The Southern Company (SO) 10-Q 30 Jul 20 2020 Q2 Quarterly report Financial data

Cover Page

Cover Page	6 Months Ended
	Jun. 30, 2020shares
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity File Number	1-3526
Entity Registrant Name	The Southern Company
Entity Tax Identification Number	58-0690070
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	30 Ivan Allen Jr. Boulevard, N.W.
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30308
City Area Code	404
Local Phone Number	506-5000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	1,056,130,748
Entity Central Index Key	0000092122
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Emerging Growth Company	false
Entity Small Business	false
Common Stock, par value $5 per share
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $5 per share
Trading Symbol	SO
Security Exchange Name	NYSE
Series 2015A 6.25% Junior Subordinated Notes due 2075
Document Information [Line Items]
Title of 12(b) Security	Series 2015A 6.25% Junior Subordinated Notes due 2075
Trading Symbol	SOJA
Security Exchange Name	NYSE
Series 2016A 5.25% Junior Subordinated Notes due 2076
Document Information [Line Items]
Title of 12(b) Security	Series 2016A 5.25% Junior Subordinated Notes due 2076
Trading Symbol	SOJB
Security Exchange Name	NYSE
Series 2017B 5.25% Junior Subordinated Notes due 2077
Document Information [Line Items]
Title of 12(b) Security	Series 2017B 5.25% Junior Subordinated Notes due 2077
Trading Symbol	SOJC
Security Exchange Name	NYSE
2019 Series A Corporate Units
Document Information [Line Items]
Title of 12(b) Security	2019 Series A Corporate Units
Trading Symbol	SOLN
Security Exchange Name	NYSE
Series 2020A 4.95% Junior Subordinated Notes due 2080
Document Information [Line Items]
Title of 12(b) Security	Series 2020A 4.95% Junior Subordinated Notes due 2080
Trading Symbol	SOJD
Security Exchange Name	NYSE
ALABAMA POWER CO
Document Information [Line Items]
Entity File Number	1-3164
Entity Registrant Name	Alabama Power Company
Entity Tax Identification Number	63-0004250
Entity Incorporation, State or Country Code	AL
Entity Address, Address Line One	600 North 18th Street
Entity Address, City or Town	Birmingham
Entity Address, State or Province	AL
Entity Address, Postal Zip Code	35203
City Area Code	205
Local Phone Number	257-1000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	30,537,500
Entity Central Index Key	0000003153
Entity Emerging Growth Company	false
Entity Small Business	false
ALABAMA POWER CO | 5.00% Series Class A Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	5.00% Series Class A Preferred Stock
Trading Symbol	ALP PR Q
Security Exchange Name	NYSE
GEORGIA POWER CO
Document Information [Line Items]
Entity File Number	1-6468
Entity Registrant Name	Georgia Power Company
Entity Tax Identification Number	58-0257110
Entity Incorporation, State or Country Code	GA
Entity Address, Address Line One	241 Ralph McGill Boulevard, N.E.
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30308
City Area Code	404
Local Phone Number	506-6526
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	9,261,500
Entity Central Index Key	0000041091
Entity Emerging Growth Company	false
Entity Small Business	false
GEORGIA POWER CO | Series 2017A 5.00% Junior Subordinated Notes due 2077
Document Information [Line Items]
Title of 12(b) Security	Series 2017A 5.00% Junior Subordinated Notes due 2077
Trading Symbol	GPJA
Security Exchange Name	NYSE
MISSISSIPPI POWER CO
Document Information [Line Items]
Entity File Number	001-11229
Entity Registrant Name	Mississippi Power Company
Entity Tax Identification Number	64-0205820
Entity Incorporation, State or Country Code	MS
Entity Address, Address Line One	2992 West Beach Boulevard
Entity Address, City or Town	Gulfport
Entity Address, State or Province	MS
Entity Address, Postal Zip Code	39501
City Area Code	228
Local Phone Number	864-1211
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	1,121,000
Entity Central Index Key	0000066904
Entity Emerging Growth Company	false
Entity Small Business	false
SOUTHERN POWER CO
Document Information [Line Items]
Entity File Number	001-37803
Entity Registrant Name	Southern Power Company
Entity Tax Identification Number	58-2598670
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	30 Ivan Allen Jr. Boulevard, N.W.
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30308
City Area Code	404
Local Phone Number	506-5000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	1,000
Entity Central Index Key	0001160661
Entity Emerging Growth Company	false
Entity Small Business	false
SOUTHERN POWER CO | Series 2016A 1.000% Senior Notes due 2022
Document Information [Line Items]
Title of 12(b) Security	Series 2016A 1.000% Senior Notes due 2022
Trading Symbol	SO/22B
Security Exchange Name	NYSE
SOUTHERN POWER CO | Series 2016B 1.850% Senior Notes due 2026
Document Information [Line Items]
Title of 12(b) Security	Series 2016B 1.850% Senior Notes due 2026
Trading Symbol	SO/26A
Security Exchange Name	NYSE
SOUTHERN Co GAS
Document Information [Line Items]
Entity File Number	1-14174
Entity Registrant Name	Southern Company Gas
Entity Tax Identification Number	58-2210952
Entity Incorporation, State or Country Code	GA
Entity Address, Address Line One	Ten Peachtree Place, N.E.
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30309
City Area Code	404
Local Phone Number	584-4000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	100
Entity Central Index Key	0001004155
Entity Emerging Growth Company	false
Entity Small Business	false

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating Revenues:
Operating revenues	$ 4,620	$ 5,098	$ 9,638	$ 10,510
Operating Expenses:
Total cost of sales	144	191	583	877
Other operations and maintenance	1,203	1,320	2,498	2,634
Depreciation and amortization	873	755	1,730	1,506
Taxes other than income taxes	298	299	629	628
Estimated loss on Plant Vogtle Units 3 and 4	149	0	149	0
(Gain) loss on dispositions, net	0	(8)	(39)	(2,506)
Total operating expenses	3,562	3,756	7,317	5,477
Operating Income	1,058	1,342	2,321	5,033
Other Income and (Expense):
Allowance for equity funds used during construction	35	31	68	63
Earnings from equity method investments	30	33	72	81
Interest expense, net of amounts capitalized	(444)	(429)	(900)	(859)
Impairment of leveraged lease	(154)	0	(154)	0
Other income (expense), net	101	99	204	176
Total other income and (expense)	(432)	(266)	(710)	(539)
Earnings Before Income Taxes	626	1,076	1,611	4,494
Income taxes (benefit)	5	145	150	1,505
Consolidated Net Income	621	931	1,461	2,989
Dividends on preferred stock of subsidiaries	4	3	7	7
Net income (loss) attributable to noncontrolling interests	5	29	(26)	0
Net Income	$ 612	$ 899	$ 1,480	$ 2,982
Earnings per share -
Basic (in dollars per share)	$ 0.58	$ 0.86	$ 1.40	$ 2.86
Diluted (in dollars per share)	$ 0.58	$ 0.85	$ 1.39	$ 2.84
Average number of shares of common stock outstanding (in millions)
Basic (in shares)	1,058	1,044	1,057	1,041
Diluted (in shares)	1,063	1,052	1,065	1,049
Retail electric revenues
Operating Revenues:
Operating revenues	$ 3,182	$ 3,540	$ 6,260	$ 6,623
Wholesale electric revenues
Operating Revenues:
Operating revenues	472	542	889	1,041
Other electric revenues
Operating Revenues:
Operating revenues	168	161	320	331
Natural gas
Operating Revenues:
Operating revenues	636	689	1,885	2,163
Operating Expenses:
Total cost of sales	144	191	583	877
Other
Operating Revenues:
Operating revenues	162	166	284	352
Operating Expenses:
Total cost of sales	74	84	129	203
Fuel
Operating Expenses:
Total cost of sales	621	914	1,257	1,764
Purchased power
Operating Expenses:
Total cost of sales	200	201	381	371
Alternative revenue programs
Operating Revenues:
Operating revenues	(2)	1	7	0
ALABAMA POWER CO
Operating Revenues:
Operating revenues	1,365	1,513	2,716	2,921
Operating Expenses:
Other operations and maintenance	342	402	690	812
Depreciation and amortization	202	200	402	399
Taxes other than income taxes	102	98	208	200
Total operating expenses	924	1,068	1,853	2,138
Operating Income	441	445	863	783
Other Income and (Expense):
Allowance for equity funds used during construction	11	14	22	28
Interest expense, net of amounts capitalized	(83)	(82)	(171)	(165)
Other income (expense), net	26	11	48	25
Total other income and (expense)	(46)	(57)	(101)	(112)
Earnings Before Income Taxes	395	388	762	671
Income taxes (benefit)	93	89	177	151
Consolidated Net Income	302	299	585	520
Dividends on preferred stock of subsidiaries	4	3	7	7
Net Income	298	296	578	513
ALABAMA POWER CO | Retail electric revenues
Operating Revenues:
Operating revenues	1,223	1,378	2,427	2,592
ALABAMA POWER CO | Wholesale electric revenues
Operating Revenues:
Operating revenues	54	62	111	123
ALABAMA POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Operating revenues	7	4	26	63
ALABAMA POWER CO | Other
Operating Revenues:
Operating revenues	81	69	152	143
ALABAMA POWER CO | Fuel
Operating Expenses:
Total cost of sales	199	252	415	553
ALABAMA POWER CO | Purchased power
Operating Expenses:
Total cost of sales	49	47	89	84
ALABAMA POWER CO | Purchased power, affiliates
Operating Expenses:
Total cost of sales	30	69	49	90
GEORGIA POWER CO
Operating Revenues:
Operating revenues	1,928	2,117	3,754	3,951
Operating Expenses:
Other operations and maintenance	463	463	928	913
Depreciation and amortization	354	244	707	483
Taxes other than income taxes	108	115	221	220
Estimated loss on Plant Vogtle Units 3 and 4	149	0	149	0
Total operating expenses	1,555	1,470	2,976	2,857
Operating Income	373	647	778	1,094
Other Income and (Expense):
Allowance for equity funds used during construction			40	31
Interest expense, net of amounts capitalized	(105)	(105)	(216)	(201)
Other income (expense), net	51	35	103	77
Total other income and (expense)	(54)	(70)	(113)	(124)
Earnings Before Income Taxes	319	577	665	970
Income taxes (benefit)	11	129	27	211
Consolidated Net Income	308	448	638	759
GEORGIA POWER CO | Retail electric revenues
Operating Revenues:
Operating revenues	1,760	1,946	3,435	3,614
GEORGIA POWER CO | Wholesale electric revenues
Operating Revenues:
Operating revenues	25	36	51	67
GEORGIA POWER CO | Other
Operating Revenues:
Operating revenues	143	135	268	270
GEORGIA POWER CO | Fuel
Operating Expenses:
Total cost of sales	226	390	458	689
GEORGIA POWER CO | Purchased power
Operating Expenses:
Total cost of sales	133	124	262	242
GEORGIA POWER CO | Purchased power, affiliates
Operating Expenses:
Total cost of sales	122	134	251	310
MISSISSIPPI POWER CO
Operating Revenues:
Operating revenues	283	313	559	600
Operating Expenses:
Other operations and maintenance	67	72	142	133
Depreciation and amortization	46	48	88	95
Taxes other than income taxes	30	28	59	55
Total operating expenses	233	259	463	490
Operating Income	50	54	96	110
Other Income and (Expense):
Interest expense, net of amounts capitalized	(15)	(17)	(31)	(35)
Other income (expense), net	6	5	14	11
Total other income and (expense)	(9)	(12)	(17)	(24)
Earnings Before Income Taxes	41	42	79	86
Income taxes (benefit)	2	5	8	12
Consolidated Net Income	39	37	71	74
MISSISSIPPI POWER CO | Retail electric revenues
Operating Revenues:
Operating revenues	199	215	398	418
MISSISSIPPI POWER CO | Wholesale electric revenues
Operating Revenues:
Operating revenues	52	57	103	114
MISSISSIPPI POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Operating revenues	25	37	47	58
MISSISSIPPI POWER CO | Other
Operating Revenues:
Operating revenues	7	4	11	10
MISSISSIPPI POWER CO | Fuel
Operating Expenses:
Total cost of sales	83	105	162	198
MISSISSIPPI POWER CO | Purchased power
Operating Expenses:
Total cost of sales	7	6	12	9
SOUTHERN POWER CO
Operating Revenues:
Operating revenues	439	510	814	953
Operating Expenses:
Other operations and maintenance	77	79	156	166
Depreciation and amortization	121	119	239	237
Taxes other than income taxes	10	11	19	21
(Gain) loss on dispositions, net	0	(23)	(39)	(23)
Total operating expenses	328	357	616	740
Operating Income	111	153	198	213
Other Income and (Expense):
Interest expense, net of amounts capitalized	(38)	(41)	(77)	(84)
Other income (expense), net	1	40	4	41
Total other income and (expense)	(37)	(1)	(73)	(43)
Earnings Before Income Taxes	74	152	125	170
Income taxes (benefit)	6	(51)	13	(60)
Consolidated Net Income	68	203	112	230
Net income (loss) attributable to noncontrolling interests	5	29	(26)	0
Net Income	63	174	138	230
SOUTHERN POWER CO | Wholesale electric revenues
Operating Revenues:
Operating revenues	343	390	629	743
SOUTHERN POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Operating revenues	92	117	178	204
SOUTHERN POWER CO | Other
Operating Revenues:
Operating revenues	4	3	7	6
SOUTHERN POWER CO | Fuel
Operating Expenses:
Total cost of sales	102	139	209	284
SOUTHERN POWER CO | Purchased power
Operating Expenses:
Total cost of sales	18	32	32	55
SOUTHERN Co GAS
Operating Revenues:
Operating revenues	636	689	1,885	2,163
Operating Expenses:
Other operations and maintenance	220	199	479	433
Depreciation and amortization	123	119	243	238
Taxes other than income taxes	47	46	118	128
Total operating expenses	534	555	1,423	1,676
Operating Income	102	134	462	487
Other Income and (Expense):
Earnings from equity method investments	30	31	72	80
Interest expense, net of amounts capitalized	(57)	(59)	(114)	(118)
Other income (expense), net	12	6	21	10
Total other income and (expense)	(15)	(22)	(21)	(28)
Earnings Before Income Taxes	87	112	441	459
Income taxes (benefit)	16	6	95	83
Consolidated Net Income	71	106	346	376
Net Income	71	106	346	376
SOUTHERN Co GAS | Natural gas
Operating Revenues:
Operating revenues	638	688	1,878	2,163
Operating Expenses:
Total cost of sales	144	191	583	877
SOUTHERN Co GAS | Alternative revenue programs
Operating Revenues:
Operating revenues	$ (2)	$ 1	$ 7	$ 0

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues	$ 4,620	$ 5,098	$ 9,638	$ 10,510
Cost, Product and Service [Extensible List]	us-gaap:NaturalGasUsRegulatedMember	us-gaap:NaturalGasUsRegulatedMember	us-gaap:NaturalGasUsRegulatedMember	us-gaap:NaturalGasUsRegulatedMember
Alternative revenue programs
Revenues	$ (2)	$ 1	$ 7	$ 0
SOUTHERN Co GAS
Revenues	636	689	1,885	2,163
Revenue taxes collected	22	23	69	78
SOUTHERN Co GAS | Alternative revenue programs
Revenues	$ (2)	$ 1	$ 7	$ 0

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net income	$ 621	$ 931	$ 1,461	$ 2,989
Qualifying hedges:
Changes in fair value, net of tax	10	(32)	(75)	(60)
Reclassification adjustment for amounts included in net income, net of tax	(9)	(3)	29	24
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	3	0	3	1
Total other comprehensive income (loss)	4	(35)	(43)	(35)
Comprehensive Income	625	896	1,418	2,954
Dividends on preferred stock of subsidiaries	4	3	7	7
Comprehensive income (loss) attributable to noncontrolling interests	5	29	(26)	0
Comprehensive Income (Loss) Attributable to Parent	616	864	1,437	2,947
ALABAMA POWER CO
Net income	302	299	585	520
Qualifying hedges:
Reclassification adjustment for amounts included in net income, net of tax	1	1	2	2
Pension and other postretirement benefit plans:
Total other comprehensive income (loss)	1	1	2	2
Comprehensive Income	303	300	587	522
Dividends on preferred stock of subsidiaries	4	3	7	7
GEORGIA POWER CO
Net income	308	448	638	759
Qualifying hedges:
Changes in fair value, net of tax	0	(28)	(2)	(28)
Reclassification adjustment for amounts included in net income, net of tax	2	1	3	1
Pension and other postretirement benefit plans:
Total other comprehensive income (loss)	2	(27)	1	(27)
Comprehensive Income	310	421	639	732
MISSISSIPPI POWER CO
Net income	39	37	71	74
Qualifying hedges:
Changes in fair value, net of tax	0	0	(1)	0
Reclassification adjustment for amounts included in net income, net of tax	0	0	1	1
Pension and other postretirement benefit plans:
Total other comprehensive income (loss)	0	0	0	1
Comprehensive Income	39	37	71	75
SOUTHERN POWER CO
Net income	68	203	112	230
Qualifying hedges:
Changes in fair value, net of tax	11	(1)	(50)	(30)
Reclassification adjustment for amounts included in net income, net of tax	(15)	(7)	13	17
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	1	0	1	0
Total other comprehensive income (loss)	(3)	(8)	(36)	(13)
Comprehensive Income	65	195	76	217
Comprehensive income (loss) attributable to noncontrolling interests	5	29	(26)	0
Comprehensive Income (Loss) Attributable to Parent	60	166	102	217
SOUTHERN Co GAS
Net income	71	106	346	376
Qualifying hedges:
Changes in fair value, net of tax	(1)	(3)	(21)	(3)
Reclassification adjustment for amounts included in net income, net of tax	1	0	6	0
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	0	0	0	(1)
Total other comprehensive income (loss)	0	(3)	(15)	(4)
Comprehensive Income	$ 71	$ 103	$ 331	$ 372

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Qualifying hedges:
Changes in fair value, tax	$ (4)	$ (11)	$ (26)	$ (21)
Reclassification adjustment for amounts included in net income, tax	(3)	(1)	10	8
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, tax	1	0	2	0
ALABAMA POWER CO
Qualifying hedges:
Reclassification adjustment for amounts included in net income, tax	0	0	1	1
GEORGIA POWER CO
Qualifying hedges:
Changes in fair value, tax	0	(9)	(1)	(9)
Reclassification adjustment for amounts included in net income, tax	1	0	1	0
MISSISSIPPI POWER CO
Qualifying hedges:
Changes in fair value, tax	0	0	0	0
Reclassification adjustment for amounts included in net income, tax	0	0	0	0
SOUTHERN POWER CO
Qualifying hedges:
Changes in fair value, tax	4	(1)	(17)	(10)
Reclassification adjustment for amounts included in net income, tax	(5)	(2)	5	6
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, tax	0	0	0	0
SOUTHERN Co GAS
Qualifying hedges:
Changes in fair value, tax	(1)	(1)	(8)	(1)
Reclassification adjustment for amounts included in net income, tax	0	0	2	0
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, tax	$ 0	$ (1)	$ 1	$ (1)

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating Activities:
Net income	$ 1,461	$ 2,989
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,916	1,623
Deferred income taxes	(218)	274
Utilization of federal investment tax credits	0	427
Allowance for equity funds used during construction	(68)	(63)
Pension, postretirement, and other employee benefits	(119)	(65)
Settlement of asset retirement obligations	(193)	(143)
Stock based compensation expense	84	75
Estimated loss on Plant Vogtle Units 3 and 4	149	0
Storm damage reserve accruals	117	23
Impairment charges	154	32
(Gain) loss on dispositions, net	(35)	(2,512)
Other, net	43	(3)
Changes in certain current assets and liabilities —
-Receivables	292	653
-Prepayments	(102)	(53)
-Natural gas for sale	182	255
-Other current assets	(253)	(18)
-Accounts payable	(467)	(1,045)
-Accrued taxes	258	511
-Accrued compensation	(347)	(312)
-Retail fuel cost over recovery	174	2
-Customer refunds	(223)	(35)
-Other current liabilities	42	(102)
Net cash provided from operating activities	2,847	2,513
Investing Activities:
Property additions	(3,202)	(3,484)
Nuclear decommissioning trust fund purchases	(524)	(405)
Nuclear decommissioning trust fund sales	519	400
Proceeds from dispositions and asset sales	983	5,000
Cost of removal, net of salvage	(130)	(197)
Change in construction payables, net	(103)	(107)
Investment in unconsolidated subsidiaries	(78)	(134)
Payments pursuant to LTSAs	(91)	(64)
Other investing activities	(29)	(7)
Net cash provided from (used for) investing activities	(2,655)	1,002
Financing Activities:
Increase (decrease) in notes payable, net		83
Decrease in notes payable, net	(1,170)
Proceeds —
Long-term debt	4,293	1,390
Common stock	59	452
Short-term borrowings	615	250
Redemptions and repurchases —
Long-term debt	(2,444)	(2,560)
Short-term borrowings	(190)	(1,850)
Distributions to noncontrolling interests	(118)	(82)
Capital contributions from noncontrolling interests	172	5
Payment of common stock dividends	(1,332)	(1,269)
Other financing activities	(170)	(67)
Net cash used for financing activities	(285)	(3,648)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(93)	(133)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	1,978	1,519
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,885	1,386
Cash paid (received) during the period for —
Interest, net of amounts capitalized	852	844
Income taxes, net	(8)	210
Accrued property additions at end of period	828	988
Right-of-use assets obtained under operating leases	87	55
Right-of-use assets obtained under finance leases	7	33
ALABAMA POWER CO
Operating Activities:
Net income	585	520
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	484	493
Deferred income taxes	38	138
Allowance for equity funds used during construction	(22)	(28)
Pension, postretirement, and other employee benefits	(50)	(13)
Settlement of asset retirement obligations	(100)	(43)
Other, net	45	(1)
Changes in certain current assets and liabilities —
-Prepayments	(62)	(59)
-Materials and supplies	(38)	5
-Other current assets	(65)	(4)
-Accounts payable	(232)	(246)
-Accrued taxes	197	8
-Accrued compensation	(75)	(88)
-Retail fuel cost over recovery	66	0
-Customer refunds	(64)	(1)
-Other current liabilities	(33)	14
Net cash provided from operating activities	674	695
Investing Activities:
Property additions	(686)	(833)
Nuclear decommissioning trust fund purchases	(160)	(139)
Nuclear decommissioning trust fund sales	160	139
Cost of removal, net of salvage	(29)	(48)
Change in construction payables, net	(53)	(103)
Other investing activities	(15)	(18)
Net cash provided from (used for) investing activities	(783)	(1,002)
Proceeds —
Pollution control revenue bonds	87	0
Capital contributions from parent company	610	1,254
Redemptions and repurchases —
Pollution control revenue bonds	(87)	0
Senior notes	0	(200)
Payment of common stock dividends	(479)	(422)
Other financing activities	(15)	(15)
Net cash used for financing activities	116	617
Net Change in Cash, Cash Equivalents, and Restricted Cash	7	310
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	894	313
Cash, Cash Equivalents, and Restricted Cash at End of Period	901	623
Cash paid (received) during the period for —
Interest, net of amounts capitalized	161	154
Income taxes, net	0	63
Accrued property additions at end of period	147	168
Right-of-use assets obtained under operating leases	2	5
Right-of-use assets obtained under finance leases	1	1
GEORGIA POWER CO
Operating Activities:
Net income	638	759
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	800	583
Deferred income taxes	(202)	153
Allowance for equity funds used during construction	(40)	(31)
Pension, postretirement, and other employee benefits	(55)	(56)
Settlement of asset retirement obligations	(78)	(76)
Estimated loss on Plant Vogtle Units 3 and 4	149	0
Storm damage reserve accruals	107	15
Other, net	19	17
Changes in certain current assets and liabilities —
-Receivables	(73)	(43)
-Fossil fuel stock	(52)	(26)
-Prepaid income taxes	0	63
-Materials and supplies	(61)	2
-Other current assets	(26)	19
-Accounts payable	0	(94)
-Accrued taxes	87	(139)
-Accrued compensation	(69)	(32)
-Retail fuel cost over recovery	109	0
-Customer refunds	(159)	(19)
-Other current liabilities	30	17
Net cash provided from operating activities	1,124	1,112
Investing Activities:
Property additions	(1,650)	(1,712)
Nuclear decommissioning trust fund purchases	(365)	(266)
Nuclear decommissioning trust fund sales	359	260
Proceeds from dispositions and asset sales	143	9
Cost of removal, net of salvage	(62)	(107)
Change in construction payables, net	(48)	(5)
Payments pursuant to LTSAs	(41)	(9)
Other investing activities	5	(4)
Net cash provided from (used for) investing activities	(1,659)	(1,834)
Financing Activities:
Increase (decrease) in notes payable, net		11
Decrease in notes payable, net	(25)
Proceeds —
FFB loan	519	835
Senior notes	1,500	0
Pollution control revenue bonds	53	513
Short-term borrowings	250	250
Capital contributions from parent company	500	46
Redemptions and repurchases —
Pollution control revenue bonds	(148)	(223)
Senior notes	(950)	0
FFB loan	(32)	0
Payment of common stock dividends	(771)	(788)
Other financing activities	(27)	(24)
Net cash used for financing activities	869	620
Net Change in Cash, Cash Equivalents, and Restricted Cash	334	(102)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	52	112
Cash, Cash Equivalents, and Restricted Cash at End of Period	386	10
Cash paid (received) during the period for —
Interest, net of amounts capitalized	180	179
Income taxes, net	0	(6)
Accrued property additions at end of period	478	650
Right-of-use assets obtained under operating leases	29	13
Right-of-use assets obtained under finance leases	0	28
MISSISSIPPI POWER CO
Operating Activities:
Net income	71	74
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	92	98
Deferred income taxes	(13)	(16)
Settlement of asset retirement obligations	(9)	(17)
Other, net	9	12
Changes in certain current assets and liabilities —
-Receivables	(7)	(8)
-Other current assets	(6)	(3)
-Accounts payable	(19)	(28)
-Accrued taxes	(21)	(43)
-Accrued compensation	(15)	(15)
-Other current liabilities	(11)	6
Net cash provided from operating activities	71	60
Investing Activities:
Property additions	(111)	(95)
Change in construction payables, net	(14)	(12)
Payments pursuant to LTSAs	(10)	(11)
Other investing activities	(10)	(10)
Net cash provided from (used for) investing activities	(145)	(128)
Proceeds —
Pollution control revenue bonds	34	43
Short-term borrowings	40	0
Capital contributions from parent company	75	7
Other long-term debt	100	0
Redemptions and repurchases —
Short-term borrowings	(40)	0
Pollution control revenue bonds	(41)	0
Senior notes	(275)	0
Return of capital to parent company	(74)	(75)
Other financing activities	3	(1)
Net cash used for financing activities	(178)	(26)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(252)	(94)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	286	293
Cash, Cash Equivalents, and Restricted Cash at End of Period	34	199
Cash paid (received) during the period for —
Interest, net of amounts capitalized	33	36
Income taxes, net	0	23
Accrued property additions at end of period	21	23
SOUTHERN POWER CO
Operating Activities:
Net income	112	230
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	251	251
Deferred income taxes	(34)	(63)
Utilization of federal investment tax credits	0	427
Amortization of investment tax credits	(30)	(122)
(Gain) loss on dispositions, net	(39)	(23)
Other, net	(31)	(46)
Changes in certain current assets and liabilities —
-Receivables	(67)	(9)
-Prepaid income taxes	73	93
-Other current assets	(8)	4
-Accounts payable	(29)	(17)
-Accrued taxes	16	19
-Other current liabilities	(19)	(25)
Net cash provided from operating activities	195	719
Investing Activities:
Business acquisitions, net of cash acquired	(81)	(2)
Property additions	(101)	(123)
Proceeds from dispositions and asset sales	660	540
Investment in unconsolidated subsidiaries	0	(116)
Payments pursuant to LTSAs	(31)	(31)
Other investing activities	43	(14)
Net cash provided from (used for) investing activities	490	254
Financing Activities:
Decrease in notes payable, net	(357)	0
Redemptions and repurchases —
Short-term borrowings	(100)	(100)
Senior notes	(300)	0
Return of capital to parent company	0	(505)
Distributions to noncontrolling interests	(118)	(82)
Capital contributions from noncontrolling interests	172	5
Payment of common stock dividends	(100)	(103)
Other financing activities	(5)	1
Net cash used for financing activities	(808)	(784)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(123)	189
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	279	181
Cash, Cash Equivalents, and Restricted Cash at End of Period	156	370
Cash paid (received) during the period for —
Interest, net of amounts capitalized	96	106
Income taxes, net	(5)	(421)
Accrued property additions at end of period	38	31
Right-of-use assets obtained under operating leases	30	0
SOUTHERN Co GAS
Operating Activities:
Net income	346	376
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	243	238
Deferred income taxes	40	59
Mark-to-market adjustments	34	30
Other, net	11	(26)
Changes in certain current assets and liabilities —
-Receivables	344	717
-Natural gas for sale	182	256
-Other current assets	6	29
-Accounts payable	(176)	(604)
-Accrued taxes	26	(54)
-Accrued compensation	(31)	(34)
-Other current liabilities	21	(56)
Net cash provided from operating activities	1,046	931
Investing Activities:
Property additions	(647)	(603)
Proceeds from dispositions and asset sales	178	32
Cost of removal, net of salvage	(31)	(33)
Investment in unconsolidated subsidiaries	(78)	(18)
Other investing activities	8	36
Net cash provided from (used for) investing activities	(570)	(586)
Financing Activities:
Decrease in notes payable, net	(321)	(158)
Proceeds —
Capital contributions from parent company	186	38
Redemptions and repurchases —
Payment of common stock dividends	(266)	(235)
Net cash used for financing activities	(401)	(355)
Net Change in Cash, Cash Equivalents, and Restricted Cash	75	(10)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	49	70
Cash, Cash Equivalents, and Restricted Cash at End of Period	124	60
Cash paid (received) during the period for —
Interest, net of amounts capitalized	119	125
Income taxes, net	(4)	96
Accrued property additions at end of period	$ 123	$ 123

