Financing - Short-term Borrowings (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
Short-term borrowings
Short-term Debt at the End of the Period, Amount Outstanding	$ 1,482,000,000	[1]	$ 820,000,000	[1]
Short-term Debt at the End of the Period, Weighted Average Interest Rate	0.40%	[1]	0.30%	[1]
Commercial paper [Member]
Short-term borrowings
Short-term Debt at the End of the Period, Amount Outstanding	1,082,000,000	[1]	820,000,000	[1]
Short-term Debt at the End of the Period, Weighted Average Interest Rate	0.20%	[1]	0.30%	[1]
Short-term bank debt [Member]
Short-term borrowings
Short-term Debt at the End of the Period, Amount Outstanding	400,000,000	[1]	0	[1]
Short-term Debt at the End of the Period, Weighted Average Interest Rate	0.90%	[1]	0.00%	[1]
Other Energy Service Contracts [Member]
Short-term borrowings
Notes Payable, Related Parties			5,000,000
Georgia Power [Member]
Short-term borrowings
Short-term Debt at the End of the Period, Amount Outstanding	1,047,000,000
Short-term Debt at the End of the Period, Weighted Average Interest Rate	0.50%
Debt Instrument, Face Amount	850,000,000
Georgia Power [Member] | Commercial paper [Member]
Short-term borrowings
Short-term Debt at the End of the Period, Amount Outstanding	647,000,000
Short-term Debt at the End of the Period, Weighted Average Interest Rate	0.20%
Georgia Power [Member] | Short-term bank debt [Member]
Short-term borrowings
Short-term Debt at the End of the Period, Amount Outstanding	400,000,000
Short-term Debt at the End of the Period, Weighted Average Interest Rate	0.90%
Gulf Power [Member] | Commercial paper [Member]
Short-term borrowings
Short-term Debt at the End of the Period, Amount Outstanding	136,000,000	[2]	124,000,000	[2]
Short-term Debt at the End of the Period, Weighted Average Interest Rate	0.20%	[2]	0.30%	[2]
Gulf Power [Member] | Other Energy Service Contracts [Member]
Short-term borrowings
Notes Payable, Related Parties			3,200,000
Mississippi Power [Member]
Short-term borrowings
Taxable Revenue Bonds	11,300,000		51,500,000
Southern Power [Member] | Commercial paper [Member]
Short-term borrowings
Short-term Debt at the End of the Period, Amount Outstanding	$ 0		$ 71,000,000
Short-term Debt at the End of the Period, Weighted Average Interest Rate			0.50%

[1] Excludes notes payable related to other energy service contracts of $5 million at December 31, 2012.

[2] Excludes notes payable related to other energy service contracts of $3.2 million for the period ended December 31, 2012.