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Revenue from Contracts with Customers and Lease Income - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | $ 7,822 | $ 7,481 | $ 22,142 | $ 20,513
Total operating revenues | 7,823 | 7,274 | 22,572 | 20,383
Residential |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 2,737 | 2,651 | 6,822 | 6,551
Commercial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 2,074 | 1,991 | 5,400 | 5,075
Industrial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 1,195 | 1,184 | 3,127 | 3,019
Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 32 | 33 | 94 | 94
Retail electric revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 6,038 | 5,859 | 15,443 | 14,739
Natural gas distribution revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 668 | 610 | 3,132 | 2,749
Residential |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 236 | 212 | 1,475 | 1,244
Commercial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 65 | 55 | 357 | 300
Transportation |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 316 | 294 | 1,053 | 959
Industrial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 4 | 4 | 30 | 25
Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 47 | 45 | 217 | 221
Wholesale electric revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 659 | 557 | 1,810 | 1,512
PPA energy revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 373 | 300 | 1,097 | 838
PPA capacity revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 180 | 190 | 478 | 495
Non-PPA revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 106 | 67 | 235 | 179
Other natural gas revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 57 | 57 | 405 | 368
Gas marketing services |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 56 | 51 | 394 | 352
Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 1 | 6 | 11 | 16
Other revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 400 | 398 | 1,352 | 1,145
Other revenue sources |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Other revenues | 1 | (207) | 430 | (130)
ALABAMA POWER CO |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 2,294 | 2,244 | 6,053 | 5,926
Total operating revenues | 2,318 | 2,138 | 6,298 | 5,803
ALABAMA POWER CO | Residential |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 982 | 975 | 2,512 | 2,477
ALABAMA POWER CO | Commercial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 614 | 607 | 1,599 | 1,583
ALABAMA POWER CO | Industrial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 481 | 483 | 1,304 | 1,338
ALABAMA POWER CO | Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 3 | 3 | 8 | 9
ALABAMA POWER CO | Retail electric revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 2,080 | 2,068 | 5,423 | 5,407
ALABAMA POWER CO | Wholesale electric revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 155 | 116 | 421 | 345
ALABAMA POWER CO | PPA energy revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 81 | 58 | 193 | 171
ALABAMA POWER CO | PPA capacity revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 32 | 24 | 89 | 71
ALABAMA POWER CO | Non-PPA revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 42 | 34 | 139 | 103
ALABAMA POWER CO | Other revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 59 | 60 | 209 | 174
ALABAMA POWER CO | Other revenue sources |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Other revenues | 24 | (106) | 245 | (123)
GEORGIA POWER CO |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 3,970 | 3,740 | 10,209 | 9,259
Total operating revenues | 3,770 | 3,472 | 9,918 | 8,745
GEORGIA POWER CO | Residential |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 1,653 | 1,580 | 4,056 | 3,832
GEORGIA POWER CO | Commercial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 1,358 | 1,288 | 3,539 | 3,243
GEORGIA POWER CO | Industrial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 620 | 606 | 1,560 | 1,424
GEORGIA POWER CO | Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 27 | 28 | 79 | 78
GEORGIA POWER CO | Retail electric revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 3,658 | 3,502 | 9,234 | 8,577
GEORGIA POWER CO | Wholesale electric revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 121 | 68 | 348 | 175
GEORGIA POWER CO | PPA energy revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 58 | 26 | 192 | 66
GEORGIA POWER CO | PPA capacity revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 40 | 42 | 113 | 106
GEORGIA POWER CO | Non-PPA revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 23 | 0 | 43 | 3
GEORGIA POWER CO | Other revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 191 | 170 | 627 | 507
GEORGIA POWER CO | Other revenue sources |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Other revenues | (200) | (268) | (291) | (514)
MISSISSIPPI POWER CO |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 481 | 424 | 1,270 | 1,131
Total operating revenues | 480 | 412 | 1,301 | 1,118
MISSISSIPPI POWER CO | Residential |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 102 | 96 | 254 | 242
MISSISSIPPI POWER CO | Commercial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 102 | 96 | 262 | 249
MISSISSIPPI POWER CO | Industrial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 94 | 95 | 263 | 257
MISSISSIPPI POWER CO | Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 2 | 2 | 7 | 7
MISSISSIPPI POWER CO | Retail electric revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 300 | 289 | 786 | 755
MISSISSIPPI POWER CO | Wholesale electric revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 169 | 122 | 442 | 342
MISSISSIPPI POWER CO | PPA energy revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 3 | 1 | 8 | 3
MISSISSIPPI POWER CO | PPA capacity revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 16 | 15 | 50 | 47
MISSISSIPPI POWER CO | Non-PPA revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 150 | 106 | 384 | 292
MISSISSIPPI POWER CO | Other revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 12 | 13 | 42 | 34
MISSISSIPPI POWER CO | Other revenue sources |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Other revenues | (1) | (12) | 31 | (13)
SOUTHERN POWER CO |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 417 | 423 | 1,212 | 1,143
Total operating revenues | 613 | 600 | 1,726 | 1,597
SOUTHERN POWER CO | Residential |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 0 | 0 | 0 | 0
SOUTHERN POWER CO | Commercial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 0 | 0 | 0 | 0
SOUTHERN POWER CO | Industrial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 0 | 0 | 0 | 0
SOUTHERN POWER CO | Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 0 | 0 | 0 | 0
SOUTHERN POWER CO | Retail electric revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 0 | 0 | 0 | 0
SOUTHERN POWER CO | Wholesale electric revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 414 | 414 | 1,195 | 1,112
SOUTHERN POWER CO | PPA energy revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 246 | 222 | 739 | 616
SOUTHERN POWER CO | PPA capacity revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 109 | 125 | 276 | 320
SOUTHERN POWER CO | Non-PPA revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 59 | 67 | 180 | 176
SOUTHERN POWER CO | Other revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 3 | 9 | 17 | 31
SOUTHERN POWER CO | Other revenue sources |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Other revenues | 196 | 177 | 514 | 454
SOUTHERN Co GAS |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 725 | 667 | 3,537 | 3,117
Total operating revenues | 734 | 682 | 3,552 | 3,220
SOUTHERN Co GAS | Natural gas distribution revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 668 | 610 | 3,132 | 2,749
SOUTHERN Co GAS | Residential |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 236 | 212 | 1,475 | 1,244
SOUTHERN Co GAS | Commercial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 65 | 55 | 357 | 300
SOUTHERN Co GAS | Transportation |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 316 | 294 | 1,053 | 959
SOUTHERN Co GAS | Industrial |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 4 | 4 | 30 | 25
SOUTHERN Co GAS | Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 47 | 45 | 217 | 221
SOUTHERN Co GAS | Other natural gas revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 57 | 57 | 405 | 368
SOUTHERN Co GAS | Gas marketing services |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 56 | 51 | 394 | 352
SOUTHERN Co GAS | Other |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 1 | 6 | 11 | 16
SOUTHERN Co GAS | Other revenues |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Total revenue from contracts with customers | 0 | 0 | 0 | 0
SOUTHERN Co GAS | Other revenue sources |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |
Other revenues | $ 9 | $ 15 | $ 15 | $ 103

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