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Interest capitalized	$ 41	$ 36
ALABAMA POWER CO
Interest capitalized	7	10
GEORGIA POWER CO
Interest capitalized	22	16
MISSISSIPPI POWER CO
Interest received	0	1
SOUTHERN POWER CO
Interest capitalized	7	7
SOUTHERN Co GAS
Interest capitalized	$ 4	$ 3

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Current Assets:
Cash and cash equivalents	$ 1,879	$ 1,975
Receivables —
Customer accounts receivable	1,613	1,614
Energy marketing receivables	273	428
Unbilled revenues	553	599
Other accounts and notes receivable	549	817
Accumulated provision for uncollectible accounts	(89)	(49)
Materials and supplies	1,490	1,388
Fossil fuel for generation	609	521
Natural gas for sale	282	479
Prepaid expenses	502	314
Assets from risk management activities, net of collateral	120	183
Regulatory assets – asset retirement obligations	252	287
Other regulatory assets	846	885
Assets held for sale	0	188
Other current assets	190	188
Total current assets	9,069	9,817
Property, Plant, and Equipment:
In service	107,320	105,114
Less: Accumulated depreciation	31,477	30,765
Plant in service, net of depreciation	75,843	74,349
Nuclear fuel, at amortized cost	835	851
Construction work in progress	8,351	7,880
Total property, plant, and equipment	85,029	83,080
Other Property and Investments:
Goodwill	5,280	5,280
Equity investments in unconsolidated subsidiaries	1,363	1,303
Other intangible assets, net of amortization	511	536
Nuclear decommissioning trusts, at fair value	2,014	2,036
Leveraged leases	647	788
Miscellaneous property and investments	379	391
Total other property and investments	10,194	10,334
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,776	1,800
Deferred charges related to income taxes	797	798
Unamortized loss on reacquired debt	290	300
Regulatory assets – asset retirement obligations, deferred	4,586	4,094
Other regulatory assets, deferred	6,606	6,805
Assets held for sale, deferred	0	601
Other deferred charges and assets	1,384	1,071
Total deferred charges and other assets	15,439	15,469
Total Assets	119,731	118,700
Current Liabilities:
Securities due within one year	1,596	2,989
Notes payable	1,185	2,055
Energy marketing trade payables	284	442
Accounts payable —
Accounts payable	1,787	2,115
Customer deposits	490	496
Accrued taxes —
Accrued income taxes	27	0
Other accrued taxes	517	659
Accrued interest	499	474
Accrued compensation	666	992
Asset retirement obligations	575	504
Other regulatory liabilities	558	756
Liabilities held for sale	0	5
Operating lease obligations	235	229
Over recovered fuel clause revenues	109	0
Other current liabilities	915	830
Total current liabilities	9,334	12,546
Long-term Debt	45,138	41,798
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	8,298	7,888
Deferred credits related to income taxes	5,860	6,078
Accumulated deferred ITCs	2,271	2,291
Employee benefit obligations	1,789	1,814
Operating lease obligations, deferred	1,611	1,615
Asset retirement obligations, deferred	9,699	9,282
Accrued environmental remediation	220	234
Other cost of removal obligations	2,258	2,239
Other regulatory liabilities, deferred	371	256
Other deferred credits and liabilities	630	609
Total deferred credits and other liabilities	33,007	32,306
Total Liabilities	87,479	86,650
Redeemable Preferred Stock of Subsidiaries	291	291
Common Stockholder's Equity (See accompanying statements)	31,961	31,759
Total Liabilities and Stockholders' Equity	119,731	118,700
ALABAMA POWER CO
Current Assets:
Cash and cash equivalents	901	894
Receivables —
Customer accounts receivable	407	425
Unbilled revenues	153	134
Affiliated	37	37
Other accounts and notes receivable	51	72
Accumulated provision for uncollectible accounts	(21)	(22)
Materials and supplies	545	512
Fossil fuel for generation	250	212
Prepaid expenses	101	50
Other regulatory assets	226	242
Other current assets	55	30
Total current assets	2,705	2,586
Property, Plant, and Equipment:
In service	30,619	30,023
Less: Accumulated depreciation	9,647	9,540
Plant in service, net of depreciation	20,972	20,483
Nuclear fuel, at amortized cost	275	296
Construction work in progress	830	890
Total property, plant, and equipment	22,077	21,669
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	63	66
Nuclear decommissioning trusts, at fair value	978	1,023
Miscellaneous property and investments	131	128
Total other property and investments	1,172	1,217
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	113	132
Deferred charges related to income taxes	243	244
Deferred under recovered regulatory clause revenues	41	40
Regulatory assets – asset retirement obligations, deferred	1,491	1,019
Other regulatory assets, deferred	1,922	1,976
Other deferred charges and assets	362	269
Total deferred charges and other assets	4,172	3,680
Total Assets	30,126	29,152
Current Liabilities:
Securities due within one year	496	251
Accounts payable —
Affiliated	261	316
Other	312	514
Customer deposits	103	100
Accrued taxes —
Accrued taxes	274	78
Accrued interest	93	92
Accrued compensation	156	216
Asset retirement obligations	254	195
Other regulatory liabilities	73	193
Other current liabilities	101	105
Total current liabilities	2,123	2,060
Long-term Debt	8,028	8,270
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	3,325	3,260
Deferred credits related to income taxes	1,932	1,960
Accumulated deferred ITCs	97	100
Employee benefit obligations	200	206
Operating lease obligations, deferred	91	107
Asset retirement obligations, deferred	3,722	3,345
Other cost of removal obligations	392	412
Other regulatory liabilities, deferred	217	146
Other deferred credits and liabilities	38	40
Total deferred credits and other liabilities	10,014	9,576
Total Liabilities	20,165	19,906
Redeemable Preferred Stock	291	291
Common Stockholder's Equity (See accompanying statements)	9,670	8,955
Total Liabilities and Stockholders' Equity	30,126	29,152
GEORGIA POWER CO
Current Assets:
Cash and cash equivalents	386	52
Receivables —
Customer accounts receivable	580	533
Unbilled revenues	261	203
Joint owner accounts receivable	104	136
Affiliated	28	21
Other accounts and notes receivable	42	209
Accumulated provision for uncollectible accounts	(28)	(2)
Materials and supplies	558	501
Fossil fuel for generation	324	272
Prepaid expenses	58	63
Regulatory assets – storm damage reserves	213	213
Regulatory assets – asset retirement obligations	215	254
Other regulatory assets	276	263
Other current assets	62	77
Total current assets	3,079	2,795
Property, Plant, and Equipment:
In service	38,852	38,137
Less: Accumulated depreciation	11,964	11,753
Plant in service, net of depreciation	26,888	26,384
Nuclear fuel, at amortized cost	560	555
Construction work in progress	6,254	5,650
Total property, plant, and equipment	33,702	32,589
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	50	52
Nuclear decommissioning trusts, at fair value	1,036	1,013
Miscellaneous property and investments	65	64
Total other property and investments	1,151	1,129
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,382	1,428
Deferred charges related to income taxes	519	519
Regulatory assets – asset retirement obligations, deferred	2,894	2,865
Other regulatory assets, deferred	2,610	2,716
Other deferred charges and assets	488	500
Total deferred charges and other assets	7,893	8,028
Total Assets	45,825	44,541
Current Liabilities:
Securities due within one year	536	1,025
Notes payable	465	365
Accounts payable —
Affiliated	493	512
Other	672	711
Customer deposits	284	283
Accrued taxes —
Accrued taxes	442	407
Accrued interest	133	118
Accrued compensation	152	233
Asset retirement obligations	279	265
Other regulatory liabilities	290	447
Operating lease obligations	150	144
Other current liabilities	206	187
Total current liabilities	4,211	4,697
Long-term Debt	12,337	10,791
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	3,190	3,257
Deferred credits related to income taxes	2,730	2,862
Accumulated deferred ITCs	273	255
Employee benefit obligations	500	540
Operating lease obligations, deferred	1,258	1,282
Asset retirement obligations, deferred	5,556	5,519
Other deferred credits and liabilities	333	273
Total deferred credits and other liabilities	13,840	13,988
Total Liabilities	30,388	29,476
Common Stockholder's Equity (See accompanying statements)	15,437	15,065
Total Liabilities and Stockholders' Equity	45,825	44,541
MISSISSIPPI POWER CO
Current Assets:
Cash and cash equivalents	34	286
Receivables —
Customer accounts receivable	39	35
Unbilled revenues	41	39
Affiliated	31	27
Other accounts and notes receivable	24	26
Materials and supplies	62	61
Fossil fuel for generation	24	26
Other regulatory assets	73	99
Other current assets	8	10
Total current assets	336	609
Property, Plant, and Equipment:
In service	4,948	4,857
Less: Accumulated depreciation	1,522	1,463
Plant in service, net of depreciation	3,426	3,394
Construction work in progress	132	126
Total property, plant, and equipment	3,558	3,520
Other Property and Investments:
Total other property and investments	129	131
Deferred Charges and Other Assets:
Deferred charges related to income taxes	32	32
Regulatory assets – asset retirement obligations, deferred	200	210
Other regulatory assets, deferred	376	360
Accumulated deferred income taxes	134	139
Other deferred charges and assets	56	34
Total deferred charges and other assets	798	775
Total Assets	4,821	5,035
Current Liabilities:
Securities due within one year	0	281
Notes payable	4	0
Accounts payable —
Affiliated	75	76
Other	44	75
Accrued taxes —
Accrued taxes	84	105
Accrued interest	15	15
Accrued compensation	21	35
Asset retirement obligations	28	33
Other regulatory liabilities	47	21
Over recovered fuel clause revenues	29	29
Other current liabilities	59	64
Total current liabilities	406	734
Long-term Debt	1,404	1,308
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	422	424
Deferred credits related to income taxes	310	352
Employee benefit obligations	97	99
Asset retirement obligations, deferred	157	157
Other cost of removal obligations	193	189
Other regulatory liabilities, deferred	66	76
Other deferred credits and liabilities	42	44
Total deferred credits and other liabilities	1,287	1,341
Total Liabilities	3,097	3,383
Common Stockholder's Equity (See accompanying statements)	1,724	1,652
Total Liabilities and Stockholders' Equity	4,821	5,035
SOUTHERN POWER CO
Current Assets:
Cash and cash equivalents	154	279
Receivables —
Customer accounts receivable	160	107
Affiliated	46	30
Other accounts and notes receivable	55	73
Materials and supplies	203	191
Prepaid income taxes	402	36
Other current assets	23	43
Total current assets	1,043	759
Property, Plant, and Equipment:
In service	13,634	13,270
Less: Accumulated depreciation	2,689	2,464
Plant in service, net of depreciation	10,945	10,806
Construction work in progress	314	515
Total property, plant, and equipment	11,259	11,321
Other Property and Investments:
Intangible assets, net of amortization	312	322
Equity investments in unconsolidated subsidiaries	19	28
Miscellaneous property and investments	19	28
Total other property and investments	331	350
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	397	369
Prepaid LTSAs	140	128
Assets held for sale, deferred	0	601
Accumulated deferred income taxes	156	551
Income taxes receivable, non-current	11	5
Other deferred charges and assets	220	216
Total deferred charges and other assets	924	1,870
Total Assets	13,557	14,300
Current Liabilities:
Securities due within one year	525	824
Notes payable	92	549
Accounts payable —
Affiliated	52	56
Other	59	85
Accrued taxes —
Accrued income taxes	10	0
Other accrued taxes	26	26
Accrued interest	23	32
Other current liabilities	127	132
Total current liabilities	914	1,704
Long-term Debt	3,572	3,574
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	114	115
Accumulated deferred ITCs	1,701	1,731
Operating lease obligations, deferred	404	376
Other deferred credits and liabilities	193	178
Total deferred credits and other liabilities	2,412	2,400
Total Liabilities	6,898	7,678
Common Stockholder's Equity (See accompanying statements)	6,659	6,622
Total Liabilities and Stockholders' Equity	13,557	14,300
SOUTHERN Co GAS
Current Assets:
Cash and cash equivalents	120	46
Receivables —
Customer accounts receivable	269	323
Energy marketing receivables	273	428
Unbilled revenues	57	183
Affiliated	5	5
Other accounts and notes receivable	117	114
Accumulated provision for uncollectible accounts	(35)	(18)
Natural gas for sale	282	479
Prepaid expenses	60	65
Assets from risk management activities, net of collateral	103	177
Other regulatory assets	86	92
Assets held for sale	0	171
Other current assets	49	41
Total current assets	1,386	2,106
Property, Plant, and Equipment:
In service	16,718	16,344
Less: Accumulated depreciation	4,704	4,650
Plant in service, net of depreciation	12,014	11,694
Construction work in progress	770	613
Total property, plant, and equipment	12,784	12,307
Other Property and Investments:
Goodwill	5,015	5,015
Equity investments in unconsolidated subsidiaries	1,308	1,251
Other intangible assets, net of amortization	60	70
Miscellaneous property and investments	20	20
Total other property and investments	6,403	6,356
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	88	93
Other regulatory assets, deferred	581	618
Other deferred charges and assets	258	207
Total deferred charges and other assets	927	918
Total Assets	21,500	21,687
Current Liabilities:
Securities due within one year	31	0
Notes payable	329	650
Energy marketing trade payables	284	442
Accounts payable —
Affiliated	50	41
Other	290	315
Customer deposits	86	96
Accrued taxes —
Accrued income taxes	32	0
Other accrued taxes	65	71
Accrued interest	53	52
Accrued compensation	68	100
Liabilities from risk management activities, net of collateral	39	21
Other regulatory liabilities	146	94
Other current liabilities	122	128
Total current liabilities	1,595	2,010
Long-term Debt	5,796	5,845
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	1,256	1,219
Deferred credits related to income taxes	859	874
Employee benefit obligations	253	265
Operating lease obligations, deferred	73	78
Accrued environmental remediation	220	233
Other cost of removal obligations	1,639	1,606
Other deferred credits and liabilities	40	51
Total deferred credits and other liabilities	4,340	4,326
Total Liabilities	11,731	12,181
Common Stockholder's Equity (See accompanying statements)	9,769	9,506
Total Liabilities and Stockholders' Equity	$ 21,500	$ 21,687

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Other intangible assets, amortization	$ 304	$ 280
SOUTHERN POWER CO
Other intangible assets, amortization	79	69
SOUTHERN Co GAS
Other intangible assets, amortization	$ 186	$ 176

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Treasury	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	ALABAMA POWER CO	ALABAMA POWER COCommon Stock	ALABAMA POWER COPaid-In Capital	ALABAMA POWER CORetained Earnings (Accumulated Deficit)	ALABAMA POWER COAccumulated Other Comprehensive Income (Loss)	GEORGIA POWER CO	GEORGIA POWER COCommon Stock	GEORGIA POWER COPaid-In Capital	GEORGIA POWER CORetained Earnings (Accumulated Deficit)	GEORGIA POWER COAccumulated Other Comprehensive Income (Loss)	MISSISSIPPI POWER CO	MISSISSIPPI POWER COCommon Stock	MISSISSIPPI POWER COPaid-In Capital	MISSISSIPPI POWER CORetained Earnings (Accumulated Deficit)	MISSISSIPPI POWER COAccumulated Other Comprehensive Income (Loss)	SOUTHERN POWER CO	SOUTHERN POWER COTotal Common Stockholders' Equity	SOUTHERN POWER COPaid-In Capital	SOUTHERN POWER CORetained Earnings (Accumulated Deficit)	SOUTHERN POWER COAccumulated Other Comprehensive Income (Loss)	SOUTHERN POWER CONoncontrolling Interests	SOUTHERN Co GAS	SOUTHERN Co GASPaid-In Capital	SOUTHERN Co GASRetained Earnings (Accumulated Deficit)	SOUTHERN Co GASAccumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2018		1,035	1						31					9					1
Beginning balance at Dec. 31, 2018	$ 29,039	$ 5,164	$ (38)	$ 11,094	$ 8,706	$ (203)	$ 4,316	$ 7,477	$ 1,222	$ 3,508	$ 2,775	$ (28)	$ 14,323	$ 398	$ 10,322	$ 3,612	$ (9)	$ 1,609	$ 38	$ 4,546	$ (2,971)	$ (4)	$ 7,284	$ 2,968	$ 1,600	$ 1,352	$ 16	$ 4,316	$ 8,570	$ 8,856	$ (312)	$ 26
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,055				2,084		(29)
Net income (loss)													311			311		37			37		27	56		56		(29)	270		270
Net income								217			217
Return of capital to parent company																		(38)		(38)
Capital contributions from parent company								1,236		1,236			29		29			2		2			1	1	1				17	17
Other comprehensive income (loss)								1				1	1				1						(4)	(4)			(4)		(1)			(1)
Stock issued (in shares)		6
Stock issued	224	$ 28		196
Stock-based compensation	24			24
Cash dividends on common stock	(623)				(623)			(211)			(211)		(394)			(394)							(51)	(51)		(51)			(118)		(118)
Contributions from noncontrolling interests	3						3																3					3
Distributions to noncontrolling interests	(41)						(41)																(41)					(41)
Other	6		$ (2)	7			1						(1)		(1)								(1)	(2)	(1)	(1)		1
Ending balance (in shares) at Mar. 31, 2019		1,041	1						31					9					1
Ending balance at Mar. 31, 2019	30,687	$ 5,192	$ (40)	11,321	10,167	(203)	4,250	8,720	$ 1,222	4,744	2,781	(27)	14,269	$ 398	10,350	3,529	(8)	1,610	$ 38	4,510	(2,934)	(4)	7,218	2,968	1,600	1,356	12	4,250	8,738	8,873	(160)	25
Beginning balance (in shares) at Dec. 31, 2018		1,035	1						31					9					1
Beginning balance at Dec. 31, 2018	29,039	$ 5,164	$ (38)	11,094	8,706	(203)	4,316	7,477	$ 1,222	3,508	2,775	(28)	14,323	$ 398	10,322	3,612	(9)	1,609	$ 38	4,546	(2,971)	(4)	7,284	2,968	1,600	1,352	16	4,316	8,570	8,856	(312)	26
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,989							520					759					74					230						376
Net income	2,982							513															230						376
Ending balance (in shares) at Jun. 30, 2019		1,046	1						31					9					1
Ending balance at Jun. 30, 2019	31,131	$ 5,217	$ (41)	11,540	10,420	(238)	4,233	8,829	$ 1,222	4,767	2,866	(26)	14,316	$ 398	10,371	3,582	(35)	1,617	$ 38	4,480	(2,897)	(4)	6,818	2,585	1,102	1,479	4	4,233	8,759	8,908	(171)	22
Beginning balance (in shares) at Mar. 31, 2019		1,041	1						31					9					1
Beginning balance at Mar. 31, 2019	30,687	$ 5,192	$ (40)	11,321	10,167	(203)	4,250	8,720	$ 1,222	4,744	2,781	(27)	14,269	$ 398	10,350	3,529	(8)	1,610	$ 38	4,510	(2,934)	(4)	7,218	2,968	1,600	1,356	12	4,250	8,738	8,873	(160)	25
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	928				899		29
Net income (loss)	931							299					448			448		37			37		203	174		174		29	106		106
Net income	899							296			296												174						106
Return of capital to parent company																		(38)		(38)			(505)	(505)	(505)
Capital contributions from parent company								23		23			20		20			8		8			7	7	7				35	35
Other comprehensive income (loss)	(35)					(35)		1				1	(27)				(27)						(8)	(8)			(8)		(3)			(3)
Stock issued (in shares)		5
Stock issued	228	$ 25		203
Stock-based compensation	11			11
Cash dividends on common stock	(646)				(646)			(211)			(211)		(394)			(394)							(52)	(52)		(52)			(117)		(117)
Contributions from noncontrolling interests	2						2																2					2
Distributions to noncontrolling interests	(47)						(47)																(47)					(47)
Other	3		$ (1)	5			(1)						0		1	(1)							0	1		1		(1)
Ending balance (in shares) at Jun. 30, 2019		1,046	1						31					9					1
Ending balance at Jun. 30, 2019	31,131	$ 5,217	$ (41)	11,540	10,420	(238)	4,233	8,829	$ 1,222	4,767	2,866	(26)	14,316	$ 398	10,371	3,582	(35)	1,617	$ 38	4,480	(2,897)	(4)	6,818	2,585	1,102	1,479	4	4,233	8,759	8,908	(171)	22
Beginning balance (in shares) at Dec. 31, 2019		1,054	1						31					9					1
Beginning balance at Dec. 31, 2019	31,759	$ 5,257	$ (42)	11,734	10,877	(321)	4,254	8,955	$ 1,222	4,755	3,001	(23)	15,065	$ 398	10,962	3,756	(51)	1,652	$ 38	4,449	(2,832)	(3)	6,622	2,368	909	1,485	(26)	4,254	9,506	9,697	(198)	7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	837				868		(31)
Net income (loss)													331			331		32			32		44	75		75		(31)	275		275
Net income								280			280
Return of capital to parent company																		(37)		(37)									(2)	(2)
Capital contributions from parent company								612		612			502		502			76		76
Other comprehensive income (loss)	(47)					(47)		1				1	(1)				(1)						(33)	(33)			(33)		(15)			(15)
Stock issued (in shares)		3
Stock issued	52	$ 9		43
Stock-based compensation	5			5
Cash dividends on common stock	(655)				(655)			(239)			(239)		(385)			(385)							(50)	(50)		(50)			(133)		(133)
Contributions from noncontrolling interests	16						16																16					16
Distributions to noncontrolling interests	(48)						(48)																(48)					(48)
Other	(3)		$ (2)		(2)	1												(1)		(1)
Ending balance (in shares) at Mar. 31, 2020		1,057	1						31					9					1
Ending balance at Mar. 31, 2020	31,916	$ 5,266	$ (44)	11,782	11,088	(367)	4,191	9,609	$ 1,222	5,367	3,042	(22)	15,512	$ 398	11,464	3,702	(52)	1,722	$ 38	4,487	(2,800)	(3)	6,551	2,360	909	1,510	(59)	4,191	9,631	9,695	(56)	(8)
Beginning balance (in shares) at Dec. 31, 2019		1,054	1						31					9					1
Beginning balance at Dec. 31, 2019	31,759	$ 5,257	$ (42)	11,734	10,877	(321)	4,254	8,955	$ 1,222	4,755	3,001	(23)	15,065	$ 398	10,962	3,756	(51)	1,652	$ 38	4,449	(2,832)	(3)	6,622	2,368	909	1,485	(26)	4,254	9,506	9,697	(198)	7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,461							585					638					71					112						346
Net income	1,480							578															138						346
Ending balance (in shares) at Jun. 30, 2020		1,057	1						31					9					1
Ending balance at Jun. 30, 2020	31,961	$ 5,266	$ (44)	11,787	11,024	(363)	4,291	9,670	$ 1,222	5,368	3,101	(21)	15,437	$ 398	11,465	3,624	(50)	1,724	$ 38	4,450	(2,761)	(3)	6,659	2,368	907	1,523	(62)	4,291	9,769	9,895	(118)	(8)
Beginning balance (in shares) at Mar. 31, 2020		1,057	1						31					9					1
Beginning balance at Mar. 31, 2020	31,916	$ 5,266	$ (44)	11,782	11,088	(367)	4,191	9,609	$ 1,222	5,367	3,042	(22)	15,512	$ 398	11,464	3,702	(52)	1,722	$ 38	4,487	(2,800)	(3)	6,551	2,360	909	1,510	(59)	4,191	9,631	9,695	(56)	(8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	617				612		5
Net income (loss)	621							302					308			308		39			39		68	63		63		5	71		71
Net income	612							298			298												63						71
Return of capital to parent company																		(37)		(37)
Capital contributions from parent company								1		1			1		1														200	200
Other comprehensive income (loss)	4					4		1				1	2				2						(3)	(3)			(3)
Stock issued	7			7
Stock-based compensation	11			11
Cash dividends on common stock	(677)				(677)			(239)			(239)		(386)			(386)							(50)	(50)		(50)			(133)		(133)
Contributions from noncontrolling interests	165						165																165					165
Distributions to noncontrolling interests	(70)						(70)																(70)					(70)
Other	(12)			(13)	1																		(2)	(2)	(2)	0	0	0
Ending balance (in shares) at Jun. 30, 2020		1,057	1						31					9					1
Ending balance at Jun. 30, 2020	$ 31,961	$ 5,266	$ (44)	$ 11,787	$ 11,024	$ (363)	$ 4,291	$ 9,670	$ 1,222	$ 5,368	$ 3,101	$ (21)	$ 15,437	$ 398	$ 11,465	$ 3,624	$ (50)	$ 1,724	$ 38	$ 4,450	$ (2,761)	$ (3)	$ 6,659	$ 2,368	$ 907	$ 1,523	$ (62)	$ 4,291	$ 9,769	$ 9,895	$ (118)	$ (8)

