Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating Activities:
Net income (loss)	$ 2,031	$ 427
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	2,647	2,564
Deferred income taxes	(286)	15
Allowance for equity funds used during construction	(99)	(133)
Pension, postretirement, and other employee benefits	(60)	(64)
Settlement of asset retirement obligations	(160)	(137)
Estimated loss on Plant Vogtle Units 3 and 4	1,105	3,155
Stock based compensation expense	108	95
Estimated loss on plants under construction	1,081	3,148
Gain on dispositions, net	(324)	(22)
Impairment charges	197	0
Gain on dispositions, net	(317)	(19)
Goodwill impairment	42
Other, net	(21)	(80)
Changes in certain current assets and liabilities —
-Receivables	37	423
-Prepayments	14	(39)
-Natural gas for sale	87	0
-Other current assets	(90)	(66)
-Accounts payable	(248)	(467)
-Accrued taxes	839	157
-Accrued compensation	(138)	(230)
-Retail fuel cost over recovery	36	(211)
-Other current liabilities	(67)	(129)
Net cash provided from operating activities	5,584	5,251
Investing Activities:
Business acquisitions, net of cash acquired	(64)	(1,016)
Property additions	(5,793)	(5,242)
Nuclear decommissioning trust fund purchases	(846)	(585)
Nuclear decommissioning trust fund sales	840	580
Asset dispositions	2,773	66
Cost of removal, net of salvage	(252)	(208)
Change in construction payables, net	91	120
Investment in unconsolidated subsidiaries	(93)	(134)
Payments pursuant to LTSAs	(157)	(189)
Other investing activities	1	(77)
Net cash provided from (used for) investing activities	(3,500)	(6,685)
Financing Activities:
Increase (decrease) in notes payable, net	(1,225)	(515)
Proceeds —
Long-term debt	1,950	4,068
Common stock	878	613
Preferred stock	0	250
Short-term borrowings	3,150	1,263
Redemptions and repurchases —
Long-term debt	(4,498)	(1,981)
Preferred and preference stock	0	(150)
Short-term borrowings	(1,800)	(409)
Distributions to noncontrolling interests	(86)	(89)
Capital contributions from noncontrolling interests	1,333	79
Payment of common stock dividends	(1,805)	(1,716)
Other financing activities	(237)	(113)
Net cash provided from (used for) financing activities	(2,340)	1,300
Net Change in Cash, Cash Equivalents, and Restricted Cash	(256)	(134)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	2,147	1,992
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,891	1,858
Cash paid (received) during the period for —
Interest, net of amounts capitalized	1,402	1,286
Income taxes, net	137	(187)
Noncash transactions — Accrued property additions at end of period	1,125	805
ALABAMA POWER CO
Operating Activities:
Net income (loss)	868	743
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	683	666
Deferred income taxes	104	260
Allowance for equity funds used during construction	(43)	(27)
Settlement of asset retirement obligations	(31)	(20)
Other, net	(6)	59
Changes in certain current assets and liabilities —
-Receivables	(207)	(163)
-Prepayments	(26)	(28)
-Materials and supplies	(69)	(29)
-Other current assets	66	33
-Accounts payable	(194)	(125)
-Accrued taxes	225	159
-Accrued compensation	(41)	(48)
-Retail fuel cost over recovery	0	(76)
-Other current liabilities	60	7
Net cash provided from operating activities	1,389	1,411
Investing Activities:
Property additions	(1,529)	(1,211)
Nuclear decommissioning trust fund purchases	(207)	(174)
Nuclear decommissioning trust fund sales	207	174
Cost of removal, net of salvage	(78)	(82)
Change in construction payables, net	30	105
Other investing activities	(23)	(29)
Net cash provided from (used for) investing activities	(1,600)	(1,217)
Proceeds —
Preferred stock	0	250
Capital contributions from parent company	495	337
Senior notes	500	550
Redemptions and repurchases —
Senior notes	0	(200)
Pollution control revenue bonds	0	(36)
Payment of common stock dividends	(602)	(536)
Other financing activities	(24)	(26)
Net cash provided from (used for) financing activities	369	339
Net Change in Cash, Cash Equivalents, and Restricted Cash	158	533
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	544	420
Cash, Cash Equivalents, and Restricted Cash at End of Period	702	953
Cash paid (received) during the period for —
Interest, net of amounts capitalized	220	217
Income taxes, net	30	146
Noncash transactions — Accrued property additions at end of period	275	189
GEORGIA POWER CO
Operating Activities:
Net income (loss)	621	1,201
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	854	821
Deferred income taxes	(185)	328
