Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities:
Net Income (Loss)	$ 2,435.0	$ 2,031.0	$ 1,710.0
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	2,395.0	2,293.0	2,298.0
Deferred income taxes	1,404.0	709.0	496.0
Investment tax credits	(48.0)	35.0	302.0
Allowance for equity funds used during construction	(226.0)	(245.0)	(190.0)
Pension, postretirement, and other employee benefits	76.0	(515.0)	131.0
Stock based compensation expense	99.0	63.0	59.0
Estimated loss on Kemper IGCC	365.0	868.0	1,180.0
Income taxes receivable, non-current	(413.0)	0.0	0.0
Amortization of Deferred Investment Tax Credits	(21.0)	(22.0)	(16.0)
Other, net	(39.0)	(39.0)	(41.0)
Changes in certain current assets and liabilities --
-Receivables	243.0	(352.0)	(153.0)
-Fossil fuel stock	61.0	408.0	481.0
-Materials and supplies	(44.0)	(67.0)	36.0
-Other current assets	(108.0)	(57.0)	(11.0)
-Accounts payable	(353.0)	267.0	72.0
-Accrued taxes	352.0	(105.0)	(85.0)
-Accrued compensation	(41.0)	255.0	(138.0)
-Retail fuel cost over-recovery—short-term	289.0	(23.0)	(66.0)
-Mirror CWIP	(271.0)	180.0	0.0
-Other current liabilities	98.0	109.0	16.0
Net cash provided from operating activities	6,274.0	5,815.0	6,097.0
Investing Activities:
Plant acquisitions	(1,719.0)	(731.0)	(132.0)
Property additions	(5,674.0)	(5,246.0)	(5,331.0)
Investment in restricted cash	(160.0)	(11.0)	(149.0)
Distribution of restricted cash	154.0	57.0	96.0
Nuclear decommissioning trust fund purchases	(1,424.0)	(916.0)	(986.0)
Nuclear decommissioning trust fund sales	1,418.0	914.0	984.0
Cost of removal, net of salvage	(167.0)	(170.0)	(131.0)
Change in construction payables	402.0	(107.0)	(126.0)
Prepaid long-term service agreement	(197.0)	(181.0)	(91.0)
Other investing activities	87.0	(17.0)	124.0
Net cash used for investing activities	(7,280.0)	(6,408.0)	(5,742.0)
Financing Activities:
Increase (decrease) in notes payable, net	73.0	(676.0)	662.0
Proceeds --
Long-term debt issuances	7,029.0	3,169.0	2,938.0
Common stock issuances	256.0	806.0	695.0
Interest-bearing refundable deposit related to asset sale	0.0	125.0	0.0
Short-term borrowings	755.0	0.0	0.0
Redemptions and repurchases --
Long-term debt	(3,604.0)	(816.0)	(2,830.0)
Common stock repurchased	(115.0)	(5.0)	(20.0)
Interest-bearing refundable deposits	(275.0)	0.0	0.0
Preferred and preference stock	(412.0)	0.0	0.0
Short-term borrowings	(255.0)	0.0	0.0
Capital contributions from noncontrolling interests	341.0	8.0	17.0
Payment of common stock dividends	(1,959.0)	(1,866.0)	(1,762.0)
Payment of dividends on preferred and preference stock of subsidiaries	(59.0)	(68.0)	(66.0)
Other financing activities	(75.0)	(33.0)	42.0
Net cash provided from (used for) financing activities	1,700.0	644.0	(324.0)
Net Change in Cash and Cash Equivalents	694.0	51.0	31.0
Cash and Cash Equivalents at Beginning of Year	710.0	659.0	628.0
Cash and Cash Equivalents at End of Year	1,404.0	710.0	659.0
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	809.0	732.0	759.0
Income taxes (net of refunds)	(9.0)	272.0	139.0
Alabama Power [Member]
Operating Activities:
Net Income (Loss)	811.0	800.0	751.0
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	780.0	724.0	816.0
