Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions |
Total |
Common Stock |
Treasury |
Paid-In Capital |
Retained Earnings (Accumulated Deficit) |
Accumulated Other Comprehensive Income (Loss) |
Noncontrolling Interests |
ALABAMA POWER CO |
ALABAMA POWER CO
Common Stock
|
ALABAMA POWER CO
Paid-In Capital
|
ALABAMA POWER CO
Retained Earnings (Accumulated Deficit)
|
ALABAMA POWER CO
Accumulated Other Comprehensive Income (Loss)
|
GEORGIA POWER CO |
GEORGIA POWER CO
Common Stock
|
GEORGIA POWER CO
Paid-In Capital
|
GEORGIA POWER CO
Retained Earnings (Accumulated Deficit)
|
GEORGIA POWER CO
Accumulated Other Comprehensive Income (Loss)
|
MISSISSIPPI POWER CO |
MISSISSIPPI POWER CO
Common Stock
|
MISSISSIPPI POWER CO
Paid-In Capital
|
MISSISSIPPI POWER CO
Retained Earnings (Accumulated Deficit)
|
MISSISSIPPI POWER CO
Accumulated Other Comprehensive Income (Loss)
|
SOUTHERN POWER CO |
SOUTHERN POWER CO
Total Common Stockholders' Equity
|
SOUTHERN POWER CO
Paid-In Capital
|
SOUTHERN POWER CO
Retained Earnings (Accumulated Deficit)
|
SOUTHERN POWER CO
Accumulated Other Comprehensive Income (Loss)
|
SOUTHERN POWER CO
Noncontrolling Interests
|
SOUTHERN Co GAS |
SOUTHERN Co GAS
Paid-In Capital
|
SOUTHERN Co GAS
Retained Earnings (Accumulated Deficit)
|
SOUTHERN Co GAS
Accumulated Other Comprehensive Income (Loss)
|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Beginning balance (in shares) at Dec. 31, 2018 | 1,035 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Beginning balance at Dec. 31, 2018 | $ 29,039 | $ 5,164 | $ (38) | $ 11,094 | $ 8,706 | $ (203) | $ 4,316 | $ 7,477 | $ 1,222 | $ 3,508 | $ 2,775 | $ (28) | $ 14,323 | $ 398 | $ 10,322 | $ 3,612 | $ (9) | $ 1,609 | $ 38 | $ 4,546 | $ (2,971) | $ (4) | $ 7,284 | $ 2,968 | $ 1,600 | $ 1,352 | $ 16 | $ 4,316 | $ 8,570 | $ 8,856 | $ (312) | $ 26 |
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | ||||||||||||||||||||||||||||||||
| Net income (loss) | 2,055 | 2,084 | (29) | |||||||||||||||||||||||||||||
| Net income (loss) | 311 | 311 | 37 | 37 | 27 | 56 | 56 | (29) | 270 | 270 | ||||||||||||||||||||||
| Net income | 217 | 217 | ||||||||||||||||||||||||||||||
| Return of capital to parent company | (38) | (38) | ||||||||||||||||||||||||||||||
| Capital contributions from parent company | 1,236 | 1,236 | 29 | 29 | 2 | 2 | 1 | 1 | 1 | 17 | 17 | |||||||||||||||||||||
| Other comprehensive income (loss) | 1 | 1 | 1 | 1 | (4) | (4) | (4) | (1) | (1) | |||||||||||||||||||||||
| Stock issued (in shares) | 6 | |||||||||||||||||||||||||||||||
| Stock issued | 224 | $ 28 | 196 | |||||||||||||||||||||||||||||
| Stock-based compensation | 24 | 24 | ||||||||||||||||||||||||||||||
| Cash dividends on common stock | (623) | (623) | (211) | (211) | (394) | (394) | (51) | (51) | (51) | (118) | (118) | |||||||||||||||||||||
| Contributions from noncontrolling interests | 3 | 3 | 3 | 3 | ||||||||||||||||||||||||||||