Allowance for equity funds used during construction	(50)	(29)
Pension, postretirement, and other employee benefits	(46)	(42)
Settlement of asset retirement obligations	(82)	(95)
Estimated loss on Plant Vogtle Units 3 and 4	1,060	0
Other, net	9	(51)
Changes in certain current assets and liabilities —
-Receivables	(205)	(254)
-Fossil fuel stock	70	(2)
-Prepaid income taxes	231	(5)
-Other current assets	(36)	(24)
-Accounts payable	109	(161)
-Accrued taxes	26	(52)
-Accrued compensation	(32)	(60)
-Retail fuel cost over recovery	0	(84)
-Other current liabilities	(111)	(11)
Net cash provided from operating activities	2,233	1,480
Investing Activities:
Property additions	(2,276)	(1,907)
Nuclear decommissioning trust fund purchases	(638)	(411)
Nuclear decommissioning trust fund sales	633	406
Asset dispositions	138	63
Cost of removal, net of salvage	(71)	(54)
Change in construction payables, net of joint owner portion	72	180
Payments pursuant to LTSAs	(52)	(59)
Other investing activities	(19)	(52)
Net cash provided from (used for) investing activities	(2,213)	(1,834)
Financing Activities:
Increase (decrease) in notes payable, net	102	(391)
Proceeds —
Short-term borrowings	0	700
Capital contributions from parent company	2,335	412
Senior notes	0	1,350
Other long-term debt	0	370
Redemptions and repurchases —
Senior notes	(1,000)	(450)
Pollution control revenue bonds	(469)	(65)
Other long-term debt	(100)	0
Short-term borrowings	(150)	(300)
Payment of common stock dividends	(1,043)	(961)
Premiums on redemption and repurchases of senior notes	(152)	0
Other financing activities	(15)	(48)
Net cash provided from (used for) financing activities	(492)	617
Net Change in Cash, Cash Equivalents, and Restricted Cash	(472)	263
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	852	3
Cash, Cash Equivalents, and Restricted Cash at End of Period	380	266
Cash paid (received) during the period for —
Interest, net of amounts capitalized	315	284
Income taxes, net	141	369
Noncash transactions — Accrued property additions at end of period	670	470
GULF POWER CO
Operating Activities:
Net income (loss)	147	121
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	147	100
Deferred income taxes	(45)	57
Loss on Plant Scherer Unit 3	0	33
Other, net	(10)	(5)
Changes in certain current assets and liabilities —
-Receivables	(5)	(65)
-Other current assets	9	18
-Accrued taxes	35	21
-Accrued compensation	(9)	(10)
-Over recovered regulatory clause revenues	39	(8)
-Other current liabilities	10	10
Net cash provided from operating activities	318	272
Investing Activities:
Property additions	(207)	(142)
Cost of removal, net of salvage	(18)	(16)
Change in construction payables, net	5	(9)
Other investing activities	(18)	(6)
Net cash provided from (used for) investing activities	(238)	(173)
Financing Activities:
Increase (decrease) in notes payable, net	5	(268)
Proceeds —
Common stock	0	175
Capital contributions from parent company	40	7
Senior notes	0	300
Redemptions and repurchases —
Preferred and preference stock	0	(150)
Senior notes	0	(85)
Payment of common stock dividends	(115)	(94)
Other financing activities	(1)	(3)
Net cash provided from (used for) financing activities	(71)	(118)
Net Change in Cash, Cash Equivalents, and Restricted Cash	9	(19)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	28	56
Cash, Cash Equivalents, and Restricted Cash at End of Period	37	37
Cash paid (received) during the period for —
Interest, net of amounts capitalized	26	24
Income taxes, net	28	19
Noncash transactions — Accrued property additions at end of period	31	25
MISSISSIPPI POWER CO
Operating Activities:
Net income (loss)	87	(2,033)
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	129	144
Deferred income taxes	420	(1,159)
Allowance for equity funds used during construction	0	(72)
Estimated loss on Plant Vogtle Units 3 and 4	45	3,155
Estimated loss on plants under construction	21	3,148
Other, net	5	(26)
Changes in certain current assets and liabilities —
-Receivables	(46)	438
-Fossil fuel stock	(2)	21
-Other current assets	(5)	(9)
-Accounts payable	(3)	(21)
-Accrued taxes	57	20
-Accrued compensation	(9)	(12)
-Over recovered regulatory clause revenues	20	(47)
-Other current liabilities	(18)	(31)
Net cash provided from operating activities	656	361
Investing Activities:
Property additions	(117)	(411)
Change in construction payables, net	(9)	(47)
Payments pursuant to LTSAs	(28)	(10)
Other investing activities	(16)	(15)