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 0.64	$ 0.62	$ 0.62	$ 0.60

INTRODUCTION

INTRODUCTION	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
INTRODUCTION	INTRODUCTION The condensed quarterly financial statements of each Registrant included herein have been prepared by such Registrant, without audit, pursuant to the rules and regulations of the SEC. The Condensed Balance Sheets as of December 31, 2019 have been derived from the audited financial statements of each Registrant. In the opinion of each Registrant's management, the information regarding such Registrant furnished herein reflects all adjustments, which, except as otherwise disclosed, are of a normal recurring nature, necessary to present fairly the results of operations for the periods ended June 30, 2020 and 2019 . Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations, although each Registrant believes that the disclosures regarding such Registrant are adequate to make the information presented not misleading. Disclosures which would substantially duplicate the disclosures in the Form 10-K and details which have not changed significantly in amount or composition since the filing of the Form 10-K are generally omitted from this Quarterly Report on Form 10-Q unless specifically required by GAAP. Therefore, these Condensed Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the Form 10-K. Due to the seasonal variations in the demand for energy and other factors, including the impacts of the COVID-19 pandemic, operating results for the periods presented are not necessarily indicative of the operating results to be expected for the full year. Certain prior year data presented in the financial statements have been reclassified to conform to the current year presentation. These reclassifications had no impact on the overall results of operations, financial position, or cash flows of any Registrant. Goodwill and Other Intangible Assets Goodwill at June 30, 2020 and December 31, 2019 was as follows: Goodwill (in millions) Southern Company $ 5,280 Southern Company Gas: Gas distribution operations $ 4,034 Gas marketing services 981 Southern Company Gas total $ 5,015 Goodwill is not amortized but is subject to an annual impairment test in the fourth quarter of the year and on an interim basis as events and changes in circumstances occur, including, but not limited to, a significant change in operating performance, the business climate, legal or regulatory factors, or a planned sale or disposition of a significant portion of the business. The continued COVID-19 pandemic and related responses continue to disrupt supply chains and capital markets, reduce labor availability and productivity, and reduce economic activity. These effects could have a variety of adverse impacts on Southern Company and its subsidiaries, including the $263 million of goodwill recorded at PowerSecure. If the impact of the COVID-19 pandemic becomes significant to the operating results of PowerSecure and its businesses, a portion of the associated goodwill may become impaired. The ultimate outcome of this matter cannot be determined at this time. Other intangible assets were as follows: At June 30, 2020 At December 31, 2019 Gross Carrying Amount Accumulated Amortization Other Intangible Assets, Net Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Other intangible assets subject to amortization: Customer relationships $ 212 $ (126 ) $ 86 $ 212 $ (116 ) $ 96 Trade names 64 (28 ) 36 64 (25 ) 39 Storage and transportation contracts 64 (63 ) 1 64 (62 ) 2 PPA fair value adjustments 390 (79 ) 311 390 (69 ) 321 Other 10 (8 ) 2 11 (8 ) 3 Total other intangible assets subject to amortization $ 740 $ (304 ) $ 436 $ 741 $ (280 ) $ 461 Other intangible assets not subject to amortization: Federal Communications Commission licenses 75 — 75 75 — 75 Total other intangible assets $ 815 $ (304 ) $ 511 $ 816 $ (280 ) $ 536 Southern Power Other intangible assets subject to amortization: PPA fair value adjustments $ 390 $ (79 ) $ 311 $ 390 $ (69 ) $ 321 Southern Company Gas Other intangible assets subject to amortization: Gas marketing services Customer relationships $ 156 $ (112 ) $ 44 $ 156 $ (104 ) $ 52 Trade names 26 (11 ) 15 26 (10 ) 16 Wholesale gas services Storage and transportation contracts 64 (63 ) 1 64 (62 ) 2 Total other intangible assets subject to amortization $ 246 $ (186 ) $ 60 $ 246 $ (176 ) $ 70 Amortization associated with other intangible assets was as follows: Three Months Ended Six Months Ended June 30, 2020 (in millions) Southern Company (a) $ 13 $ 25 Southern Power (b) $ 5 $ 10 Southern Company Gas Gas marketing services $ 5 $ 9 Wholesale gas services (b) — 1 Southern Company Gas total $ 5 $ 10 (a) Includes $5 million and $11 million for the three and six months ended June 30, 2020 , respectively, recorded as a reduction to operating revenues. (b) Recorded as a reduction to operating revenues. Restricted Cash The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed balance sheets that total to the amounts shown in the condensed statements of cash flows for the Registrants that had restricted cash at June 30, 2020 and/or December 31, 2019 : Southern Company Southern Power Southern Company Gas At June 30, 2020 At December 31, 2019 At June 30, 2020 At June At December 31, 2019 (in millions) (in millions) (in millions) Cash and cash equivalents $ 1,879 $ 1,975 $ 154 $ 120 $ 46 Restricted cash (*) : Other accounts and notes receivable — 3 — — 3 Other current assets 4 — — 4 — Other deferred charges and assets 2 — 2 — — Total cash, cash equivalents, and restricted cash $ 1,885 $ 1,978 $ 156 $ 124 $ 49 (*) For Southern Company Gas, reflects restricted cash held as collateral for workers' compensation, life insurance, and long-term disability insurance. For Southern Power, reflects restricted cash held for construction payables. Natural Gas for Sale Southern Company Gas, with the exception of Nicor Gas, carries natural gas inventory on a WACOG basis. For any declines in market prices below the WACOG considered to be other than temporary, an adjustment is recorded to reduce the value of natural gas inventories to market value. Southern Company Gas recorded no material adjustments for the three and six months ended June 30, 2020 and recorded adjustments of $7 million and $10 million for the three and six months ended June 30, 2019 , respectively. Nicor Gas' natural gas inventory is carried at cost on a LIFO basis. Inventory decrements occurring during the year that are restored prior to year end are charged to cost of natural gas at the estimated annual replacement cost. Inventory decrements that are not restored prior to year end are charged to cost of natural gas at the actual LIFO cost of the inventory layers liquidated. Nicor Gas' inventory decrement at June 30, 2020 is expected to be restored prior to year end. Asset Retirement Obligations See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information. Details of changes in AROs for Southern Company and Alabama Power during the first six months of 2020 are shown in the following table. There were no material changes in AROs for the other Registrants during the first six months of 2020. Southern Company Alabama Power (in millions) Balance at December 31, 2019 $ 9,786 $ 3,540 Liabilities incurred 15 — Liabilities settled (193 ) (100 ) Accretion 204 74 Cash flow revisions 462 462 Balance at June 30, 2020 $ 10,274 $ 3,976 In June 2020, Alabama Power recorded an increase of approximately $462 million to its AROs related to the CCR Rule and the related state rule primarily due to management's completion of a feasibility study and the related cost estimates during the second quarter 2020 for one of its ash ponds. Alabama Power's increase also reflects costs associated with the addition of a water treatment system to the design of another ash pond. The additional estimated costs to close these ash ponds under the planned closure-in-place methodology primarily relate to inputs from contractor bids, design revisions, and changes in the expected volume of ash handling. The traditional electric operating companies expect to continue updating their cost estimates and ARO liabilities periodically as additional information related to ash pond closure methodologies, schedules, and/or costs becomes available. Additionally, the closure designs and plans in the States of Alabama and Georgia are subject to approval by environmental regulatory agencies. Absent continued recovery of ARO costs through regulated rates, results of operations, cash flows, and financial condition for Southern Company and the traditional electric operating companies could be materially impacted. See Note (B) under "Georgia Power – Integrated Resource Plan " for additional information. The ultimate outcome of these matters cannot be determined at this time. Depreciation and Amortization See Note 5 to the financial statements under "Depreciation and Amortization – Southern Power" in Item 8 of the Form 10-K for additional information. Effective January 1, 2020, Southern Power revised the depreciable lives of its natural gas generating facilities from up to 45 years to up to 50 years . This revision resulted in an immaterial decrease in depreciation for the three and six months ended June 30, 2020 and is expected to result in an immaterial decrease in annual depreciation for 2020.

REGULATORY MATTERS

REGULATORY MATTERS	6 Months Ended
	Jun. 30, 2020
Regulated Operations [Abstract]
REGULATORY MATTERS	REGULATORY MATTERS See Note 2 to the financial statements in Item 8 of the Form 10-K for additional information relating to regulatory matters. The recovery balances for certain retail regulatory clauses of the traditional electric operating companies and Southern Company Gas at June 30, 2020 and December 31, 2019 were as follows: Regulatory Clause Balance Sheet Line Item June 30, December 31, (in millions) Alabama Power Rate CNP Compliance Other regulatory liabilities, current $ 25 $ 55 Other regulatory liabilities, deferred — 7 Rate CNP PPA Deferred under recovered regulatory clause revenues 41 40 Retail Energy Cost Recovery Other regulatory liabilities, current 22 32 Other regulatory liabilities, deferred 93 17 Natural Disaster Reserve Other regulatory liabilities, current 16 37 Other regulatory liabilities, deferred 96 113 Georgia Power Fuel Cost Recovery Other current liabilities $ 109 $ — Other deferred credits and liabilities 95 73 Mississippi Power Fuel Cost Recovery Over recovered regulatory clause liabilities $ 22 $ 23 Ad Valorem Tax Other regulatory assets 11 47 Other regulatory assets, deferred 39 — Property Damage Reserve Other regulatory liabilities, deferred 50 54 Southern Company Gas Natural Gas Cost Recovery Other regulatory liabilities $ 100 $ 74 Alabama Power Petition for Certificate of Convenience and Necessity On June 9, 2020, the Alabama PSC approved in part Alabama Power's petition for a certificate of convenience and necessity (CCN) which authorizes Alabama Power to (i) construct an approximately 720 -MW combined cycle facility at Alabama Power's Plant Barry (Plant Barry Unit 8), which is expected to be placed in service by the end of 2023, (ii) complete the Autauga Combined Cycle Acquisition, which was approved by the FERC on April 22, 2020 and is expected to close by September 1, 2020, (iii) purchase approximately 240 MWs of combined cycle generation under a long-term PPA expected to begin later in 2020 and (iv) pursue up to approximately 200 MWs of certain demand-side management and distributed energy resource programs. The Alabama PSC authorized the recovery of actual costs for the construction of Plant Barry Unit 8 up to 5% above the estimated in-service cost of $652 million . In so doing, it recognized the potential for developments that could cause the project costs to exceed the capped amount, in which case Alabama Power would provide documentation to the Alabama PSC to explain and justify potential recovery of the additional costs. The Alabama PSC further directed that the proposed solar generation of approximately 400 MWs, coupled with battery energy storage systems (solar/battery systems), be evaluated under an existing Renewable Generation Certificate issued by the Alabama PSC in September 2015. Alabama Power expects to recover all approved costs associated with the CCN through existing rate mechanisms as outlined in Note 2 to the financial statements in Item 8 of the Form 10-K. The Alabama PSC's approval in part of the CCN will be followed by a written order which is subject to any rehearing request or judicial appeal filed within 30 days of the date of such order. The ultimate outcome of these matters cannot be determined at this time. Georgia Power Deferral of Incremental COVID-19 Costs On April 7, 2020 and June 2, 2020, in response to the COVID-19 pandemic, the Georgia PSC approved orders directing Georgia Power to continue its previous, voluntary suspension of customer disconnections through July 14, 2020 and to defer the resulting incremental bad debt as a regulatory asset. On June 16, 2020 and July 7, 2020, the Georgia PSC approved orders establishing a methodology for identifying incremental bad debt and allowing the deferral of other incremental costs associated with the COVID-19 pandemic. The period over which such costs will be recovered is expected to be determined in Georgia Power's next base rate case. At June 30, 2020 , the incremental costs deferred totaled approximately $34 million . The ultimate outcome of this matter cannot be determined at this time. Integrated Resource Plan On March 5, 2020, the Sierra Club filed a petition for judicial review in the Superior Court of Fulton County to appeal the Georgia PSC's decision in the 2019 ARP allowing Georgia Power to recover compliance costs for CCR AROs. Georgia Power intervened in the appeal on June 22, 2020. The ultimate outcome of this matter cannot be determined at this time. Fuel Cost Recovery On May 28, 2020, the Georgia PSC approved a stipulation agreement among Georgia Power, the staff of the Georgia PSC, and certain intervenors to lower total fuel billings by approximately $740 million over a two -year period effective June 1, 2020. In addition, Georgia Power will further lower fuel billings by approximately $44 million under an interim fuel rider effective June 1, 2020 through September 30, 2020. Georgia Power continues to be allowed to adjust its fuel cost recovery rates under an interim fuel rider prior to its next fuel case if the under or over recovered fuel balance exceeds $200 million . Georgia Power is scheduled to file its next fuel case no later than February 28, 2023. Nuclear Construction In 2009, the Georgia PSC certified construction of Plant Vogtle Units 3 and 4, in which Georgia Power holds a 45.7% ownership interest. In 2012, the NRC issued the related combined construction and operating licenses, which allowed full construction of the two AP1000 nuclear units (with electric generating capacity of approximately 1,100 MWs each) and related facilities to begin. Until March 2017, construction on Plant Vogtle Units 3 and 4 continued under the Vogtle 3 and 4 Agreement, which was a substantially fixed price agreement. In March 2017, the EPC Contractor filed for bankruptcy protection under Chapter 11 of the U.S. Bankruptcy Code. In connection with the EPC Contractor's bankruptcy filing, Georgia Power, acting for itself and as agent for the other Vogtle Owners, entered into several transitional arrangements to allow construction to continue. In July 2017, Georgia Power, acting for itself and as agent for the other Vogtle Owners, entered into the Vogtle Services Agreement, whereby Westinghouse provides facility design and engineering services, procurement and technical support, and staff augmentation on a time and materials cost basis. The Vogtle Services Agreement provides that it will continue until the start-up and testing of Plant Vogtle Units 3 and 4 are complete and electricity is generated and sold from both units. The Vogtle Services Agreement is terminable by the Vogtle Owners upon 30 days' written notice. In October 2017, Georgia Power, acting for itself and as agent for the other Vogtle Owners, executed the Bechtel Agreement, a cost reimbursable plus fee arrangement, whereby Bechtel is reimbursed for actual costs plus a base fee and an at-risk fee, which is subject to adjustment based on Bechtel's performance against cost and schedule targets. Each Vogtle Owner is severally (not jointly) liable for its proportionate share, based on its ownership interest, of all amounts owed to Bechtel under the Bechtel Agreement. The Vogtle Owners may terminate the Bechtel Agreement at any time for their convenience, provided that the Vogtle Owners will be required to pay amounts related to work performed prior to the termination (including the applicable portion of the base fee), certain termination-related costs, and, at certain stages of the work, the applicable portion of the at-risk fee. Bechtel may terminate the Bechtel Agreement under certain circumstances, including certain Vogtle Owner suspensions of work, certain breaches of the Bechtel Agreement by the Vogtle Owners, Vogtle Owner insolvency, and certain other events. See Note 8 to the financial statements under "Long-term Debt – DOE Loan Guarantee Borrowings" in Item 8 of the Form 10-K for information on the Amended and Restated Loan Guarantee Agreement, including applicable covenants, events of default, mandatory prepayment events, and conditions to borrowing. Cost and Schedule Georgia Power's approximate proportionate share of the remaining estimated capital cost to complete Plant Vogtle Units 3 and 4 by the expected in-service dates of November 2021 and November 2022, respectively, is as follows: (in billions) Base project capital cost forecast (a)(b) $ 8.4 Construction contingency estimate 0.1 Total project capital cost forecast (a)(b) 8.5 Net investment as of June 30, 2020 (b) (6.6 ) Remaining estimate to complete (a) $ 1.9 (a) Excludes financing costs expected to be capitalized through AFUDC of approximately $260 million , of which $52 million had been accrued through June 30, 2020 . (b) Net of $1.7 billion received from Toshiba under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds. Georgia Power estimates that its financing costs for construction of Plant Vogtle Units 3 and 4 will total approximately $3.0 billion , of which $2.4 billion had been incurred through June 30, 2020 . As part of its ongoing processes, Southern Nuclear continues to evaluate cost and schedule forecasts on a regular basis to incorporate current information available, particularly in the areas of engineering support, commodity installation, system turnovers, and workforce statistics. During the second quarter 2020, approximately $194 million of construction contingency was assigned to the base capital cost forecast for cost risks including, among other things, construction productivity, including the April 2020 reduction in workforce designed to mitigate impacts of the COVID-19 pandemic described below, field support, subcontracts, engineering resources, and procurement. The second quarter 2020 assignment of contingency exceeded the remaining balance of the $366 million construction contingency originally established in the second quarter 2018 by approximately $34 million . Through June 30, 2020, assignments of contingency for cost risks also have included, among other factors, construction productivity; craft labor incentives; adding resources for supervision, field support, project management, initial test program, start-up, and operations and engineering support; subcontracts; and procurement. As a result of these factors, Southern Nuclear recommended establishing additional construction contingency, of which Georgia Power's share is approximately $115 million , for further potential risks including, among other factors, construction productivity and expected impacts of the COVID-19 pandemic; adding resources for supervision, field support, project management, initial test program, start-up, and operations and engineering support; subcontracts; and procurement. After considering the significant level of uncertainty that exists regarding the future recoverability of these costs since the ultimate outcome of these matters is subject to the outcome of future assessments by management, as well as Georgia PSC decisions in future regulatory proceedings, Georgia Power recorded a total pre-tax charge to income of $149 million ( $111 million after tax) for the increase in the total project capital cost forecast as of June 30, 2020. As and when these amounts are spent, Georgia Power may request the Georgia PSC to evaluate those expenditures for rate recovery. In April 2019, Southern Nuclear established aggressive target values for monthly construction production and system turnover activities as part of a strategy to maintain and, where possible, build margin to the regulatory-approved in-service dates of November 2021 for Unit 3 and November 2022 for Unit 4. Through early 2020, the project faced challenges with the April 2019 aggressive strategy targets including, but not limited to, electrical and pipefitting labor productivity and work package closure rates, which resulted in a backlog of activities and completion percentages below the April 2019 aggressive strategy targets. In February 2020, Southern Nuclear updated its cost and schedule forecast, which, at that time, did not change the total project capital cost forecast and confirmed the expected in-service dates of November 2021 for Unit 3 and November 2022 for Unit 4. This update included initiatives to improve productivity while refining and extending system turnover plans and certain near-term milestone dates. Other milestone dates did not change. Achievement of the February 2020 aggressive site work plan relied on meeting increased monthly production and activity target values during 2020. In mid-March 2020, Southern Nuclear began implementing policies and procedures designed to mitigate the risk of transmission of COVID-19 at the construction site, including worker distancing measures, isolating individuals who have tested positive for COVID-19, are showing symptoms consistent with COVID-19, are being tested for COVID-19, or have been in close contact with such persons, requiring self-quarantine, and adopting additional precautionary measures. In April 2020, Georgia Power, acting for itself and as agent for the other Vogtle Owners, announced a reduction in workforce at Plant Vogtle Units 3 and 4, which totaled approximately 20% of the then-existing site workforce. This reduction in workforce was a mitigation action intended to address the impact of the COVID-19 pandemic on the Plant Vogtle Units 3 and 4 workforce and construction site, including challenges with labor productivity that were exacerbated by the impact of the COVID-19 pandemic. The April 2020 workforce reduction was intended to provide operational efficiencies by increasing productivity of the remaining workforce and reducing workforce fatigue and absenteeism. Further, it was also intended to allow for increased social distancing by the workforce and facilitate compliance with the recommendations from the Centers for Disease Control and Prevention. The April 2020 workforce reduction did reduce absenteeism, providing an improvement in operational efficiency and allowing for increased social distancing. From the initial peak in April 2020, the number of active cases at the site declined significantly during May and early June, but began increasing again in mid-June and continues to impact productivity levels and pace of activity completion. As a result of these factors, overall production improvements have not been achieved at the levels anticipated, contributing to the allocation of, and increase in, construction contingency described above. Through mid-July 2020, Unit 3 mechanical, electrical, and subcontract activities continued to build a backlog to Southern Nuclear's February 2020 aggressive site work plan. To address these issues, in July 2020, Southern Nuclear updated its aggressive site work plan for both Unit 3 and Unit 4. To meet the targets in the July 2020 aggressive site work plan, absenteeism rates must continue to normalize and overall construction productivity and production levels, including subcontractors, must significantly improve and be sustained above pre-pandemic levels. In addition, appropriate levels of craft laborers, particularly electrical and pipefitter craft labor, must be added and maintained. While Southern Nuclear's July 2020 aggressive site work plan extended milestone dates from the February 2020 aggressive site work plan, Georgia Power still expects to achieve the regulatory-approved in-service dates of November 2021 and November 2022 for Plant Vogtle Units 3 and 4, respectively. Southern Nuclear and Georgia Power continue to believe that pursuit of an aggressive site work plan is an appropriate strategy to achieve completion of the units by their regulatory-approved in-service dates. As construction, including subcontract work, continues and testing and system turnover activities increase, challenges with management of contractors and vendors; subcontractor performance; supervision of craft labor and related productivity, particularly in the installation of electrical, mechanical, and instrumentation and controls commodities, ability to attract and retain craft labor, and/or related cost escalation; procurement, fabrication, delivery, assembly, installation, system turnover, and the initial testing and start-up, including any required engineering changes or any remediation related thereto, of plant systems, structures, or components (some of which are based on new technology that only within the last few years began initial operation in the global nuclear industry at this scale), any of which may require additional labor and/or materials; or other issues could arise and change the projected schedule and estimated cost. In addition, the continuing effects of the COVID-19 pandemic could further disrupt or delay construction, testing, supervisory, and support activities at Plant Vogtle Units 3 and 4. Georgia Power's proportionate share of the estimated incremental cost associated with COVID-19 mitigation actions and impacts on construction productivity is currently estimated to be between $70 million and $115 million , which is included in the total project capital cost forecast and assumes (i) absenteeism rates continue to normalize and (ii) the intended productivity efficiencies and production targets assumed in Southern Nuclear's July 2020 aggressive site work plan are realized in the coming months. However, the ultimate impact of the COVID-19 pandemic on the construction schedule and budget for Plant Vogtle Units 3 and 4 cannot be determined at this time. There have been technical and procedural challenges to the construction and licensing of Plant Vogtle Units 3 and 4 at the federal and state level and additional challenges may arise. Processes are in place that are designed to assure compliance with the requirements specified in the Westinghouse Design Control Document and the combined construction and operating licenses, including inspections by Southern Nuclear and the NRC that occur throughout construction. As a result of such compliance processes, certain license amendment requests have been filed and approved or are pending before the NRC. Various design and other licensing-based compliance matters, including the timely submittal by Southern Nuclear of the ITAAC documentation for each unit and the related reviews and approvals by the NRC necessary to support NRC authorization to load fuel, may arise, which may result in additional license amendments or require other resolution. As part of the aggressive site work plan, in January 2020, Southern Nuclear notified the NRC of its intent to load fuel in 2020. On May 11, 2020, the Blue Ridge Environmental Defense League filed a petition with the NRC that challenges a license amendment request. On June 15, 2020, the NRC issued an appealable order rejecting Nuclear Watch South's April 20, 2020 petition requesting a hearing and challenging the closure of certain ITAAC. If any license amendment requests or other licensing-based compliance issues are not resolved in a timely manner, there may be delays in the project schedule that could result in increased costs. The ultimate outcome of these matters cannot be determined at this time. However, any extension of the regulatory-approved project schedule is currently estimated to result in additional base capital costs of approximately $50 million per month, based on Georgia Power's ownership interests, and AFUDC of approximately $10 million per month. While Georgia Power is not precluded from seeking recovery of any future capital cost forecast increase, management will ultimately determine whether or not to seek recovery. Any further changes to the capital cost forecast that are not expected to be recoverable through regulated rates will be required to be charged to income and such charges could be material. Joint Owner Contracts In November 2017, the Vogtle Owners entered into an amendment to their joint ownership agreements for Plant Vogtle Units 3 and 4 to provide for, among other conditions, additional Vogtle Owner approval requirements. Effective in August 2018, the Vogtle Owners further amended the joint ownership agreements to clarify and provide procedures for certain provisions of the joint ownership agreements related to adverse events that require the vote of the holders of at least 90% of the ownership interests in Plant Vogtle Units 3 and 4 to continue construction (as amended, and together with the November 2017 amendment, the Vogtle Joint Ownership Agreements). The Vogtle Joint Ownership Agreements also confirm that the Vogtle Owners' sole recourse against Georgia Power or Southern Nuclear for any action or inaction in connection with their performance as agent for the Vogtle Owners is limited to removal of Georgia Power and/or Southern Nuclear as agent, except in cases of willful misconduct. As a result of an increase in the total project capital cost forecast and Georgia Power's decision not to seek rate recovery of the increase in the base capital costs in conjunction with the nineteenth VCM report in 2018, the holders of at least 90% of the ownership interests in Plant Vogtle Units 3 and 4 were required to vote to continue construction. In September 2018, the Vogtle Owners unanimously voted to continue construction of Plant Vogtle Units 3 and 4. Amendments to the Vogtle Joint Ownership Agreements In connection with the vote to continue construction, Georgia Power entered into (i) a binding term sheet (Vogtle Owner Term Sheet) with the other Vogtle Owners and MEAG Power's wholly-owned subsidiaries MEAG Power SPVJ, LLC (MEAG SPVJ), MEAG Power SPVM, LLC (MEAG SPVM), and MEAG Power SPVP, LLC (MEAG SPVP) to take certain actions which partially mitigate potential financial exposure for the other Vogtle Owners, including additional amendments to the Vogtle Joint Ownership Agreements and the purchase of PTCs from the other Vogtle Owners at pre-established prices, and (ii) a term sheet (MEAG Term Sheet) with MEAG Power and MEAG SPVJ to provide up to $300 million of funding with respect to MEAG SPVJ's ownership interest in Plant Vogtle Units 3 and 4 under certain circumstances. In January 2019, Georgia Power, MEAG Power, and MEAG SPVJ entered into an agreement to implement the provisions of the MEAG Term Sheet. In February 2019, Georgia Power, the other Vogtle Owners, and MEAG Power's wholly-owned subsidiaries MEAG SPVJ, MEAG SPVM, and MEAG SPVP entered into certain amendments to the Vogtle Joint Ownership Agreements to implement the provisions of the Vogtle Owner Term Sheet (Global Amendments). As previously disclosed, pursuant to the Global Amendments: (i) each Vogtle Owner must pay its proportionate share of qualifying construction costs for Plant Vogtle Units 3 and 4 based on its ownership percentage up to the estimated cost at completion (EAC) for Plant Vogtle Units 3 and 4 which formed the basis of Georgia Power's forecast of $8.4 billion in the nineteenth VCM plus $800 million ; (ii) Georgia Power will be responsible for 55.7% of actual qualifying construction costs between $800 million and $1.6 billion over the EAC in the nineteenth VCM (resulting in $80 million of potential additional costs to Georgia Power), with the remaining Vogtle Owners responsible for 44.3% of such costs pro rata in accordance with their respective ownership interests; and (iii) Georgia Power will be responsible for 65.7% of qualifying construction costs between $1.6 billion and $2.1 billion over the EAC in the nineteenth VCM (resulting in a further $100 million of potential additional costs to Georgia Power), with the remaining Vogtle Owners responsible for 34.3% of such costs pro rata in accordance with their respective ownership interests. If the EAC is revised and exceeds the EAC in the nineteenth VCM by more than $2.1 billion , each of the other Vogtle Owners will have a one-time option at the time the project budget forecast is so revised to tender a portion of its ownership interest to Georgia Power in exchange for Georgia Power's agreement to pay 100% of such Vogtle Owner's remaining share of total construction costs in excess of the EAC in the nineteenth VCM plus $2.1 billion . In addition, pursuant to the Global Amendments, the holders of at least 90% of the ownership interests in Plant Vogtle Units 3 and 4 must vote to continue construction if certain adverse events occur, including, among other events: (i) the bankruptcy of Toshiba; (ii) the termination or rejection in bankruptcy of certain agreements, including the Vogtle Services Agreement, the Bechtel Agreement, or the agency agreement with Southern Nuclear; (iii) Georgia Power's public announcement of its intention not to submit for rate recovery any portion of its investment in Plant Vogtle Units 3 and 4 or the Georgia PSC determines that any of Georgia Power's costs relating to the construction of Plant Vogtle Units 3 and 4 will not be recovered in retail rates, excluding any additional amounts paid by Georgia Power on behalf of the other Vogtle Owners pursuant to the Global Amendments described above and the first 6% of costs during any six -month VCM reporting period that are disallowed by the Georgia PSC for recovery, or for which Georgia Power elects not to seek cost recovery, through retail rates; and (iv) an incremental extension of one year or more over the most recently approved schedule. The ultimate outcome of these matters cannot be determined at this time. Regulatory Matters In 2009, the Georgia PSC voted to certify construction of Plant Vogtle Units 3 and 4 with a certified capital cost of $4.418 billion . In addition, in 2009 the Georgia PSC approved inclusion of the Plant Vogtle Units 3 and 4 related CWIP accounts in rate base, and the State of Georgia enacted the Georgia Nuclear Energy Financing Act, which allows Georgia Power to recover financing costs for Plant Vogtle Units 3 and 4. Financing costs are recovered on all applicable certified costs through annual adjustments to the NCCR tariff up to the certified capital cost of $4.418 billion . At June 30, 2020 , Georgia Power had recovered approximately $2.4 billion of financing costs. Financing costs related to capital costs above $4.418 billion are being recognized through AFUDC and are expected to be recovered through retail rates over the life of Plant Vogtle Units 3 and 4; however, Georgia Power will not record AFUDC related to any capital costs in excess of the total deemed reasonable by the Georgia PSC (currently $7.3 billion ) and not requested for rate recovery. In December 2019, the Georgia PSC approved Georgia Power's request to decrease the NCCR tariff by $62 million annually, effective January 1, 2020. Georgia Power is required to file semi-annual VCM reports with the Georgia PSC by February 28 and August 31 of each year. In 2013, in connection with the eighth VCM report, the Georgia PSC approved a stipulation between Georgia Power and the staff of the Georgia PSC to waive the requirement to amend the Plant Vogtle Units 3 and 4 certificate in accordance with the 2009 certification order until the completion of Plant Vogtle Unit 3, or earlier if deemed appropriate by the Georgia PSC and Georgia Power. In 2016, the Georgia PSC voted to approve a settlement agreement (Vogtle Cost Settlement Agreement) resolving certain prudency matters in connection with the fifteenth VCM report. In December 2017, the Georgia PSC voted to approve (and issued its related order on January 11, 2018) Georgia Power's seventeenth VCM report and modified the Vogtle Cost Settlement Agreement. The Vogtle Cost Settlement Agreement, as modified by the January 11, 2018 order, resolved the following regulatory matters related to Plant Vogtle Units 3 and 4: (i) none of the $3.3 billion of costs incurred through December 31, 2015 and reflected in the fourteenth VCM report should be disallowed from rate base on the basis of imprudence; (ii) the Contractor Settlement Agreement was reasonable and prudent and none of the amounts paid pursuant to the Contractor Settlement Agreement should be disallowed from rate base on the basis of imprudence; (iii) (a) capital costs incurred up to $5.68 billion would be presumed to be reasonable and prudent with the burden of proof on any party challenging such costs, (b) Georgia Power would have the burden to show that any capital costs above $5.68 billion were prudent, and (c) a revised capital cost forecast of $7.3 billion (after reflecting the impact of payments received under the Guarantee Settlement Agreement and related customer refunds) was found reasonable; (iv) construction of Plant Vogtle Units 3 and 4 should be completed, with Southern Nuclear serving as project manager and Bechtel as primary contractor; (v) approved and deemed reasonable Georgia Power's revised schedule placing Plant Vogtle Units 3 and 4 in service in November 2021 and November 2022, respectively; (vi) confirmed that the revised cost forecast does not represent a cost cap and that prudence decisions on cost recovery will be made at a later date, consistent with applicable Georgia law; (vii) reduced the ROE used to calculate the NCCR tariff (a) from 10.95% (the ROE rate setting point authorized by the Georgia PSC in the 2013 ARP) to 10.00% effective January 1, 2016, (b) from 10.00% to 8.30% , effective January 1, 2020, and (c) from 8.30% to 5.30% , effective January 1, 2021 (provided that the ROE in no case will be less than Georgia Power's average cost of long-term debt); (viii) reduced the ROE used for AFUDC equity for Plant Vogtle Units 3 and 4 from 10.00% to Georgia Power's average cost of long-term debt, effective January 1, 2018; and (ix) agreed that upon Unit 3 reaching commercial operation, retail base rates would be adjusted to include carrying costs on those capital costs deemed prudent in the Vogtle Cost Settlement Agreement. The January 11, 2018 order also stated that if Plant Vogtle Units 3 and 4 are not commercially operational by June 1, 2021 and June 1, 2022, respectively, the ROE used to calculate the NCCR tariff will be further reduced by 10 basis points each month (but not lower than Georgia Power's average cost of long-term debt) until the respective Unit is commercially operational. The ROE reductions negatively impacted earnings by approximately $75 million in 2019 and are estimated to have negative earnings impacts of approximately $145 million , $255 million , and $200 million in 2020, 2021, and 2022, respectively. In its January 11, 2018 order, the Georgia PSC also stated if other conditions change and assumptions upon which Georgia Power's seventeenth VCM report are based do not materialize, the Georgia PSC reserved the right to reconsider the decision to continue construction. In February 2018, Georgia Interfaith Power & Light, Inc. (GIPL) and Partnership for Southern Equity, Inc. (PSE) filed a petition appealing the Georgia PSC's January 11, 2018 order with the Fulton County Superior Court. In March 2018, Georgia Watch filed a similar appeal to the Fulton County Superior Court for judicial review of the Georgia PSC's decision and denial of Georgia Watch's motion for reconsideration. In December 2018, the Fulton County Superior Court granted Georgia Power's motion to dismiss the two appeals. In January 2019, GIPL, PSE, and Georgia Watch filed an appeal of this decision with the Georgia Court of Appeals. In October 2019, the Georgia Court of Appeals issued an opinion affirming the Fulton County Superior Court's ruling that the Georgia PSC's January 11, 2018 order was not a final, appealable decision. In addition, the Georgia Court of Appeals remanded the case to the Fulton County Superior Court to clarify its ruling as to whether the petitioners showed that review of the Georgia PSC's final order would not provide them an adequate remedy. On April 21, 2020, the Fulton County Superior Court granted Georgia Power's motion to dismiss the two appeals. The petitioners filed a notice of appeal of the dismissal on May 20, 2020. Georgia Power believes the petitions have no merit; however, an adverse outcome in the litigation combined with subsequent adverse action by the Georgia PSC could have a material impact on Southern Company's and Georgia Power's results of operations, financial condition, and liquidity. The Georgia PSC has approved 21 VCM reports covering the periods through June 30, 2019, including total construction capital costs incurred through that date of $6.7 billion (before $1.7 billion of payments received under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds). On August 18, 2020, the Georgia PSC is scheduled to vote on Georgia Power's twenty-second VCM report, which requested approval of $674 mil