| Distributions to noncontrolling interests | (41) | (41) | (41) | (41) | ||||||||||||||||||||||||||||
| Other | 6 | $ (2) | 7 | 1 | (1) | (1) | (1) | (2) | (1) | (1) | 1 | |||||||||||||||||||||
| Ending balance (in shares) at Mar. 31, 2019 | 1,041 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Ending balance at Mar. 31, 2019 | 30,687 | $ 5,192 | $ (40) | 11,321 | 10,167 | (203) | 4,250 | 8,720 | $ 1,222 | 4,744 | 2,781 | (27) | 14,269 | $ 398 | 10,350 | 3,529 | (8) | 1,610 | $ 38 | 4,510 | (2,934) | (4) | 7,218 | 2,968 | 1,600 | 1,356 | 12 | 4,250 | 8,738 | 8,873 | (160) | 25 |
| Beginning balance (in shares) at Dec. 31, 2018 | 1,035 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Beginning balance at Dec. 31, 2018 | 29,039 | $ 5,164 | $ (38) | 11,094 | 8,706 | (203) | 4,316 | 7,477 | $ 1,222 | 3,508 | 2,775 | (28) | 14,323 | $ 398 | 10,322 | 3,612 | (9) | 1,609 | $ 38 | 4,546 | (2,971) | (4) | 7,284 | 2,968 | 1,600 | 1,352 | 16 | 4,316 | 8,570 | 8,856 | (312) | 26 |
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | ||||||||||||||||||||||||||||||||
| Net income (loss) | 2,989 | 520 | 759 | 74 | 230 | 376 | ||||||||||||||||||||||||||
| Net income | 2,982 | 513 | 230 | 376 | ||||||||||||||||||||||||||||
| Ending balance (in shares) at Jun. 30, 2019 | 1,046 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Ending balance at Jun. 30, 2019 | 31,131 | $ 5,217 | $ (41) | 11,540 | 10,420 | (238) | 4,233 | 8,829 | $ 1,222 | 4,767 | 2,866 | (26) | 14,316 | $ 398 | 10,371 | 3,582 | (35) | 1,617 | $ 38 | 4,480 | (2,897) | (4) | 6,818 | 2,585 | 1,102 | 1,479 | 4 | 4,233 | 8,759 | 8,908 | (171) | 22 |
| Beginning balance (in shares) at Mar. 31, 2019 | 1,041 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Beginning balance at Mar. 31, 2019 | 30,687 | $ 5,192 | $ (40) | 11,321 | 10,167 | (203) | 4,250 | 8,720 | $ 1,222 | 4,744 | 2,781 | (27) | 14,269 | $ 398 | 10,350 | 3,529 | (8) | 1,610 | $ 38 | 4,510 | (2,934) | (4) | 7,218 | 2,968 | 1,600 | 1,356 | 12 | 4,250 | 8,738 | 8,873 | (160) | 25 |
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | ||||||||||||||||||||||||||||||||
| Net income (loss) | 928 | 899 | 29 | |||||||||||||||||||||||||||||
| Net income (loss) | 931 | 299 | 448 | 448 | 37 | 37 | 203 | 174 | 174 | 29 | 106 | 106 | ||||||||||||||||||||
| Net income | 899 | 296 | 296 | 174 | 106 | |||||||||||||||||||||||||||
| Return of capital to parent company | (38) | (38) | (505) | (505) | (505) | |||||||||||||||||||||||||||
| Capital contributions from parent company | 23 | 23 | 20 | 20 | 8 | 8 | 7 | 7 | 7 | 35 | 35 | |||||||||||||||||||||
| Other comprehensive income (loss) | (35) | (35) | 1 | 1 | (27) | (27) | (8) | (8) | (8) | (3) | (3) | |||||||||||||||||||||
| Stock issued (in shares) | 5 | |||||||||||||||||||||||||||||||
| Stock issued | 228 | $ 25 | 203 | |||||||||||||||||||||||||||||
| Stock-based compensation | 11 | 11 | ||||||||||||||||||||||||||||||
