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INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Deferred tax liabilities — |  |
Deferred income tax liabilities | $ 17,451 | $ 16,781
Deferred tax assets — |  |
Deferred income tax assets | 8,914 | 8,874
Valuation allowance | (207) | (136)
Net deferred income tax assets | 8,707 | 8,738
Net deferred income taxes liabilities | 8,744 | 8,043
Accumulated deferred income taxes – assets | (118) | (132)
Accumulated deferred income taxes – liabilities | 8,862 | 8,175
Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 9,300 | 8,950
Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 2,301 | 1,999
Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Deferred tax assets — |  |
Deferred income tax assets | 305 | 284
Leveraged lease basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 61 | 142
Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 820 | 739
Deferred tax assets — |  |
Deferred income tax assets | 1,035 | 1,511
Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 315 |
Storm damage reserves |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 18 | 80
Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 825 | 1,313
Remaining book value of retired assets |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 271 | 270
Premium on reacquired debt |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 72 | 78
AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 2,232 | 1,969
AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 868 | 804
Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 368 | 437
State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 135 | 126
Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 231 | 223
ITC and PTC carryforward |  |
Deferred tax assets — |  |
Deferred income tax assets | 1,750 | 1,853
Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 91 | 86
Other partnership basis difference |  |
Deferred tax assets — |  |
Deferred income tax assets | 160 | 166
Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 92 | 128
AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | 3,100 | 2,773
Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 825 | 369
Other deferred state tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 361 | 357
Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) |  |
Deferred tax assets — |  |
Deferred income tax assets | 268 | 338
Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 561 | 660
Alabama Power |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 5,737 | 5,416
Deferred tax assets — |  |
Deferred income tax assets | 2,164 | 2,143
Valuation allowance | 0 | 0
Net deferred income tax assets | 2,164 | 2,143
Net deferred income taxes liabilities | 3,573 | 3,273
Accumulated deferred income taxes – assets | 0 | 0
Accumulated deferred income taxes – liabilities | 3,573 | 3,273
Alabama Power | Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 2,541 | 2,453
Alabama Power | Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,182 | 1,010
Alabama Power | Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Deferred tax assets — |  |
Deferred income tax assets | 165 | 151
Alabama Power | Leveraged lease basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Alabama Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 268 | 250
Deferred tax assets — |  |
Deferred income tax assets | 225 | 369
Alabama Power | Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 47 |
Alabama Power | Storm damage reserves |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Alabama Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 205 | 348
Alabama Power | Remaining book value of retired assets |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 145 | 123
Alabama Power | Premium on reacquired debt |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 10 | 12
Alabama Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 863 | 764
Alabama Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 329 | 328
Alabama Power | Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 147 | 128
Alabama Power | State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 135 | 126
Alabama Power | Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Alabama Power | ITC and PTC carryforward |  |
Deferred tax assets — |  |
Deferred income tax assets | 12 | 12
Alabama Power | Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Alabama Power | Other partnership basis difference |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Alabama Power | Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 5 | 7
Alabama Power | AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | 1,192 | 1,092
Alabama Power | Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Alabama Power | Other deferred state tax attributes |  |
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 | 237 | 243
Alabama Power | Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 193 | 143
Georgia Power |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 6,965 | 6,680
Deferred tax assets — |  |
Deferred income tax assets | 4,019 | 3,443
Valuation allowance | (73) | (35)
Net deferred income tax assets | 3,946 | 3,408
Net deferred income taxes liabilities | 3,019 | 3,272
Accumulated deferred income taxes – assets | 0 | 0
Accumulated deferred income taxes – liabilities | 3,019 | 3,272
Georgia Power | Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 3,340 | 3,228
Georgia Power | Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 781 | 689
Georgia Power | Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Deferred tax assets — |  |
Deferred income tax assets | 41 | 59
Georgia Power | Leveraged lease basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Georgia Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 382 | 362
Deferred tax assets — |  |
Deferred income tax assets | 342 | 522
Georgia Power | Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 109 |
Georgia Power | Storm damage reserves |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 18 | 80
Georgia Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 256 | 438
Georgia Power | Remaining book value of retired assets |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 121 | 141
Georgia Power | Premium on reacquired debt |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 62 | 66
Georgia Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,325 | 1,165
Georgia Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 494 | 429
Georgia Power | Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 77 | 82
Georgia Power | State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Georgia Power | Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 90 | 72
Georgia Power | ITC and PTC carryforward |  |
Deferred tax assets — |  |
Deferred income tax assets | 704 | 539
Georgia Power | Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Georgia Power | Other partnership basis difference |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Georgia Power | Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 15 | 17
Georgia Power | AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | 1,819 | 1,594
Georgia Power | Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 825 | 369
