Consolidated Statements of Capitalization - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Maturity
Long-term debt payable to affiliated trusts —	$ 206,000,000	$ 206,000,000
2016	0	1,360,000,000
2017	2,019,000,000	1,995,000,000
2018	2,353,000,000	1,697,000,000
2019	3,076,000,000	1,176,000,000
2020	1,326,000,000	1,327,000,000
2021	2,655,000,000	200,000,000
2022 through 2051	21,797,000,000	10,972,000,000
Total long -term senior notes and debt	35,247,000,000	20,418,000,000
Pollution control revenue bonds --
Total other long -term debt	9,404,000,000	6,808,000,000
Unamortized Fair Value Adjustment of Long-term Debt	578,000,000	0
Capitalized lease obligations	136,000,000	146,000,000
Unamortized debt premium	52,000,000	61,000,000
Unamortized debt discount	(194,000,000)	(36,000,000)
Unamortized debt issuance expense	(213,000,000)	(241,000,000)
Total long-term debt (annual interest requirement — $1.6 billion)	45,216,000,000	27,362,000,000
Less amount due within one year	2,587,000,000	2,674,000,000
Long-term debt excluding amount due within one year	$ 42,629,000,000	$ 24,688,000,000
Percent capitalization	61.30%	52.60%
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	$ 118,000,000	$ 118,000,000
Total redeemable preferred stock - percent capitalization	0.20%	0.30%
Preferred and preference stock of subsidiaries	$ 1,854,000,000	$ 1,390,000,000
Total preferred and preference stock of subsidiaries - percent capitalization	2.70%	3.00%
Redeemable Noncontrolling Interests	$ 164,000,000	$ 43,000,000
Redeemable Noncontrolling Interest As Percent Of Capitalization	0.20%	0.10%
Common Stockholders' Equity:
Common stock	$ 4,952,000,000	$ 4,572,000,000
Paid-in capital	9,661,000,000	6,282,000,000
Treasury, at cost	(31,000,000)	(142,000,000)
Retained earnings	10,356,000,000	10,010,000,000
Accumulated other comprehensive loss	(180,000,000)	(130,000,000)
Common Stockholders' Equity	$ 24,758,000,000	$ 20,592,000,000
Total common stockholders' equity - percent capitalization	35.60%	44.00%
Total stockholders' equity	$ 26,612,000,000	$ 21,982,000,000
Total Capitalization	$ 69,523,000,000	$ 46,831,000,000
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	$ 81,000,000	$ 81,000,000
Redeemable Preferred Stock, $1 par value [Member] | Cumulative Preferred Stock [Member]
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	37,000,000	37,000,000
Noncumulative Preferred Stock [Member]
Redeemable Preferred and Preference Stock:
Preferred and preference stock of subsidiaries	45,000,000	45,000,000
Preference Stock, $1 par value [Member]
Redeemable Preferred and Preference Stock:
Preferred and preference stock of subsidiaries	196,000,000	196,000,000
Preference Stock , $100 par or stated value [Member]
Redeemable Preferred and Preference Stock:
Preferred and preference stock of subsidiaries	368,000,000	368,000,000
Redeemable Preferred Stock [Member]
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	118,000,000	118,000,000
Noncontrolling Interest [Member]
Redeemable Preferred and Preference Stock:
Preferred and preference stock of subsidiaries	1,245,000,000	781,000,000
Adjustable Rate Loans [Member]
Maturity
2016	0	1,278,000,000
2017	461,000,000	400,000,000
2018	1,520,000,000	0
2021	25,000,000	0
2022 through 2051	15,000,000	13,000,000
Pollution control revenue bonds due 2019 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	25,000,000	25,000,000
Pollution control revenue bonds due 2022 through 2049 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	1,429,000,000	1,509,000,000
Pollution control revenue bonds variable rate, Due 2016 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	0	4,000,000
Pollution control revenue bonds variable rate, Due 2017 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	76,000,000	76,000,000
Pollution control revenue bonds variable rate due 2021 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	65,000,000	65,000,000
