Quarterly Financial Information (Unaudited) (Details) - USD ($) |
1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended | 65 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jun. 04, 2018 |
Jun. 30, 2017 |
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
May 31, 2017 |
|
| Summarized quarterly financial information | ||||||||||||||||
| Operating revenues | $ 5,337,000,000 | $ 6,159,000,000 | $ 5,627,000,000 | $ 6,372,000,000 | $ 5,629,000,000 | $ 6,201,000,000 | $ 5,430,000,000 | $ 5,771,000,000 | ||||||||
| Operating Income | 578,000,000 | 2,174,000,000 | 63,000,000 | 1,376,000,000 | 739,000,000 | 1,991,000,000 | (1,649,000,000) | 1,252,000,000 | $ 4,191,000,000 | $ 2,333,000,000 | $ 4,486,000,000 | |||||
| Net Income (Loss) | 269,000,000 | 1,222,000,000 | (127,000,000) | 936,000,000 | 500,000,000 | 1,109,000,000 | (1,348,000,000) | 665,000,000 | 2,226,000,000 | 842,000,000 | 2,448,000,000 | |||||
| Consolidated Net Income Attributable to Southern Company | 278,000,000 | $ 1,164,000,000 | $ (154,000,000) | $ 938,000,000 | 496,000,000 | $ 1,069,000,000 | $ (1,381,000,000) | $ 658,000,000 | ||||||||
| Tax Cuts And Jobs Act Of 2017, income tax expense (benefit) | $ 264,000,000 | |||||||||||||||
| Impairment charges | 210,000,000 | 0 | 0 | |||||||||||||
| Income taxes | 449,000,000 | 142,000,000 | 951,000,000 | |||||||||||||
| Goodwill impairment | $ 0 | 42,000,000 | ||||||||||||||
| Gain (loss) on dispositions | $ (291,000,000) | $ (40,000,000) | $ 1,000,000 | |||||||||||||
| Basic (in dollars per share) | $ 0.27 | $ 1.14 | $ (0.15) | $ 0.93 | $ 0.49 | $ 1.07 | $ (1.38) | $ 0.66 | $ 2.18 | $ 0.84 | $ 2.57 | |||||
| Diluted (in dollars per share) | 0.27 | 1.13 | (0.15) | 0.92 | 0.49 | 1.06 | (1.37) | 0.66 | 2.17 | 0.84 | 2.55 | |||||
| Cash dividends (in dollars per share) | $ 0.60 | $ 0.60 | $ 0.60 | $ 0.58 | $ 0.58 | $ 0.58 | $ 0.58 | $ 0.56 | $ 2.3800 | $ 2.3000 | $ 2.2225 | |||||
| Alabama Power | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Operating revenues | $ 1,316,000,000 | $ 1,740,000,000 | $ 1,503,000,000 | $ 1,473,000,000 | $ 1,433,000,000 | $ 1,740,000,000 | $ 1,484,000,000 | $ 1,382,000,000 | ||||||||
| Operating Income | 164,000,000 | 561,000,000 | 380,000,000 | 372,000,000 | 255,000,000 | 601,000,000 | 440,000,000 | 361,000,000 | $ 1,477,000,000 | $ 1,657,000,000 | $ 1,618,000,000 | |||||
| Net Income (Loss) | 73,000,000 | 373,000,000 | 259,000,000 | 225,000,000 | 119,000,000 | 325,000,000 | 230,000,000 | 174,000,000 | 930,000,000 | 848,000,000 | 822,000,000 | |||||
| Consolidated Net Income Attributable to Southern Company | 73,000,000 | 373,000,000 | 259,000,000 | 225,000,000 | 119,000,000 | 325,000,000 | 230,000,000 | 174,000,000 | ||||||||
| Income taxes | 291,000,000 | 568,000,000 | 531,000,000 | |||||||||||||
| Georgia Power | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Operating revenues | 1,818,000,000 | 2,593,000,000 | 2,048,000,000 | 1,961,000,000 | 1,884,000,000 | 2,546,000,000 | 2,048,000,000 | 1,832,000,000 | ||||||||
| Operating Income | 257,000,000 | 991,000,000 | (472,000,000) | 513,000,000 | 452,000,000 | 1,017,000,000 | 621,000,000 | 483,000,000 | 1,289,000,000 | 2,573,000,000 | 2,434,000,000 | |||||
| Net Income (Loss) | 173,000,000 | 664,000,000 | (396,000,000) | 352,000,000 | 227,000,000 | 580,000,000 | 347,000,000 | 260,000,000 | 793,000,000 | 1,414,000,000 | 1,330,000,000 | |||||
| Consolidated Net Income Attributable to Southern Company | 173,000,000 | 664,000,000 | (396,000,000) | 352,000,000 | 227,000,000 | 580,000,000 | 347,000,000 | 260,000,000 | ||||||||
| Income taxes | 214,000,000 | 830,000,000 | 780,000,000 | |||||||||||||
| Mississippi Power | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Operating revenues | 308,000,000 | 358,000,000 | 297,000,000 | 302,000,000 | 271,000,000 | 341,000,000 | 303,000,000 | 272,000,000 | ||||||||
| Operating Income | 52,000,000 | 80,000,000 | 54,000,000 | 7,000,000 | (180,000,000) | 49,000,000 | (2,956,000,000) | (64,000,000) | 193,000,000 | (3,151,000,000) | (200,000,000) | |||||
| Net Income (Loss) | 149,000,000 | 47,000,000 | 46,000,000 | (7,000,000) | (556,000,000) | 40,000,000 | (2,054,000,000) | (20,000,000) | 235,000,000 | (2,590,000,000) | (50,000,000) | |||||
| Consolidated Net Income Attributable to Southern Company | 149,000,000 | 47,000,000 | 46,000,000 | (7,000,000) | (556,000,000) | 40,000,000 | (2,054,000,000) | (20,000,000) | ||||||||
| Pre-tax charge (credit) to income | (9,000,000) | |||||||||||||||
