Financing - Textual (Details) (USD $)	12 Months Ended							0 Months Ended	1 Months Ended		12 Months Ended			0 Months Ended																		1 Months Ended		12 Months Ended			2 Months Ended	12 Months Ended												12 Months Ended											12 Months Ended				12 Months Ended		1 Months Ended				12 Months Ended					2 Months Ended	12 Months Ended		12 Months Ended															12 Months Ended		12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Trust Preferred Securities Subject to Mandatory Redemption [Member]	Dec. 31, 2012 Trust Preferred Securities Subject to Mandatory Redemption [Member]	Dec. 31, 2013 Senior Notes [Member]	Feb. 20, 2014 Georgia Power [Member]	Nov. 30, 2013 Georgia Power [Member] loan	Mar. 31, 2013 Georgia Power [Member] loan	Dec. 31, 2013 Georgia Power [Member]	Dec. 31, 2012 Georgia Power [Member]	Dec. 31, 2011 Georgia Power [Member]	Feb. 20, 2014 Georgia Power [Member] Subsequent Event [Member]	Dec. 31, 2013 Georgia Power [Member] Corporate, Non-Segment [Member]	Dec. 31, 2012 Georgia Power [Member] Corporate, Non-Segment [Member]	Dec. 31, 2013 Georgia Power [Member] Issued and Repurchased [Member]	Feb. 20, 2014 Georgia Power [Member] Line of Credit [Member] Debt Due 2029 [Member] Subsequent Event [Member]	Feb. 20, 2014 Georgia Power [Member] Line of Credit [Member] Debt Due 2044 [Member] Subsequent Event [Member]	Dec. 31, 2013 Georgia Power [Member] Capital Lease Obligations [Member]	Dec. 31, 2012 Georgia Power [Member] Capital Lease Obligations [Member]	Dec. 31, 2013 Georgia Power [Member] Secured Debt [Member]	Dec. 31, 2012 Georgia Power [Member] Secured Debt [Member]	Dec. 31, 2013 Georgia Power [Member] Bank Loan Obligations [Member]	Dec. 31, 2013 Georgia Power [Member] Senior Notes [Member]	Dec. 31, 2013 Georgia Power [Member] Plant Vogtle Units 3 And 4 [Member] Subsequent Event [Member]	Dec. 31, 2013 Subsidiaries [Member]	Dec. 31, 2012 Subsidiaries [Member]	Dec. 31, 2013 Subsidiaries [Member] Capital Lease Obligations [Member] Minimum [Member]	Dec. 31, 2013 Subsidiaries [Member] Capital Lease Obligations [Member] Maximum [Member]	Dec. 31, 2013 Southern Power and Traditional Operating Companies [Member] Senior Notes [Member]	Jun. 30, 2013 Gulf Power [Member]	Feb. 28, 2013 Gulf Power [Member]	Dec. 31, 2013 Gulf Power [Member] series	Dec. 31, 2012 Gulf Power [Member]	Dec. 31, 2011 Gulf Power [Member]	Feb. 27, 2014 Gulf Power [Member] Subsequent Event [Member]	Dec. 31, 2013 Gulf Power [Member] Minimum [Member]	Dec. 31, 2013 Gulf Power [Member] Maximum [Member]	Dec. 31, 2013 Gulf Power [Member] Plant Daniel [Member]	Jun. 30, 2013 Gulf Power [Member] Senior Notes [Member]	May 31, 2013 Gulf Power [Member] First Series 2002 [Member]	Jun. 30, 2013 Gulf Power [Member] First Series 2010 [Member]	Dec. 31, 2013 Gulf Power [Member] Series Two Thousand Twelve [Member]	Jun. 30, 2013 Gulf Power [Member] Series 2013A [Member] Senior Notes [Member]	Jul. 15, 2013 Gulf Power [Member] Series G [Member] Senior Notes [Member]	Jul. 31, 2013 Gulf Power [Member] Series H [Member] Senior Notes [Member]	Dec. 31, 2013 Southern Company [Member]	Dec. 31, 2012 Southern Company [Member]	Dec. 31, 2013 Alabama Power [Member]	Dec. 31, 2012 Alabama Power [Member]	Dec. 31, 2011 Alabama Power [Member]	Dec. 31, 2013 Alabama Power [Member] Natural Gas Pipeline [Member]	Dec. 31, 2013 Alabama Power [Member] Trust Preferred Securities Subject to Mandatory Redemption [Member]	Dec. 31, 2012 Alabama Power [Member] Trust Preferred Securities Subject to Mandatory Redemption [Member]	Dec. 31, 2013 Alabama Power [Member] Senior Notes And Pollution Control Bond [Member]	Dec. 31, 2013 Alabama Power [Member] Secured Debt [Member]	Dec. 31, 2013 Alabama Power [Member] Unsecured Debt [Member]	Nov. 30, 2013 Alabama Power [Member] Unsecured Debt [Member]	Dec. 31, 2012 Alabama Power [Member] Unsecured Debt [Member]	Dec. 31, 2013 Southern Power [Member]	Dec. 31, 2012 Southern Power [Member]	Dec. 31, 2011 Southern Power [Member]	Feb. 28, 2013 Southern Power [Member]	Dec. 31, 2011 Southern Power [Member] Series B 6.25% Senior Notes due July 15, 2012 [Member]	Dec. 31, 2013 Southern Power [Member] Series 2013A [Member] Senior Notes [Member]	Sep. 30, 2013 Mississippi Power [Member]	Mar. 31, 2013 Mississippi Power [Member] loan	Jan. 31, 2013 Mississippi Power [Member]	Nov. 30, 2012 Mississippi Power [Member]	Dec. 31, 2013 Mississippi Power [Member]	Dec. 31, 2012 Mississippi Power [Member]	Dec. 31, 2011 Mississippi Power [Member]	Sep. 19, 2013 Mississippi Power [Member]	Mar. 31, 2012 Mississippi Power [Member]	Feb. 27, 2014 Mississippi Power [Member] Subsequent Event [Member]	Dec. 31, 2013 Mississippi Power [Member] Subsequent Event [Member]	Dec. 31, 2013 Mississippi Power [Member] Kemper IGCC [Member]	Dec. 31, 2011 Mississippi Power [Member] Plant Daniel Units 3 