| Cash dividends on common stock | (646) | (646) | (211) | (211) | (394) | (394) | (52) | (52) | (52) | (117) | (117) | |||||||||||||||||||||
| Contributions from noncontrolling interests | 2 | 2 | 2 | 2 | ||||||||||||||||||||||||||||
| Distributions to noncontrolling interests | (47) | (47) | (47) | (47) | ||||||||||||||||||||||||||||
| Other | 3 | $ (1) | 5 | (1) | 0 | 1 | (1) | 0 | 1 | 1 | (1) | |||||||||||||||||||||
| Ending balance (in shares) at Jun. 30, 2019 | 1,046 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Ending balance at Jun. 30, 2019 | 31,131 | $ 5,217 | $ (41) | 11,540 | 10,420 | (238) | 4,233 | 8,829 | $ 1,222 | 4,767 | 2,866 | (26) | 14,316 | $ 398 | 10,371 | 3,582 | (35) | 1,617 | $ 38 | 4,480 | (2,897) | (4) | 6,818 | 2,585 | 1,102 | 1,479 | 4 | 4,233 | 8,759 | 8,908 | (171) | 22 |
| Beginning balance (in shares) at Dec. 31, 2019 | 1,054 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Beginning balance at Dec. 31, 2019 | 31,759 | $ 5,257 | $ (42) | 11,734 | 10,877 | (321) | 4,254 | 8,955 | $ 1,222 | 4,755 | 3,001 | (23) | 15,065 | $ 398 | 10,962 | 3,756 | (51) | 1,652 | $ 38 | 4,449 | (2,832) | (3) | 6,622 | 2,368 | 909 | 1,485 | (26) | 4,254 | 9,506 | 9,697 | (198) | 7 |
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | ||||||||||||||||||||||||||||||||
| Net income (loss) | 837 | 868 | (31) | |||||||||||||||||||||||||||||
| Net income (loss) | 331 | 331 | 32 | 32 | 44 | 75 | 75 | (31) | 275 | 275 | ||||||||||||||||||||||
| Net income | 280 | 280 | ||||||||||||||||||||||||||||||
| Return of capital to parent company | (37) | (37) | (2) | (2) | ||||||||||||||||||||||||||||
| Capital contributions from parent company | 612 | 612 | 502 | 502 | 76 | 76 | ||||||||||||||||||||||||||
| Other comprehensive income (loss) | (47) | (47) | 1 | 1 | (1) | (1) | (33) | (33) | (33) | (15) | (15) | |||||||||||||||||||||
| Stock issued (in shares) | 3 | |||||||||||||||||||||||||||||||
| Stock issued | 52 | $ 9 | 43 | |||||||||||||||||||||||||||||
| Stock-based compensation | 5 | 5 | ||||||||||||||||||||||||||||||
| Cash dividends on common stock | (655) | (655) | (239) | (239) | (385) | (385) | (50) | (50) | (50) | (133) | (133) | |||||||||||||||||||||
| Contributions from noncontrolling interests | 16 | 16 | 16 | 16 | ||||||||||||||||||||||||||||
| Distributions to noncontrolling interests | (48) | (48) | (48) | (48) | ||||||||||||||||||||||||||||
| Other | (3) | $ (2) | (2) | 1 | (1) | (1) | ||||||||||||||||||||||||||
| Ending balance (in shares) at Mar. 31, 2020 | 1,057 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Ending balance at Mar. 31, 2020 | 31,916 | $ 5,266 | $ (44) | 11,782 | 11,088 | (367) | 4,191 | 9,609 | $ 1,222 | 5,367 | 3,042 | (22) | 15,512 | $ 398 | 11,464 | 3,702 | (52) | 1,722 | $ 38 | 4,487 | (2,800) | (3) | 6,551 | 2,360 | 909 | 1,510 | (59) | 4,191 | 9,631 | 9,695 | (56) | (8) |
