Introduction - Asset Retirement Obligations (Details) (Alabama Power [Member], USD $)	1 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013
Alabama Power [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year		$ 730,000,000	$ 589,000,000
Liabilities incurred		0	0
Liabilities settled		(2,000,000)	0
Accretion		33,000,000	29,000,000
Cash flow revisions	52,000,000	52,000,000	102,000,000
Balance at end of period	$ 813,000,000	$ 813,000,000	$ 720,000,000