Commitments - Estimated Long-term obligations (Details) (USD $)	Dec. 31, 2013
Minimum Lease Payments, Operating Leases [Abstract]
2014	$ 101,000,000
2015	75,000,000
2016	65,000,000
2017	44,000,000
2018	31,000,000
2019 and thereafter	135,000,000
Total	451,000,000
Minimum Lease Payments, Capital Leases [Abstract]
2014	0	[1]
2015	20,000,000	[1]
2016	26,000,000	[1]
2017	27,000,000	[1]
2018	27,000,000	[1]
2019 and thereafter	541,000,000	[1]
Total	641,000,000	[1]
Less: amounts representing executory costs	142,000,000	[1],[2]
Net minimum lease payments	499,000,000	[1]
Less: amounts representing interest	166,000,000	[1],[3]
Present value of net minimum lease payments	333,000,000	[1],[4]
Alabama Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	15,000,000
2015	12,000,000
2016	12,000,000
2017	6,000,000
2018	4,000,000
2019 and thereafter	15,000,000
Total	64,000,000
Georgia Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	26,000,000
2015	20,000,000
2016	13,000,000
2017	9,000,000
2018	6,000,000
2019 and thereafter	11,000,000
Total	85,000,000
Capital And Operating Leases, Future Minimum Payments Due	4,415,000,000
Capital And Operating Leases, Future Minimum Payments Due Thereafter	3,119,000,000
Capital And Operating Leases, Future Minimum Payments Due In Five Years	264,000,000
Capital And Operating Leases, Future Minimum Payments Due In Four Years	273,000,000
Capital And Operating Leases, Future Minimum Payments Due In Three Years	300,000,000
Capital And Operating Leases, Future Minimum Payments Due In Two Years	271,000,000
Capital And Operating Leases, Future Minimum Payments Due, Next Twelve Months	188,000,000
Minimum Lease Payments, Capital Leases [Abstract]
Capital Leases, Future Minimum Payments, Lesser Of Fair Value and Present Value	482,000,000
Gulf Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	13,500,000
2015	10,000,000
2016	10,000,000
2017	600,000
Total	34,100,000
Railcars [Member] | Alabama Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	12,000,000
2015	10,000,000
2016	11,000,000
2017	6,000,000
2018	4,000,000
2019 and thereafter	15,000,000
Total	58,000,000
Vehicles And Other [Member] | Alabama Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	3,000,000
2015	2,000,000
2016	1,000,000
2017	0
2018	0
2019 and thereafter	0
Total	6,000,000
Barges and Rail Cars [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	56,000,000
2015	35,000,000
2016	30,000,000
2017	12,000,000
2018	6,000,000
2019 and thereafter	15,000,000
Total	154,000,000
Barges and Rail Cars [Member] | Georgia Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	20,000,000
2015	14,000,000
2016	8,000,000
2017	5,000,000
2018	2,000,000
2019 and thereafter	0
Total	49,000,000
Barges and Rail Cars [Member] | Gulf Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	13,300,000
2015	9,900,000
2016	9,900,000
2017	500,000
Total	33,600,000
Other Lease Payments [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	45,000,000
2015	40,000,000
2016	35,000,000
2017	32,000,000
2018	25,000,000
2019 and thereafter	120,000,000
Total	297,000,000
Other Lease Payments [Member] | Georgia Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	6,000,000
2015	6,000,000
2016	5,000,000
2017	4,000,000
2018	4,000,000
2019 and thereafter	11,000,000
Total	36,000,000
Other Lease Payments [Member] | Gulf Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	200,000
2015	100,000
2016	100,000
2017	100,000
Total	500,000
Purchased Power [Member]
Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract]
2014	201,000,000
2015	244,000,000
2016	260,000,000
2017	263,000,000
2018	266,000,000
2019 and thereafter	2,104,000,000
Total	3,338,000,000
Purchased Power [Member] | Alabama Power [Member]
Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract]
2014	36,000,000
2015	38,000,000
2016	39,000,000
2017	40,000,000
2018	42,000,000
2019 and thereafter	182,000,000
Total	377,000,000
Purchased Power [Member] | Gulf Power [Member]
Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract]
2014	52,900,000
2015	78,600,000
2016	78,700,000
2017	78,800,000
2018	78,900,000
2019 and thereafter	349,200,000
Total	717,100,000
Other Lease Payments [Member]
Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract]
2014	21,000,000
2015	13,000,000
2016	11,000,000
2017	8,000,000
2018	7,000,000
2019 and thereafter	58,000,000
Total	118,000,000
Affiliate Capital Lease PPA [Member] | Georgia Power [Member]
Minimum Lease Payments, Capital Leases [Abstract]
2014	0
2015	22,000,000
2016	22,000,000
2017	23,000,000
2018	23,000,000
2019 and thereafter	278,000,000
Total	368,000,000
Less: amounts representing executory costs	55,000,000	[2]
Net minimum lease payments	313,000,000
Less: amounts representing interest	85,000,000	[5]
Present value of net minimum lease payments	228,000,000	[6]
Non-Affiliate Capital Lease PPA [Member] | Georgia Power [Member]
Minimum Lease Payments, Capital Leases [Abstract]
2014	0	[1]
2015	20,000,000	[1]
2016	26,000,000	[1]
2017	27,000,000	[1]
2018	27,000,000	[1]
2019 and thereafter	541,000,000	[1]
Total	641,000,000	[1]
Less: amounts representing executory costs	142,000,000	[1],[2]
Net minimum lease payments	499,000,000	[1]
Less: amounts representing interest	166,000,000	[1],[5]
Present value of net minimum lease payments	333,000,000	[1],[6]
Affiliate Operating Lease PPA [Member] | Georgia Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	55,000,000
2015	89,000,000
2016	99,000,000
2017	71,000,000
2018	62,000,000
2019 and thereafter	669,000,000
Total	1,045,000,000
Non-Affiliate Operating Lease PPA [Member] | Georgia Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	112,000,000	[1]
2015	127,000,000	[1]
2016	142,000,000	[1]
2017	144,000,000	[1]
2018	145,000,000	[1]
2019 and thereafter	1,573,000,000	[1]
Total	2,243,000,000	[1]
Minimum Lease Payments, Capital Leases [Abstract]
Biomass PPAs Amount	1,300,000,000
Plant Vogtle Nuclear Units 1 and 2 [Member] | Georgia Power [Member]
Minimum Lease Payments, Operating Leases [Abstract]
2014	21,000,000
2015	13,000,000
2016	11,000,000
2017	8,000,000
2018	7,000,000
2019 and thereafter	58,000,000
Total	$ 118,000,000

[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.

[2] Executory costs such as taxes, maintenance, and insurance (including the estimated profit thereon) are estimated and included in total minimum lease payments.

[3] Calculated Georgia Power's incremental borrowing rate at the inception of the leases.

[4] When the PPAs with non-affiliates begin in 2015, Georgia Power will recognize capital lease assets and capital lease obligations totaling $333 million, equal to the lesser of the present value of the net minimum lease payments or the estimated fair value of the leased property.

[5] Calculated at the Company's incremental borrowing rate at the inception of the leases.

[6] When the PPAs begin in 2015, the Company will recognize capital lease assets and capital lease obligations totaling $482 million, equal to the lesser of the present value of the net minimum lease payments or the estimated fair value of the leased property.