and 4 [Member]	Oct. 20, 2011 Mississippi Power [Member] Plant Daniel Units 3 and 4 [Member]	Dec. 31, 2011 Mississippi Power [Member] Revenue Bonds [Member]	Nov. 30, 2013 Mississippi Power [Member] Series Two 2008A [Member]	Nov. 30, 2013 Mississippi Power [Member] Revenue Bonds [Member] Mississippi Business Finance Corporation Taxable Revenue Bonds, Series 2012A [Member]	Sep. 30, 2013 Mississippi Power [Member] Revenue Bonds [Member] Mississippi Business Finance Corporation Taxable Revenue Bonds, Series 2012A [Member]	Jul. 31, 2013 Mississippi Power [Member] Revenue Bonds [Member] Mississippi Business Finance Corporation Taxable Revenue Bonds, Series 2012A [Member]	Mar. 31, 2013 Mississippi Power [Member] Revenue Bonds [Member] Mississippi Business Finance Corporation Taxable Revenue Bonds, Series 2012A [Member]	Nov. 30, 2013 Mississippi Power [Member] Revenue Bonds [Member] Mississippi Business Finance Corporation Taxable Revenue Bonds, Series 2012B [Member]	Sep. 30, 2013 Mississippi Power [Member] Revenue Bonds [Member] Mississippi Business Finance Corporation Taxable Revenue Bonds, Series 2012B [Member]	Sep. 30, 2013 Mississippi Power [Member] Revenue Bonds [Member] Mississippi Business Finance Corporation Taxable Revenue Bonds, Series 2012C [Member]	Dec. 31, 2013 Mississippi Power [Member] Capital Lease Obligations [Member]	Nov. 30, 2013 Mississippi Power [Member] Senior Notes [Member] Series Two 2008A [Member]	Dec. 31, 2013 Southern Company And Subsidiaries [Member] Senior Notes [Member]	Dec. 31, 2013 Alabama Power and Gulf Power [Member] Secured Debt [Member]	Dec. 31, 2013 Traditional Operating Companies [Member]	Dec. 31, 2012 Traditional Operating Companies [Member]	Dec. 31, 2013 Notes due April 30, 2033 [Member] Southern Power [Member]	Dec. 31, 2013 Notes due September 30, 2032 [Member] Southern Power [Member]
Financing (Textual) [Abstract]
Proceeds from issuance of junior subordinated notes	$ 206,000,000		$ 206,000,000																																															$ 206,000,000	$ 206,000,000
Preferred securities, outstanding					200,000,000	200,000,000																																																200,000,000	200,000,000
Prepayment of debt																																																													9,300,000
Promissory Note																																																																																																19,400,000	4,200,000
Senior notes, current	428,000,000		2,085,000,000								0	1,675,000,000																																							250,000,000																				0	50,000,000
Long term debt and capital lease obligations, maturities in 2014											5,000,000																																																												13,800,000
Long term debt and capital lease obligations, maturities in 2014	469,000,000																																	75,000,000
Long term debt and capital lease obligations, maturities in 2015	2,970,000,000										1,100,000,000																																																												527,700,000
Long term debt and capital lease obligations, maturities in 2016	1,830,000,000										710,000,000																																																												302,800,000
Long Term Debt and Capital Lease Obligation Maturities Repayments in Year Four	1,140,000,000										457,000,000																																																												37,900,000
Long term debt and capital lease obligations, maturities in 2018	880,000,000										277,000,000																																																												3,100,000
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	428,000,000		434,000,000																															75,000,000	75,000,000																					0
Long-term debt maturities, 2015	2,375,000,000		2,375,000,000								1,050,000,000	1,050,000,000																																						400,000,000	400,000,000					454,000,000
Long-term debt maturities, 2016	1,360,000,000		1,360,000,000								250,000,000	250,000,000																						110,000,000	110,000,000															200,000,000	200,000,000					200,000,000															300,000,000	300,000,000
Long-term debt maturities, 2017	1,095,000,000		1,095,000,000								450,000,000	450,000,000																						85,000,000	85,000,000															525,000,000	525,000,000					561,000,000															35,000,000	35,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Five	850,000,000		250,000,000								250,000,000	250,000,000																																												0
Description of variable rate basis	one-month									one-month	one-month																																																								one-month	one-month		one-month		one-month					one-month
Bank Loans											400,000,000																																																									300,000,000			525,000,000	175,000,000