Pollution control revenue bonds variable rate, 2022 to 2053 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	1,739,000,000	1,659,000,000
Plant Daniel revenue bonds due 2021 [Member]
Pollution control revenue bonds --
Plant Daniel revenue bonds (7.13%) due 2021	270,000,000	270,000,000
Maturity Of FFB Loans Due 2020 [Member]
Pollution control revenue bonds --
Loan For Federal Financing Bank	44,000,000	37,000,000
Maturity Of FFB Loans Due 2021 [Member]
Pollution control revenue bonds --
Loan For Federal Financing Bank	44,000,000	37,000,000
Maturity Of FFB Bank Loans Due 2022 to 2053 [Member]
Pollution control revenue bonds --
Loan For Federal Financing Bank	2,537,000,000	2,126,000,000
Maturity Of First Mortgage Bonds Due 2019 [Member]
Pollution control revenue bonds --
First Mortgage Bonds	50,000,000	0
First Mortgage Bonds Due Two Thousand Twenty Two To Two Thousand Thirty Eight [Member]
Pollution control revenue bonds --
First Mortgage Bonds	575,000,000	0
Maturity Of Gas Facility Revenue Bonds Due Two Thousand Twenty Two To Two Thousand Thirty Eight [Member]
Pollution control revenue bonds --
Gas Facility Revenue Bonds	200,000,000	0
Maturity of Junior Subordinated Notes Due Two Thousand Seventy Five [Member]
Pollution control revenue bonds --
Junior subordinated notes	2,350,000,000	1,000,000,000
Alabama Power [Member]
Maturity
Long-term debt payable to affiliated trusts —	206,000,000	206,000,000
2016	0	200,000,000
2017	525,000,000	525,000,000
2019	200,000,000	200,000,000
2020	250,000,000	250,000,000
2021	220,000,000	200,000,000
2022 through 2051	4,625,000,000	4,225,000,000
Total long-term notes payable	5,845,000,000	5,600,000,000
Pollution control revenue bonds --
Long-term pollution control bonds	1,100,000,000	1,100,000,000
Total other long -term debt	1,096,000,000	1,097,000,000
Capitalized lease obligations	4,000,000	5,000,000
Unamortized debt (discount), net	(9,000,000)	(9,000,000)
Unamortized debt issuance expense	(46,000,000)	(45,000,000)
Total long-term debt (annual interest requirement — $1.6 billion)	7,096,000,000	6,854,000,000
Less amount due within one year	561,000,000	200,000,000
Long-term debt excluding amount due within one year	$ 6,535,000,000	$ 6,654,000,000
Percent capitalization	49.70%	51.40%
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	$ 85,000,000	$ 85,000,000
Total redeemable preferred stock - percent capitalization	0.70%	0.70%
Preferred stock	$ 85,000,000	$ 85,000,000
Preference stock	$ 196,000,000	$ 196,000,000
Total preferred and preference stock of subsidiaries - percent capitalization	1.50%	1.50%
Common Stockholders' Equity:
Common stock	$ 1,222,000,000	$ 1,222,000,000
Paid-in capital	2,613,000,000	2,341,000,000
Retained earnings	2,518,000,000	2,461,000,000
Accumulated other comprehensive loss	(30,000,000)	(32,000,000)
Common Stockholders' Equity	$ 6,323,000,000	$ 5,992,000,000
Total common stockholders' equity - percent capitalization	48.10%	46.40%
Total stockholders' equity	$ 6,323,000,000	$ 5,992,000,000
Total Capitalization	$ 13,139,000,000	$ 12,927,000,000
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	$ 48,000,000	$ 48,000,000
Alabama Power [Member] | Redeemable Preferred Stock, $1 par value [Member] | Cumulative Preferred Stock [Member]
Redeemable Preferred and Preference Stock:
Redeemable preferred stock	37,000,000	37,000,000
Alabama Power [Member] | Adjustable Rate Loans [Member]
Maturity
2021	25,000,000	0
Alabama Power [Member] | Pollution control revenue bonds variable rate, Due 2017 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	36,000,000	36,000,000
Alabama Power [Member] | Pollution control revenue bonds variable rate due 2021 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	65,000,000	65,000,000
Alabama Power [Member] | Pollution control revenue bonds due 2034 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	207,000,000	287,000,000
