferred income tax liabilities | $ 18,574 | $ 18,066
Deferred tax assets — |  |
Deferred income tax assets | 7,886 | 8,398
Valuation allowance | (206) | (257)
Net deferred income tax assets | 7,680 | 8,141
Net deferred income taxes liabilities | 10,894 | 9,925
Accumulated deferred income taxes – assets | (96) | (111)
Accumulated deferred income taxes – liabilities | 10,990 | 10,036
Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 9,683 | 9,443
Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 2,647 | 2,350
Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 979 | 888
Deferred tax assets — |  |
Deferred income tax assets | 985 | 890
AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 833 | 876
Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 601 | 805
AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,902 | 2,006
Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 797 | 677
Remaining book value of retired assets |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 369 | 400
Premium on reacquired debt |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 63 | 66
Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 700 | 555
ITC and PTC carryforwards |  |
Deferred tax assets — |  |
Deferred income tax assets | 1,387 | 1,685
Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 857 | 888
Estimated loss on regulatory disallowance |  |
Deferred tax assets — |  |
Deferred income tax assets | 26 |
Other state deferred tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 363 | 388
Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax assets — |  |
Deferred income tax assets | 418 | 365
Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 197 | 207
State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 115 | 136
Other partnership basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 85 | 111
Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) |  |
Deferred tax assets — |  |
Deferred income tax assets | 34 | 137
Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 79 | 85
Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 67 | 72
Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 538 | 552
AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | 2,735 | 2,882
Alabama Power |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 6,101 | 6,024
Deferred tax assets — |  |
Deferred income tax assets | 1,931 | 2,043
Valuation allowance | 0 | 0
Net deferred income tax assets | 1,931 | 2,043
Net deferred income taxes liabilities | 4,170 | 3,981
Accumulated deferred income taxes – assets | 0 | 0
Accumulated deferred income taxes – liabilities | 4,170 | 3,981
Alabama Power | Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 2,566 | 2,564
Alabama Power | Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,444 | 1,303
Alabama Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 321 | 284
Deferred tax assets — |  |
Deferred income tax assets | 224 | 198
Alabama Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 476 | 499
Alabama Power | Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 80 | 185
Alabama Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 667 | 679
Alabama Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 213 | 180
Alabama Power | Remaining book value of retired assets |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 143 | 142
Alabama Power | Premium on reacquired debt |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 9 | 9
Alabama Power | Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 182 | 179
Alabama Power | ITC and PTC carryforwards |  |
Deferred tax assets — |  |
Deferred income tax assets | 12 | 12
Alabama Power | Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Alabama Power | Estimated loss on regulatory disallowance |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 |
Alabama Power | Other state deferred tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Alabama Power | Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax assets — |  |
Deferred income tax assets | 215 | 175
Alabama Power | Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Alabama Power | State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 115 | 136
Alabama Power | Other partnership basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Alabama Power | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) |  |
Deferred tax assets — |  |
Deferred income tax assets | 30 | 127
Alabama Power | Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Alabama Power | Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 4 | 4
Alabama Power | Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 188 | 213
Alabama Power | AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | 1,143 | 1,178
Georgia Power |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 7,661 | 7,426
Deferred tax assets — |  |
Deferred income tax assets | 3,718 | 3,844
Valuation allowance | (75) | (125)
Net deferred income tax assets | 3,643 | 3,719
Net deferred income taxes liabilities | 4,018 | 3,707
Accumulated deferred income taxes – assets | 0 | 0
Accumulated deferred income taxes – liabilities | 4,018 | 3,707
Georgia Power | Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 3,628 | 3,447
Georgia Power | Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 812 | 693
Georgia Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 446 | 412
Deferred tax assets — |  |
Deferred income tax assets | 316 | 304
Georgia Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 314 | 324
Georgia Power | Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 508 | 548
Georgia Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,196 | 1,285
Georgia Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 260 | 226
Georgia Power | Remaining book value of retired assets |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 221 | 253
Georgia Power | Premium on reacquired debt |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 53 | 57
Georgia Power | Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 223 | 181
Georgia Power | ITC and PTC carryforwards |  |
Deferred tax assets — |  |
Deferred income tax assets | 691 | 673
Georgia Power | Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 857 | 888
Georgia Power | Estimated loss on regulatory disallowance |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 |
Georgia Power | Other state deferred tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 13 | 12
Georgia Power | Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax assets — |  |
Deferred income tax assets | 92 | 88