Georgia Power | Other deferred state tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 11 | 9
Georgia Power | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) |  |
Deferred tax assets — |  |
Deferred income tax assets | 19 | 76
Georgia Power | Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 153 | 186
Mississippi Power |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 698 | 705
Deferred tax assets — |  |
Deferred income tax assets | 393 | 428
Valuation allowance | (41) | (41)
Net deferred income tax assets | 352 | 387
Net deferred income taxes liabilities | 346 | 318
Accumulated deferred income taxes – assets | (118) | (129)
Accumulated deferred income taxes – liabilities | 464 | 447
Mississippi Power | Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 330 | 319
Mississippi Power | Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 169 | 148
Mississippi Power | Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 22 | 25
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Leveraged lease basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Mississippi Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 41 | 39
Deferred tax assets — |  |
Deferred income tax assets | 57 | 80
Mississippi Power | Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 15 |
Mississippi Power | Storm damage reserves |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Mississippi Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 38 | 62
Mississippi Power | Remaining book value of retired assets |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 5 | 6
Mississippi Power | Premium on reacquired debt |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Mississippi Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 44 | 40
Mississippi Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Mississippi Power | Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 34 | 66
Mississippi Power | State effect of federal deferred taxes |  |
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 | ITC and PTC carryforward |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Other partnership basis difference |  |
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 | AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | 44 | 40
Mississippi Power | Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Mississippi Power | Other deferred state tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 246 | 250
Mississippi Power | Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) |  |
Deferred tax assets — |  |
Deferred income tax assets | 12 | 19
Mississippi Power | Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 34 | 39
Southern Power |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,446 | 1,413
Deferred tax assets — |  |
Deferred income tax assets | 1,258 | 1,587
Valuation allowance | (27) | (35)
Net deferred income tax assets | 1,231 | 1,552
Net deferred income taxes liabilities | 215 |
Net deferred income taxes assets |  | (139)
Accumulated deferred income taxes – assets | 0 | (262)
Accumulated deferred income taxes – liabilities | 215 | 123
Southern Power | Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,421 | 1,389
Southern Power | Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Deferred tax assets — |  |
Deferred income tax assets | 27 | 26
Southern Power | Leveraged lease basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 11 | 12
Deferred tax assets — |  |
Deferred income tax assets | 7 | 6
Southern Power | Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 |
Southern Power | Storm damage reserves |  |
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 | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Power | Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 14 | 12
Southern Power | State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Power | Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 121 | 134
Southern Power | ITC and PTC carryforward |  |
Deferred tax assets — |  |
Deferred income tax assets | 827 | 1,110
Southern Power | Long-term debt fair value adjustment |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Power | Other partnership basis difference |  |
Deferred tax assets — |  |
Deferred income tax assets | 160 | 166
Southern Power | Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 11 | 25
Southern Power | AROs |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Power | Estimated loss on plants under construction |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Power | Other deferred state tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 52 | 68
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 | Other |  |
Deferred tax assets — |  |
Deferred income tax assets | 53 | 52
Southern Company Gas |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,874 | 1,693
Deferred tax assets — |  |
Deferred income tax assets | 328 | 432
Valuation allowance | (9) | (4)
Net deferred income tax assets | 319 | 428
Net deferred income taxes liabilities | 1,555 | 1,265
Accumulated deferred income taxes – assets | 0 | 0
Accumulated deferred income taxes – liabilities | 1,555 | 1,265
Southern Company Gas | Accelerated depreciation |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 1,428 | 1,349
Southern Company Gas | Property basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 148 | 135
Southern Company Gas | Federal effect of net state deferred tax assets/liabilities |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Deferred tax assets — |  |
Deferred income tax assets | 93 | 70
Southern Company Gas | Leveraged lease basis differences |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Company Gas | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 57 | 26
Deferred tax assets — |  |
Deferred income tax assets | 77 | 100
Southern Company Gas | Under recovered fuel and natural gas costs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 144 |
Southern Company Gas | Storm damage reserves |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Company Gas | Employee benefit obligations |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 15 | 45
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 | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Company Gas | AROs |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 0 | 0
Southern Company Gas | Other |  |
Deferred tax liabilities — |  |
Deferred income tax liabilities | 82 | 138
Southern Company Gas | State effect of federal deferred taxes |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | Other property basis differences |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | ITC and PTC carryforward |  |
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 | 91 | 86
Southern Company Gas | Other partnership basis difference |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | Other comprehensive losses |  |
Deferred tax assets — |  |
Deferred income tax assets | 0 | 0
Southern Company Gas | AROs |  |
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 | Other deferred state tax attributes |  |
Deferred tax assets — |  |
Deferred income tax assets | 5 | 10
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 | Other |  |
Deferred tax assets — |  |
Deferred income tax assets | $ 62 | $ 166

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