Consolidated Statements of Capitalization - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Maturity
Total long term debt payable to affiliated trusts	$ 206	$ 206
Long-term debt, due 2015	0	2,375
Long-term debt maturities, 2015	1,360	1,360
Long-term debt maturities, 2016	1,995	1,495
Long-term debt maturities, 2017	1,697	850
Long-term debt maturities, 2018	1,176	1,175
Long-term debt maturities, 2019	1,327	425
Long-term debt maturities, thereafter	11,185	10,150
Long-term senior notes and debt:
Total long -term senior notes and debt	20,418	19,055
Pollution control revenue bonds --
Total other long -term debt	6,808	4,719
Capitalized lease obligations	146	159
Unamortized debt premium (related to plant acquisition)	61	69
Unamortized debt discount	(36)	(33)
Unamortized Debt Issuance Expense	(241)	(202)
Total long-term debt (annual interest requirement )	27,362	23,973
Less amount due within one year	2,674	3,329
Long-term debt excluding amount due within one year	$ 24,688	$ 20,644
Percent capitalization	52.60%	49.20%
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	$ 118	$ 375
Total redeemable preferred stock - percent capitalization	0.30%	0.90%
Preferred and preference stock of subsidiaries	$ 1,390	$ 977
Total preferred and preference stock of subsidiaries - percent capitalization	3.00%	2.30%
Redeemable Noncontrolling Interests	$ 43	$ 39
Redeemable Noncontrolling Interest As Percent Of Capitalization	0.10%	0.10%
Common Stockholders' Equity:
Common stock	$ 4,572	$ 4,539
Paid-in capital	6,282	5,955
Treasury, at cost	(142)	(26)
Retained earnings	10,010	9,609
Accumulated other comprehensive loss	(130)	(128)
Common Stockholders' Equity	$ 20,592	$ 19,949
Total common stockholders' equity - percent capitalization	44.00%	47.50%
Total stockholders' equity	$ 21,982	$ 20,926
Total Capitalization	$ 46,831	$ 41,984
Percent Capitalization	100.00%	100.00%
Redeemable Preferred Stock, $100 par or stated value [Member] | Cumulative Preferred Stock [Member]
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	$ 81	$ 81
Redeemable Preferred Stock, $1 par value [Member] | Cumulative Preferred Stock [Member]
Long-term senior notes and debt:
Fixed stated interest rate of debt obligation	5.83%
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	$ 37	294
Noncumulative Preferred Stock [Member]
Redeemable Preferred and Preference Stock:
Preferred and preference stock of subsidiaries	45	45
Preference Stock, $1 par value [Member]
Redeemable Preferred and Preference Stock:
Preferred and preference stock of subsidiaries	196	343
Preference Stock , $100 par or stated value [Member]
Redeemable Preferred and Preference Stock:
Preferred and preference stock of subsidiaries	368	368
Noncontrolling Interest [Member]
Redeemable Preferred and Preference Stock:
Preferred and preference stock of subsidiaries	781	221
Adjustable Rate Loans [Member]
Maturity
Long-term debt, due 2015	0	775
Long-term debt maturities, 2015	1,278	450
Long-term debt maturities, 2016	$ 400	$ 0
Affiliate trusts, variable rate, due 2042 [Member]
Long-term senior notes and debt:
Fixed stated interest rate of debt obligation	3.43%	3.43%
Pollution control revenue bonds due 2019 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	$ 25	$ 25
Pollution control revenue bonds due 2022 through 2049 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	1,509	1,466
Pollution control revenue bonds variable rate, Due 2015 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	0	152
Pollution control revenue bonds variable rate, Due 2016 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	4	4
Pollution control revenue bonds variable rate, Due 2017 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	36	36
Maturity Of Pollution Control Bonds Variable Rate Due 2020 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	7	7
Pollution control revenue bonds variable rate, Due 2020 to 2052 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	1,757	1,559
Loan For Federal Financing Bank	2,163	1,180
Plant Daniel revenue bonds due 2021 [Member]
Pollution control revenue bonds --
Taxable Revenue Bonds	270	270
Debt Due 2020 [Member]
Pollution control revenue bonds --
Loan For Federal Financing Bank	37	20
Maturity of Pollution Control Bonds Period Three [Member]
Pollution control revenue bonds --
Junior Subordinated Notes, Noncurrent	1,000	0
Alabama Power [Member]
Maturity
Total long term debt payable to affiliated trusts	206	206
Long-term debt maturities, 2015	0	400
Long-term debt maturities, 2016	200	200
Long-term debt maturities, 2017	525	525
Long-term debt maturities, 2018	200	200
Long-term debt maturities, 2019	250	250
Long-term debt maturities, thereafter	4,425	3,700