Deferred income taxes	388.0	270.0	198.0
Allowance for equity funds used during construction	(60.0)	(49.0)	(32.0)
Pension, postretirement, and other employee benefits	20.0	(61.0)	9.0
Stock based compensation expense	15.0	11.0	10.0
Amortization of Deferred Investment Tax Credits	(8.0)	(8.0)	(8.0)
Other, net	(20.0)	17.0	(38.0)
Changes in certain current assets and liabilities --
-Receivables	(160.0)	(58.0)	2.0
-Fossil fuel stock	28.0	61.0	146.0
-Materials and supplies	15.0	(17.0)	19.0
-Other current assets	(3.0)	(11.0)	5.0
-Accounts payable	3.0	157.0	35.0
-Accrued taxes	138.0	(199.0)	(23.0)
-Accrued compensation	(16.0)	50.0	(23.0)
-Retail fuel cost over-recovery—short-term	191.0	5.0	42.0
-Other current liabilities	12.0	9.0	(3.0)
Net cash provided from operating activities	2,142.0	1,709.0	1,914.0
Investing Activities:
Property additions	(1,367.0)	(1,457.0)	(1,107.0)
Nuclear decommissioning trust fund purchases	(439.0)	(245.0)	(280.0)
Nuclear decommissioning trust fund sales	438.0	244.0	279.0
Cost of removal, net of salvage	(71.0)	(77.0)	(47.0)
Change in construction payables	(15.0)	(10.0)	(13.0)
Other investing activities	(34.0)	(22.0)	26.0
Net cash used for investing activities	(1,488.0)	(1,567.0)	(1,142.0)
Proceeds --
Capital contributions from parent company	22.0	28.0	24.0
Pollution control revenue bonds issuances and remarketings	80.0	254.0	0.0
Senior note issuances	975.0	400.0	300.0
Redemptions and repurchases --
Preferred and preference stock	(412.0)	0.0	0.0
Pollution control revenue bonds	(134.0)	(254.0)	0.0
Senior notes	(650.0)	0.0	(250.0)
Payment of preferred and preference stock dividends	(31.0)	(39.0)	(39.0)
Payment of common stock dividends	(571.0)	(550.0)	(644.0)
Other financing activities	(12.0)	(3.0)	(5.0)
Net cash provided from (used for) financing activities	(733.0)	(164.0)	(614.0)
Net Change in Cash and Cash Equivalents	(79.0)	(22.0)	158.0
Cash and Cash Equivalents at Beginning of Year	273.0	295.0	137.0
Cash and Cash Equivalents at End of Year	194.0	273.0	295.0
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	250.0	231.0	243.0
Income taxes (net of refunds)	121.0	436.0	296.0
Noncash transactions -
Accrued property additions at year-end	121.0	8.0	18.0
Georgia Power [Member]
Operating Activities:
Net Income (Loss)	1,277.0	1,242.0	1,191.0
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	1,029.0	1,019.0	979.0
Deferred income taxes	173.0	352.0	476.0
Allowance for equity funds used during construction	(40.0)	(45.0)	(30.0)
Retail fuel cost-recovery - long-term	106.0	(44.0)	(123.0)
Pension, postretirement, and other employee benefits	40.0	19.0	66.0
Pension and postretirement funding	(7.0)	(156.0)	(8.0)
Amortization of Deferred Investment Tax Credits	(10.0)	(10.0)	(5.0)
Other, net	(59.0)	39.0	38.0
Changes in certain current assets and liabilities --
-Receivables	187.0	(248.0)	(58.0)
-Fossil fuel stock	37.0	303.0	250.0
-Prepaid income taxes	89.0	(216.0)	(17.0)
-Other current assets	(62.0)	(37.0)	40.0
-Accounts payable	(259.0)	16.0	67.0
-Accrued taxes	25.0	17.0	(14.0)
-Accrued compensation	(17.0)	62.0	(37.0)
-Retail fuel cost over-recovery—short-term	10.0	(14.0)	(49.0)
-Other current liabilities	(12.0)	54.0	(5.0)
