Financing Debt Instruments (Details) (USD $)	9 Months Ended							1 Months Ended	9 Months Ended						1 Months Ended	9 Months Ended					1 Months Ended			3 Months Ended	9 Months Ended				1 Months Ended		3 Months Ended						1 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Aug. 31, 2013 Senior Notes [Member]	Sep. 30, 2013 Debt Redemptions [Member]	Sep. 30, 2013 Debt Issuances [Member]	Sep. 30, 2013 Parent Company [Member] Debt Redemptions [Member]	Sep. 30, 2013 Parent Company [Member] Debt Issuances [Member]	Mar. 31, 2013 Georgia Power [Member]	Sep. 30, 2013 Georgia Power [Member]	Sep. 30, 2012 Georgia Power [Member]	Aug. 31, 2013 Georgia Power [Member]	Aug. 31, 2013 Georgia Power [Member] Senior Notes [Member]	Sep. 30, 2013 Georgia Power [Member] Debt Redemptions [Member]	Sep. 30, 2013 Georgia Power [Member] Debt Issuances [Member]	Jun. 30, 2013 Gulf Power [Member]	Sep. 30, 2013 Gulf Power [Member]	Sep. 30, 2012 Gulf Power [Member]	Jun. 30, 2013 Gulf Power [Member] Senior Notes [Member]	Sep. 30, 2013 Gulf Power [Member] Debt Redemptions [Member]	Sep. 30, 2013 Gulf Power [Member] Debt Issuances [Member]	Sep. 30, 2013 Mississippi Power [Member]	Mar. 31, 2013 Mississippi Power [Member] loan	Nov. 30, 2012 Mississippi Power [Member]	Dec. 31, 2012 Mississippi Power [Member]	Sep. 30, 2013 Mississippi Power [Member]	Jul. 31, 2013 Mississippi Power [Member]	Sep. 30, 2013 Mississippi Power [Member] Debt Redemptions [Member]	Sep. 30, 2013 Mississippi Power [Member] Debt Issuances [Member]	Sep. 30, 2013 Southern Power [Member]	Mar. 31, 2013 Southern Power [Member]	Sep. 30, 2013 Southern Power [Member]	Jun. 30, 2013 Southern Power [Member]	Sep. 30, 2013 Southern Power [Member] Debt Redemptions [Member]	Sep. 30, 2013 Southern Power [Member] Debt Issuances [Member]	Sep. 30, 2013 Other Subsidiaries [Member] Debt Redemptions [Member]	Sep. 30, 2013 Other Subsidiaries [Member] Debt Issuances [Member]	Sep. 30, 2013 First Series Nineteen Ninety Six [Member] Georgia Power [Member]	Sep. 30, 2013 First Series Nineteen Ninety Eight [Member] Georgia Power [Member]	Aug. 31, 2013 SeriesTwoThousandThirteenA [Member] Senior Notes [Member]	Mar. 31, 2013 SeriesTwoThousandThirteenA [Member] Georgia Power [Member] Senior Notes [Member]	Jun. 30, 2013 SeriesTwoThousandThirteenA [Member] Gulf Power [Member] Senior Notes [Member]	Jul. 31, 2013 SeriesTwoThousandThirteenA [Member] Southern Power [Member] Senior Notes [Member]	Mar. 31, 2013 SeriesTwoThousandThirteenB [Member] Georgia Power [Member] Senior Notes [Member]	Mar. 31, 2013 SeriesTwoThousandTenA [Member] Georgia Power [Member] Senior Notes [Member]	Aug. 31, 2013 SeriesTwoThousandThirteenC [Member] Georgia Power [Member]	Aug. 31, 2013 Series Two Thousand Ten D [Member] Georgia Power [Member] Senior Notes [Member]	Jun. 30, 2013 Series G [Member] Gulf Power [Member] Senior Notes [Member]	Jun. 30, 2013 Series H [Member] Gulf Power [Member] Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 500,000,000																																					$ 400,000,000	$ 90,000,000	$ 300,000,000	$ 250,000,000		$ 200,000,000
Senior Notes				1,390,000,000	1,740,000,000	0	500,000,000						1,250,000,000	850,000,000					90,000,000	90,000,000							0	0					0	300,000,000	50,000,000	0
Revenue Bond				172,000,000	120,000,000	0	0						89,000,000	89,000,000					0	0							83,000,000	31,000,000							0	0
Other Long-term Debt				125,000,000	498,000,000	0	0						0	0					0	0							125,000,000	475,000,000					0	23,000,000	0	0
Debt Instrument, Interest Rate, Stated Percentage												4.90%																											2.45%	4.30%	5.00%	5.25%				1.30%	4.35%	5.25%
Redemption Amount Of Principal Notes												100,000,000						125,000,000																										350,000,000		500,000,000	60,000,000	30,000,000
Long-term Pollution Control Bond								17,500,000			71,700,000
Repayments of Pollution Control Bond								17,500,000	89,000,000	234,000,000						63,000,000	0																				24,900,000	46,800,000
Preferred Stock, Shares Issued															500,000
Preferred Stock, Dividend Rate, Percentage															5.60%
Preference stock	50,000,000	0														50,000,000	0
Bank Loans Period Of Extension																90 days					2 years	2 years		366 days
Aggregate Principal Amount Of Floating Rate Bank Loan																					125,000,000		100,000,000		125,000,000
Debt Instrument, Description of Variable Rate Basis																									P1M
First Term Loan																						50,000,000
Second Term Loan																						75,000,000
Third Term Loan																						75,000,000
Forth Term Loan																						100,000,000
Taxable Revenue Bonds																						15,800,000				15,300,000
First Advance On Bank Loan																							50,000,000
Second Advance On Bank Loan																							50,000,000
Number Of Bank Loans																						4
Repayment Aggregate Principal Amount Of Floating Rate Bank Loan																					125,000,000				125,000,000
Promissory Note																													$ 2,200,000	$ 1,700,000	$ 10,200,000	$ 8,700,000