| Beginning balance (in shares) at Dec. 31, 2019 | 1,054 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Beginning balance at Dec. 31, 2019 | 31,759 | $ 5,257 | $ (42) | 11,734 | 10,877 | (321) | 4,254 | 8,955 | $ 1,222 | 4,755 | 3,001 | (23) | 15,065 | $ 398 | 10,962 | 3,756 | (51) | 1,652 | $ 38 | 4,449 | (2,832) | (3) | 6,622 | 2,368 | 909 | 1,485 | (26) | 4,254 | 9,506 | 9,697 | (198) | 7 |
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | ||||||||||||||||||||||||||||||||
| Net income (loss) | 1,461 | 585 | 638 | 71 | 112 | 346 | ||||||||||||||||||||||||||
| Net income | 1,480 | 578 | 138 | 346 | ||||||||||||||||||||||||||||
| Ending balance (in shares) at Jun. 30, 2020 | 1,057 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Ending balance at Jun. 30, 2020 | 31,961 | $ 5,266 | $ (44) | 11,787 | 11,024 | (363) | 4,291 | 9,670 | $ 1,222 | 5,368 | 3,101 | (21) | 15,437 | $ 398 | 11,465 | 3,624 | (50) | 1,724 | $ 38 | 4,450 | (2,761) | (3) | 6,659 | 2,368 | 907 | 1,523 | (62) | 4,291 | 9,769 | 9,895 | (118) | (8) |
| Beginning balance (in shares) at Mar. 31, 2020 | 1,057 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Beginning balance at Mar. 31, 2020 | 31,916 | $ 5,266 | $ (44) | 11,782 | 11,088 | (367) | 4,191 | 9,609 | $ 1,222 | 5,367 | 3,042 | (22) | 15,512 | $ 398 | 11,464 | 3,702 | (52) | 1,722 | $ 38 | 4,487 | (2,800) | (3) | 6,551 | 2,360 | 909 | 1,510 | (59) | 4,191 | 9,631 | 9,695 | (56) | (8) |
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | ||||||||||||||||||||||||||||||||
| Net income (loss) | 617 | 612 | 5 | |||||||||||||||||||||||||||||
| Net income (loss) | 621 | 302 | 308 | 308 | 39 | 39 | 68 | 63 | 63 | 5 | 71 | 71 | ||||||||||||||||||||
| Net income | 612 | 298 | 298 | 63 | 71 | |||||||||||||||||||||||||||
| Return of capital to parent company | (37) | (37) | ||||||||||||||||||||||||||||||
| Capital contributions from parent company | 1 | 1 | 1 | 1 | 200 | 200 | ||||||||||||||||||||||||||
| Other comprehensive income (loss) | 4 | 4 | 1 | 1 | 2 | 2 | (3) | (3) | (3) | |||||||||||||||||||||||
| Stock issued | 7 | 7 | ||||||||||||||||||||||||||||||
| Stock-based compensation | 11 | 11 | ||||||||||||||||||||||||||||||
| Cash dividends on common stock | (677) | (677) | (239) | (239) | (386) | (386) | (50) | (50) | (50) | (133) | (133) | |||||||||||||||||||||
| Contributions from noncontrolling interests | 165 | 165 | 165 | 165 | ||||||||||||||||||||||||||||
| Distributions to noncontrolling interests | (70) | (70) | (70) | (70) | ||||||||||||||||||||||||||||
| Other | (12) | (13) | 1 | (2) | (2) | (2) | 0 | 0 | 0 | |||||||||||||||||||||||
| Ending balance (in shares) at Jun. 30, 2020 | 1,057 | 1 | 31 | 9 | 1 | |||||||||||||||||||||||||||
| Ending balance at Jun. 30, 2020 | $ 31,961 | $ 5,266 | $ (44) | $ 11,787 | $ 11,024 | $ (363) | $ 4,291 | $ 9,670 | $ 1,222 | $ 5,368 | $ 3,101 | $ (21) | $ 15,437 | $ 398 | $ 11,465 | $ 3,624 | $ (50) | $ 1,724 | $ 38 | $ 4,450 | $ (2,761) | $ (3) | $ 6,659 | $ 2,368 | $ 907 | $ 1,523 | $ (62) | $ 4,291 | $ 9,769 | $ 9,895 | $ (118) | $ (8) |