CONTINGENCIES

CONTINGENCIES	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES	CONTINGENCIES See Note 3 to the financial statements in Item 8 of the Form 10-K for information relating to various lawsuits and other contingencies. General Litigation Matters The Registrants are involved in various other matters being litigated and regulatory matters. The ultimate outcome of such pending or potential litigation or regulatory matters against each Registrant and any subsidiaries cannot be determined at this time; however, for current proceedings not specifically reported herein, management does not anticipate that the ultimate liabilities, if any, arising from such current proceedings would have a material effect on such Registrant's financial statements. The Registrants believe the pending legal challenges discussed below have no merit; however, the ultimate outcome of these matters cannot be determined at this time. Southern Company In January 2017, a securities class action complaint was filed in the U.S. District Court for the Northern District of Georgia by Monroe County Employees' Retirement System on behalf of all persons who purchased shares of Southern Company's common stock between April 25, 2012 and October 29, 2013. The complaint names as defendants Southern Company, certain of its current and former officers, and certain former Mississippi Power officers and alleges that the defendants made materially false and misleading statements regarding the Kemper County energy facility in violation of certain provisions under the Securities Exchange Act of 1934, as amended. The complaint seeks, among other things, compensatory damages and litigation costs and attorneys' fees. In 2017, the plaintiffs filed an amended complaint that provided additional detail about their claims, increased the purported class period by one day, and added certain other former Mississippi Power officers as defendants. Also in 2017, the defendants filed a motion to dismiss the plaintiffs' amended complaint with prejudice, to which the plaintiffs filed an opposition. In 2018, the court issued an order dismissing certain claims against certain officers of Southern Company and Mississippi Power and dismissing the allegations related to a number of the statements that plaintiffs challenged as being false or misleading. In 2018, the court denied the defendants' motion for reconsideration and also denied a motion to certify the issue for interlocutory appeal. In the third quarter 2019, the court certified the plaintiffs' proposed class and the defendants filed a petition for interlocutory appeal of the class certification order with the U.S. Court of Appeals for the Eleventh Circuit. In December 2019, the U.S. District Court for the Northern District of Georgia entered an order staying all deadlines in the case pending mediation. The stay automatically expired on March 31, 2020; however, in light of the COVID-19 pandemic, the U.S. District Court for the Northern District of Georgia vacated all existing discovery deadlines until June 15, 2020. On June 30, 2020, the court entered a revised scheduling order, which resumed discovery and set out remaining case deadlines. In February 2017, Jean Vineyard and Judy Mesirov each filed a shareholder derivative lawsuit in the U.S. District Court for the Northern District of Georgia. Each of these lawsuits names as defendants Southern Company, certain of its directors, certain of its current and former officers, and certain former Mississippi Power officers. In 2017, these two shareholder derivative lawsuits were consolidated in the U.S. District Court for the Northern District of Georgia. The complaints allege that the defendants caused Southern Company to make false or misleading statements regarding the Kemper County energy facility cost and schedule. Further, the complaints allege that the defendants were unjustly enriched and caused the waste of corporate assets and also allege that the individual defendants violated their fiduciary duties. Each plaintiff seeks to recover, on behalf of Southern Company, unspecified actual damages and, on each plaintiff's own behalf, attorneys' fees and costs in bringing the lawsuit. Each plaintiff also seeks certain changes to Southern Company's corporate governance and internal processes. In 2018, the court entered an order staying this lawsuit until 30 days after the resolution of any dispositive motions or any settlement, whichever is earlier, in the securities class action. In May 2017, Helen E. Piper Survivor's Trust filed a shareholder derivative lawsuit in the Superior Court of Gwinnett County, Georgia that names as defendants Southern Company, certain of its directors, certain of its current and former officers, and certain former Mississippi Power officers. The complaint alleges that the individual defendants, among other things, breached their fiduciary duties in connection with schedule delays and cost overruns associated with the construction of the Kemper County energy facility. The complaint further alleges that the individual defendants authorized or failed to correct false and misleading statements regarding the Kemper County energy facility schedule and cost and failed to implement necessary internal controls to prevent harm to Southern Company. The plaintiff seeks to recover, on behalf of Southern Company, unspecified actual damages and disgorgement of profits and, on its behalf, attorneys' fees and costs in bringing the lawsuit. The plaintiff also seeks certain unspecified changes to Southern Company's corporate governance and internal processes. In 2018, the court entered an order staying this lawsuit until 30 days after the resolution of any dispositive motions or any settlement, whichever is earlier, in the securities class action. In August 2019, the court granted a motion filed by the plaintiff in July 2019 to substitute a new named plaintiff, Martin J. Kobuck, in place of Helen E. Piper Survivor's Trust. Georgia Power In 2011, plaintiffs filed a putative class action against Georgia Power in the Superior Court of Fulton County, Georgia alleging that Georgia Power's collection in rates of amounts for municipal franchise fees (which fees are paid to municipalities) exceeded the amounts allowed in orders of the Georgia PSC and alleging certain state law claims. This case has been ruled upon and appealed numerous times over the last several years. In one recent appeal, the Georgia Supreme Court remanded the case and noted that the trial court could refer the matter to the Georgia PSC to interpret its tariffs. Following a motion by Georgia Power, in February 2019, the Superior Court of Fulton County ordered the parties to submit petitions to the Georgia PSC for a declaratory ruling and also conditionally certified the proposed class. In March 2019, Georgia Power and the plaintiffs filed petitions with the Georgia PSC seeking confirmation of the proper application of the municipal franchise fee schedule pursuant to the Georgia PSC's orders. Also in March 2019, Georgia Power appealed the class certification decision to the Georgia Court of Appeals. In October 2019, the Georgia PSC issued an order that found Georgia Power has appropriately implemented the municipal franchise fee schedule. On March 11, 2020, the Georgia Court of Appeals vacated the Superior Court of Fulton County's February 2019 order granting conditional class certification. The Court of Appeals remanded the case to the Superior Court of Fulton County for further proceedings. The amount of any possible losses cannot be calculated at this time because, among other factors, it is unknown whether a class will be certified, the ultimate composition of any class, and whether any losses would be subject to recovery from any municipalities. On July 29, 2020, a group of individual plaintiffs filed a complaint in the Superior Court of Fulton County, Georgia against Georgia Power alleging that releases from Plant Scherer have impacted groundwater, surface water, and air, resulting in alleged personal injuries and property damage. The plaintiffs seek an unspecified amount of monetary damages including punitive damages, a medical monitoring fund, and injunctive relief. Mississippi Power In May 2018, Southern Company and Mississippi Power received a notice of dispute and arbitration demand filed by Martin Product Sales, LLC (Martin) based on two agreements, both related to Kemper IGCC byproducts for which Mississippi Power provided termination notices in 2017. Martin alleges breach of contract, breach of good faith and fair dealing, fraud and misrepresentation, and civil conspiracy and makes a claim for damages in the amount of approximately $143 million , as well as additional unspecified damages, attorney's fees, costs, and interest. A portion of the claim for damages was on behalf of Martin Transport, Inc. (Martin Transport), an affiliate of Martin. In May 2019, the arbitration panel denied Mississippi Power's and Southern Company's motions to dismiss. In September 2019, Martin Transport filed a separate complaint against Mississippi Power in the Circuit Court of Kemper County, Mississippi alleging claims of fraud, negligent misrepresentation, promissory estoppel, and equitable estoppel, each arising out of the same alleged facts and circumstances that underlie Martin's arbitration demand. Martin Transport seeks compensatory damages of $5 million and punitive damages of $50 million . In November 2019, Martin Transport's claim was combined with the Martin arbitration case and the separate court case was dismissed. In December 2019, Southern Company and Mississippi Power each filed motions for summary judgment on all claims. On February 17, 2020, the arbitration panel granted Southern Company's motion and dismissed Southern Company from the arbitration. On March 12, 2020, the arbitration panel denied Mississippi Power's motions for summary judgment. An adverse outcome in this proceeding could have a material impact on Southern Company's and Mississippi Power's financial statements. In November 2018, Ray C. Turnage and 10 other individual plaintiffs filed a putative class action complaint against Mississippi Power and the three then-serving members of the Mississippi PSC in the U.S. District Court for the Southern District of Mississippi. Mississippi Power received Mississippi PSC approval in 2013 to charge a mirror CWIP rate premised upon including in its rate base pre-construction and construction costs for the Kemper IGCC prior to placing the Kemper IGCC into service. The Mississippi Supreme Court reversed that approval and ordered Mississippi Power to refund the amounts paid by customers under the previously-approved mirror CWIP rate. The plaintiffs allege that the initial approval process, and the amount approved, were improper. They also allege that Mississippi Power underpaid customers by up to $23.5 million in the refund process by applying an incorrect interest rate. The plaintiffs seek to recover, on behalf of themselves and their putative class, actual damages, punitive damages, pre-judgment interest, post-judgment interest, attorney's fees, and costs. In response to Mississippi Power and the Mississippi PSC each filing a motion to dismiss, the plaintiffs filed an amended complaint in March 2019. The amended complaint included four additional plaintiffs and additional claims for gross negligence, reckless conduct, and intentional wrongdoing. Mississippi Power and the Mississippi PSC have each filed a motion to dismiss the amended complaint. On March 27, 2020, the Mississippi PSC's motion to dismiss was granted. Also on March 27, 2020, the plaintiffs filed a motion seeking to name the new members of the Mississippi PSC, the Mississippi Development Authority, and Southern Company as additional defendants and add a cause of action against all defendants based on a dormant commerce clause theory under the U.S. Constitution. On April 9, 2020 and April 10, 2020, Mississippi Power and the Mississippi PSC, respectively, filed responses opposing the motion for leave to file a second amended complaint. On May 26, 2020, Mississippi Power's motion to dismiss the first amended complaint filed in 2019 was granted. On July 6, 2020, the plaintiffs filed a motion for revision of the court's decision. The plaintiffs' motion for leave to file a second amended complaint also remains pending before the court. An adverse outcome in this proceeding could have a material impact on Mississippi Power's financial statements. See Note 2 to the financial statements under "Mississippi Power – Kemper County Energy Facility" in Item 8 of the Form 10-K for additional information. Environmental Remediation The Southern Company system must comply with environmental laws and regulations governing the handling and disposal of waste and releases of hazardous substances. Under these various laws and regulations, the Southern Company system could incur substantial costs to clean up affected sites. The traditional electric operating companies and the natural gas distribution utilities in Illinois and Georgia have each received authority from their respective state PSCs or other applicable state regulatory agencies to recover approved environmental compliance costs through regulatory mechanisms. These regulatory mechanisms are adjusted annually or as necessary within limits approved by the state PSCs or other applicable state regulatory agencies. Georgia Power's environmental remediation liability was $14 million and $15 million as of June 30, 2020 and December 31, 2019 , respectively. Georgia Power has been designated or identified as a potentially responsible party at sites governed by the Georgia Hazardous Site Response Act and/or by the federal Comprehensive Environmental Response, Compensation, and Liability Act, and assessment and potential cleanup of such sites is expected. In December 2019, Mississippi Power entered into an agreement with the Mississippi Commission on Environmental Quality related to groundwater conditions arising from the closed ash pond at Plant Watson. Mississippi Power will complete an assessment and remediation consistent with the requirements of the agreement and the CCR Rule. Potential remediation activities and related cost estimates are pending the result of further site assessment and cannot be determined at this time. Mississippi Power expects to recover the retail portion of remedial costs through the ECO Plan and the wholesale portion through MRA rates. Southern Company Gas' environmental remediation liability was $253 million and $269 million as of June 30, 2020 and December 31, 2019 , respectively, based on the estimated cost of environmental investigation and remediation associated with known current and former manufactured gas plant operating sites. These environmental remediation expenditures are generally recoverable from customers through rate mechanisms approved by the applicable state regulatory agencies of the natural gas distribution utilities. The ultimate outcome of these matters cannot be determined at this time; however, as a result of the regulatory treatment for environmental remediation expenses described above, the final disposition of these matters is not expected to have a material impact on the financial statements of the applicable Registrants. Other Matters Southern Company See Notes 1 and 3 under "Leveraged Leases" and "Other Matters – Southern Company," respectively, in Item 8 of the Form 10-K for discussion of challenges associated with a leveraged lease agreement with a subsidiary of Southern Holdings. While all required lease payments through June 30, 2020 have been paid in full, the operational and remarketing risks and the resulting cash liquidity challenges persist and significant concerns continue regarding the lessee's ability to make the remaining required semi-annual lease payments to the Southern Holdings subsidiary through the term of the lease. In its annual impairment analysis of the expected residual value of the generation assets and the overall collectability of the related lease receivable, Southern Company uses multiple scenarios of long-term market energy prices to estimate the cash flows expected to be received from remarketing the generation assets following the expiration of the existing PPA in 2032 and the residual value of the generation assets at the end of the lease in 2047. Southern Company received the latest annual forecasts of natural gas prices during the second quarter 2020 and considered the significant decline in forecasted prices to be an indicator of potential impairment that required an interim impairment assessment. Accordingly, consistent with prior years, Southern Company evaluated the recoverability of the lease receivable and the expected residual value of the generation assets under various natural gas price scenarios. Based on the current forecasts of energy prices in the years following the expiration of the existing PPA, Southern Company concluded that it is no longer probable that any of the associated rental payments will be received, because it is no longer probable the generation assets will be successfully remarketed and continue to operate after that date. During the second quarter 2020, Southern Company revised the estimated cash flows to be received under the leveraged lease to reflect this conclusion, which resulted in a full impairment of the lease investment and a pre-tax charge to earnings of $154 million ( $74 million after tax). If any future lease payment due prior to the expiration of the associated PPA is not paid in full, the Southern Holdings subsidiary may be unable to make its corresponding payment to the holders of the underlying non-recourse debt related to the generation assets. Failure to make the required payment to the debtholders could represent an event of default that would give the debtholders the right to foreclose on, and take ownership of, the generation assets, in effect terminating the lease. As the full amount of the lease investment has been charged against earnings as of June 30, 2020, termination would not be expected to result in additional charges. Southern Company will continue to monitor the operational performance of the underlying assets and evaluate the ability of the lessee to continue to make the required lease payments and meet its obligations associated with a future closure or retirement of the generation assets and associated properties, including the dry ash landfill. Mississippi Power Kemper County Energy Facility See Note 2 to the financial statements under "Mississippi Power – Kemper County Energy Facility" in Item 8 of the Form 10-K for additional information. As the mining permit holder, Liberty Fuels Company, LLC has a legal obligation to perform mine reclamation and Mississippi Power has a contractual obligation to fund all reclamation activities related to the lignite mine and equipment and mineral reserves located around the Kemper County energy facility site. As a result of the abandonment of the Kemper IGCC, final mine reclamation began in 2018 and is expected to be substantially completed in 2020, with monitoring expected to continue through 2027. See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information. Dismantlement of the abandoned gasifier-related assets and site restoration activities are expected to be completed in 2025. The additional pre-tax period costs associated with dismantlement and site restoration activities, including related costs for compliance and safety, ARO accretion, and property taxes, are estimated to total $5 million for the remainder of 2020, $16 million in 2021, and $11 million to $13 million annually in 2022 through 2025. In addition, closure costs for the mine and gasifier-related assets, currently estimated at up to $6 million pre-tax (excluding dismantlement costs, net of salvage), may be incurred during the remainder of 2020. In December 2019, Mississippi Power transferred ownership of the CO 2 pipeline to an unrelated gas pipeline company, with no resulting impact on income. In conjunction with the transfer of the CO 2 pipeline, the parties agreed to enter into a 15 -year firm transportation agreement, which is expected to be signed by the end of 2020, providing for the conversion by the pipeline company of the CO 2 pipeline to a natural gas pipeline to be used for the delivery of natural gas to Plant Ratcliffe. The agreement will be treated as a finance lease for accounting purposes upon commencement. In 2018, Mississippi Power filed with the DOE its request for property closeout certification under the contract related to the $387 million of grants received for the Kemper County energy facility. Mississippi Power expects to close out the DOE contract in 2020. In connection with the DOE closeout discussions, in April 2019, the Civil Division of the Department of Justice informed Southern Company and Mississippi Power of an investigation related to the Kemper County energy facility. The ultimate outcome of this matter cannot be determined at this time; however, it could have a material impact on Southern Company's and Mississippi Power's financial statements. Plant Daniel In conjunction with Southern Company's sale of Gulf Power, Mississippi Power and Gulf Power agreed to seek a restructuring of their 50% undivided ownership interests in Plant Daniel such that each of them would, after the restructuring, own 100% of a generating unit. On April 24, 2020, Mississippi Power and Gulf Power amended the terms of the agreement to extend the deadline from May 1, 2020 to August 1, 2020 for Mississippi Power to notify Gulf Power of which generating unit it has selected for 100% ownership. Mississippi Power and Gulf Power are continuing negotiations on a mutually acceptable revised operating agreement for Plant Daniel and, as a result, the parties have agreed not to select a specific unit on August 1, 2020. The impacts of operating the units on an individual basis continue to be evaluated by Mississippi Power and any transfer of ownership would be subject to approval by the FERC and the Mississippi PSC. The ultimate outcome of this matter cannot be determined at this time. Southern Company Gas See Notes 3 and 7 to the financial statements in Item 8 of the Form 10-K under "Other Matters – Southern Company Gas" and "Southern Company Gas," respectively, and Note (E) under " Southern Company Gas " for additional information. On March 24, 2020, Southern Company Gas completed the sale of its interest in Atlantic Coast Pipeline. See Note (K) under "Southern Company Gas" for additional information. On February 20, 2020, the FERC approved a two-year extension for PennEast Pipeline to complete the project by January 19, 2022. In September 2019, an appellate court ruled that the PennEast Pipeline does not have federal eminent domain authority over lands in which a state has property rights interests. On June 29, 2020, the U.S. Supreme Court requested the U.S. Solicitor General to provide an opinion on PennEast Pipeline's petition for a writ of certiorari seeking its review of the appellate court's decision. Expected project costs related to the PennEast Pipeline for Southern Company Gas total approximately $300 million , excluding financing costs. The ultimate outcome of the PennEast Pipeline construction project cannot be determined at this time; however, any work delays, whether caused by judicial or regulatory action, abnormal weather, or other conditions, may result in additional cost or schedule modifications or, ultimately, in project cancellation, any of which could result in impairment of Southern Company Gas' investment and could have a significant impact on Southern Company's financial statements and a material impact on Southern Company Gas' financial statements.