| After tax charge (credit) to income | (95,000,000) | |||||||||||||||
| Tax Cuts And Jobs Act Of 2017, income tax expense (benefit) | 372,000,000 | |||||||||||||||
| Income taxes | (102,000,000) | (532,000,000) | (104,000,000) | |||||||||||||
| Southern Power | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Operating revenues | 506,000,000 | 635,000,000 | 555,000,000 | 509,000,000 | 478,000,000 | 618,000,000 | 529,000,000 | 450,000,000 | ||||||||
| Operating Income | 30,000,000 | 136,000,000 | 16,000,000 | 60,000,000 | 32,000,000 | 159,000,000 | 112,000,000 | 65,000,000 | 242,000,000 | 368,000,000 | 290,000,000 | |||||
| Net Income (Loss) | (60,000,000) | 146,000,000 | 45,000,000 | 115,000,000 | 793,000,000 | 154,000,000 | 104,000,000 | 66,000,000 | 187,000,000 | 1,071,000,000 | 338,000,000 | |||||
| Consolidated Net Income Attributable to Southern Company | (48,000,000) | 92,000,000 | 22,000,000 | 121,000,000 | 795,000,000 | 124,000,000 | 82,000,000 | 70,000,000 | 1,071,000,000 | 338,000,000 | ||||||
| Tax Cuts And Jobs Act Of 2017, income tax expense (benefit) | (743,000,000) | |||||||||||||||
| Impairment charges | 156,000,000 | 0 | 0 | |||||||||||||
| After tax impairment charges | 117,000,000 | |||||||||||||||
| Income taxes | 75,000,000 | (164,000,000) | (939,000,000) | (195,000,000) | ||||||||||||
| Southern Company Gas | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Operating revenues | 1,048,000,000 | 492,000,000 | 730,000,000 | 1,639,000,000 | 1,079,000,000 | 565,000,000 | 716,000,000 | 1,560,000,000 | ||||||||
| Operating Income | 104,000,000 | 374,000,000 | 49,000,000 | 388,000,000 | 109,000,000 | 67,000,000 | 95,000,000 | 389,000,000 | $ 199,000,000 | 915,000,000 | 660,000,000 | |||||
| Net Income (Loss) | 78,000,000 | 46,000,000 | (31,000,000) | 279,000,000 | (60,000,000) | 15,000,000 | 49,000,000 | 239,000,000 | 114,000,000 | 372,000,000 | 243,000,000 | |||||
| Consolidated Net Income Attributable to Southern Company | 78,000,000 | 46,000,000 | (31,000,000) | 279,000,000 | (60,000,000) | 15,000,000 | 49,000,000 | 239,000,000 | ||||||||
| Tax Cuts And Jobs Act Of 2017, income tax expense (benefit) | 93,000,000 | |||||||||||||||
| Income taxes | 76,000,000 | 464,000,000 | 367,000,000 | |||||||||||||
| Goodwill impairment | 0 | 42,000,000 | 0 | 42,000,000 | 0 | |||||||||||
| Gain (loss) on dispositions | $ 0 | (291,000,000) | 0 | |||||||||||||
| Plant Vogtle Units 3 And 4 | Georgia Power | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Estimated loss on plants under construction | 1,100,000,000 | |||||||||||||||
| Kemper IGCC | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| After tax charge (credit) to income | 722,000,000 | $ 2,400,000,000 | $ 264,000,000 | |||||||||||||
| Kemper IGCC | Mississippi Power | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Pre-tax charge (credit) to income | $ 2,800,000,000 | 44,000,000 | 208,000,000 | 34,000,000 | 3,000,000,000 | 108,000,000 | $ 242,000,000 | 37,000,000 | $ 3,070,000,000 | |||||||
| After tax charge (credit) to income | $ 2,000,000,000 | 95,000,000 | 33,000,000 | $ 185,000,000 | $ 21,000,000 | $ 2,100,000,000 | 67,000,000 | $ 206,000,000 | $ 1,890,000,000 | |||||||
| Florida Plants | Southern Power | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Impairment charges | 119,000,000 | |||||||||||||||
| After tax impairment charges | 89,000,000 | |||||||||||||||
| Plant Scherer Unit 3 | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Pre-tax charge (credit) to income | 33,000,000 | |||||||||||||||
| After tax charge (credit) to income | $ 20,000,000 | |||||||||||||||
| Wind Turbine Equipment | Southern Power | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Impairment charges | 36,000,000 | |||||||||||||||
| After tax impairment charges | 27,000,000 | |||||||||||||||
| Disposal Group, Disposed of by Sale, Not Discontinued Operations | Southern Company Gas | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Gain (loss) on dispositions | (27,000,000) | 353,000,000 | (36,000,000) | |||||||||||||
| Gain (loss) on dispositions, after tax | $ (15,000,000) | $ 40,000,000 | $ (76,000,000) | |||||||||||||
| Disposal Group, Disposed of by Sale, Not Discontinued Operations | Pivotal Home Solutions | Southern Company Gas | ||||||||||||||||
| Summarized quarterly financial information | ||||||||||||||||
| Goodwill impairment | $ 42,000,000 | $ 42,000,000 | ||||||||||||||
| Gain (loss) on dispositions, after tax | $ (67,000,000) | |||||||||||||||