Long-term senior notes and debt:
Total long-term notes payable	5,600	5,275
Pollution control revenue bonds --
Long-term pollution control bonds	1,100	1,200
Total other long -term debt	1,097	1,151
Capitalized lease obligations	5	5
Unamortized debt (discount), net	(9)	(7)
Unamortized Debt Issuance Expense	(45)	(39)
Total long-term debt (annual interest requirement )	6,854	6,591
Less amount due within one year	200	454
Long-term debt excluding amount due within one year	$ 6,654	$ 6,137
Percent capitalization	51.40%	48.80%
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	$ 85	$ 342
Preferred stock	85	342
Preference stock	$ 196	$ 343
Total redeemable preferred stock - percent capitalization	0.70%	2.70%
Total preferred and preference stock of subsidiaries - percent capitalization	1.50%	2.70%
Common Stockholders' Equity:
Common stock	$ 1,222	$ 1,222
Paid-in capital	2,341	2,304
Retained earnings	2,461	2,255
Accumulated other comprehensive loss	(32)	(29)
Common Stockholders' Equity	$ 5,992	$ 5,752
Total common stockholders' equity - percent capitalization	46.40%	45.80%
Total stockholders' equity	$ 5,992	$ 5,752
Total Capitalization	$ 12,927	$ 12,574
Percent Capitalization	100.00%	100.00%
Alabama Power [Member] | Redeemable Preferred Stock, $100 par or stated value [Member] | Cumulative Preferred Stock [Member]
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	$ 48	$ 48
Alabama Power [Member] | Redeemable Preferred Stock, $1 par value [Member] | Cumulative Preferred Stock [Member]
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	$ 37	$ 294
Alabama Power [Member] | Affiliate trusts, variable rate, due 2042 [Member]
Long-term senior notes and debt:
Fixed stated interest rate of debt obligation	3.43%	3.43%
Alabama Power [Member] | Pollution control revenue bonds due 2034 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	$ 287	$ 367
Alabama Power [Member] | Pollution control revenue bonds due 2015 [Member]
Long-term senior notes and debt:
Fixed stated interest rate of debt obligation		0.03%
Pollution control revenue bonds --
Long-term pollution control bonds	0	$ 54
Alabama Power [Member] | Pollution control revenue bonds variable rate, Due 2017 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	36	36
Alabama Power [Member] | Pollution control revenue bonds due 2021-2038 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	774	694
Georgia Power [Member]
Maturity
Long-term debt maturities, variable, 2016	450	450
Long-term debt maturities, 2015	0	1,050
Long-term debt maturities, 2016	250	250
Long-term debt maturities, 2017	450	450
Long-term debt maturities, 2018	747	250
Long-term debt maturities, 2019	502	500
Long-term debt maturities, thereafter	3,850	3,975
Long-term senior notes and debt:
Total long-term notes payable	6,249	6,925
Pollution control revenue bonds --
Long-term pollution control bonds	1,800	1,600
Total other long -term debt	4,024	2,883
Capitalized lease obligations	183	40
Unamortized debt (discount), net	(10)	(11)
Unamortized Debt Issuance Expense	(118)	(124)
Total long-term debt (annual interest requirement )	10,328	9,713
Less amount due within one year	712	1,150
Long-term debt excluding amount due within one year	$ 9,616	$ 8,563
Percent capitalization	46.70%	44.50%
Redeemable Preferred and Preference Stock:
Preferred stock	$ 45	$ 45
Preference stock	$ 221	$ 221
Total preferred and preference stock of subsidiaries - percent capitalization	1.30%	1.40%
Common Stockholders' Equity:
Common stock	$ 398	$ 398
Paid-in capital	6,275	6,196
Retained earnings	4,061	3,835
Accumulated other comprehensive loss	(15)	(8)
Common Stockholders' Equity	$ 10,719	$ 10,421
Total common stockholders' equity - percent capitalization	52.00%	54.10%
Total stockholders' equity	$ 10,719	$ 10,421
Total Capitalization	$ 20,601	$ 19,250
Percent Capitalization	100.00%	100.00%
Georgia Power [Member] | Noncumulative Preferred Stock, $25 par value [Member]
Redeemable Preferred and Preference Stock:
Preferred stock	$ 45	$ 45
Georgia Power [Member] | Noncumulative Preferred Stock, $100 par value [Member]
Redeemable Preferred and Preference Stock:
Preference stock	221	221
Georgia Power [Member] | Noncumulative Preferred Stock [Member]
Redeemable Preferred and Preference Stock:
Total preferred and preference stock	266	266
Georgia Power [Member] | Pollution control revenue bonds due 2022 - 2049 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	952	818
Georgia Power [Member] | Pollution control revenue bonds variable rate, Due 2015 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	$ 0	$ 98
Georgia Power [Member] | Pollution control revenue bonds variable rate, Due 2016 [Member]