Net cash provided from (used for) investing activities	(170)	(483)
Financing Activities:
Increase (decrease) in notes payable, net	(4)	(23)
Proceeds —
Short-term borrowings	300	113
Capital contributions from parent company	(2)	1,002
Senior notes	600	0
Long-term debt to parent company	0	40
Redemptions and repurchases —
Pollution control revenue bonds	(43)	0
Other long-term debt	(900)	(300)
Short-term borrowings	(300)	(109)
Long-term debt to parent company	0	(591)
Other financing activities	(6)	(3)
Net cash provided from (used for) financing activities	(355)	129
Net Change in Cash, Cash Equivalents, and Restricted Cash	131	7
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	248	224
Cash, Cash Equivalents, and Restricted Cash at End of Period	379	231
Cash paid (received) during the period for —
Interest, net of amounts capitalized	57	45
Income taxes, net	(483)	(209)
Noncash transactions — Accrued property additions at end of period	23	32
SOUTHERN POWER CO
Operating Activities:
Net income (loss)	306	324
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	394	404
Deferred income taxes	(337)	240
Amortization of investment tax credits	(43)	(42)
Income taxes receivable, non-current	(12)	(42)
Impairment charges	155	0
Other, net	10	(4)
Changes in certain current assets and liabilities —
-Receivables	(41)	(77)
-Prepaid income taxes	5	24
-Other current assets	1	14
-Accounts payable	(27)	(31)
-Accrued taxes	256	79
-Other current liabilities	(1)	5
Net cash provided from operating activities	666	894
Investing Activities:
Business acquisitions, net of cash acquired	(64)	(1,016)
Property additions	(226)	(218)
Change in construction payables, net	3	(166)
Payments pursuant to LTSAs	(57)	(99)
Other investing activities	20	7
Net cash provided from (used for) investing activities	(324)	(1,492)
Financing Activities:
Increase (decrease) in notes payable, net	(68)	(89)
Proceeds —
Short-term borrowings	200	0
Other long-term debt	0	43
Redemptions and repurchases —
Senior notes	(350)	0
Other long-term debt	(420)	(4)
Return of capital	(650)	0
Distributions to noncontrolling interests	(86)	(89)
Capital contributions from noncontrolling interests	1,333	79
Payment of common stock dividends	(234)	(238)
Other financing activities	(15)	(27)
Net cash provided from (used for) financing activities	(290)	(325)
Net Change in Cash, Cash Equivalents, and Restricted Cash	52	(923)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	140	1,112
Cash, Cash Equivalents, and Restricted Cash at End of Period	192	189
Cash paid (received) during the period for —
Interest, net of amounts capitalized	138	144
Income taxes, net	(102)	(343)
Noncash transactions — Accrued property additions at end of period	37	16
SOUTHERN Co GAS
Operating Activities:
Net income (loss)	294	303
Adjustments to reconcile net income (loss) to net cash provided from operating activities —
Depreciation and amortization, total	374	370
Deferred income taxes	(83)	265
Mark-to-market adjustments	23	(32)
Gain on dispositions, net	(317)	0
Goodwill impairment	42	0
Other, net	(41)	(46)
Changes in certain current assets and liabilities —
-Receivables	445	531
-Natural gas for sale	87	0
-Prepaid income taxes	(23)	(7)
-Other current assets	21	(42)
-Accounts payable	(59)	(169)
-Accrued taxes	(64)	(24)
-Accrued compensation	2	(11)
-Other current liabilities	35	8
Net cash provided from operating activities	736	1,146
Investing Activities:
Property additions	(1,029)	(1,093)
Asset dispositions	2,631	0
Cost of removal, net of salvage	(67)	(45)
Change in construction payables, net	(14)	49
Investment in unconsolidated subsidiaries	(90)	(128)
Other investing activities	18	28
Net cash provided from (used for) investing activities	1,449	(1,189)
Financing Activities:
Increase (decrease) in notes payable, net	(1,382)	(323)
Proceeds —
First mortgage bonds	100	200
Capital contributions from parent company	35	79
Senior notes	0	450
Redemptions and repurchases —
Long-term debt	(200)	0
Return of capital	(400)	0
Payment of common stock dividends	(351)	(332)
Other financing activities	(3)	(29)
Net cash provided from (used for) financing activities	(2,201)	45
Net Change in Cash, Cash Equivalents, and Restricted Cash	(16)	2
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	78	24
Cash, Cash Equivalents, and Restricted Cash at End of Period	62	26
Cash paid (received) during the period for —
Interest, net of amounts capitalized	175	146
Income taxes, net	682	17
Noncash transactions — Accrued property additions at end of period	$ 121	$ 112