Net cash provided from operating activities	2,517.0	2,363.0	2,766.0
Investing Activities:
Property additions	(2,091.0)	(2,023.0)	(1,743.0)
Investment in restricted cash from pollution control bonds	0.0	0.0	(89.0)
Distribution of restricted cash from pollution control revenue bonds	0.0	0.0	89.0
Nuclear decommissioning trust fund purchases	(985.0)	(671.0)	(706.0)
Nuclear decommissioning trust fund sales	980.0	669.0	705.0
Cost of removal, net of salvage	(71.0)	(65.0)	(59.0)
Change in construction payables, net of joint owner portion	217.0	(54.0)	(67.0)
Prepaid long-term service agreement	(66.0)	(70.0)	(18.0)
Sale of property	70.0	7.0	7.0
Other investing activities	2.0	1.0	(9.0)
Net cash used for investing activities	(1,944.0)	(2,206.0)	(1,890.0)
Financing Activities:
Increase (decrease) in notes payable, net	2.0	(891.0)	1,047.0
Proceeds --
Capital contributions from parent company	62.0	549.0	37.0
Pollution control revenue bonds issuances and remarketings	409.0	40.0	194.0
Senior note issuances	500.0	0.0	850.0
Federal Financing Bank Loan	1,000.0	1,200.0	0.0
Short-term borrowings	250.0	0.0	0.0
Redemptions and repurchases --
Pollution control revenue bonds	(268.0)	(37.0)	(298.0)
Senior notes	(1,175.0)	0.0	(1,775.0)
Short-term borrowings	(250.0)	0.0	0.0
Payment of preferred and preference stock dividends	(17.0)	(17.0)	(17.0)
Payment of common stock dividends	(1,034.0)	(954.0)	(907.0)
FFB loan issuance costs	0.0	(49.0)	(5.0)
Other financing activities	(9.0)	(4.0)	(17.0)
Net cash provided from (used for) financing activities	(530.0)	(163.0)	(891.0)
Net Change in Cash and Cash Equivalents	43.0	(6.0)	(15.0)
Cash and Cash Equivalents at Beginning of Year	24.0	30.0	45.0
Cash and Cash Equivalents at End of Year	67.0	24.0	30.0
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	353.0	319.0	344.0
Income taxes (net of refunds)	506.0	507.0	298.0
Noncash transactions -
Accrued property additions at year-end	387.0	154.0	208.0
Capital lease obligation	149.0	0.0	0.0
Gulf Power [Member]
Operating Activities:
Net Income (Loss)	157.0	149.0	132.0
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	152.0	153.0	156.0
Deferred income taxes	90.0	65.0	77.0
Allowance for equity funds used during construction	(13.0)	(12.0)	(6.0)
Pension, postretirement, and other employee benefits	10.0	(23.0)	11.0
Amortization of Deferred Investment Tax Credits	(1.0)	0.0	(1.4)
Other, net	7.0	2.0	9.0
Changes in certain current assets and liabilities --
-Receivables	33.0	(17.0)	(49.0)
-Fossil fuel stock	(6.0)	34.0	19.0
-Prepaid income taxes	32.0	(19.0)	16.0
-Other current assets	(2.0)	(2.0)	(1.0)
-Accounts payable	(22.0)	8.0	(7.0)
-Accrued compensation	2.0	11.0	(3.0)
-Over recovered regulatory clause revenues	22.0	0.0	(17.0)
-Other current liabilities	(2.0)	(5.0)	(6.0)
Net cash provided from operating activities	460.0	344.0	331.0
Investing Activities:
Property additions	(235.0)	(348.0)	(293.0)
Cost of removal, net of salvage	(10.0)	(13.0)	(14.0)
Change in construction payables	(28.0)	12.0	7.0
Payments pursuant to long-term service agreements	(8.0)	(8.0)	(7.0)
Other investing activities	0.0	(1.0)	0.0
Net cash used for investing activities	(281.0)	(358.0)	(307.0)
Financing Activities:
Increase (decrease) in notes payable, net	32.0	(26.0)	12.0
Proceeds --
Common stock issuances	20.0	50.0	40.0
Capital contributions from parent company	4.0	4.0	3.0
Preference stock	0.0	0.0	50.0
Pollution control revenue bonds issuances and remarketings	13.0	42.0	63.0
Senior note issuances	0.0	200.0	90.0
Redemptions and repurchases --
Pollution control revenue bonds	(13.0)	(29.0)	(76.0)
Senior notes	(60.0)	(75.0)	(90.0)
Payment of preferred and preference stock dividends	(9.0)	(9.0)	(7.0)
Payment of common stock dividends	(130.0)	(123.0)	(115.0)
Other financing activities	(1.0)	(3.0)	(4.0)
Net cash provided from (used for) financing activities	(144.0)	31.0	(34.0)
Net Change in Cash and Cash Equivalents	35.0	17.0	(10.0)
Cash and Cash Equivalents at Beginning of Year	39.0	22.0	32.0
Cash and Cash Equivalents at End of Year	74.0	39.0	22.0
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	52.0	48.0	53.0
Income taxes (net of refunds)	(7.0)	44.0	(11.0)
Noncash transactions -
Accrued property additions at year-end	20.0	42.0	32.0
Mississippi Power [Member]
Operating Activities:
Net Income (Loss)	(6.0)	(327.0)	(475.0)
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	126.0	104.0	92.0
Deferred income taxes	777.0	145.0	(396.0)
Investment tax credits	(210.0)	(38.0)	144.0
Allowance for equity funds used during construction	(110.0)	(136.0)	(122.0)
Pension, postretirement, and other employee benefits	10.0	(29.0)	14.0
Regulatory assets associated with Kemper IGCC	(61.0)	(72.0)	(35.0)
Estimated loss on Kemper IGCC	365.0	868.0	1,102.0
Income taxes receivable, non-current	(544.0)	0.0	0.0
Amortization of Deferred Investment Tax Credits	(1.0)
Other, net	(2.0)	18.0	107.0
Changes in certain current assets and liabilities --
-Receivables	28.0	(22.0)	(25.0)
-Fossil fuel stock	(4.0)	13.0	63.0
-Materials and supplies	(13.0)	(15.0)	(11.0)
-Prepaid income taxes	(35.0)	(50.0)	17.0
-Other current assets	(1.0)	(4.0)	(4.0)
-Accounts payable	(34.0)	33.0	13.0
-Accrued interest	(2.0)	29.0	17.0
-Accrued taxes	(11.0)	39.0	11.0
-Over recovered regulatory clause revenues	96.0	(18.0)	(59.0)
-Mirror CWIP	(271.0)	180.0	0.0
-Customer liability associated with Kemper refunds	73.0	0.0	0.0
-Other current liabilities	2.0	17.0	(5.0)
Net cash provided from operating activities	173.0	735.0	448.0
Investing Activities:
Property additions	(857.0)	(1,257.0)	(1,641.0)
Investment in restricted cash	0.0	(11.0)	0.0
Distribution of restricted cash	0.0	11.0	0.0
Cost of removal, net of salvage	(14.0)	(13.0)	(10.0)
Change in construction payables	(9.0)	(50.0)	(50.0)
Proceeds from asset sales	0.0	0.0	79.0
Other investing activities	(26.0)	(20.0)	19.0
Net cash used for investing activities	(906.0)	(1,340.0)	(1,603.0)
Proceeds --
Capital contributions from parent company	277.0	451.0	1,077.0
Bonds-Other	0.0	23.0	42.0
Interest-bearing refundable deposit related to asset sale	0.0	125.0	0.0
Long-term debt issuance to parent company	275.0	220.0	0.0
Other long-term debt issuances	0.0	250.0	475.0
Short-term borrowings	505.0	0.0	0.0
Redemptions and repurchases --
Bonds-Other	0.0	(34.0)	(83.0)
Senior notes	0.0	0.0	(50.0)
Other long-term debt	(350.0)	(220.0)	(125.0)
Return of paid in capital	0.0	(220.0)	(105.0)