REVENUE FROM CONTRACTS WITH CUS

REVENUE FROM CONTRACTS WITH CUSTOMERS AND LEASE INCOME	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
REVENUE FROM CONTRACTS WITH CUSTOMERS AND LEASE INCOME	REVENUE FROM CONTRACTS WITH CUSTOMERS AND LEASE INCOME Revenue from Contracts with Customers The Registrants generate revenues from a variety of sources, some of which are not accounted for as revenue from contracts with customers, such as leases, derivatives, and certain cost recovery mechanisms. See Note 1 to the financial statements under "Revenues" in Item 8 of the Form 10-K for additional information on the revenue policies of the Registrants. See " Lease Income " herein and Note (J) for additional information on revenue accounted for under lease and derivative accounting guidance, respectively. The following table disaggregates revenue from contracts with customers for the three and six months ended June 30, 2020 and 2019 : Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended June 30, 2020 Operating revenues Retail electric revenues Residential $ 1,430 $ 549 $ 817 $ 64 $ — $ — Commercial 1,103 353 689 61 — — Industrial 642 302 273 67 — — Other 23 6 15 2 — — Total retail electric revenues 3,198 1,210 1,794 194 — — Natural gas distribution revenues Residential 239 — — — — 239 Commercial 58 — — — — 58 Transportation 234 — — — — 234 Industrial 5 — — — — 5 Other 49 — — — — 49 Total natural gas distribution revenues 585 — — — — 585 Wholesale electric revenues PPA energy revenues 167 28 7 2 134 — PPA capacity revenues 108 25 13 1 71 — Non-PPA revenues 50 5 2 73 59 — Total wholesale electric revenues 325 58 22 76 264 — Other natural gas revenues Wholesale gas services 341 — — — — 341 Gas marketing services 57 — — — — 57 Other natural gas revenues 8 — — — — 8 Total natural gas revenues 406 — — — — 406 Other revenues 251 44 119 6 4 — Total revenue from contracts with customers 4,765 1,312 1,935 276 268 991 Other revenue sources (a) 728 53 (7 ) 7 171 518 Other adjustments (b) (873 ) — — — — (873 ) Total operating revenues $ 4,620 $ 1,365 $ 1,928 $ 283 $ 439 $ 636 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Six Months Ended June 30, 2020 Operating revenues Retail electric revenues Residential $ 2,801 $ 1,103 $ 1,577 $ 121 $ — $ — Commercial 2,247 717 1,409 121 — — Industrial 1,323 623 555 145 — — Other 46 11 31 4 — — Total retail electric revenues 6,417 2,454 3,572 391 — — Natural gas distribution revenues Residential 736 — — — — 736 Commercial 188 — — — — 188 Transportation 499 — — — — 499 Industrial 17 — — — — 17 Other 144 — — — — 144 Total natural gas distribution revenues 1,584 — — — — 1,584 Wholesale electric revenues PPA energy revenues 326 55 15 4 259 — PPA capacity revenues 213 52 25 2 136 — Non-PPA revenues 100 24 4 142 117 — Total wholesale electric revenues 639 131 44 148 512 — Other natural gas revenues Wholesale gas services 737 — — — — 737 Gas marketing services 220 — — — — 220 Other natural gas revenues 15 — — — — 15 Total natural gas revenues 972 — — — — 972 Other revenues 441 78 214 13 7 — Total revenue from contracts with customers 10,053 2,663 3,830 552 519 2,556 Other revenue sources (a) 1,599 53 (76 ) 7 295 1,343 Other adjustments (b) (2,014 ) — — — — (2,014 ) Total operating revenues $ 9,638 $ 2,716 $ 3,754 $ 559 $ 814 $ 1,885 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended June 30, 2019 Operating revenues Retail electric revenues Residential $ 1,491 $ 592 $ 831 $ 68 $ — $ — Commercial 1,264 422 770 72 — — Industrial 766 369 327 70 — — Other 25 7 15 3 — — Total retail electric revenues 3,546 1,390 1,943 213 — — Natural gas distribution revenues Residential 229 — — — — 229 Commercial 65 — — — — 65 Transportation 213 — — — — 213 Industrial 5 — — — — 5 Other 45 — — — — 45 Total natural gas distribution revenues 557 — — — — 557 Wholesale electric revenues PPA energy revenues 208 35 17 3 163 — PPA capacity revenues 109 25 13 1 81 — Non-PPA revenues 53 3 1 89 68 — Total wholesale electric revenues 370 63 31 93 312 — Other natural gas revenues Wholesale gas services 444 — — — — 444 Gas marketing services 55 — — — — 55 Other natural gas revenues 12 — — — — 12 Total natural gas revenues 511 — — — — 511 Other revenues 238 37 95 4 3 — Total revenue from contracts with customers 5,222 1,490 2,069 310 315 1,068 Other revenue sources (a) 1,050 23 48 3 195 795 Other adjustments (b) (1,174 ) — — — — (1,174 ) Total operating revenues $ 5,098 $ 1,513 $ 2,117 $ 313 $ 510 $ 689 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Six Months Ended June 30, 2019 Operating revenues Retail electric revenues Residential $ 2,818 $ 1,151 $ 1,539 $ 128 $ — $ — Commercial 2,390 790 1,463 137 — — Industrial 1,474 707 623 144 — — Other 44 13 25 6 — — Total retail electric revenues 6,726 2,661 3,650 415 — — Natural gas distribution revenues Residential 830 — — — — 830 Commercial 235 — — — — 235 Transportation 469 — — — — 469 Industrial 22 — — — — 22 Other 161 — — — — 161 Total natural gas distribution revenues 1,717 — — — — 1,717 Wholesale electric revenues PPA energy revenues 398 67 28 5 314 — PPA capacity revenues 217 52 27 2 163 — Non-PPA revenues 108 62 3 164 109 — Total wholesale electric revenues 723 181 58 171 586 — Other natural gas revenues Wholesale gas services 1,165 — — — — 1,165 Gas marketing services 276 — — — — 276 Other natural gas revenues 22 — — — — 22 Total natural gas revenues 1,463 — — — — 1,463 Other revenues 502 83 186 10 6 — Total revenue from contracts with customers 11,131 2,925 3,894 596 592 3,180 Other revenue sources (a) 2,413 (4 ) 57 4 361 2,017 Other adjustments (b) (3,034 ) — — — — (3,034 ) Total operating revenues $ 10,510 $ 2,921 $ 3,951 $ 600 $ 953 $ 2,163 (a) Other revenue sources primarily relate to revenues from customers accounted for as derivatives and leases, as well as alternative revenue programs at Southern Company Gas and other cost recovery mechanisms at the traditional electric operating companies. (b) Other adjustments relate to the cost of Southern Company Gas' energy and risk management activities. Wholesale gas services revenues are presented net of the related costs of those activities on the statement of income. See Note (L) under " Southern Company Gas " for additional information on the components of wholesale gas services' operating revenues. Contract Balances The following table reflects the closing balances of receivables, contract assets, and contract liabilities related to revenues from contracts with customers at June 30, 2020 and December 31, 2019 : Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Accounts Receivables As of June 30, 2020 $ 2,283 $ 592 $ 796 $ 84 $ 115 $ 523 As of December 31, 2019 2,413 586 688 79 97 749 Contract Assets As of June 30, 2020 $ 103 $ — $ 54 $ 1 $ — $ — As of December 31, 2019 117 — 69 — — — Contract Liabilities As of June 30, 2020 $ 57 $ 6 $ 23 $ — $ 1 $ 2 As of December 31, 2019 52 10 13 — 1 1 As of June 30, 2020 and December 31, 2019 , Georgia Power had contract assets primarily related to unregulated service agreements, where payment is contingent on project completion, and fixed retail customer bill programs, where the payment is contingent upon Georgia Power's continued performance and the customer's continued participation in the program over a one-year contract term. Contract liabilities for Georgia Power relate to cash collections recognized in advance of revenue for certain unregulated service agreements. Alabama Power had contract liabilities for outstanding performance obligations primarily related to extended service agreements. Southern Company's unregulated distributed generation business had $41 million and $40 million of contract assets and $26 million and $28 million of contract liabilities at June 30, 2020 and December 31, 2019 , respectively, for outstanding performance obligations. Revenues recognized by Southern Company in the three and six months ended June 30, 2020 , which were included in contract liabilities at December 31, 2019 , were $11 million and $21 million , respectively, and immaterial for all other applicable Registrants. Remaining Performance Obligations The traditional electric operating companies and Southern Power have long-term contracts with customers in which revenues are recognized as performance obligations are satisfied over the contract term. These contracts primarily relate to PPAs whereby the traditional electric operating companies and Southern Power provide electricity and generation capacity to a customer. The revenue recognized for the delivery of electricity is variable; however, certain PPAs include a fixed payment for fixed generation capacity over the term of the contract. Southern Company's unregulated distributed generation business also has partially satisfied performance obligations related to certain fixed price contracts. Revenue from contracts with customers related to these performance obligations remaining at June 30, 2020 are expected to be recognized as follows: 2020 (remaining) 2021 2022 2023 2024 2025 and Thereafter (in millions) Southern Company $ 319 $ 432 $ 362 $ 339 $ 319 $ 3,062 Alabama Power 12 33 31 24 7 5 Georgia Power 37 70 39 34 23 62 Southern Power 156 290 292 282 290 3,013 Revenue expected to be recognized for performance obligations remaining at June 30, 2020 was immaterial for Mississippi Power. Lease Income Lease income for the three and six months ended June 30, 2020 and 2019 is as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) For the Three Months Ended June 30, 2020 Lease income - interest income on sales-type leases $ 3 $ — $ — $ 3 $ — $ — Lease income - operating leases 47 6 15 — 21 9 Variable lease income 126 — — — 136 — Total lease income $ 176 $ 6 $ 15 $ 3 $ 157 $ 9 For the Six Months Ended June 30, 2020 Lease income - interest income on sales-type leases $ 6 $ — $ — $ 5 $ — $ — Lease income - operating leases 97 13 30 — 45 17 Variable lease income 200 — — — 215 — Total lease income $ 303 $ 13 $ 30 $ 5 $ 260 $ 17 For the Three Months Ended June 30, 2019 Lease income - interest income on sales-type leases $ 2 $ — $ — $ 2 $ — $ — Lease income - operating leases 67 7 19 — 44 9 Variable lease income 115 — — — 129 — Total lease income $ 184 $ 7 $ 19 $ 2 $ 173 $ 9 For the Six Months Ended June 30, 2019 Lease income - interest income on sales-type leases $ 5 $ — $ — $ 5 $ — $ — Lease income - operating leases 139 13 39 — 90 17 Variable lease income 182 — — — 204 — Total lease income $ 326 $ 13 $ 39 $ 5 $ 294 $ 17 Lease income for Southern Power is included in wholesale revenues. Lease payments received under tolling arrangements and PPAs consist of either scheduled payments or variable payments based on the amount of energy produced by the underlying electric generating units.

CONSOLIDATED ENTITIES AND EQUIT

CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS	6 Months Ended
	Jun. 30, 2020
Regulated Operations [Abstract]
CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS	CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS See Note 7 to the financial statements in Item 8 of the Form 10-K for additional information. Southern Power Variable Interest Entities Southern Power has certain subsidiaries that are determined to be VIEs. Southern Power is considered the primary beneficiary of these VIEs because it controls the most significant activities of the VIEs, including operating and maintaining the respective assets, and has the obligation to absorb expected losses of these VIEs to the extent of its equity interests. SP Solar and SP Wind At June 30, 2020 and December 31, 2019 , SP Solar had total assets of $6.2 billion and $6.4 billion , respectively, and total liabilities of $381 million . Noncontrolling interests totaled $1.1 billion at both June 30, 2020 and December 31, 2019 . Cash distributions from SP Solar are allocated 67% to Southern Power and 33% to Global Atlantic in accordance with their partnership interest percentage. Under the terms of the limited partnership agreement, distributions without limited partner consent are limited to available cash and SP Solar is obligated to distribute all such available cash to its partners each quarter. Available cash includes all cash generated in the quarter subject to the maintenance of appropriate operating reserves. At June 30, 2020 and December 31, 2019 , SP Wind had total assets of $2.4 billion and $2.5 billion , respectively, total liabilities of $125 million and $128 million , respectively, and noncontrolling interests of $44 million and $45 million , respectively. Under the terms of the limited liability agreement, distributions without Class A member consent are limited to available cash and SP Wind is obligated to distribute all such available cash to its members each quarter. Available cash includes all cash generated in the quarter subject to the maintenance of appropriate operating reserves. Cash distributions from SP Wind are generally allocated 60% to Southern Power and 40% to the three financial investors in accordance with the limited liability agreement. Southern Power consolidates both SP Solar and SP Wind, as the primary beneficiary, since it controls the most significant activities of each entity, including operating and maintaining their assets. Certain transfers and sales of the assets in the VIEs are subject to partner consent and the liabilities are non-recourse to the general credit of Southern Power. Liabilities consist of customary working capital items and do not include any long-term debt. Other Variable Interest Entities Southern Power has other consolidated VIEs that relate to certain subsidiaries that have either sold noncontrolling interests to tax-equity investors or acquired less than a 100% interest from facility developers. These entities are considered VIEs because the arrangements are structured similar to a limited partnership and the noncontrolling members do not have substantive kick-out rights. At June 30, 2020 and December 31, 2019 , the other VIEs had total assets of $1.5 billion and $1.1 billion , respectively, total liabilities of $160 million and $104 million , respectively, and noncontrolling interests of $557 million and $409 million , respectively. Under the terms of the partnership agreements, distributions of all available cash are required each month or quarter and additional distributions require partner consent. Equity Method Investments At June 30, 2020 and December 31, 2019 , Southern Power had equity method investments in wind and battery storage projects totaling $19 million and $28 million , respectively. Southern Company Gas Equity Method Investments On March 24, 2020, Southern Company Gas completed the sale of its interests in Pivotal LNG and Atlantic Coast Pipeline. See Note (K) under "Southern Company Gas" for additional information. The carrying amounts of Southern Company Gas' equity method investments as of June 30, 2020 and December 31, 2019 and related income from those investments for the three and six months ended June 30, 2020 and 2019 were as follows: Investment Balance June 30, 2020 December 31, 2019 (a) (in millions) SNG (b) $ 1,189 $ 1,137 PennEast Pipeline (c) 87 82 Other 32 32 Total $ 1,308 $ 1,251 (a) Excludes investments in Atlantic Coast Pipeline and Pivotal JAX LNG classified as held for sale at December 31, 2019. See Note 15 to the financial statements under "Assets Held for Sale" in Item 8 of the Form 10-K for additional information. (b) Increase primarily relates to a capital contribution, partially offset by the continued amortization of deferred tax assets established upon acquisition. (c) See Note (C) under "Other Matters – Southern Company Gas" for additional information on the PennEast Pipeline. Earnings from Equity Method Investments Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 (in millions) SNG $ 28 $ 32 $ 65 $ 74 Atlantic Coast Pipeline (a)(b) — 3 3 6 PennEast Pipeline (a) 1 1 3 3 Other 1 (5 ) 1 (3 ) Total $ 30 $ 31 $ 72 $ 80 (a) Amounts primarily result from AFUDC equity recorded by the project entity. (b) On March 24, 2020, Southern Company Gas completed the sale of its interest in Atlantic Coast Pipeline. See Note (K) under "Southern Company Gas" for additional information. SNG Selected financial information of SNG for the three and six months ended June 30, 2020 and 2019 is as follows: Income Statement Information Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 (in millions) Revenues $ 149 $ 155 $ 307 $ 321 Operating income 78 86 176 192 Net income 55 64 130 148

FINANCING

FINANCING	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
FINANCING	FINANCING Bank Credit Arrangements See Note 8 to the financial statements under "Bank Credit Arrangements" in Item 8 of the Form 10-K for additional information. At June 30, 2020 , committed credit arrangements with banks were as follows: Expires Company 2020 2021 2022 2023 2024 Total Unused Due within One Year (in millions) Southern Company parent $ — $ — $ — $ — $ 2,000 $ 2,000 $ 1,999 $ — Alabama Power 3 — 525 — 800 1,328 1,328 3 Georgia Power — — — — 1,750 1,750 1,733 — Mississippi Power — — 150 125 — 275 250 — Southern Power (a) — — — — 600 600 590 — Southern Company Gas (b) — — — — 1,750 1,750 1,745 — SEGCO — 30 — — — 30 30 30 Southern Company $ 3 $ 30 $ 675 $ 125 $ 6,900 $ 7,733 $ 7,675 $ 33 (a) Does not include Southern Power Company's $120 million and $60 million continuing letter of credit facilities for standby letters of credit expiring in 2021 and 2023, respectively, of which $19 million and $60 million , respectively, was unused at June 30, 2020 . Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities. (b) Southern Company Gas, as the parent entity, guarantees the obligations of Southern Company Gas Capital, which is the borrower of $1.25 billion of this arrangement. Southern Company Gas' committed credit arrangement also includes $500 million for which Nicor Gas is the borrower and which is restricted for working capital needs of Nicor Gas. Pursuant to this multi-year credit arrangement, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted. As reflected in the table above, in March 2020, Mississippi Power entered into a $125 million revolving credit facility that matures in March 2023. Subject to applicable market conditions, Southern Company and its subsidiaries expect to renew or replace their bank credit arrangements as needed, prior to expiration. In connection therewith, Southern Company and its subsidiaries may extend the maturity dates and/or increase or decrease the lending commitments thereunder. These bank credit arrangements, as well as the term loan arrangements of the Registrants and SEGCO, contain covenants that limit debt levels and contain cross-acceleration or, in the case of Southern Power, cross-default provisions to other indebtedness (including guarantee obligations) that are restricted only to the indebtedness of the individual company. Such cross-default provisions to other indebtedness would trigger an event of default if Southern Power defaulted on indebtedness or guarantee obligations over a specified threshold. Such cross-acceleration provisions to other indebtedness would trigger an event of default if the applicable borrower defaulted on indebtedness, the payment of which was then accelerated. At June 30, 2020 , the Registrants, Nicor Gas, and SEGCO were in compliance with all such covenants. None of the bank credit arrangements contain material adverse change clauses at the time of borrowings. A portion of the unused credit with banks is allocated to provide liquidity support to the revenue bonds of the traditional electric operating companies and the commercial paper programs of the Registrants, Nicor Gas, and SEGCO. The amount of variable rate revenue bonds of the traditional electric operating companies outstanding requiring liquidity support at June 30, 2020 was approximately $1.4 billion (comprised of approximately $854 million at Alabama Power, $550 million at Georgia Power, and $34 million at Mississippi Power). In addition, at June 30, 2020 , Georgia Power had approximately $257 million of fixed rate revenue bonds outstanding that are required to be remarketed within the next 12 months. Earnings per Share For Southern Company, the only differences in computing basic and diluted earnings per share are attributable to awards outstanding under stock-based compensation plans and, as a result of stock price volatility in the first six months of 2020, the equity units issued in August 2019. Earnings per share dilution resulting from stock-based compensation plans and the equity units issuance is determined using the treasury stock method. See Note 8 to the financial statements under "Equity Units" in Item 8 of the Form 10-K for information on the August 2019 equity units issuance and Note 12 to the financial statements in Item 8 of the Form 10-K for information on stock-based compensation plans. Shares used to compute diluted earnings per share were as follows: Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 (in millions) As reported shares 1,058 1,044 1,057 1,041 Effect of stock-based compensation 5 8 7 8 Effect of equity units — — 1 — Diluted shares 1,063 1,052 1,065 1,049 An immaterial number of stock-based compensation awards was not included in the diluted earnings per share calculation because the awards were anti-dilutive for the three and six months ended June 30, 2020 . There were no such amounts for the three and six months ended June 30, 2019 .