Aggregate Principal Amount of Floating Rate Bank Loan																																																																																														550,000,000
Bank loans, period of extension									4 months	60 days																						90 days																																			2 years	2 years		366 days	366 days					18 months
Aggregate Principal Amount Of Floating Rate Bank Loan									400,000,000	100,000,000																																																									125,000,000			100,000,000						250,000,000
First Advance On Bank Loan																																																																						50,000,000
Second Advance On Bank Loan																																																																					50,000,000
Number Of Bank Loans									3	3																																																										4
Repayment Aggregate Principal Amount Of Floating Rate Bank Loan																																																																			125,000,000
Bank loans outstanding																																																																							525,000,000	175,000,000
Ratio of indebtedness to capitalization, debt covenant, required	65.00%										65.00%																							65.00%																65.00%											65.00%										65.00%
Percent Of Eligible Project Costs To Be Reimbursed														70.00%
Eligible Project Costs To Be Reimbursed														3,460,000,000
Jointly Owned Utility Plant, Proportionate Ownership Share																										45.70%																								14.00%
Debt Instrument, Basis Spread on Variable Rate														0.375%
Line of Credit Facility, Amount Outstanding																																																														0
Line of Credit Facility, Amount Available to Support Variable Rate Pollution Control Revenue Bonds																																		69,000,000
Line of Credit Facility, Amount Available for Commercial Paper Program and General Corporate Purposes																																		206,000,000
Debt Instrument, Face Amount							500,000,000				850,000,000							500,000,000	500,000,000												1,600,000,000														90,000,000													300,000,000								300,000,000																					11,250,000.00					2,100,000,000
Payments of Debt Issuance Costs								67,000,000
Unsecured Debt																								300,000,000	1,800,000,000
Redemption Amount of Principal Notes																																									125,000,000					60,000,000	30,000,000												250,000,000				19,800,000
Senior Notes outstanding	17,300,000,000		17,400,000,000								6,900,000,000	7,900,000,000																						945,000,000	945,000,000													1,800,000,000	1,300,000,000									4,900,000,000		4,800,000,000	1,600,000,000	1,300,000,000									1,100,000,000	1,100,000,000										50,000,000
Line of Credit Facility, Current Borrowing Capacity														1,000,000,000																				275,000,000																														500,000,000
Secured Debt																																		41,000,000
Long-term Debt																						45,000,000	50,000,000																																		153,000,000
Amortization Period For Line Of Credit Facility														5 years
Pollution control revenue bonds, outstanding											1,700,000,000	1,800,000,000																						296,000,000	309,000,000					41,000,000		42,000,000	21,000,000	13,000,000						1,200,000,000	1,200,000,000						153,000,000														82,700,000	82,700,000																					194,000,000	3,200,000,000	3,400,000,000
Aggregate Pollution Control Revenue Bond											194,000,000						104,600,000
Redemption Amount of Principal											194,000,000
Revenue bond obligations face value																																																																									270,000,000						270,000,000
Fixed stated interest rate of debt obligation																		3.488%	3.86%	7.90%	7.90%								1.40%	3.20%															5.00%	4.35%	5.25%						6.90%												6.25%	5.25%					9.932%	9.967%	7.13%							7.13%	7.13%									4.90%	6.00%
Repayments of Senior Debt											1,775,000,000	850,000,000	427,000,000																					90,000,000	91,363,000	608,000														250,000,000	950,000,000	750,000,000									0	0	575,000,000		575,000,000						50,000,000	90,000,000	0
Significant Acquisitions and Disposals, Acquisition Costs, Assumption of Debt, at Fair Value																																																																															346,100,000	346,051,000
Fair value adjustment at date of purchase																																																																															76,100,000	76,051,000
Debt Instrument, Face Amount, Authorized to Issue																																																																																			33,750,000.00	40,070,000	15,300,000	15,800,000	11,250,000.00	21,250,000	21,250,000
Other revenue bond obligation																																																																							50,000,000	50,000,000