Long-term senior notes and debt:
Fixed stated interest rate of debt obligation	0.22%	0.22%
Pollution control revenue bonds --
Long-term pollution control bonds	$ 4	$ 4
Georgia Power [Member] | Pollution control revenue bonds due 2022-2052 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	868	763
Georgia Power [Member] | Debt Due 2020 [Member]
Pollution control revenue bonds --
Loan For Federal Financing Bank	37	20
Georgia Power [Member] | Debt Due 2021-2044 [Member]
Pollution control revenue bonds --
Loan For Federal Financing Bank	2,163	1,180
Gulf Power [Member]
Maturity
Long-term debt maturities, 2015	110	110
Long-term debt maturities, 2016	85	85
Long-term debt maturities, 2019	175	175
Long-term debt maturities, thereafter	640	700
Long-term senior notes and debt:
Total long-term notes payable	1,010	1,070
Pollution control revenue bonds --
Long-term pollution control bonds	309	309
Total other long -term debt	309	309
Unamortized debt (discount), net	(8)	(9)
Unamortized Debt Issuance Expense	(8)	(8)
Total long-term debt (annual interest requirement )	1,303	1,362
Less amount due within one year	110	0
Long-term debt excluding amount due within one year	$ 1,193	$ 1,362
Percent capitalization	44.30%	48.30%
Redeemable Preferred and Preference Stock:
Preference stock	$ 147	$ 147
Total redeemable preferred stock - percent capitalization	5.40%	5.20%
Common Stockholders' Equity:
Common stock	$ 503	$ 483
Paid-in capital	567	560
Retained earnings	285	267
Accumulated other comprehensive loss	0	(1)
Common Stockholders' Equity	$ 1,355	$ 1,309
Total common stockholders' equity - percent capitalization	50.30%	46.50%
Total stockholders' equity	$ 1,355	$ 1,309
Total Capitalization	$ 2,695	$ 2,818
Percent Capitalization	100.00%	100.00%
Gulf Power [Member] | 6% Preference stock [Member]
Redeemable Preferred and Preference Stock:
Preference stock	$ 54	$ 54
Gulf Power [Member] | 6.45 % Preference stock [Member]
Redeemable Preferred and Preference Stock:
Preference stock	44	44
Gulf Power [Member] | 5.6% Preference Stock [Member]
Redeemable Preferred and Preference Stock:
Preference stock	49	49
Gulf Power [Member] | Pollution control revenue bonds due 2022 - 2049 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	227	240
Gulf Power [Member] | Pollution control revenue bonds due 2022-2039 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	82	69
Mississippi Power [Member]
Maturity
Long-term debt maturities, 2016	300	300
Long-term debt maturities, 2017	35	35
Long-term debt maturities, 2018	125	125
Long-term debt maturities, thereafter	680	680
Bank term loans	425	775
Long-term senior notes and debt:
Total long-term notes payable	1,565	1,915
Pollution control revenue bonds --
Long-term pollution control bonds	83	83
Total other long -term debt	929	353
Capitalized lease obligations	77	79
Unamortized debt premium (related to plant acquisition)	53	63
Unamortized debt discount	(2)	(2)
Unamortized Debt Issuance Expense	(8)	(9)
Total long-term debt (annual interest requirement )	2,614	2,399
Less amount due within one year	728	778
Long-term debt excluding amount due within one year	$ 1,886	$ 1,621
Percent capitalization	44.10%	43.30%
Redeemable Preferred and Preference Stock:
Preferred stock	$ 33	$ 33
Total redeemable preferred stock - percent capitalization	0.80%	0.90%
Common Stockholders' Equity:
Common stock	$ 38	$ 38
Paid-in capital	2,893	2,612
Retained earnings	(566)	(559)
Accumulated other comprehensive loss	(6)	(7)
Common Stockholders' Equity	$ 2,359	$ 2,084
Total common stockholders' equity - percent capitalization	55.10%	55.80%
Total stockholders' equity	$ 2,359	$ 2,084
Total Capitalization	$ 4,278	$ 3,738
Percent Capitalization	100.00%	100.00%
Mississippi Power [Member] | Pollution control revenue bonds due 2028 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	$ 43	$ 43
Mississippi Power [Member] | Maturity Of Pollution Control Bonds Variable Rate Due 2020 [Member]
Long-term senior notes and debt:
Fixed stated interest rate of debt obligation	0.16%	0.16%
Pollution control revenue bonds --
Long-term pollution control bonds	$ 7	$ 7
Mississippi Power [Member] | Pollution control revenue bonds due 2020-2028 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	$ 33	$ 33
Mississippi Power [Member] | Plant Daniel revenue bonds due 2021 [Member]
Long-term senior notes and debt:
Fixed stated interest rate of debt obligation	7.13%	7.13%
Pollution control revenue bonds --
Taxable Revenue Bonds	$ 270	$ 270
Mississippi Power [Member] | Maturity of Long-Term Debt Payable To Parent Company Period One [Member]
Pollution control revenue bonds --
Long-term Debt Payable To Parent Company	$ 576	$ 0