INCOME TAXES

INCOME TAXES	6 Months Ended
	Jun. 30, 2020
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES See Note 10 to the financial statements in Item 8 of the Form 10-K for additional tax information. Current and Deferred Income Taxes Tax Credit and Net Operating Loss Carryforwards The utilization of each Registrants' estimated tax credit and net operating loss carryforwards and related valuation allowances could be impacted by numerous factors, including the acquisition of additional renewable projects, the purchase of rights to additional PTCs of Plant Vogtle Units 3 and 4 pursuant to certain joint ownership agreements, potential impacts of the COVID-19 pandemic, and changes in taxable income projections. See Note (B) and Note 2 to the financial statements in Item 8 of the Form 10-K under "Georgia Power – Nuclear Construction" for additional information on Plant Vogtle Units 3 and 4. Effective Tax Rate Details of significant changes in the effective tax rate for the applicable Registrants are provided herein. Southern Company Southern Company's effective tax rate is typically lower than the statutory rate due to employee stock plans' dividend deduction, non-taxable AFUDC equity at the traditional electric operating companies, flowback of excess deferred income taxes at the regulated utilities, and federal income tax benefits from ITCs and PTCs primarily at Southern Power. Southern Company's effective tax rate was 9.3% for the six months ended June 30, 2020 compared to 33.5% for the corresponding period in 2019 . The effective tax rate decrease was primarily due to the tax impact from the sale of Gulf Power in 2019, as well as an increase in the flowback of excess deferred income taxes in 2020 primarily at Georgia Power. See Note 15 to the financial statements under "Southern Company" in Item 8 of the Form 10-K for additional information. Georgia Power Georgia Power's effective tax rate was 4.0% for the six months ended June 30, 2020 compared to 21.7% for the corresponding period in 2019 . The effective tax rate decrease was primarily due to an increase in the flowback of excess deferred income taxes in 2020 as authorized in the 2019 ARP, as well as the second quarter 2020 charge to earnings associated with the construction of Plant Vogtle Units 3 and 4. See Note (B) under "Georgia Power – Nuclear Construction " and Note 2 to the financial statements under "Georgia Power" in Item 8 of the Form 10-K for additional information. Mississippi Power Mississippi Power's effective tax rate was 10.6% for the six months ended June 30, 2020 compared to 14.0% for the corresponding period in 2019 . The effective tax rate decrease was primarily due to an increase in the flowback of excess deferred income taxes in 2020 as authorized in the Mississippi Power Rate Case Settlement Agreement. See Note (B) under " Mississippi Power – 2019 Base Rate Case" for additional information. Southern Power Southern Power's effective tax rate was 10.5% for the six months ended June 30, 2020 compared to a benefit rate of (35.5)% for the corresponding period in 2019 . The effective tax rate increase was primarily due to tax benefits resulting from ITCs recognized upon the sale of Plant Nacogdoches in 2019. See Note (K) under "Southern Power" for additional information. Southern Company Gas Southern Company Gas' effective tax rate was 21.5% for the six months ended June 30, 2020 compared to 18.0% for the corresponding period in 2019 . The effective tax rate increase was primarily due to higher flowback of excess deferred income taxes in 2019, primarily at Atlanta Gas Light as previously authorized by the Georgia PSC, and the reversal of a federal tax valuation allowance in connection with Southern Company Gas' sale of its investment in Triton in 2019. See Notes 2 and 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information.

RETIREMENT BENEFITS

RETIREMENT BENEFITS	6 Months Ended
	Jun. 30, 2020
Retirement Benefits [Abstract]
RETIREMENT BENEFITS	RETIREMENT BENEFITS The Southern Company system has a qualified defined benefit, trusteed, pension plan covering substantially all employees, with the exception of employees at PowerSecure. The qualified pension plan is funded in accordance with requirements of the Employee Retirement Income Security Act of 1974, as amended (ERISA). No mandatory contributions to the qualified pension plan are anticipated for the year ending December 31, 2020 . The Southern Company system also provides certain non-qualified defined benefits for a select group of management and highly compensated employees, which are funded on a cash basis. In addition, the Southern Company system provides certain medical care and life insurance benefits for retired employees through other postretirement benefit plans. The traditional electric operating companies fund other postretirement trusts to the extent required by their respective regulatory commissions. Southern Company Gas has a separate unfunded supplemental retirement health care plan that provides medical care and life insurance benefits to employees of discontinued businesses. See Note 11 to the financial statements in Item 8 of the Form 10-K for additional information. Effective January 1, 2020, Southern Company adopted a change in method of calculating the market-related value of the liability-hedging securities included in its pension plan assets. The market-related value is used to determine the expected return on plan assets component of net periodic pension cost. Southern Company previously used the calculated value approach for all plan assets, which smoothed asset returns and deferred gains and losses by amortizing them into the calculation of the market-related value over five years. Southern Company changed to the fair value approach for liability-hedging securities, which includes measuring the market-related value of that portion of the plan assets at fair value for purposes of determining the expected return on plan assets. The remaining asset classes of plan assets will continue to use the calculated value approach in determining the market-related value. Southern Company considers the fair value approach to be preferable because it results in a current reflection of changes in the value of plan assets in the measurement of net periodic pension cost. Southern Company evaluated the effect of this change in accounting method and deemed it immaterial to the historical and current financial statements of all Registrants and therefore did not account for the change retrospectively. The change in accounting principle was recorded through earnings as a prior period adjustment for the amounts related to the unregulated businesses of Southern Company and Southern Power. Amounts related to the traditional electric operating companies and the natural gas distribution utilities have been reflected as adjustments to regulatory assets as appropriate, consistent with the expected regulatory treatment. On each Registrant's condensed statements of income, the service cost component of net periodic benefit costs is included in other operations and maintenance expenses and all other components of net periodic benefit costs are included in other income (expense), net. Components of the net periodic benefit costs for the three and six months ended June 30, 2020 and 2019 are presented in the following tables. Three Months Ended June 30, 2020 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Pension Plans Service cost $ 94 $ 22 $ 24 $ 4 $ 2 $ 8 Interest cost 108 25 34 5 2 7 Expected return on plan assets (275 ) (66 ) (87 ) (12 ) (3 ) (20 ) Amortization: Prior service costs — — 1 — — — Regulatory asset — — — — — 4 Net (gain)/loss 67 18 21 3 — 3 Net periodic pension cost (income) $ (6 ) $ (1 ) $ (7 ) $ — $ 1 $ 2 Postretirement Benefits Service cost $ 6 $ 1 $ 2 $ 1 $ — $ 1 Interest cost 14 3 5 1 — 4 Expected return on plan assets (18 ) (7 ) (6 ) (1 ) — (2 ) Amortization: Prior service costs (1 ) — — — — — Regulatory asset — — — — — 1 Net (gain)/loss — — — — — (1 ) Net periodic postretirement benefit cost $ 1 $ (3 ) $ 1 $ 1 $ — $ 3 Six Months Ended June 30, 2020 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Pension Plans Service cost $ 188 $ 44 $ 48 $ 8 $ 4 $ 16 Interest cost 216 50 67 10 3 15 Expected return on plan assets (550 ) (132 ) (174 ) (25 ) (6 ) (39 ) Amortization: Prior service costs 1 — 1 — — (1 ) Regulatory asset — — — — — 8 Net (gain)/loss 134 36 43 6 1 5 Net periodic pension cost (income) $ (11 ) $ (2 ) $ (15 ) $ (1 ) $ 2 $ 4 Six Months Ended June 30, 2020 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Postretirement Benefits Service cost $ 11 $ 3 $ 3 $ 1 $ — $ 1 Interest cost 27 6 10 1 — 6 Expected return on plan assets (36 ) (14 ) (13 ) (1 ) — (4 ) Amortization: Prior service costs (1 ) — — — — — Regulatory asset — — — — — 3 Net (gain)/loss 1 — 1 — — (2 ) Net periodic postretirement benefit cost $ 2 $ (5 ) $ 1 $ 1 $ — $ 4 Three Months Ended June 30, 2019 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Pension Plans Service cost $ 73 $ 17 $ 18 $ 3 $ 1 $ 6 Interest cost 123 29 39 5 2 9 Expected return on plan assets (221 ) (52 ) (73 ) (10 ) (3 ) (15 ) Amortization: Prior service costs 1 1 1 — — — Regulatory asset — — — — — 4 Net (gain)/loss 30 9 11 2 — — Net periodic pension cost (income) $ 6 $ 4 $ (4 ) $ — $ — $ 4 Postretirement Benefits Service cost $ 4 $ 1 $ 1 $ — $ — $ — Interest cost 17 4 6 1 — 3 Expected return on plan assets (17 ) (7 ) (6 ) (1 ) — (1 ) Amortization: Prior service costs 1 1 — — — — Regulatory asset — — — — — 1 Net (gain)/loss — — — — — (1 ) Net periodic postretirement benefit cost $ 5 $ (1 ) $ 1 $ — $ — $ 2 Six Months Ended June 30, 2019 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Pension Plans Service cost $ 146 $ 34 $ 37 $ 6 $ 3 $ 12 Interest cost 246 57 78 11 3 18 Expected return on plan assets (442 ) (103 ) (146 ) (20 ) (5 ) (30 ) Amortization: Prior service costs 1 1 1 — — (1 ) Regulatory asset — — — — — 7 Net (gain)/loss 60 18 22 3 — 1 Net periodic pension cost (income) $ 11 $ 7 $ (8 ) $ — $ 1 $ 7 Postretirement Benefits Service cost $ 9 $ 2 $ 2 $ — $ — $ 1 Interest cost 34 8 13 2 — 5 Expected return on plan assets (33 ) (13 ) (12 ) (1 ) — (3 ) Amortization: Prior service costs 2 2 — — — — Regulatory asset — — — — — 3 Net (gain)/loss (1 ) — — — — (2 ) Net periodic postretirement benefit cost $ 11 $ (1 ) $ 3 $ 1 $ — $ 4

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS As of June 30, 2020 , assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using: As of June 30, 2020: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 388 $ 181 $ 143 $ — $ 712 Interest rate derivatives — 23 — — 23 Investments in trusts: (b)(c) Domestic equity 703 128 — — 831 Foreign equity 65 202 — — 267 U.S. Treasury and government agency securities — 268 — — 268 Municipal bonds — 106 — — 106 Pooled funds – fixed income — 16 — — 16 Corporate bonds 19 369 — — 388 Mortgage and asset backed securities — 75 — — 75 Private equity — — — 61 61 Other 26 3 — — 29 Cash equivalents 1,315 13 — — 1,328 Other investments 9 21 — — 30 Total $ 2,525 $ 1,405 $ 143 $ 61 $ 4,134 Liabilities: Energy-related derivatives (a) $ 468 $ 187 $ 63 $ — $ 718 Interest rate derivatives — 23 — — 23 Foreign currency derivatives — 49 — — 49 Contingent consideration — — 19 — 19 Total $ 468 $ 259 $ 82 $ — $ 809 Fair Value Measurements Using: As of June 30, 2020: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 11 $ — $ — $ 11 Nuclear decommissioning trusts: (b) Domestic equity 442 117 — — 559 Foreign equity 65 59 — — 124 U.S. Treasury and government agency securities — 22 — — 22 Municipal bonds — 1 — — 1 Corporate bonds 19 155 — — 174 Mortgage and asset backed securities — 28 — — 28 Private equity — — — 61 61 Other 8 — — — 8 Cash equivalents 692 13 — — 705 Other investments — 21 — — 21 Total $ 1,226 $ 427 $ — $ 61 $ 1,714 Liabilities: Energy-related derivatives $ — $ 19 $ — $ — $ 19 Georgia Power Assets: Energy-related derivatives $ — $ 10 $ — $ — $ 10 Nuclear decommissioning trusts: (b)(c) Domestic equity 261 1 — — 262 Foreign equity — 141 — — 141 U.S. Treasury and government agency securities — 246 — — 246 Municipal bonds — 105 — — 105 Corporate bonds — 214 — — 214 Mortgage and asset backed securities — 47 — — 47 Other 18 3 — — 21 Cash equivalents 349 — — — 349 Total $ 628 $ 767 $ — $ — $ 1,395 Liabilities: Energy-related derivatives $ — $ 40 $ — $ — $ 40 Fair Value Measurements Using: As of June 30, 2020: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 6 $ — $ — $ 6 Liabilities: Energy-related derivatives $ — $ 22 $ — $ — $ 22 Southern Power Assets: Energy-related derivatives $ — $ 2 $ — $ — $ 2 Liabilities: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 49 — — 49 Contingent consideration — — 19 — 19 Total $ — $ 52 $ 19 $ — $ 71 Southern Company Gas Assets: Energy-related derivatives (a) $ 388 $ 152 $ 143 $ — $ 683 Non-qualified deferred compensation trusts: Domestic equity — 10 — — 10 Foreign equity — 2 — — 2 Pooled funds – fixed income — 16 — — 16 Cash equivalents and restricted cash 40 — — — 40 Total $ 428 $ 180 $ 143 $ — $ 751 Liabilities: Energy-related derivatives (a) $ 468 $ 103 $ 63 $ — $ 634 Interest rate derivatives — 23 — — 23 Total $ 468 $ 126 $ 63 $ — $ 657 (a) Energy-related derivatives exclude cash collateral of $114 million . (b) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information. (c) Includes investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. As of June 30, 2020 , approximately $45 million of the fair market value of Georgia Power's nuclear decommissioning trust funds' securities were on loan to creditors under the funds' managers' securities lending program. See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information. Southern Company, Alabama Power, and Georgia Power continue to elect the option to fair value investment securities held in the nuclear decommissioning trust funds. The fair value of the funds, including reinvested interest and dividends and excluding the funds' expenses, increased (decreased) by the amounts shown in the table below for the three and six months ended June 30, 2020 and 2019 . The changes were recorded as a change to the regulatory assets and liabilities related to AROs for Georgia Power and Alabama Power, respectively. Fair value increases (decreases) Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 (in millions) Southern Company $ 223 $ 75 $ (23 ) $ 227 Alabama Power 124 38 (42 ) 125 Georgia Power 99 37 19 102 Valuation Methodologies The energy-related derivatives primarily consist of exchange-traded and over-the-counter financial products for natural gas and physical power products, including, from time to time, basis swaps. These are standard products used within the energy industry and are valued using the market approach. The inputs used are mainly from observable market sources, such as forward natural gas prices, power prices, implied volatility, and overnight index swap interest rates. Interest rate derivatives are also standard over-the-counter products that are valued using observable market data and assumptions commonly used by market participants. The fair value of interest rate derivatives reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future interest rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and occasionally, implied volatility of interest rate options. The fair value of cross-currency swaps reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future foreign currency exchange rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and discount rates. The interest rate derivatives and cross-currency swaps are categorized as Level 2 under Fair Value Measurements as these inputs are based on observable data and valuations of similar instruments. See Note (J) for additional information on how these derivatives are used. For fair value measurements of the investments within the nuclear decommissioning trusts and the non-qualified deferred compensation trusts, external pricing vendors are designated for each asset class with each security specifically assigned a primary pricing source. For investments held within commingled funds, fair value is determined at the end of each business day through the net asset value, which is established by obtaining the underlying securities' individual prices from the primary pricing source. A market price secured from the primary source vendor is then evaluated by management in its valuation of the assets within the trusts. As a general approach, fixed income market pricing vendors gather market data (including indices and market research reports) and integrate relative credit information, observed market movements, and sector news into proprietary pricing models, pricing systems, and mathematical tools. Dealer quotes and other market information, including live trading levels and pricing analysts' judgments, are also obtained when available. The NRC requires licensees of commissioned nuclear power reactors to establish a plan for providing reasonable assurance of funds for future decommissioning. See Note 6 to the financial statements under "Nuclear Decommissioning" in Item 8 of the Form 10-K for additional information. Southern Power has contingent payment obligations related to certain acquisitions whereby Southern Power is primarily obligated to make generation-based payments to the seller, which commenced at the commercial operation of the respective facility and continue through 2026. The obligation is categorized as Level 3 under Fair Value Measurements as the fair value is determined using significant unobservable inputs for the forecasted facility generation in MW-hours, as well as other inputs such as a fixed dollar amount per MW-hour, and a discount rate. The fair value of contingent consideration reflects the net present value of expected payments and any periodic change arising from forecasted generation is expected to be immaterial. "Other investments" include investments traded in the open market that have maturities greater than 90 days, which are categorized as Level 2 under Fair Value Measurements and are comprised of corporate bonds, bank certificates of deposit, treasury bonds, and/or agency bonds. As of June 30, 2020 , the fair value measurements of private equity investments held in Alabama Power's nuclear decommissioning trusts that are calculated at net asset value per share (or its equivalent) as a practical expedient totaled $61 million and unfunded commitments related to the private equity investments totaled $72 million . Private equity investments include high-quality private equity funds across several market sectors and funds that invest in real estate assets. Private equity funds do not have redemption rights. Distributions from these funds will be received as the underlying investments in the funds are liquidated. As of June 30, 2020 , other financial instruments for which the carrying amount did not equal fair value were as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (*) (in millions) Long-term debt, including securities due within one year: Carrying amount $ 46,513 $ 8,519 $ 12,720 $ 1,404 $ 4,097 $ 5,827 Fair value 53,079 10,008 15,092 1,571 4,423 6,817 (*) The long-term debt of Southern Company Gas is recorded at amortized cost, including the fair value adjustments at the effective date of the 2016 merger with Southern Company. Southern Company Gas amortizes the fair value adjustments over the lives of the respective bonds. The fair values are determined using Level 2 measurements and are based on quoted market prices for the same or similar issues or on the current rates available to the Registrants. Commodity Contracts with Level 3 Valuation Inputs As of June 30, 2020 , the fair value of Southern Company Gas' Level 3 physical natural gas forward contracts was $80 million . Since commodity contracts classified as Level 3 typically include a combination of observable and unobservable components, the changes in fair value may include amounts due in part to observable market factors, or changes to assumptions on the unobservable components. The following table includes transfers to Level 3, which represent the fair value of Southern Company Gas' commodity derivative contracts that include a significant unobservable component for the first time during the period. Three Months Ended June 30, 2020 Six Months Ended June 30, 2020 (in millions) Beginning balance $ 76 $ 14 Transfers to Level 3 — 70 Transfers from Level 3 — (3 ) Instruments realized or otherwise settled during period (6 ) (7 ) Changes in fair value 10 6 Ending balance $ 80 $ 80 Changes in fair value of Level 3 instruments represent changes in gains and losses for the periods that are reported on Southern Company Gas' statements of income in natural gas revenues. The valuation of certain commodity contracts requires the use of certain unobservable inputs. All forward pricing used in the valuation of such contracts is directly based on third-party market data, such as broker quotes and exchange settlements, when that data is available. If third-party market data is not available, then industry standard methodologies are used to develop inputs that maximize the use of relevant observable inputs and minimize the use of unobservable inputs. Observable inputs, including some forward prices used for determining fair value, reflect the best available market information. Unobservable inputs are updated using industry standard techniques such as extrapolation, combining observable forward inputs supplemented by historical market and other relevant data. Level 3 physical natural gas forward contracts include unobservable forward price inputs (ranging from $(0.91) to $0.99 per mmBtu). Forward price increases (decreases) as of June 30, 2020 would have resulted in higher (lower) values on a net basis.

