v3.25.0.1
SEGMENT AND RELATED INFORMATION - Financial Data for Business Segments (Details)
$ in Millions
 1 Months Ended 3 Months Ended 12 Months Ended
Nov. 30, 2024
MW
Sep. 30, 2024
USD ($)
Jun. 30, 2024
USD ($)
Dec. 31, 2023
USD ($)
Jun. 30, 2023
USD ($)
Dec. 31, 2022
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Segment Reporting Information [Line Items]                  
Total operating revenues             $ 26,724 $ 25,253 $ 29,279
Other segment items             13,995 13,954 19,426
Depreciation and amortization             4,755 4,525 3,663
Earnings from equity method investments             139 144 151
Interest expense             2,743 2,446 2,022
Income taxes (benefit)             969 496 795
Segment net income (loss)             4,401 3,976 3,524
Goodwill       $ 5,161   $ 5,161 5,161 5,161 5,161
Total assets       139,331   134,891 145,180 139,331 134,891
Segment and Related Information (Textual) [Abstract]                  
Estimated loss on Plant Vogtle Units 3 and 4             (21) (68) 183
Southern Company Gas                  
Segment Reporting Information [Line Items]                  
Total operating revenues             4,456 4,702 5,962
Operating Segments                  
Segment Reporting Information [Line Items]                  
Total operating revenues             26,059 24,700 28,835
Other segment items             13,342 13,405 18,793
Depreciation and amortization             4,684 4,447 3,588
Earnings from equity method investments             154 139 148
Interest expense             1,713 1,584 1,330
Income taxes (benefit)             1,261 794 1,028
Segment net income (loss)             5,213 4,609 4,244
Goodwill       5,017   5,017 5,017 5,017 5,017
Total assets       137,728   132,904 143,382 137,728 132,904
Operating Segments | Electric Utilities                  
Segment Reporting Information [Line Items]                  
Total operating revenues             21,603 19,998 22,873
Other segment items             10,729 10,281 14,257
Depreciation and amortization             4,034 3,865 3,029
Earnings from equity method investments             8 (1) 0
Interest expense             1,372 1,274 1,067
Income taxes (benefit)             1,003 583 848
Segment net income (loss)             4,473 3,994 3,672
Goodwill       2   2 2 2 2
Total assets       112,645   108,283 117,205 112,645 108,283
Operating Segments | Traditional Electric Operating Companies                  
Segment Reporting Information [Line Items]                  
Total operating revenues             19,977 18,358 20,408
Other segment items             10,057 9,643 12,820
Depreciation and amortization             3,512 3,361 2,513
Earnings from equity method investments             8 (1) 0
Interest expense             1,255 1,145 929
Income taxes (benefit)             1,016 571 828
Segment net income (loss)             4,145 3,637 3,318
Goodwill       0   0 0 0 0
Total assets       100,429   95,861 105,577 100,429 95,861
Operating Segments | Southern Power                  
Segment Reporting Information [Line Items]                  
Total operating revenues             2,014 2,189 3,369
Other segment items             1,060 1,187 2,341
Depreciation and amortization             522 504 516
Earnings from equity method investments             0 0 0
Interest expense             117 129 138
Income taxes (benefit)             (13) 12 20
Segment net income (loss)             328 357 354
Goodwill       2   2 2 2 2
Total assets       12,761   13,081 12,653 12,761 13,081
Operating Segments | Southern Company Gas                  
Segment Reporting Information [Line Items]                  
Total operating revenues             4,456 4,702 5,962
Other segment items             2,613 3,124 4,536
Depreciation and amortization             650 582 559
Earnings from equity method investments             146 140 148
Interest expense             341 310 263
Income taxes (benefit)             258 211 180
Segment net income (loss)             740 615 572
Goodwill       5,015   5,015 5,015 5,015 5,015
Total assets       25,083   24,621 26,177 25,083 24,621
Eliminations                  
Segment Reporting Information [Line Items]                  
Total operating revenues             (178) (165) (149)
Other segment items             (149) (150) (138)
Depreciation and amortization             0 0 0
Earnings from equity method investments             2 0 0
Interest expense             0 (17) (2)
Income taxes (benefit)             0 0 0
Segment net income (loss)             (27) 2 (9)
Goodwill       0   0 0 0 0
Total assets       (843)   (678) (573) (843) (678)
Eliminations | Electric Utilities                  
Segment Reporting Information [Line Items]                  
Total operating revenues             (388) (549) (904)
Other segment items             (388) (549) (904)
Depreciation and amortization             0 0 0
Earnings from equity method investments             0 0 0
Interest expense             0 0 0
Income taxes (benefit)             0 0 0
Segment net income (loss)             0 0 0
Goodwill       0   0 0 0 0
Total assets       (545)   (659) (1,025) (545) (659)
All Other                  
Segment Reporting Information [Line Items]                  
Total operating revenues             843 718 593
Other segment items             802 699 771
Depreciation and amortization             71 78 75
Earnings from equity method investments             (17) 5 3
Interest expense             1,030 879 694
Income taxes (benefit)             (292) (298) (233)
