Introduction - Narrative (Details) $ in Millions		3 Months Ended			9 Months Ended
	Feb. 06, 2015 MW	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Public Utility, Property, Plant and Equipment [Line Items]
Decrease to net income		$ (959)		$ (718)	$ (2,096)	$ (1,680)
Asset Retirement Obligation, Liabilities Incurred					644
Gulf Power [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Decrease in retail revenues		(363)		(366)	(983)	(979)
Decrease to net income		(48)		(47)	(120)	(117)
Asset Retirement Obligation, Liabilities Incurred		30			101
Georgia Power [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Decrease in retail revenues		(2,537)		(2,452)	(6,223)	(6,502)
Decrease to net income		$ (551)		$ (525)	(1,064)	$ (1,102)
Asset Retirement Obligation, Liabilities Incurred					$ 0
Plant Smith Units 1 and 2 [Member] | Gulf Power [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Capacity Of Units Included In Request For Decertification Of Units (in MWs) | MW	357
Restatement Adjustment [Member] | Georgia Power [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Decrease in retail revenues			$ 75
Decrease to net income			$ 47