DERIVATIVES

DERIVATIVES	6 Months Ended
	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES	DERIVATIVES Southern Company, the traditional electric operating companies, Southern Power, and Southern Company Gas are exposed to market risks, including commodity price risk, interest rate risk, weather risk, and occasionally foreign currency exchange rate risk. To manage the volatility attributable to these exposures, each company nets its exposures, where possible, to take advantage of natural offsets and enters into various derivative transactions for the remaining exposures pursuant to each company's policies in areas such as counterparty exposure and risk management practices. Southern Company Gas' wholesale gas operations use various contracts in its commercial activities that generally meet the definition of derivatives. For the traditional electric operating companies, Southern Power, and Southern Company Gas' other businesses, each company's policy is that derivatives are to be used primarily for hedging purposes and mandates strict adherence to all applicable risk management policies. Derivative positions are monitored using techniques including, but not limited to, market valuation, value at risk, stress testing, and sensitivity analysis. Derivative instruments are recognized at fair value in the balance sheets as either assets or liabilities and are presented on a net basis. See Note (I) for additional fair value information. In the statements of cash flows, any cash impacts of settled energy-related and interest rate derivatives are recorded as operating activities. Any cash impacts of settled foreign currency derivatives are classified as operating or financing activities to correspond with classification of the hedged interest or principal, respectively. See Note 1 to the financial statements under "Financial Instruments" in Item 8 of the Form 10-K for additional information. Energy-Related Derivatives The traditional electric operating companies, Southern Power, and Southern Company Gas enter into energy-related derivatives to hedge exposures to electricity, natural gas, and other fuel price changes. However, due to cost-based rate regulations and other various cost recovery mechanisms, the traditional electric operating companies and the natural gas distribution utilities have limited exposure to market volatility in energy-related commodity prices. Each of the traditional electric operating companies and certain of the natural gas distribution utilities of Southern Company Gas manage fuel-hedging programs, implemented per the guidelines of their respective state PSCs or other applicable state regulatory agencies, through the use of financial derivative contracts, which are expected to continue to mitigate price volatility. The traditional electric operating companies (with respect to wholesale generating capacity) and Southern Power have limited exposure to market volatility in energy-related commodity prices because their long-term sales contracts shift substantially all fuel cost responsibility to the purchaser. However, the traditional electric operating companies and Southern Power may be exposed to market volatility in energy-related commodity prices to the extent any uncontracted capacity is used to sell electricity. Southern Company Gas retains exposure to price changes that can, in a volatile energy market, be material and can adversely affect its results of operations. Southern Company Gas also enters into weather derivative contracts as economic hedges of operating margins in the event of warmer-than-normal weather. Exchange-traded options are carried at fair value, with changes reflected in operating revenues. Non-exchange-traded options are accounted for using the intrinsic value method. Changes in the intrinsic value for non-exchange-traded contracts are reflected in operating revenues. Energy-related derivative contracts are accounted for under one of three methods: • Regulatory Hedges — Energy-related derivative contracts designated as regulatory hedges relate primarily to the traditional electric operating companies' and the natural gas distribution utilities' fuel-hedging programs, where gains and losses are initially recorded as regulatory liabilities and assets, respectively, and then are included in fuel expense as the underlying fuel is used in operations and ultimately recovered through the respective fuel cost recovery clauses. • Cash Flow Hedges — Gains and losses on energy-related derivatives designated as cash flow hedges (which are mainly used to hedge anticipated purchases and sales) are initially deferred in accumulated OCI before being recognized in the statements of income in the same period and in the same income statement line item as the earnings effect of the hedged transactions. • Not Designated — Gains and losses on energy-related derivative contracts that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Some energy-related derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the electric and natural gas industries. When an energy-related derivative contract is settled physically, any cumulative unrealized gain or loss is reversed and the contract price is recognized in the respective line item representing the actual price of the underlying goods being delivered. At June 30, 2020 , the net volume of energy-related derivative contracts for natural gas positions, together with the longest hedge date over which the respective entity is hedging its exposure to the variability in future cash flows for forecasted transactions and the longest non-hedge date for derivatives not designated as hedges, were as follows: Net Purchased mmBtu Longest Hedge Date Longest Non-Hedge Date (in millions) Southern Company (*) 944 2024 2031 Alabama Power 85 2024 — Georgia Power 152 2023 — Mississippi Power 91 2024 — Southern Power 15 2022 2021 Southern Company Gas (*) 601 2022 2031 (*) Southern Company Gas' derivative instruments include both long and short natural gas positions. A long position is a contract to purchase natural gas and a short position is a contract to sell natural gas. Southern Company Gas' volume represents the net of long natural gas positions of 4.6 billion mmBtu and short natural gas positions of 4.0 billion mmBtu as of June 30, 2020 , which is also included in Southern Company's total volume. At June 30, 2020 , the net volume of Southern Power's energy-related derivative contracts for power to be sold was 1 million MWHs, all of which expire in 2020. In addition to the volumes discussed above, the traditional electric operating companies and Southern Power enter into physical natural gas supply contracts that provide the option to sell back excess natural gas due to operational constraints. The maximum expected volume of natural gas subject to such a feature is 16 million mmBtu for Southern Company, which includes 4 million mmBtu for Alabama Power, 5 million mmBtu for Georgia Power, 2 million mmBtu for Mississippi Power, and 5 million mmBtu for Southern Power. For cash flow hedges of energy-related derivatives, the estimated pre-tax gains (losses) expected to be reclassified from accumulated OCI to earnings for the 12 -month period ending June 30, 2021 are immaterial for all Registrants. Interest Rate Derivatives Southern Company and certain subsidiaries may enter into interest rate derivatives to hedge exposure to changes in interest rates. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. Derivatives related to existing variable rate securities or forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and presented on the same income statement line item as the earnings effect of the hedged transactions. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item. Fair value gains or losses on derivatives that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. At June 30, 2020 , the following interest rate derivatives were outstanding: Notional Amount Interest Rate Received Weighted Average Interest Rate Paid Hedge Maturity Date Fair Value Gain (Loss) at June 30, 2020 (in millions) (in millions) Cash Flow Hedges of Forecasted Debt Southern Company Gas $ 200 3-month LIBOR 1.81% September 2030 $ (23 ) Cash Flow Hedges of Existing Debt Mississippi Power 60 1-month LIBOR 0.58% December 2021 — Fair Value Hedges of Existing Debt Southern Company parent 1,500 2.35% 1-month LIBOR + 0.87% July 2021 23 Southern Company $ 1,760 $ — The estimated pre-tax gains (losses) related to interest rate derivatives expected to be reclassified from accumulated OCI to interest expense for the 12 -month period ending June 30, 2021 total $(25) million for Southern Company and are immaterial for all other Registrants. Deferred gains and losses related to interest rate derivatives are expected to be amortized into earnings through 2046 for the Southern Company parent entity, 2035 for Alabama Power, 2044 for Georgia Power, 2028 for Mississippi Power, and 2046 for Southern Company Gas. Foreign Currency Derivatives Southern Company and certain subsidiaries, including Southern Power, may enter into foreign currency derivatives to hedge exposure to changes in foreign currency exchange rates, such as that arising from the issuance of debt denominated in a currency other than U.S. dollars. Derivatives related to forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and on the same income statement line as the earnings effect of the hedged transactions, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. At June 30, 2020 , the following foreign currency derivatives were outstanding: Pay Notional Pay Rate Receive Notional Receive Rate Hedge Fair Value Gain (Loss) at June 30, 2020 (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 677 2.95% € 600 1.00% June 2022 $ (18 ) Southern Power 564 3.78% 500 1.85% June 2026 (31 ) Total $ 1,241 € 1,100 $ (49 ) The estimated pre-tax gains (losses) related to Southern Power's foreign currency derivatives expected to be reclassified from accumulated OCI to earnings for the 12 -month period ending June 30, 2021 are $(24) million . Derivative Financial Statement Presentation and Amounts Southern Company, the traditional electric operating companies, Southern Power, and Southern Company Gas enter into derivative contracts that may contain certain provisions that permit intra-contract netting of derivative receivables and payables for routine billing and offsets related to events of default and settlements. Southern Company and certain subsidiaries also utilize master netting agreements to mitigate exposure to counterparty credit risk. These agreements may contain provisions that permit netting across product lines and against cash collateral. The fair value amounts of derivative assets and liabilities on the balance sheet are presented net to the extent that there are netting arrangements or similar agreements with the counterparties. The fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows: As of June 30, 2020 As of December 31, 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Southern Company Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 19 $ 64 $ 3 $ 70 Other deferred charges and assets/Other deferred credits and liabilities 13 28 6 44 Total derivatives designated as hedging instruments for regulatory purposes $ 32 $ 92 $ 9 $ 114 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities $ 3 $ 6 $ 1 $ 6 Interest rate derivatives: Other current assets/Other current liabilities 12 23 2 23 Other deferred charges and assets/Other deferred credits and liabilities 10 — — 1 Foreign currency derivatives: Other current assets/Other current liabilities — 24 — 24 Other deferred charges and assets/Other deferred credits and liabilities — 25 16 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 25 $ 78 $ 19 $ 54 Derivatives not designated as hedging instruments Energy-related derivatives: Other current assets/Other current liabilities $ 361 $ 367 $ 461 $ 358 Other deferred charges and assets/Other deferred credits and liabilities 316 253 207 225 Total derivatives not designated as hedging instruments $ 677 $ 620 $ 668 $ 583 Gross amounts recognized $ 734 $ 790 $ 696 $ 751 Gross amounts offset (a) (520 ) (634 ) (463 ) (562 ) Net amounts recognized in the Balance Sheets (b) $ 214 $ 156 $ 233 $ 189 As of June 30, 2020 As of December 31, 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Alabama Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 7 $ 12 $ 2 $ 14 Other deferred charges and assets/Other deferred credits and liabilities 4 7 2 10 Total derivatives designated as hedging instruments for regulatory purposes $ 11 $ 19 $ 4 $ 24 Gross amounts recognized $ 11 $ 19 $ 4 $ 24 Gross amounts offset (8 ) (8 ) (2 ) (2 ) Net amounts recognized in the Balance Sheets $ 3 $ 11 $ 2 $ 22 Georgia Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 5 $ 28 $ 1 $ 32 Other deferred charges and assets/Other deferred credits and liabilities 5 12 3 21 Total derivatives designated as hedging instruments for regulatory purposes $ 10 $ 40 $ 4 $ 53 Derivatives designated as hedging instruments in cash flow and fair value hedges Interest rate derivatives: Other current assets/Other current liabilities $ — $ — $ — $ 17 Total derivatives designated as hedging instruments in cash flow and fair value hedges $ — $ — $ — $ 17 Gross amounts recognized $ 10 $ 40 $ 4 $ 70 Gross amounts offset (10 ) (10 ) (3 ) (3 ) Net amounts recognized in the Balance Sheets $ — $ 30 $ 1 $ 67 As of June 30, 2020 As of December 31, 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Mississippi Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 3 $ 13 $ — $ 15 Other deferred charges and assets/Other deferred credits and liabilities 3 9 1 12 Total derivatives designated as hedging instruments for regulatory purposes $ 6 $ 22 $ 1 $ 27 Gross amounts recognized $ 6 $ 22 $ 1 $ 27 Gross amounts offset (6 ) (6 ) (1 ) (1 ) Net amounts recognized in the Balance Sheets $ — $ 16 $ — $ 26 Southern Power Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities $ 2 $ 3 $ 1 $ 2 Foreign currency derivatives: Other current assets/Other current liabilities — 24 — 24 Other deferred charges and assets/Other deferred credits and liabilities — 25 16 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 2 $ 52 $ 17 $ 26 Derivatives not designated as hedging instruments Energy-related derivatives: Other current assets/Other current liabilities $ — $ — $ 2 $ 1 Total derivatives not designated as hedging instruments $ — $ — $ 2 $ 1 Gross amounts recognized $ 2 $ 52 $ 19 $ 27 Gross amounts offset (1 ) (1 ) — — Net amounts recognized in the Balance Sheets $ 1 $ 51 $ 19 $ 27 As of June 30, 2020 As of December 31, 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Southern Company Gas Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Assets from risk management activities/Liabilities from risk management activities-current $ 4 $ 11 $ — $ 9 Other deferred charges and assets/Other deferred credits and liabilities 1 — — 1 Total derivatives designated as hedging instruments for regulatory purposes $ 5 $ 11 $ — $ 10 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Assets from risk management activities/Liabilities from risk management activities-current $ 1 $ 3 $ — $ 4 Interest rate derivatives: Assets from risk management activities/Liabilities from risk management activities-current — 23 2 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 1 $ 26 $ 2 $ 4 Derivatives not designated as hedging instruments Energy-related derivatives: Assets from risk management activities/Liabilities from risk management activities-current $ 361 $ 367 $ 459 $ 357 Other deferred charges and assets/Other deferred credits and liabilities 316 253 207 225 Total derivatives not designated as hedging instruments $ 677 $ 620 $ 666 $ 582 Gross amounts of recognized $ 683 $ 657 $ 668 $ 596 Gross amounts offset (a) (495 ) (609 ) (456 ) (555 ) Net amounts recognized in the Balance Sheets (b) $ 188 $ 48 $ 212 $ 41 (a) Gross amounts offset include cash collateral held on deposit in broker margin accounts of $114 million and $99 million as of June 30, 2020 and December 31, 2019 , respectively. (b) Net amounts of derivative instruments outstanding exclude premium and intrinsic value associated with weather derivatives of $4 million as of December 31, 2019 . Energy-related derivatives not designated as hedging instruments were immaterial for the traditional electric operating companies at June 30, 2020 and December 31, 2019 . At June 30, 2020 and December 31, 2019 , the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows: Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet Derivative Category and Balance Sheet Location Southern Company (*) Alabama Power Georgia Power Mississippi Power Southern Company Gas (*) (in millions) At June 30, 2020: Energy-related derivatives: Other regulatory assets, current $ (42 ) $ (8 ) $ (23 ) $ (10 ) $ (1 ) Other regulatory assets, deferred (16 ) (3 ) (7 ) (6 ) — Other regulatory liabilities, current 10 3 — — 7 Total energy-related derivative gains (losses) $ (48 ) $ (8 ) $ (30 ) $ (16 ) $ 6 At December 31, 2019: Energy-related derivatives: Other regulatory assets, current $ (63 ) $ (14 ) $ (31 ) $ (15 ) $ (3 ) Other regulatory assets, deferred (37 ) (8 ) (18 ) (11 ) — Other regulatory liabilities, current 6 2 — — 4 Total energy-related derivative gains (losses) $ (94 ) $ (20 ) $ (49 ) $ (26 ) $ 1 (*) Fair value gains and losses recorded in regulatory assets and liabilities include cash collateral held on deposit in broker margin accounts of $12 million and $11 million at June 30, 2020 and December 31, 2019, respectively. For the three and six months ended June 30, 2020 and 2019 , the pre-tax effects of cash flow hedge accounting on accumulated OCI were as follows: Gain (Loss) Recognized in OCI on Derivative For the Three Months Ended June 30, For the Six Months Ended June 30, 2020 2019 2020 2019 (in millions) (in millions) Southern Company Energy-related derivatives $ (2 ) $ (6 ) $ (6 ) $ (6 ) Interest rate derivatives (1 ) (37 ) (28 ) (37 ) Foreign currency derivatives 17 (1 ) (65 ) (39 ) Total $ 14 $ (44 ) $ (99 ) $ (82 ) Georgia Power Interest rate derivatives $ — $ (37 ) $ (3 ) $ (37 ) Southern Power Energy-related derivatives $ (2 ) $ (2 ) $ (2 ) $ (2 ) Foreign currency derivatives $ 17 $ (1 ) (65 ) (39 ) Total $ 15 $ (3 ) $ (67 ) $ (41 ) Southern Company Gas Energy-related derivatives $ — $ (4 ) $ (4 ) $ (4 ) Interest rate derivatives (1 ) — (25 ) — Total $ (1 ) $ (4 ) $ (29 ) $ (4 ) For the three and six months ended June 30, 2020 and 2019 , the pre-tax effects of energy-related derivatives and interest rate derivatives designated as cash flow hedging instruments on accumulated OCI were immaterial for the other Registrants. For the three and six months ended June 30, 2020 and 2019 , the pre-tax effects of cash flow and fair value hedge accounting on income were as follows: Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships For the Three Months Ended June 30, For the Six Months Ended June 30, 2020 2019 2020 2019 (in millions) (in millions) Southern Company Total cost of natural gas $ 144 $ 191 $ 583 $ 877 Gain (loss) on energy-related cash flow hedges (a) (1 ) — (8 ) — Total depreciation and amortization 873 755 1,730 1,506 Gain (loss) on energy-related cash flow hedges (a) (1 ) (1 ) (2 ) (4 ) Total interest expense, net of amounts capitalized (444 ) (429 ) (900 ) (859 ) Gain (loss) on interest rate cash flow hedges (a) (6 ) (5 ) (13 ) (9 ) Gain (loss) on foreign currency cash flow hedges (a) (6 ) (6 ) (12 ) (12 ) Gain (loss) on interest rate fair value hedges (b) 1 19 30 33 Total other income (expense), net 101 99 204 176 Gain (loss) on foreign currency cash flow hedges (a)(c) 27 16 (4 ) (8 ) Southern Power Total depreciation and amortization $ 121 $ 119 $ 239 $ 237 Gain (loss) on energy-related cash flow hedges (a) (1 ) (1 ) (2 ) (4 ) Total interest expense, net of amounts capitalized (38 ) (41 ) (77 ) (84 ) Gain (loss) on foreign currency cash flow hedges (a) (6 ) (6 ) (12 ) (12 ) Total other income (expense), net 1 40 4 41 Gain (loss) on foreign currency cash flow hedges (a)(c) 27 16 (4 ) (8 ) (a) Reclassified from accumulated OCI into earnings. (b) For fair value hedges, changes in the fair value of the derivative contracts are generally equal to changes in the fair value of the underlying debt and have no material impact on income. (c) The reclassification from accumulated OCI into other income (expense), net completely offsets currency gains and losses arising from changes in the U.S. currency exchange rates used to record the euro-denominated notes. For the three and six months ended June 30, 2020 and 2019 , the pre-tax effects of cash flow and fair value hedge accounting on income for energy-related derivatives and interest rate derivatives were immaterial for the traditional electric operating companies and Southern Company Gas. As of June 30, 2020 and December 31, 2019 , the following amounts were recorded on the balance sheets related to cumulative basis adjustments for fair value hedges: Carrying Amount of the Hedged Item Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item Balance Sheet Location of Hedged Items As of June 30, 2020 As of December 31, 2019 As of June 30, 2020 As of December 31, 2019 (in millions) (in millions) Southern Company Securities due within one year $ — $ (599 ) $ — $ — Long-term debt (1,517 ) (1,494 ) (20 ) 3 For the three and six months ended June 30, 2020 and 2019 , the pre-tax effects of energy-related derivatives not designated as hedging instruments on the statements of income of Southern Company and Southern Company Gas were as follows: Gain (Loss) Three Months Ended June 30, Six Months Ended June 30, Derivatives in Non-Designated Hedging Relationships Statements of Income Location 2020 2019 2020 2019 (in millions) (in millions) Energy-related derivatives: Natural gas revenues (*) $ 14 $ 50 $ 84 $ 83 Cost of natural gas 5 (5 ) 13 3 Total derivatives in non-designated hedging relationships $ 19 $ 45 $ 97 $ 86 (*) Excludes immaterial gains (losses) recorded in natural gas revenues associated with weather derivatives for all periods presented. For the three and six months ended June 30, 2020 and 2019 , the pre-tax effects of energy-related derivatives and interest rate derivatives not designated as hedging instruments were immaterial for all other Registrants. Contingent Features Southern Company, the traditional electric operating companies, Southern Power, and Southern Company Gas do not have any credit arrangements that would require material changes in payment schedules or terminations as a result of a credit rating downgrade. There are certain derivatives that could require collateral, but not accelerated payment, in the event of various credit rating changes of certain Southern Company subsidiaries. At June 30, 2020 , the Registrants had no collateral posted with derivative counterparties to satisfy these arrangements. For the Registrants with interest rate derivatives at June 30, 2020 , the fair value of interest rate derivative liabilities with contingent features and the maximum potential collateral requirements arising from the credit-risk-related contingent features, at a rating below BBB- and/or Baa3, was immaterial. At June 30, 2020 , the fair value of energy-related derivative liabilities with contingent features and the maximum potential collateral requirements arising from the credit-risk-related contingent features, at a rating below BBB- and/or Baa3, were immaterial for all Registrants. The maximum potential collateral requirements arising from the credit-risk-related contingent features for the traditional electric operating companies and Southern Power include certain agreements that could require collateral in the event that one or more Southern Company power pool participants has a credit rating change to below investment grade. Following the sale of Gulf Power to NextEra Energy, Gulf Power is continuing to participate in the Southern Company power pool for a defined transition period that, subject to certain potential adjustments, is scheduled to end on January 1, 2024. Generally, collateral may be provided by a Southern Company guaranty, letter of credit, or cash. If collateral is required, fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral are not offset against fair value amounts recognized for derivatives executed with the same counterparty. Alabama Power and Southern Power maintain accounts with certain regional transmission organizations to facilitate financial derivative transactions. Based on the value of the positions in these accounts and the associated margin requirements, Alabama Power and Southern Power may be required to post collateral. At June 30, 2020 , cash collateral posted in these accounts was immaterial. Southern Company Gas maintains accounts with brokers or the clearing houses of certain exchanges to facilitate financial derivative transactions. Based on the value of the positions in these accounts and the associated margin requirements, Southern Company Gas may be required to deposit cash into these accounts. At June 30, 2020 , cash collateral held on deposit in broker margin accounts was $114 million . The Registrants are exposed to losses related to financial instruments in the event of counterparties' nonperformance. The Registrants only enter into agreements and material transactions with counterparties that have investment grade credit ratings by Moody's and S&P or with counterparties who have posted collateral to cover potential credit exposure. The Registrants have also established risk management policies and controls to determine and monitor the creditworthiness of counterparties in order to mitigate their exposure to counterparty credit risk. Prior to entering into a physical transaction, Southern Company Gas assigns physical wholesale counterparties an internal credit rating and credit limit based on the counterparties' Moody's, S&P, and Fitch ratings, commercially available credit reports, and audited financial statements. Southern Company Gas may require counterparties to pledge additional collateral when deemed necessary. In addition, Southern Company Gas conducts credit evaluations and obtains appropriate internal approvals for the counterparty's line of credit before any transaction with the counterparty is executed. In most cases, the counterparty must have an investment grade rating, which includes a minimum long-term debt rating of Baa3 from Moody's and BBB- from S&P. Generally, Southern Company Gas requires credit enhancements by way of a guaranty, cash deposit, or letter of credit for transaction counterparties that do not have investment grade ratings. Southern Company Gas also utilizes master netting agreements whenever possible to mitigate exposure to counterparty credit risk. When Southern Company Gas is engaged in more than one outstanding derivative transaction with the same counterparty and it also has a legally enforceable netting agreement with that counterparty, the "net" mark-to-market exposure represents the netting of the positive and negative exposures with that counterparty and a reasonable measure of Southern Company Gas' credit risk. Southern Company Gas also uses other netting agreements with certain counterparties with whom it conducts significant transactions. Master netting agreements enable Southern Company Gas to net certain assets and liabilities by counterparty. Southern Company Gas also nets across product lines and against cash collateral provided the master netting and cash collateral agreements include such provisions. Southern Company Gas may require counterparties to pledge additional collateral when deemed necessary. The Registrants do not anticipate a material adverse effect on their respective financial statements as a result of counterparty nonperformance.

ACQUISITIONS AND DISPOSITIONS

ACQUISITIONS AND DISPOSITIONS	6 Months Ended
	Jun. 30, 2020
Business Combinations [Abstract]
ACQUISITIONS AND DISPOSITIONS	ACQUISITIONS AND DISPOSITIONS See Note 15 to the financial statements in Item 8 of the Form 10-K for additional information, including details of assets and liabilities held for sale at December 31, 2019 for Southern Company, Southern Power, and Southern Company Gas. The Registrants had no material assets or liabilities held for sale at June 30, 2020 . Alabama Power On April 22, 2020 and June 9, 2020, the FERC and the Alabama PSC, respectively, approved the Autauga Combined Cycle Acquisition, which is expected to close by September 1, 2020. See Note (B) under "Alabama Power" for additional information. The ultimate outcome of this matter cannot be determined at this time. Southern Power Asset Acquisitions During the six months ended June 30, 2020 , Southern Power acquired a controlling interest in the wind facility listed below. Acquisition-related costs were expensed as incurred and were not material. Project Facility Resource Seller Approximate Nameplate Capacity ( MW ) Location Southern Power Ownership Percentage COD PPA Contract Period Beech Ridge II Wind Invenergy Renewables LLC 56 Greenbrier County, West Virginia 100% of Class A (*) May 2020 12 years (*) In May 2020, Southern Power purchased 100% of the Class A membership interests and now owns the controlling interest in the project, with the Class B member, Invenergy Renewables LLC, owning the noncontrolling interest. In March 2020, Southern Power entered into an agreement to acquire a controlling membership interest in an approximately 300 -MW wind facility located in South Dakota. The acquisition is subject to FERC approval and certain other customary conditions to closing, including commercial operation of the facility, which is expected to occur in late 2020 or early 2021. The facility's output is contracted under two long-term PPAs. The ultimate outcome of this matter cannot be determined at this time. Construction Projects During the six months ended June 30, 2020 , Southern Power completed construction of and placed in service the Reading wind facility, continued construction of the Skookumchuck wind facility, and commenced construction of the Garland and Tranquillity battery energy storage facilities. Total aggregate construction costs, excluding acquisition costs, are expected to be between $475 million and $545 million for the facilities under construction. At June 30, 2020 , total costs of construction incurred for these projects were $232 million and are included in CWIP . The ultimate outcome of these matters cannot be determined at this time. Project Facility Resource Approximate Nameplate Capacity ( MW ) Location Actual/Expected COD PPA Contract Period Projects Completed During the Six Months Ended June 30, 2020 Reading (a) Wind 200 Osage and Lyon Counties, KS May 2020 12 years Projects Under Construction as of June 30, 2020 Skookumchuck (b) Wind 136 Lewis and Thurston Counties, WA Fourth quarter 2020 20 years Garland Solar Storage (c) Battery energy storage system 88 Kern County, CA Second quarter 2021 20 years Tranquillity Solar Storage (c) Battery energy storage system 72 Fresno County, CA Second quarter 2021 20 years (a) In 2018, Southern Power purchased 100% of the membership interests of the Reading facility pursuant to a joint development arrangement. At the time the facility was placed in service, Southern Power recorded an operating lease right-of-use asset and an operating lease liability, each in the amount of $24 million . In June 2020, Southern Power completed a tax equity transaction whereby it received $156 million and now owns 100% of the Class B membership interests. (b) In October 2019, Southern Power purchased 100% of the membership interests of the Skookumchuck facility pursuant to a joint development arrangement. Southern Power expects to complete a tax equity transaction upon commercial operation and retain the Class B membership interests. Shortly after commercial operation, Southern Power may sell a noncontrolling interest in these Class B membership interests to another partner. The ultimate outcome of these matters cannot be determined at this time. (c) Prior to commercial operation, Southern Power may enter into one or more partnerships, in which case it would ultimately own less than 100% of the Class B membership interests, but would retain ownership of the controlling interest. The PPAs for these facilities are pending approval from the California Public Utilities Commission. The ultimate outcome of these matters cannot be determined at this time. Development Projects Southern Power continues to evaluate and refine the deployment of the remaining wind turbine equipment purchased in 2016 and 2017 to development and construction projects. During the six months ended June 30, 2020, certain wind turbine equipment was sold, resulting in an immaterial gain. Sales of Natural Gas and Biomass Plants On January 17, 2020, Southern Power completed the sale of its equity interests in Plant Mankato (including the 385 -MW expansion unit completed in May 2019) to a subsidiary of Xcel for a purchase price of approximately $663 million , including final working capital adjustments. The sale resulted in a gain of approximately $39 million ( $23 million after tax). The assets and liabilities of Plant Mankato were classified as held for sale on Southern Company's and Southern Power's balance sheets at December 31, 2019. Plants Nacogdoches (sold in June 2019) and Mankato represented individually significant components of Southern Power; therefore, pre-tax income for these components for the three months ended June 30, 2019 and the six months ended June 30, 2020 and 2019 is presented below: Three Months Ended June 30, 2019 Six Months Ended June 30, 2020 2019 (in millions) Southern Power's earnings before income taxes: (*) Plant Nacogdoches $ 9 N/A $ 16 Plant Mankato $ 6 $ 2 $ 8 (*) Earnings before income taxes for components reflect the cessation of depreciation and amortization on the long-lived assets being sold upon classification as held for sale in November 2018 and April 2019 for Plant Mankato and Plant Nacogdoches, respectively. Southern Company Gas On March 24, 2020, Southern Company Gas completed the sale of its interests in Pivotal LNG and Atlantic Coast Pipeline to Dominion Modular LNG Holdings, Inc. and Dominion Atlantic Coast Pipeline, LLC, respectively, with aggregate proceeds of $178 million , including working capital adjustments. The preliminary loss associated with the transactions was immaterial. Southern Company Gas may also receive two future payments of $5 million each, contingent upon certain milestones related to Pivotal LNG being met by Dominion Modular LNG Holdings, Inc. The assets and liabilities of Pivotal LNG and the interest in Atlantic Coast Pipeline were classified as held for sale at December 31, 2019. See Notes 3 and 7 under "Other Matters – Southern Company Gas – Gas Pipeline Projects" and "Southern Company Gas – Equity Method Investments," respectively, in Item 8 of the Form 10-K and Notes (C) and (E) under " Other Matters – Southern Company Gas" and " Southern Company Gas ," respectively.

