v3.26.1
Segment and Related Information - Schedule of Financial Data for Business Segments (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Segment Reporting [Line Items]              
Operating revenues $ 6,977   $ 6,973   $ 15,374 $ 14,748  
Other segment items 3,472   3,617   8,138 7,812  
Depreciation and amortization(b) 1,434   1,323   2,854 2,608  
Earnings from equity method investments 86   10   136 43  
Interest expense(d) 796   874   1,573 1,588  
Income taxes (benefit) 187   289   414 569  
Consolidated Net Income Attributable to Southern Company 1,174   880   2,531 2,214  
Goodwill 5,161       5,161   $ 5,161
Total assets 162,027       162,027   155,720
Loss from extinguishment of debt     129   11 129  
Loss from extinguishment of debt, net of tax     97   8 97  
SOUTHERN POWER CO              
Segment Reporting [Line Items]              
Operating revenues 535   546   1,216 1,113  
Depreciation and amortization(b) 280   177   558 329  
Earnings from equity method investments         0 0  
Interest expense(d) 28   24   55 50  
Income taxes (benefit) (77)   (2)   (147) (3)  
Consolidated Net Income Attributable to Southern Company (25)   51   (22) 138  
Total assets 12,780       12,780   12,657
SOUTHERN POWER CO | Kay Wind Facility              
Segment Reporting [Line Items]              
Depreciation before tax 140   42   293 69  
Depreciation after tax 109   31   228 51  
SOUTHERN Co GAS              
Segment Reporting [Line Items]              
Operating revenues 966   979   3,157 2,818  
Other segment items 554   599   1,911 1,670  
Depreciation and amortization(b) 185   172   369 341  
Earnings from equity method investments 32   23   78 62  
Interest expense(d) 101   92   206 183  
Income taxes (benefit) 32   33   176 162  
Consolidated Net Income Attributable to Southern Company 126 $ 447 106 $ 418 573 524  
Goodwill 5,015       5,015   5,015
Total assets 27,604       27,604   27,387
GEORGIA POWER CO              
Segment Reporting [Line Items]              
Operating revenues 3,133   3,110   6,276 6,148  
Depreciation and amortization(b) 503   512   987 1,015  
Interest expense(d) 228   198   431 385  
Income taxes (benefit) 151   236   236 334  
Consolidated Net Income Attributable to Southern Company 779 628 607 596 1,408 1,204  
Total assets 73,371       73,371   68,077
ALABAMA POWER CO              
Segment Reporting [Line Items]              
Operating revenues 1,963   1,968   4,055 3,980  
Depreciation and amortization(b) 385   371   766 741  
Interest expense(d) 117   116   232 225  
Income taxes (benefit) 135   115   263 226  
Consolidated Net Income Attributable to Southern Company 437 $ 425 381 $ 375 862 755  
Total assets 38,679       38,679   38,124
Operating Segments              
Segment Reporting [Line Items]              
Operating revenues 6,792   6,783   15,005 14,378  
Other segment items 3,306   3,447   7,824 7,492  
Depreciation and amortization(b) 1,417   1,306   2,820 2,575  
Earnings from equity method investments 44   27   89 64  
Interest expense(d) 484   452   954 885  
Income taxes (benefit) 259   401   563 755  
Consolidated Net Income Attributable to Southern Company 1,370   1,204   2,933 2,735  
Goodwill 5,017       5,017   5,017
Total assets 158,477       158,477   153,416
Operating Segments | SOUTHERN Co GAS              
Segment Reporting [Line Items]              
Operating revenues 966   976   3,159 2,815  
Other segment items 551   595   1,911 1,668  
Depreciation and amortization(b) 185   171   367 340  
Earnings from equity method investments 32   23   78 62  
Interest expense(d) 100   92   201 183  
Income taxes (benefit) 34   27   189 165  
Consolidated Net Income Attributable to Southern Company 128   114   569 521  
Total assets 29,500       29,500   28,615
Operating Segments | Electric Utilities              
Segment Reporting [Line Items]              
Operating revenues 5,826   5,804   11,848 11,560  
Other segment items 2,752   2,848   5,913 5,822  
Depreciation and amortization(b) 1,232   1,134   2,451 2,234  
Earnings from equity method investments 12   4   11 2  
Interest expense(d) 383   360   748 702  
Income taxes (benefit) 227   368   387 593  