Georgia Power | Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 83 | 79
Georgia Power | State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Georgia Power | Other partnership basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Georgia Power | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Georgia Power | Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Georgia Power | Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 4 | 5
Georgia Power | Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 152 | 186
Georgia Power | AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | 1,510 | 1,609
Mississippi Power |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 714 | 717
Deferred tax assets — |  |
Deferred income tax assets | 382 | 399
Valuation allowance | (41) | (41)
Net deferred income tax assets | 341 | 358
Net deferred income taxes liabilities | 373 | 359
Accumulated deferred income taxes – assets | (96) | (107)
Accumulated deferred income taxes – liabilities | 469 | 466
Mississippi Power | Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 339 | 338
Mississippi Power | Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 188 | 179
Mississippi Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 49 | 43
Deferred tax assets — |  |
Deferred income tax assets | 52 | 47
Mississippi Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Mississippi Power | Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 13 | 40
Mississippi Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 39 | 42
Mississippi Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 37 | 30
Mississippi Power | Remaining book value of retired assets |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 5 | 5
Mississippi Power | Premium on reacquired debt |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1 | 0
Mississippi Power | Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 43 | 40
Mississippi Power | ITC and PTC carryforwards |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Estimated loss on regulatory disallowance |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 |
Mississippi Power | Other state deferred tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 231 | 239
Mississippi Power | Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Other partnership basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) |  |
Deferred tax assets — |  |
Deferred income tax assets | 3 | 9
Mississippi Power | Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 57 | 62
Mississippi Power | AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | 39 | 42
Southern Power |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,360 | 1,376
Deferred tax assets — |  |
Deferred income tax assets | 773 | 1,124
Valuation allowance | (27) | (27)
Net deferred income tax assets | 746 | 1,097
Net deferred income taxes liabilities | 614 | 279
Accumulated deferred income taxes – assets | 0 | 0
Accumulated deferred income taxes – liabilities | 614 | 279
Southern Power | Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,346 | 1,351
Southern Power | Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 12 | 11
Deferred tax assets — |  |
Deferred income tax assets | 10 | 9
Southern Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | Remaining book value of retired assets |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | Premium on reacquired debt |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 2 | 14
Southern Power | ITC and PTC carryforwards |  |
Deferred tax assets — |  |
Deferred income tax assets | 481 | 794
Southern Power | Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Power | Estimated loss on regulatory disallowance |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 |
Southern Power | Other state deferred tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 49 | 51
Southern Power | Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax assets — |  |
Deferred income tax assets | 27 | 28
Southern Power | Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 97 | 109
Southern Power | State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Power | Other partnership basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 85 | 111
Southern Power | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Power | Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Power | Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 6 | 5
Southern Power | Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 18 | 17
Southern Power | AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 2,041 | 1,852
Deferred tax assets — |  |
Deferred income tax assets | 377 | 301
Valuation allowance | (7) | (9)
Net deferred income tax assets | 370 | 292
Net deferred income taxes liabilities | 1,671 | 1,560
Accumulated deferred income taxes – assets | 0 | 0
Accumulated deferred income taxes – liabilities | 1,671 | 1,560
Southern Company Gas | Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,576 | 1,505
Southern Company Gas | Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 189 | 150
Southern Company Gas | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 74 | 68
Deferred tax assets — |  |
Deferred income tax assets | 89 | 89
Southern Company Gas | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Company Gas | Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 32
Southern Company Gas | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Company Gas | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 11 | 15
Southern Company Gas | Remaining book value of retired assets |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Company Gas | Premium on reacquired debt |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Company Gas | Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 191 | 82
Southern Company Gas | ITC and PTC carryforwards |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | Estimated loss on regulatory disallowance |  |
Deferred tax assets — |  |
Deferred income tax assets | 26 |
Southern Company Gas | Other state deferred tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 8 | 7
Southern Company Gas | Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax assets — |  |
Deferred income tax assets | 101 | 92
Southern Company Gas | Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | Other partnership basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 79 | 85
Southern Company Gas | Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 74 | 28
Southern Company Gas | AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | $ 0 | $ 0

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