Taxable Revenue Bonds																																																																							11,300,000	51,500,000
Period Of Nitrogen Supply Agreement																																																																										20 years
Capitalized lease obligations	163,000,000		80,000,000								45,000,000	50,000,000			61,000,000	61,000,000											30,000,000	30,000,000																						5,000,000	0		5,000,000																		82,217,000	0						82,900,000
Capital leases, due 2014	0	[1]																																																																					1,800,000
Capital leases, due 2015	20,000,000	[1]																																																																					6,500,000
Capital leases, due 2016	26,000,000	[1]																																																																					6,500,000
Capital leases, due 2017	27,000,000	[1]																																																																					6,500,000
Capital leases, due 2018	27,000,000	[1]																																																																					6,500,000
Capital leases, due 2019 and thereafter	541,000,000	[1]																																																																					6,500,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	23,059,000,000		21,964,000,000								10,970,000,000	10,431,000,000			16,000,000	11,000,000																		1,211,336,000	1,168,055,000															8,114,000,000	7,761,000,000										871,963,000	786,620,000									1,095,352,000	1,065,474,000
Deposit Received																																																																											150,000,000	75,000,000
Maximum Period to Refund Deposit upon Termination of Asset Purchase Agreement																																																																							60 days
Maximum Period of Discretion																																																																							15 days
Purchased price of plant																																																																															85,000,000	84,800,000
Amount of Principal obligation assumed under Lease																																																																									270,000,000
Revenue Bond Obligations Fair Value																																																																									346,000,000
Unused credit with banks	5,214,000,000										1,736,000,000																							275,000,000														1,000,000,000		1,303,000,000											500,000,000										300,000,000
Amount of Variable Rate Pollution Control Revenue Bonds Outstanding Requiring Liquidity Support	1,800,000,000										862,000,000																																							793,000,000																					40,100,000
Remarketed pollution control bonds	442,000,000
Pollution Control Revenue Bonds Required To Be Remarketed											242,000,000																																							200,000,000
Short-term debt outstanding, regulatory approved maximum																																																		2,000,000,000
Redeemable preferred stock, redemption period																																						5 years	10 years
Redemption price of redeemable preferred stock, as a percent of liquidation amount											100.00%																							100.00%																																					100.00%
Preferred Stock, Shares Issued																																500,000	400,000				500,000
Preferred Stock, Dividend Rate, Percentage																																5.60%
Issuance of preference stock	50,000,000		0	0																												50,000,000	40,000,000	50,000,000	0	0	50,000,000
Number of Issuance Pollution Control Revenue Bonds																																		2
Short-term Debt	1,482,000,000		825,000,000								1,047,000,000	2,000,000																						135,878,000	127,002,000																										0	70,968,000
Short-term borrowings related to other energy service contracts												2,000,000
Deposit Liability, Current																																																																											$ 150,000,000	$ 75,000,000
Maximum Period to Refund Deposit, Upon Notification, Due to Not Meeting Minimum Credit Rating																																																																							15 days
Commitment fee percentage (less than 1/4 of 1%)	0.25%										0.25%																							0.25%																0.25%											0.25%										0.25%
Projected cash flows from fixed price PPAs, as a percentage of total projected cash flows for the next 12 months																																																													80.00%
Ratio of indebtedness to capitalization, actual, end of period																																																													60.00%

[1] A total of $1.3 billion of biomass PPAs included under the non-affiliate capital and operating leases is contingent upon the counterparty meeting specified contract dates for posting collateral and commercial operation.