Common Stock and Stock Compensation - Stock Option Activity (Details) (USD $)	12 Months Ended
	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Option, Outstanding, Beginning Balance	35,916,303
Shares Subject to Option, Granted	9,152,716
Shares Subject to Option, Exercised	(6,078,735)
Shares Subject to Options, Cancelled	(170,918)
Shares Subject to Option, Outstanding, Ending Balance	38,819,366
Shares Subject to Options, Exercisable, Ending Balance	24,150,442
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options Outstanding, Weighted Average Exercise Price, Beginning of Period	$ 36.37
Options Granted, Weighted Average Exercise Price	$ 44.17
Options Exercised, Weighted Average Exercise Price	$ 33.39
Options Cancelled, Weighted Average Exercise Price	$ 43.30
Options Outstanding, Weighted Average Exercise Price, End of Period	$ 38.64
Options Exercisable, Weighted Average Exercise Price, End of Period	$ 35.70
Alabama Power [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Option, Outstanding, Beginning Balance	6,060,552
Shares Subject to Option, Granted	1,319,038
Shares Subject to Option, Exercised	(1,035,611)
Shares Subject to Options, Cancelled	(4,271)
Shares Subject to Option, Outstanding, Ending Balance	6,339,708
Shares Subject to Options, Exercisable, Ending Balance	4,021,541
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options Outstanding, Weighted Average Exercise Price, Beginning of Period	$ 36.02
Options Granted, Weighted Average Exercise Price	$ 44.07
Options Exercised, Weighted Average Exercise Price	$ 32.74
Options Cancelled, Weighted Average Exercise Price	$ 42.88
Options Outstanding, Weighted Average Exercise Price, End of Period	$ 38.23
Options Exercisable, Weighted Average Exercise Price, End of Period	$ 35.29
Georgia Power [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Option, Outstanding, Beginning Balance	6,547,498
Shares Subject to Option, Granted	1,509,662
Shares Subject to Option, Exercised	(1,196,585)
Shares Subject to Options, Cancelled	(11,421)
Shares Subject to Option, Outstanding, Ending Balance	6,849,154
Shares Subject to Options, Exercisable, Ending Balance	4,321,853
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options Outstanding, Weighted Average Exercise Price, Beginning of Period	$ 0
Options Granted, Weighted Average Exercise Price	$ 0
Options Exercised, Weighted Average Exercise Price	$ 0
Options Cancelled, Weighted Average Exercise Price	$ 0
Options Outstanding, Weighted Average Exercise Price, End of Period	$ 0
Options Exercisable, Weighted Average Exercise Price, End of Period	$ 0
Gulf Power [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Option, Outstanding, Beginning Balance	1,388,915
Shares Subject to Option, Granted	285,209
Shares Subject to Option, Exercised	(281,377)
Shares Subject to Options, Cancelled	0
Shares Subject to Option, Outstanding, Ending Balance	1,392,747
Shares Subject to Options, Exercisable, Ending Balance	883,985
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options Outstanding, Weighted Average Exercise Price, Beginning of Period	$ 36.08
Options Granted, Weighted Average Exercise Price	$ 44.06
Options Exercised, Weighted Average Exercise Price	$ 33.62
Options Cancelled, Weighted Average Exercise Price	$ 0.00
Options Outstanding, Weighted Average Exercise Price, End of Period	$ 38.21
Options Exercisable, Weighted Average Exercise Price, End of Period	$ 35.29
Mississippi Power [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Option, Outstanding, Beginning Balance	1,373,566
Shares Subject to Option, Granted	345,830
Shares Subject to Option, Exercised	(379,933)
Shares Subject to Options, Cancelled	(5,870)
Shares Subject to Option, Outstanding, Ending Balance	1,333,593
Shares Subject to Options, Exercisable, Ending Balance	898,518
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options Outstanding, Weighted Average Exercise Price, Beginning of Period	$ 0
Options Granted, Weighted Average Exercise Price	$ 0
Options Exercised, Weighted Average Exercise Price	$ 0
Options Cancelled, Weighted Average Exercise Price	$ 0
Options Outstanding, Weighted Average Exercise Price, End of Period	$ 0
Options Exercisable, Weighted Average Exercise Price, End of Period	$ 0