Segment net income (loss)             (785) (635) (711)
Goodwill       144   144 144 144 144
Total assets       2,446   2,665 2,371 2,446 2,665
Georgia Power                  
Segment Reporting Information [Line Items]                  
Total operating revenues             11,331 10,118 11,584
Depreciation and amortization             1,774 1,681 1,430
Interest expense             725 626 485
Income taxes (benefit)             603 448 370
Total assets       56,817     61,255 56,817  
Segment and Related Information (Textual) [Abstract]                  
Estimated loss on Plant Vogtle Units 3 and 4     $ (21)       (21) (68) 183
Estimated loss on Plant Vogtle Units 3 and 4, net of tax     $ (16)            
Georgia Power | Traditional Electric Operating Companies | Plant Vogtle Units 3 and 4                  
Segment and Related Information (Textual) [Abstract]                  
Estimated loss on Plant Vogtle Units 3 and 4             (21) (68) 183
Estimated loss on Plant Vogtle Units 3 and 4, net of tax             (16) (50) 137
Southern Power                  
Segment Reporting Information [Line Items]                  
Total operating revenues             2,014 2,189 3,369
Depreciation and amortization             522 504 516
Interest expense             117 129 138
Income taxes (benefit)             (13) 12 20
Segment net income (loss)             328 357 354
Total assets       12,761     12,653 12,761  
Segment and Related Information (Textual) [Abstract]                  
Litigation settlement             18    
Amount awarded from other party             9    
Gain (loss) on dispositions             0 20 2
Southern Power | Kay Wind Facility                  
Segment and Related Information (Textual) [Abstract]                  
Pre-tax accelerated depreciation             9    
Accelerated depreciation, net of tax             7    
Approximate Nameplate Capacity (MW) | MW 299                
Southern Company Gas                  
Segment Reporting Information [Line Items]                  
Total operating revenues             4,456 4,702 5,962
Other segment items             2,613 3,124 4,536
Depreciation and amortization             650 582 559
Earnings from equity method investments             146 140 148
Interest expense             341 310 263
Income taxes (benefit)             258 211 180
Segment net income (loss)             740 615 572
Goodwill       5,015     5,015 5,015  
Total assets       25,083   24,621 26,177 25,083 24,621
Segment and Related Information (Textual) [Abstract]                  
Impairment charges             0 0 131
Estimated loss on regulatory disallowance             0 (96) 0
Southern Company Gas | Operating Segments                  
Segment Reporting Information [Line Items]                  
Total operating revenues             4,447 4,685 5,937
Other segment items             2,598 3,109 4,401
Depreciation and amortization             649 581 537
Earnings from equity method investments             146 140 148
Interest expense             349 310 259
Income taxes (benefit)             244 195 217
Segment net income (loss)             753 630 671
Total assets       26,055   25,233 27,336 26,055 25,233
Southern Company Gas | Eliminations                  
Segment Reporting Information [Line Items]                  
Total operating revenues             (14) (19) (30)
Other segment items             (14) (19) (30)
Depreciation and amortization             0 0 0
Earnings from equity method investments             0 0 0
Interest expense             0 0 0
Income taxes (benefit)             0 0 0
Segment net income (loss)             0 0 0
Total assets       (10,647)   (9,555) (11,206) (10,647) (9,555)
Southern Company Gas | All Other                  
Segment Reporting Information [Line Items]                  
Total operating revenues             23 36 55
Other segment items             29 34 165
Depreciation and amortization             1 1 22
Earnings from equity method investments             0 0 0
Interest expense             (8) 0 4
Income taxes (benefit)             14 16 (37)
Segment net income (loss)             (13) (15) (99)
Total assets       9,675   8,943 10,047 9,675 8,943
Nicor Gas                  
Segment and Related Information (Textual) [Abstract]                  
Estimated loss on regulatory disallowance       (58) $ (38)   96    
Estimated loss on regulatory disallowance, after tax       (44) $ (28)   72    
Alabama Power                  
Segment Reporting Information [Line Items]                  
Total operating revenues             7,554 7,050 7,817
Depreciation and amortization             1,459 1,401 875
Interest expense             448 425 382
Income taxes (benefit)             360 81 423
Segment net income (loss)             1,403 1,370 $ 1,340
Total assets       $ 35,780     36,538 $ 35,780  
Segment and Related Information (Textual) [Abstract]                  
Impairment charges   $ 36              
Impairment charges, after tax   $ 27              
Spare Parts | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Power                  
Segment and Related Information (Textual) [Abstract]                  
Gain on sale             16    
Gain on sale, after tax             $ 12    
Natural Gas Storage Facilities | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Company Gas                  
Segment and Related Information (Textual) [Abstract]                  
Gain (loss) on dispositions           (131)      
Gain (loss) on dispositions, after tax           $ (99)