Alabama Power [Member] | Pollution Control Revenue Bonds Variable Rate Due 2024 - 2038 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	788,000,000	709,000,000
Georgia Power [Member]
Maturity
2016	0	250,000,000
2017	450,000,000	450,000,000
2018	748,000,000	747,000,000
2019	500,000,000	502,000,000
2020	325,000,000	0
2022 through 2051	4,175,000,000	3,850,000,000
Total long-term notes payable	6,198,000,000	6,249,000,000
Pollution control revenue bonds --
Long-term pollution control bonds	1,800,000,000	1,800,000,000
Total other long -term debt	4,445,000,000	4,024,000,000
Capitalized lease obligations	169,000,000	183,000,000
Unamortized debt (discount), net	(10,000,000)	(10,000,000)
Unamortized debt issuance expense	(117,000,000)	(118,000,000)
Total long-term debt (annual interest requirement — $1.6 billion)	10,685,000,000	10,328,000,000
Less amount due within one year	460,000,000	712,000,000
Long-term debt excluding amount due within one year	$ 10,225,000,000	$ 9,616,000,000
Percent capitalization	46.80%	46.70%
Redeemable Preferred and Preference Stock:
Preferred stock	$ 45,000,000	$ 45,000,000
Preference stock	$ 221,000,000	$ 221,000,000
Total preferred and preference stock of subsidiaries - percent capitalization	1.20%	1.30%
Common Stockholders' Equity:
Common stock	$ 398,000,000	$ 398,000,000
Paid-in capital	6,885,000,000	6,275,000,000
Retained earnings	4,086,000,000	4,061,000,000
Accumulated other comprehensive loss	(13,000,000)	(15,000,000)
Common Stockholders' Equity	$ 11,356,000,000	$ 10,719,000,000
Total common stockholders' equity - percent capitalization	52.00%	52.00%
Total stockholders' equity	$ 11,356,000,000	$ 10,719,000,000
Total Capitalization	$ 21,847,000,000	$ 20,601,000,000
Percent Capitalization	100.00%	100.00%
Georgia Power [Member] | Noncumulative Preferred Stock [Member]
Redeemable Preferred and Preference Stock:
Total preferred and preference stock	$ 266,000,000	$ 266,000,000
Georgia Power [Member] | Noncumulative Preferred Stock, $25 par value [Member]
Redeemable Preferred and Preference Stock:
Preferred stock	45,000,000	45,000,000
Georgia Power [Member] | Noncumulative Preferred Stock, $100 par value [Member]
Redeemable Preferred and Preference Stock:
Preference stock	221,000,000	221,000,000
Georgia Power [Member] | Adjustable Rate Loans [Member]
Maturity
2016	0	450,000,000
Georgia Power [Member] | Pollution control revenue bonds due 2022 through 2049 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	952,000,000	952,000,000
Georgia Power [Member] | Pollution control revenue bonds variable rate, Due 2016 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	0	4,000,000
Georgia Power [Member] | Pollution control revenue bonds variable rate, 2022 to 2053 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	868,000,000	868,000,000
Georgia Power [Member] | Maturity Of FFB Loans Due 2020 [Member]
Pollution control revenue bonds --
Loan For Federal Financing Bank	44,000,000	37,000,000
Georgia Power [Member] | Maturity Of FFB Loans Due 2021 [Member]
Pollution control revenue bonds --
Loan For Federal Financing Bank	44,000,000	37,000,000
Georgia Power [Member] | Maturity Of FFB Bank Loans Due 2022 to 2053 [Member]
Pollution control revenue bonds --
Loan For Federal Financing Bank	2,537,000,000	2,126,000,000
Gulf Power [Member]
Maturity
2016	0	110,000,000
2017	87,000,000	85,000,000
2018	0
2019	0
2020	175,000,000	175,000,000
2021	0
2022 through 2051	515,000,000	640,000,000
Total long-term notes payable	777,000,000	1,010,000,000
Pollution control revenue bonds --
Long-term pollution control bonds	309,000,000	309,000,000
Total other long -term debt	309,000,000	309,000,000
Unamortized debt (discount), net	(5,000,000)	(8,000,000)
Unamortized debt issuance expense	(7,000,000)	(8,000,000)
Total long-term debt (annual interest requirement — $1.6 billion)	1,074,000,000	1,303,000,000