Payment of preferred and preference stock dividends	(2.0)	(2.0)	(2.0)
Payment of common stock dividends	0.0	0.0	(72.0)
Other financing activities	(7.0)	0.0	(2.0)
Net cash provided from (used for) financing activities	698.0	593.0	1,155.0
Net Change in Cash and Cash Equivalents	(35.0)	(12.0)	0.0
Cash and Cash Equivalents at Beginning of Year	133.0	145.0	145.0
Cash and Cash Equivalents at End of Year	98.0	133.0	145.0
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	45.0	7.0	20.0
Income taxes (net of refunds)	(33.0)	(379.0)	(134.0)
Noncash transactions -
Accrued property additions at year-end	105.0	114.0	165.0
Capital lease obligation	0.0	0.0	83.0
Issuance of Promissory note to parent related to repayment of interest-bearing refundable deposits and accrued interest	301.0	0.0	0.0
Southern Power [Member]
Operating Activities:
Net Income (Loss)	229.0	175.0	166.0
Adjustments to reconcile net income to net cash provided from operating activities --
Depreciation and amortization, total	254.0	225.0	183.0
Deferred income taxes	42.0	(168.0)	171.0
Investment tax credits	162.0	74.0	158.0
Amortization of Deferred Investment Tax Credits	(19.0)	(11.0)	(6.0)
Deferred revenues	(15.0)	(21.0)	(18.0)
Increase (Decrease) in Accrued Taxes Payable	109.0	0.0	0.0
Other, net	13.0	11.0	4.0
Changes in certain current assets and liabilities --
-Receivables	18.0	(26.0)	(11.0)
-Prepaid income taxes	(26.0)	35.0	(30.0)
-Other current assets	(4.0)	(8.0)	(8.0)
-Accounts payable	(19.0)	30.0	(12.0)
-Accrued taxes	269.0	284.0	0.0
-Other current liabilities	(10.0)	3.0	7.0
Net cash provided from operating activities	1,003.0	603.0	604.0
Investing Activities:
Plant acquisitions	(1,719.0)	(731.0)	(132.0)
Property additions	(1,005.0)	(21.0)	(501.0)
Investment in restricted cash	(159.0)	0.0	0.0
Distribution of restricted cash	154.0	0.0	0.0
Change in construction payables, net of joint owner portion	251.0	0.0	(4.0)
Payments pursuant to long-term service agreements	(82.0)	(61.0)	(57.0)
Other investing activities	22.0	(1.0)	(2.0)
Net cash used for investing activities	(2,538.0)	(814.0)	(696.0)
Financing Activities:
Increase (decrease) in notes payable, net	(58.0)	195.0	(71.0)
Proceeds --
Capital contributions from parent company	646.0	146.0	1.0
Senior note issuances	1,650.0	0.0	300.0
Other long-term debt issuances	402.0	10.0	24.0
Redemptions and repurchases --
Senior notes	(525.0)	0.0	0.0
Other long-term debt	(4.0)	(10.0)	(9.0)
Distributions to noncontrolling interests	(18.0)	(1.0)	(1.0)
Capital contributions from noncontrolling interests	341.0	8.0	17.0
Payment of common stock dividends	(131.0)	(131.0)	(129.0)
Other financing activities	(13.0)	0.0	0.0
Net cash provided from (used for) financing activities	2,290.0	217.0	132.0
Net Change in Cash and Cash Equivalents	755.0	6.0	40.0
Cash and Cash Equivalents at Beginning of Year	75.0	69.0	29.0
Cash and Cash Equivalents at End of Year	830.0	75.0	69.0
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	74.0	85.0	60.0
Income taxes (net of refunds)	(518.0)	(220.0)	(226.0)
Noncash transactions -
Accrued property additions at year-end	257.0	1.0	6.0
Acquisitions	0.0	229.0	0.0
Capital contributions from noncontrolling interests	$ 0.0	$ 221.0	$ 0.0