Financing - Schedule of Long-Term Debt Financing Activities (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Debt Instrument [Line Items]
Senior Note Issuances	$ 1,350
Senior Note Maturities	350
Revenue Bond Issuances and Remarketings of Purchased Bonds	82	[1]
Revenue Bond Redemptions	66
Debt Issuances [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	1,283
Debt Redemptions [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	22	[2]
Southern Company [Member]
Debt Instrument [Line Items]
Senior Note Issuances	750
Senior Note Maturities	350
Revenue Bond Issuances and Remarketings of Purchased Bonds	0	[1]
Revenue Bond Redemptions	0
Southern Company [Member] | Debt Issuances [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	0
Southern Company [Member] | Debt Redemptions [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	0	[2]
Alabama Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances	400
Senior Note Maturities	0
Revenue Bond Issuances and Remarketings of Purchased Bonds	0	[1]
Revenue Bond Redemptions	0
Alabama Power [Member] | Debt Issuances [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	0
Alabama Power [Member] | Debt Redemptions [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	0	[2]
Georgia Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances	0
Senior Note Maturities	0
Revenue Bond Issuances and Remarketings of Purchased Bonds	40	[1]
Revenue Bond Redemptions	37
Remarketing Revenue Bond	40
Georgia Power [Member] | Debt Issuances [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	1,000
Georgia Power [Member] | Debt Redemptions [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	4	[2]
Gulf Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances	200
Senior Note Maturities	0
Revenue Bond Issuances and Remarketings of Purchased Bonds	42	[1]
Revenue Bond Redemptions	29
Remarketing Revenue Bond	13
Gulf Power [Member] | Debt Issuances [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	0
Gulf Power [Member] | Debt Redemptions [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	0	[2]
Mississippi Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances	0
Senior Note Maturities	0
Revenue Bond Issuances and Remarketings of Purchased Bonds	0	[1]
Revenue Bond Redemptions	0
Mississippi Power [Member] | Debt Issuances [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	493
Mississippi Power [Member] | Debt Redemptions [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	222	[2]
Southern Power [Member]
Debt Instrument [Line Items]
Senior Note Issuances	0
Senior Note Maturities	0
Revenue Bond Issuances and Remarketings of Purchased Bonds	0	[1]
Revenue Bond Redemptions	0
Southern Power [Member] | Debt Issuances [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	10
Southern Power [Member] | Debt Redemptions [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	1	[2]
Other Subsidiaries [Member]
Debt Instrument [Line Items]
Senior Note Issuances	0
Senior Note Maturities	0
Revenue Bond Issuances and Remarketings of Purchased Bonds	0	[1]
Revenue Bond Redemptions	0
Other Subsidiaries [Member] | Debt Issuances [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	0
Other Subsidiaries [Member] | Debt Redemptions [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	15	[2]
Consolidation, Eliminations [Member]
Debt Instrument [Line Items]
Senior Note Issuances	0	[3]
Senior Note Maturities	0	[3]
Revenue Bond Issuances and Remarketings of Purchased Bonds	0	[1],[3]
Revenue Bond Redemptions	0	[3]
Consolidation, Eliminations [Member] | Debt Issuances [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	(220)	[3]
Consolidation, Eliminations [Member] | Debt Redemptions [Member]
Debt Instrument [Line Items]
Other Long-Term Debt	$ (220)	[2],[3]

[1] Includes remarketing by Gulf Power of $13 million aggregate principal amount of revenue bonds previously purchased and held by Gulf Power since December 2013 and remarketing by Georgia Power of $40 million aggregate principal amount of revenue bonds previously purchased and held by Georgia Power since 2010.

[2] Includes reductions in capital lease obligations resulting from cash payments under capital leases.

[3] Intercompany loan from Southern Company to Mississippi Power eliminated in Southern Company's Condensed Consolidated Financial Statements. This loan was repaid on September 29, 2014.