Less amount due within one year	87,000,000	110,000,000
Long-term debt excluding amount due within one year	$ 987,000,000	$ 1,193,000,000
Percent capitalization	39.10%	44.30%
Redeemable Preferred and Preference Stock:
Total redeemable preferred stock - percent capitalization	5.80%	5.40%
Preference stock	$ 147,000,000	$ 147,000,000
Common Stockholders' Equity:
Common stock	503,000,000	503,000,000
Paid-in capital	589,000,000	567,000,000
Retained earnings	296,000,000	285,000,000
Accumulated other comprehensive loss	1,000,000	0
Common Stockholders' Equity	$ 1,389,000,000	$ 1,355,000,000
Total common stockholders' equity - percent capitalization	55.10%	50.30%
Total stockholders' equity	$ 1,389,000,000	$ 1,355,000,000
Total Capitalization	$ 2,523,000,000	$ 2,695,000,000
Percent Capitalization	100.00%	100.00%
Gulf Power [Member] | 6% Preference stock [Member]
Redeemable Preferred and Preference Stock:
Preference stock	$ 54,000,000	$ 54,000,000
Gulf Power [Member] | 6.45 % Preference stock [Member]
Redeemable Preferred and Preference Stock:
Preference stock	44,000,000	44,000,000
Gulf Power [Member] | 5.6% Preference Stock [Member]
Redeemable Preferred and Preference Stock:
Preference stock	49,000,000	49,000,000
Gulf Power [Member] | Pollution control revenue bonds due 2022 through 2049 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	227,000,000	227,000,000
Gulf Power [Member] | Pollution control revenue bonds variable rate, 2022 to 2053 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	82,000,000	82,000,000
Mississippi Power [Member]
Maturity
2016	0	300,000,000
2017	35,000,000	35,000,000
2019	125,000,000	125,000,000
2022 through 2051	680,000,000	680,000,000
Total long-term notes payable	2,040,000,000	1,565,000,000
Pollution control revenue bonds --
Long-term pollution control bonds	83,000,000	83,000,000
Total other long -term debt	904,000,000	929,000,000
Capitalized lease obligations	74,000,000	77,000,000
Unamortized debt premium	45,000,000	53,000,000
Unamortized debt discount	(2,000,000)	(2,000,000)
Unamortized debt issuance expense	(8,000,000)	(8,000,000)
Total long-term debt (annual interest requirement — $1.6 billion)	3,053,000,000	2,614,000,000
Less amount due within one year	629,000,000	728,000,000
Long-term debt excluding amount due within one year	$ 2,424,000,000	$ 1,886,000,000
Percent capitalization	44.90%	44.10%
Redeemable Preferred and Preference Stock:
Total redeemable preferred stock - percent capitalization	0.60%	0.80%
Preferred stock	$ 33,000,000	$ 33,000,000
Common Stockholders' Equity:
Common stock	38,000,000	38,000,000
Paid-in capital	3,525,000,000	2,893,000,000
Retained earnings	(616,000,000)	(566,000,000)
Accumulated other comprehensive loss	(4,000,000)	(6,000,000)
Common Stockholders' Equity	$ 2,943,000,000	$ 2,359,000,000
Total common stockholders' equity - percent capitalization	54.50%	55.10%
Total stockholders' equity	$ 2,943,000,000	$ 2,359,000,000
Total Capitalization	$ 5,400,000,000	$ 4,278,000,000
Percent Capitalization	100.00%	100.00%
Mississippi Power [Member] | Adjustable Rate Loans [Member]
Maturity
2016	$ 0	$ 425,000,000
2018	1,200,000,000	0
Mississippi Power [Member] | Plant Daniel revenue bonds due 2021 [Member]
Pollution control revenue bonds --
Plant Daniel revenue bonds (7.13%) due 2021	270,000,000	270,000,000
Mississippi Power [Member] | Pollution control revenue bonds due 2028 [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	43,000,000	43,000,000
Mississippi Power [Member] | Maturity Of Pollution Control Bonds Two Thousand Seventeen [Member]
Pollution control revenue bonds --
Long-term pollution control bonds	40,000,000	40,000,000
Mississippi Power [Member] | Maturity of Long-Term Debt Payable To Parent Company Period One [Member]
Pollution control revenue bonds --
Long-term debt due to parent company	$ 551,000,000	$ 576,000,000