Consolidated Net Income Attributable to Southern Company 1,244   1,098   2,360 2,211  
Goodwill 2       2   2
Total assets 130,873       130,873   126,029
Operating Segments | Traditional Electric Operating Companies              
Segment Reporting [Line Items]              
Operating revenues 5,396   5,380   10,878 10,692  
Other segment items 2,501   2,674   5,360 5,468  
Depreciation and amortization(b) 967   957   1,908 1,905  
Earnings from equity method investments 12   4   11 2  
Interest expense(d) 367   336   705 652  
Income taxes (benefit) 304   370   534 596  
Consolidated Net Income Attributable to Southern Company 1,269   1,047   2,382 2,073  
Goodwill 0       0   0
Total assets 120,194       120,194   114,287
Operating Segments | SOUTHERN POWER CO              
Segment Reporting [Line Items]              
Operating revenues 535   546   1,216 1,113  
Other segment items 329   296   772 599  
Depreciation and amortization(b) 280   177   558 329  
Earnings from equity method investments 0   0   0 0  
Interest expense(d) 28   24   55 50  
Income taxes (benefit) (77)   (2)   (147) (3)  
Consolidated Net Income Attributable to Southern Company (25)   51   (22) 138  
Goodwill 2       2   2
Total assets 12,780       12,780   12,657
Operating Segments | SOUTHERN Co GAS              
Segment Reporting [Line Items]              
Operating revenues 966   979   3,157 2,818  
Other segment items 554   599   1,911 1,670  
Depreciation and amortization(b) 185   172   369 341  
Earnings from equity method investments 32   23   78 62  
Interest expense(d) 101   92   206 183  
Income taxes (benefit) 32   33   176 162  
Consolidated Net Income Attributable to Southern Company 126   106   573 524  
Goodwill 5,015       5,015   5,015
Total assets 27,604       27,604   27,387
Eliminations              
Segment Reporting [Line Items]              
Operating revenues (38)   (35)   (72) (84)  
Other segment items (27)   (23)   (68) (81)  
Depreciation and amortization(b) 0   0   0 0  
Earnings from equity method investments 0   0   0 0  
Interest expense(d) 0   0   0 0  
Income taxes (benefit) 0   0   0 0  
Consolidated Net Income Attributable to Southern Company (11)   (12)   (4) (3)  
Goodwill 0       0   0
Total assets (733)       (733)   (525)
Eliminations | SOUTHERN Co GAS              
Segment Reporting [Line Items]              
Operating revenues (2)   (2)   (6) (6)  
Other segment items (2)   (2)   (6) (6)  
Depreciation and amortization(b) 0   0   0 0  
Earnings from equity method investments 0   0   0 0  
Interest expense(d) 0   0   0 0  
Income taxes (benefit) 0   0   0 0  
Consolidated Net Income Attributable to Southern Company 0   0   0 0  
Total assets (13,161)       (13,161)   (11,871)
Eliminations | Electric Utilities              
Segment Reporting [Line Items]              
Operating revenues (105)   (122)   (246) (245)  
Other segment items (78)   (122)   (219) (245)  
Depreciation and amortization(b) (15)   0   (15) 0  
Earnings from equity method investments 0   0   0 0  
Interest expense(d) (12)   0   (12) 0  
Income taxes (benefit) 0   0   0 0  
Consolidated Net Income Attributable to Southern Company 0   0   0 0  
Goodwill 0       0   0
Total assets (2,101)       (2,101)   (915)
All Other              
Segment Reporting [Line Items]              
Operating revenues 223   225   441 454  
Other segment items 193   193   382 401  
Depreciation and amortization(b) 17   17   34 33  
Earnings from equity method investments 42   (17)   47 (21)  
Interest expense(d) 312   422   619 703  
Income taxes (benefit) (72)   (112)   (149) (186)  
Consolidated Net Income Attributable to Southern Company (185)   (312)   (398) (518)  
Goodwill 144       144   144
Total assets 4,283       4,283   2,829
All Other | SOUTHERN Co GAS              
Segment Reporting [Line Items]              
Operating revenues 2   5   4 9  
Other segment items 5   6   6 8  
Depreciation and amortization(b) 0   1   2 1  
Earnings from equity method investments 0   0   0 0  
Interest expense(d) 1   0   5 0  
Income taxes (benefit) (2)   6   (13) (3)  
Consolidated Net Income Attributable to Southern Company (2)   $ (8)   4 $ 3  
Total assets $ 11,265       $ 11,265   $ 10,643