SEGMENT AND RELATED INFORMATION

SEGMENT AND RELATED INFORMATION	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
SEGMENT AND RELATED INFORMATION	SEGMENT AND RELATED INFORMATION Southern Company The primary businesses of the Southern Company system are electricity sales by the traditional electric operating companies and Southern Power and the distribution of natural gas by Southern Company Gas. The traditional electric operating companies – Alabama Power, Georgia Power, and Mississippi Power – are vertically integrated utilities providing electric service in three Southeastern states. Southern Power develops, constructs, acquires, owns, and manages power generation assets, including renewable energy projects, and sells electricity at market-based rates in the wholesale market. Southern Company Gas distributes natural gas through its natural gas distribution utilities and is involved in several other complementary businesses including gas pipeline investments, wholesale gas services, and gas marketing services. Southern Company's reportable business segments are the sale of electricity by the traditional electric operating companies, the sale of electricity in the competitive wholesale market by Southern Power, and the sale of natural gas and other complementary products and services by Southern Company Gas. Revenues from sales by Southern Power to the traditional electric operating companies were $92 million and $178 million for the three and six months ended June 30, 2020 , respectively, and $117 million and $204 million for the three and six months ended June 30, 2019 , respectively. Revenues from sales of natural gas from Southern Company Gas to the traditional electric operating companies were immaterial for all periods presented. Revenues from sales of natural gas from Southern Company Gas to Southern Power were $3 million and $13 million for the three and six months ended June 30, 2020 , respectively, and $16 million and $33 million for the three and six months ended June 30, 2019 , respectively. The "All Other" column includes the Southern Company parent entity, which does not allocate operating expenses to business segments. Also, this category includes segments below the quantitative threshold for separate disclosure. These segments include providing energy solutions to electric utilities and their customers in the areas of distributed generation, energy storage and renewables, and energy efficiency, as well as investments in telecommunications and leveraged lease projects. All other inter-segment revenues are not material. Financial data for business segments and products and services for the three and six months ended June 30, 2020 and 2019 was as follows: Electric Utilities Traditional Electric Operating Companies Southern Power Eliminations Total Southern Company Gas All Other Eliminations Consolidated (in millions) Three Months Ended June 30, 2020 Operating revenues $ 3,539 $ 439 $ (94 ) $ 3,884 $ 636 $ 135 $ (35 ) $ 4,620 Segment net income (loss) (a)(b)(c) 645 63 — 708 71 (177 ) 10 612 Six Months Ended June 30, 2020 Operating revenues $ 6,946 $ 814 $ (181 ) $ 7,579 $ 1,885 $ 248 $ (74 ) $ 9,638 Segment net income (loss) (a)(b)(c)(d) 1,287 138 — 1,425 346 (299 ) 8 1,480 At June 30, 2020 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 263 $ — $ 5,280 Total assets 83,158 13,557 (713 ) 96,002 21,500 3,325 (1,096 ) 119,731 Three Months Ended June 30, 2019 Operating revenues $ 3,899 $ 510 $ (119 ) $ 4,290 $ 689 $ 186 $ (67 ) $ 5,098 Segment net income (loss) (a)(e)(f) 782 174 — 956 106 (154 ) (9 ) 899 Six Months Ended June 30, 2019 Operating revenues $ 7,343 $ 953 $ (211 ) $ 8,085 $ 2,163 $ 368 $ (106 ) $ 10,510 Segment net income (loss) (a)(e)(f) 1,346 230 — 1,576 376 1,041 (11 ) 2,982 At December 31, 2019 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 263 $ — $ 5,280 Total assets 81,063 14,300 (713 ) 94,650 21,687 3,511 (1,148 ) 118,700 (a) Attributable to Southern Company. (b) Segment net income (loss) for the traditional electric operating companies includes a pre-tax charge of $149 million ( $111 million after tax) related to Plant Vogtle Units 3 and 4 for the three and six months ended June 30, 2020. See Note (B) under "Georgia Power – Nuclear Construction " for additional information. (c) Segment net income (loss) for the "All Other" column includes a pre-tax impairment charge of $154 million ( $74 million after tax) related to a leveraged lease investment for the three and six months ended June 30, 2020. See Note (C) under "Other Matters – Southern Company" for additional information. (d) Segment net income (loss) for Southern Power includes a $39 million pre-tax gain ( $23 million gain after tax) on the sale of Plant Mankato for the six months ended June 30, 2020 . See Note (K) under " Southern Power " for additional information. (e) Segment net income (loss) for the "All Other" column includes the preliminary pre-tax gain associated with the sale of Gulf Power of $2.5 billion ( $1.3 billion after tax) for the six months ended June 30, 2019, of which $(15) million ( $(11) million after tax) was recorded in the three months ended June 30, 2019, as well as a goodwill impairment charge of $32 million for the three and six months ended June 30, 2019 in contemplation of the sale of one of PowerSecure's business units. See Note 15 to the financial statements in Item 8 of the Form 10-K under " Southern Company" for additional information. (f) Segment net income (loss) for Southern Power includes a $23 million pre-tax gain ( $88 million gain after tax) on the sale of Plant Nacogdoches for the three and six months ended June 30, 2019. See Note 15 to the financial statements in Item 8 of the Form 10-K under "Southern Power – Sale of Natural Gas and Biomass Plants" for additional information. Products and Services Electric Utilities' Revenues Retail Wholesale Other Total (in millions) Three Months Ended June 30, 2020 $ 3,182 $ 472 $ 230 $ 3,884 Three Months Ended June 30, 2019 3,540 542 208 4,290 Six Months Ended June 30, 2020 $ 6,260 $ 889 $ 430 $ 7,579 Six Months Ended June 30, 2019 6,623 1,041 421 8,085 Southern Company Gas' Revenues Gas Wholesale Gas Services (*) Gas Other Total (in millions) Three Months Ended June 30, 2020 $ 583 $ (19 ) $ 56 $ 16 $ 636 Three Months Ended June 30, 2019 563 48 58 20 689 Six Months Ended June 30, 2020 $ 1,596 $ 32 $ 233 $ 24 $ 1,885 Six Months Ended June 30, 2019 1,724 134 287 18 2,163 (*) The revenues for wholesale gas services are netted with costs associated with its energy and risk management activities. See "Southern Company Gas" herein for additional information. Southern Company Gas Southern Company Gas manages its business through four reportable segments – gas distribution operations, gas pipeline investments, wholesale gas services, and gas marketing services. The non-reportable segments are combined and presented as all other. Gas distribution operations is the largest component of Southern Company Gas' business and includes natural gas local distribution utilities that construct, manage, and maintain intrastate natural gas pipelines and gas distribution facilities in four states. Gas pipeline investments consists of joint ventures in natural gas pipeline investments including a 50% interest in SNG, a 20% ownership interest in the PennEast Pipeline construction project, a 50% joint ownership interest in the Dalton Pipeline, and a 5% ownership interest in the Atlantic Coast Pipeline construction project through its sale on March 24, 2020. These natural gas pipelines enable the provision of diverse sources of natural gas supplies to the customers of Southern Company Gas. Wholesale gas services provides natural gas asset management and/or related logistics services for each of Southern Company Gas' utilities except Nicor Gas as well as for non-affiliated companies. Additionally, wholesale gas services engages in natural gas storage and gas pipeline arbitrage and related activities. Gas marketing services provides natural gas marketing to end-use customers primarily in Georgia and Illinois through SouthStar. The all other column includes segments below the quantitative threshold for separate disclosure, including natural gas storage businesses, fuels operations through the sale of Southern Company Gas' interest in Pivotal LNG on March 24, 2020, the investment in Triton through its sale on May 29, 2019, and other subsidiaries that fall below the quantitative threshold for separate disclosure. See Notes (E) and (K) under " Southern Company Gas " for additional information. Business segment financial data for the three and six months ended June 30, 2020 and 2019 was as follows: Gas Distribution Operations Gas Pipeline Investments Wholesale Gas Services (*) Gas Marketing Services Total All Other Eliminations Consolidated (in millions) Three Months Ended June 30, 2020 Operating revenues $ 587 $ 8 $ (19 ) $ 56 $ 632 $ 8 $ (4 ) $ 636 Segment net income (loss) 74 21 (23 ) 5 77 (6 ) — 71 Six Months Ended June 30, 2020 Operating revenues $ 1,607 $ 16 $ 32 $ 233 $ 1,888 $ 16 $ (19 ) $ 1,885 Segment net income (loss) 238 51 — 62 351 (5 ) — 346 Total assets at June 30, 2020 18,276 1,617 637 1,480 22,010 10,645 (11,155 ) 21,500 Three Months Ended June 30, 2019 Operating revenues $ 568 $ 8 $ 48 $ 58 $ 682 $ 13 $ (6 ) $ 689 Segment net income (loss) 58 25 23 (3 ) 103 3 — 106 Six Months Ended June 30, 2019 Operating revenues $ 1,740 $ 16 $ 134 $ 287 $ 2,177 $ 24 $ (38 ) $ 2,163 Segment net income (loss) 191 57 70 58 376 — — 376 Total assets at December 31, 2019 18,204 1,678 850 1,496 22,228 10,759 (11,300 ) 21,687 (*) The revenues for wholesale gas services are netted with costs associated with its energy and risk management activities. A reconciliation of operating revenues and intercompany revenues is shown in the following table. Third Party Gross Revenues Intercompany Revenues Total Gross Revenues Less Gross Gas Costs Operating Revenues (in millions) Three Months Ended June 30, 2020 $ 854 $ 18 $ 872 $ 891 $ (19 ) Three Months Ended June 30, 2019 1,223 63 1,286 1,238 48 Six Months Ended June 30, 2020 $ 2,039 $ 47 $ 2,086 $ 2,054 $ 32 Six Months Ended June 30, 2019 3,148 151 3,299 3,165 134

INTRODUCTION (Policies)

INTRODUCTION (Policies)	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting	The condensed quarterly financial statements of each Registrant included herein have been prepared by such Registrant, without audit, pursuant to the rules and regulations of the SEC. The Condensed Balance Sheets as of December 31, 2019 have been derived from the audited financial statements of each Registrant. In the opinion of each Registrant's management, the information regarding such Registrant furnished herein reflects all adjustments, which, except as otherwise disclosed, are of a normal recurring nature, necessary to present fairly the results of operations for the periods ended June 30, 2020 and 2019 . Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations, although each Registrant believes that the disclosures regarding such Registrant are adequate to make the information presented not misleading. Disclosures which would substantially duplicate the disclosures in the Form 10-K and details which have not changed significantly in amount or composition since the filing of the Form 10-K are generally omitted from this Quarterly Report on Form 10-Q unless specifically required by GAAP. Therefore, these Condensed Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the Form 10-K. Due to the seasonal variations in the demand for energy and other factors, including the impacts of the COVID-19 pandemic, operating results for the periods presented are not necessarily indicative of the operating results to be expected for the full year.
Reclassifications	Certain prior year data presented in the financial statements have been reclassified to conform to the current year presentation. These reclassifications had no impact on the overall results of operations, financial position, or cash flows of any Registrant.
Goodwill and Other Intangible Assets	Goodwill is not amortized but is subject to an annual impairment test in the fourth quarter of the year and on an interim basis as events and changes in circumstances occur, including, but not limited to, a significant change in operating performance, the business climate, legal or regulatory factors, or a planned sale or disposition of a significant portion of the business. The continued COVID-19 pandemic and related responses continue to disrupt supply chains and capital markets, reduce labor availability and productivity, and reduce economic activity. These effects could have a variety of adverse impacts on Southern Company and its subsidiaries, including the $263 million of goodwill recorded at PowerSecure. If the impact of the COVID-19 pandemic becomes significant to the operating results of PowerSecure and its businesses, a portion of the associated goodwill may become impaired. The ultimate outcome of this matter cannot be determined at this time.
Natural Gas For Sale	Southern Company Gas, with the exception of Nicor Gas, carries natural gas inventory on a WACOG basis. For any declines in market prices below the WACOG considered to be other than temporary, an adjustment is recorded to reduce the value of natural gas inventories to market value. Southern Company Gas recorded no material adjustments for the three and six months ended June 30, 2020 and recorded adjustments of $7 million and $10 million for the three and six months ended June 30, 2019 , respectively. Nicor Gas' natural gas inventory is carried at cost on a LIFO basis. Inventory decrements occurring during the year that are restored prior to year end are charged to cost of natural gas at the estimated annual replacement cost. Inventory decrements that are not restored prior to year end are charged to cost of natural gas at the actual LIFO
Valuation Methodologies	Valuation Methodologies The energy-related derivatives primarily consist of exchange-traded and over-the-counter financial products for natural gas and physical power products, including, from time to time, basis swaps. These are standard products used within the energy industry and are valued using the market approach. The inputs used are mainly from observable market sources, such as forward natural gas prices, power prices, implied volatility, and overnight index swap interest rates. Interest rate derivatives are also standard over-the-counter products that are valued using observable market data and assumptions commonly used by market participants. The fair value of interest rate derivatives reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future interest rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and occasionally, implied volatility of interest rate options. The fair value of cross-currency swaps reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future foreign currency exchange rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and discount rates. The interest rate derivatives and cross-currency swaps are categorized as Level 2 under Fair Value Measurements as these inputs are based on observable data and valuations of similar instruments. See Note (J) for additional information on how these derivatives are used. For fair value measurements of the investments within the nuclear decommissioning trusts and the non-qualified deferred compensation trusts, external pricing vendors are designated for each asset class with each security specifically assigned a primary pricing source. For investments held within commingled funds, fair value is determined at the end of each business day through the net asset value, which is established by obtaining the underlying securities' individual prices from the primary pricing source. A market price secured from the primary source vendor is then evaluated by management in its valuation of the assets within the trusts. As a general approach, fixed income market pricing vendors gather market data (including indices and market research reports) and integrate relative credit information, observed market movements, and sector news into proprietary pricing models, pricing systems, and mathematical tools. Dealer quotes and other market information, including live trading levels and pricing analysts' judgments, are also obtained when available. The NRC requires licensees of commissioned nuclear power reactors to establish a plan for providing reasonable assurance of funds for future decommissioning. See Note 6 to the financial statements under "Nuclear Decommissioning" in Item 8 of the Form 10-K for additional information.
Derivatives	Southern Company, the traditional electric operating companies, Southern Power, and Southern Company Gas are exposed to market risks, including commodity price risk, interest rate risk, weather risk, and occasionally foreign currency exchange rate risk. To manage the volatility attributable to these exposures, each company nets its exposures, where possible, to take advantage of natural offsets and enters into various derivative transactions for the remaining exposures pursuant to each company's policies in areas such as counterparty exposure and risk management practices. Southern Company Gas' wholesale gas operations use various contracts in its commercial activities that generally meet the definition of derivatives. For the traditional electric operating companies, Southern Power, and Southern Company Gas' other businesses, each company's policy is that derivatives are to be used primarily for hedging purposes and mandates strict adherence to all applicable risk management policies. Derivative positions are monitored using techniques including, but not limited to, market valuation, value at risk, stress testing, and sensitivity analysis. Derivative instruments are recognized at fair value in the balance sheets as either assets or liabilities and are presented on a net basis. See Note (I) for additional fair value information. In the statements of cash flows, any cash impacts of settled energy-related and interest rate derivatives are recorded as operating activities. Any cash impacts of settled foreign currency derivatives are classified as operating or financing activities to correspond with classification of the hedged interest or principal, respectively. See Note 1 to the financial statements under "Financial Instruments" in Item 8 of the Form 10-K for additional information. Energy-Related Derivatives The traditional electric operating companies, Southern Power, and Southern Company Gas enter into energy-related derivatives to hedge exposures to electricity, natural gas, and other fuel price changes. However, due to cost-based rate regulations and other various cost recovery mechanisms, the traditional electric operating companies and the natural gas distribution utilities have limited exposure to market volatility in energy-related commodity prices. Each of the traditional electric operating companies and certain of the natural gas distribution utilities of Southern Company Gas manage fuel-hedging programs, implemented per the guidelines of their respective state PSCs or other applicable state regulatory agencies, through the use of financial derivative contracts, which are expected to continue to mitigate price volatility. The traditional electric operating companies (with respect to wholesale generating capacity) and Southern Power have limited exposure to market volatility in energy-related commodity prices because their long-term sales contracts shift substantially all fuel cost responsibility to the purchaser. However, the traditional electric operating companies and Southern Power may be exposed to market volatility in energy-related commodity prices to the extent any uncontracted capacity is used to sell electricity. Southern Company Gas retains exposure to price changes that can, in a volatile energy market, be material and can adversely affect its results of operations. Southern Company Gas also enters into weather derivative contracts as economic hedges of operating margins in the event of warmer-than-normal weather. Exchange-traded options are carried at fair value, with changes reflected in operating revenues. Non-exchange-traded options are accounted for using the intrinsic value method. Changes in the intrinsic value for non-exchange-traded contracts are reflected in operating revenues. Energy-related derivative contracts are accounted for under one of three methods: • Regulatory Hedges — Energy-related derivative contracts designated as regulatory hedges relate primarily to the traditional electric operating companies' and the natural gas distribution utilities' fuel-hedging programs, where gains and losses are initially recorded as regulatory liabilities and assets, respectively, and then are included in fuel expense as the underlying fuel is used in operations and ultimately recovered through the respective fuel cost recovery clauses. • Cash Flow Hedges — Gains and losses on energy-related derivatives designated as cash flow hedges (which are mainly used to hedge anticipated purchases and sales) are initially deferred in accumulated OCI before being recognized in the statements of income in the same period and in the same income statement line item as the earnings effect of the hedged transactions. • Not Designated — Gains and losses on energy-related derivative contracts that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Some energy-related derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the electric and natural gas industries. When an energy-related derivative contract is settled physically, any cumulative unrealized gain or loss is reversed and the contract price is recognized in the respective line item representing the actual price of the underlying goods being delivered. Foreign Currency Derivatives Southern Company and certain subsidiaries, including Southern Power, may enter into foreign currency derivatives to hedge exposure to changes in foreign currency exchange rates, such as that arising from the issuance of debt denominated in a currency other than U.S. dollars. Derivatives related to forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and on the same income statement line as the earnings effect of the hedged transactions, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. Interest Rate Derivatives Southern Company and certain subsidiaries may enter into interest rate derivatives to hedge exposure to changes in interest rates. The derivatives employed as hedging instruments are structured to minimize ineffectiveness. Derivatives related to existing variable rate securities or forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and presented on the same income statement line item as the earnings effect of the hedged transactions. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item. Fair value gains or losses on derivatives that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred.

INTRODUCTION (Tables)

INTRODUCTION (Tables)	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Goodwill	Goodwill at June 30, 2020 and December 31, 2019 was as follows: Goodwill (in millions) Southern Company $ 5,280 Southern Company Gas: Gas distribution operations $ 4,034 Gas marketing services 981 Southern Company Gas total $ 5,015
Schedule of Other Intangible Assets, Indefinite-Lived	Other intangible assets were as follows: At June 30, 2020 At December 31, 2019 Gross Carrying Amount Accumulated Amortization Other Intangible Assets, Net Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Other intangible assets subject to amortization: Customer relationships $ 212 $ (126 ) $ 86 $ 212 $ (116 ) $ 96 Trade names 64 (28 ) 36 64 (25 ) 39 Storage and transportation contracts 64 (63 ) 1 64 (62 ) 2 PPA fair value adjustments 390 (79 ) 311 390 (69 ) 321 Other 10 (8 ) 2 11 (8 ) 3 Total other intangible assets subject to amortization $ 740 $ (304 ) $ 436 $ 741 $ (280 ) $ 461 Other intangible assets not subject to amortization: Federal Communications Commission licenses 75 — 75 75 — 75 Total other intangible assets $ 815 $ (304 ) $ 511 $ 816 $ (280 ) $ 536 Southern Power Other intangible assets subject to amortization: PPA fair value adjustments $ 390 $ (79 ) $ 311 $ 390 $ (69 ) $ 321 Southern Company Gas Other intangible assets subject to amortization: Gas marketing services Customer relationships $ 156 $ (112 ) $ 44 $ 156 $ (104 ) $ 52 Trade names 26 (11 ) 15 26 (10 ) 16 Wholesale gas services Storage and transportation contracts 64 (63 ) 1 64 (62 ) 2 Total other intangible assets subject to amortization $ 246 $ (186 ) $ 60 $ 246 $ (176 ) $ 70
Schedule of Other Intangible Assets, Finite-Lived	Other intangible assets were as follows: At June 30, 2020 At December 31, 2019 Gross Carrying Amount Accumulated Amortization Other Intangible Assets, Net Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Other intangible assets subject to amortization: Customer relationships $ 212 $ (126 ) $ 86 $ 212 $ (116 ) $ 96 Trade names 64 (28 ) 36 64 (25 ) 39 Storage and transportation contracts 64 (63 ) 1 64 (62 ) 2 PPA fair value adjustments 390 (79 ) 311 390 (69 ) 321 Other 10 (8 ) 2 11 (8 ) 3 Total other intangible assets subject to amortization $ 740 $ (304 ) $ 436 $ 741 $ (280 ) $ 461 Other intangible assets not subject to amortization: Federal Communications Commission licenses 75 — 75 75 — 75 Total other intangible assets $ 815 $ (304 ) $ 511 $ 816 $ (280 ) $ 536 Southern Power Other intangible assets subject to amortization: PPA fair value adjustments $ 390 $ (79 ) $ 311 $ 390 $ (69 ) $ 321 Southern Company Gas Other intangible assets subject to amortization: Gas marketing services Customer relationships $ 156 $ (112 ) $ 44 $ 156 $ (104 ) $ 52 Trade names 26 (11 ) 15 26 (10 ) 16 Wholesale gas services Storage and transportation contracts 64 (63 ) 1 64 (62 ) 2 Total other intangible assets subject to amortization $ 246 $ (186 ) $ 60 $ 246 $ (176 ) $ 70
Finite-lived Intangible Assets Amortization Expense	Amortization associated with other intangible assets was as follows: Three Months Ended Six Months Ended June 30, 2020 (in millions) Southern Company (a) $ 13 $ 25 Southern Power (b) $ 5 $ 10 Southern Company Gas Gas marketing services $ 5 $ 9 Wholesale gas services (b) — 1 Southern Company Gas total $ 5 $ 10 (a) Includes $5 million and $11 million for the three and six months ended June 30, 2020 , respectively, recorded as a reduction to operating revenues. (b) Recorded as a reduction to operating revenues.
Restrictions on Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed balance sheets that total to the amounts shown in the condensed statements of cash flows for the Registrants that had restricted cash at June 30, 2020 and/or December 31, 2019 : Southern Company Southern Power Southern Company Gas At June 30, 2020 At December 31, 2019 At June 30, 2020 At June At December 31, 2019 (in millions) (in millions) (in millions) Cash and cash equivalents $ 1,879 $ 1,975 $ 154 $ 120 $ 46 Restricted cash (*) : Other accounts and notes receivable — 3 — — 3 Other current assets 4 — — 4 — Other deferred charges and assets 2 — 2 — — Total cash, cash equivalents, and restricted cash $ 1,885 $ 1,978 $ 156 $ 124 $ 49 (*) For Southern Company Gas, reflects restricted cash held as collateral for workers' compensation, life insurance, and long-term disability insurance. For Southern Power, reflects restricted cash held for construction payables.
Schedule of Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed balance sheets that total to the amounts shown in the condensed statements of cash flows for the Registrants that had restricted cash at June 30, 2020 and/or December 31, 2019 : Southern Company Southern Power Southern Company Gas At June 30, 2020 At December 31, 2019 At June 30, 2020 At June At December 31, 2019 (in millions) (in millions) (in millions) Cash and cash equivalents $ 1,879 $ 1,975 $ 154 $ 120 $ 46 Restricted cash (*) : Other accounts and notes receivable — 3 — — 3 Other current assets 4 — — 4 — Other deferred charges and assets 2 — 2 — — Total cash, cash equivalents, and restricted cash $ 1,885 $ 1,978 $ 156 $ 124 $ 49 (*) For Southern Company Gas, reflects restricted cash held as collateral for workers' compensation, life insurance, and long-term disability insurance. For Southern Power, reflects restricted cash held for construction payables.
Schedule of Changes in Asset Retirement Obligations	Details of changes in AROs for Southern Company and Alabama Power during the first six months of 2020 are shown in the following table. There were no material changes in AROs for the other Registrants during the first six months of 2020. Southern Company Alabama Power (in millions) Balance at December 31, 2019 $ 9,786 $ 3,540 Liabilities incurred 15 — Liabilities settled (193 ) (100 ) Accretion 204 74 Cash flow revisions 462 462 Balance at June 30, 2020 $ 10,274 $ 3,976

REGULATORY MATTERS (Tables)

REGULATORY MATTERS (Tables)	6 Months Ended
	Jun. 30, 2020
Regulated Operations [Abstract]
Cost Recovery Clauses	The recovery balances for certain retail regulatory clauses of the traditional electric operating companies and Southern Company Gas at June 30, 2020 and December 31, 2019 were as follows: Regulatory Clause Balance Sheet Line Item June 30, December 31, (in millions) Alabama Power Rate CNP Compliance Other regulatory liabilities, current $ 25 $ 55 Other regulatory liabilities, deferred — 7 Rate CNP PPA Deferred under recovered regulatory clause revenues 41 40 Retail Energy Cost Recovery Other regulatory liabilities, current 22 32 Other regulatory liabilities, deferred 93 17 Natural Disaster Reserve Other regulatory liabilities, current 16 37 Other regulatory liabilities, deferred 96 113 Georgia Power Fuel Cost Recovery Other current liabilities $ 109 $ — Other deferred credits and liabilities 95 73 Mississippi Power Fuel Cost Recovery Over recovered regulatory clause liabilities $ 22 $ 23 Ad Valorem Tax Other regulatory assets 11 47 Other regulatory assets, deferred 39 — Property Damage Reserve Other regulatory liabilities, deferred 50 54 Southern Company Gas Natural Gas Cost Recovery Other regulatory liabilities $ 100 $ 74
Cost and Schedule	Georgia Power's approximate proportionate share of the remaining estimated capital cost to complete Plant Vogtle Units 3 and 4 by the expected in-service dates of November 2021 and November 2022, respectively, is as follows: (in billions) Base project capital cost forecast (a)(b) $ 8.4 Construction contingency estimate 0.1 Total project capital cost forecast (a)(b) 8.5 Net investment as of June 30, 2020 (b) (6.6 ) Remaining estimate to complete (a) $ 1.9 (a) Excludes financing costs expected to be capitalized through AFUDC of approximately $260 million , of which $52 million had been accrued through June 30, 2020 . (b) Net of $1.7 billion received from Toshiba under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds.

REVENUE FROM CONTRACTS WITH C_2

REVENUE FROM CONTRACTS WITH CUSTOMERS AND LEASE INCOME (Tables)	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table disaggregates revenue from contracts with customers for the three and six months ended June 30, 2020 and 2019 : Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended June 30, 2020 Operating revenues Retail electric revenues Residential $ 1,430 $ 549 $ 817 $ 64 $ — $ — Commercial 1,103 353 689 61 — — Industrial 642 302 273 67 — — Other 23 6 15 2 — — Total retail electric revenues 3,198 1,210 1,794 194 — — Natural gas distribution revenues Residential 239 — — — — 239 Commercial 58 — — — — 58 Transportation 234 — — — — 234 Industrial 5 — — — — 5 Other 49 — — — — 49 Total natural gas distribution revenues 585 — — — — 585 Wholesale electric revenues PPA energy revenues 167 28 7 2 134 — PPA capacity revenues 108 25 13 1 71 — Non-PPA revenues 50 5 2 73 59 — Total wholesale electric revenues 325 58 22 76 264 — Other natural gas revenues Wholesale gas services 341 — — — — 341 Gas marketing services 57 — — — — 57 Other natural gas revenues 8 — — — — 8 Total natural gas revenues 406 — — — — 406 Other revenues 251 44 119 6 4 — Total revenue from contracts with customers 4,765 1,312 1,935 276 268 991 Other revenue sources (a) 728 53 (7 ) 7 171 518 Other adjustments (b) (873 ) — — — — (873 ) Total operating revenues $ 4,620 $ 1,365 $ 1,928 $ 283 $ 439 $ 636 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Six Months Ended June 30, 2020 Operating revenues Retail electric revenues Residential $ 2,801 $ 1,103 $ 1,577 $ 121 $ — $ — Commercial 2,247 717 1,409 121 — — Industrial 1,323 623 555 145 — — Other 46 11 31 4 — — Total retail electric revenues 6,417 2,454 3,572 391 — — Natural gas distribution revenues Residential 736 — — — — 736 Commercial 188 — — — — 188 Transportation 499 — — — — 499 Industrial 17 — — — — 17 Other 144 — — — — 144 Total natural gas distribution revenues 1,584 — — — — 1,584 Wholesale electric revenues PPA energy revenues 326 55 15 4 259 — PPA capacity revenues 213 52 25 2 136 — Non-PPA revenues 100 24 4 142 117 — Total wholesale electric revenues 639 131 44 148 512 — Other natural gas revenues Wholesale gas services 737 — — — — 737 Gas marketing services 220 — — — — 220 Other natural gas revenues 15 — — — — 15 Total natural gas revenues 972 — — — — 972 Other revenues 441 78 214 13 7 — Total revenue from contracts with customers 10,053 2,663 3,830 552 519 2,556 Other revenue sources (a) 1,599 53 (76 ) 7 295 1,343 Other adjustments (b) (2,014 ) — — — — (2,014 ) Total operating revenues $ 9,638 $ 2,716 $ 3,754 $ 559 $ 814 $ 1,885 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended June 30, 2019 Operating revenues Retail electric revenues Residential $ 1,491 $ 592 $ 831 $ 68 $ — $ — Commercial 1,264 422 770 72 — — Industrial 766 369 327 70 — — Other 25 7 15 3 — — Total retail electric revenues 3,546 1,390 1,943 213 — — Natural gas distribution revenues Residential 229 — — — — 229 Commercial 65 — — — — 65 Transportation 213 — — — — 213 Industrial 5 — — — — 5 Other 45 — — — — 45 Total natural gas distribution revenues 557 — — — — 557 Wholesale electric revenues PPA energy revenues 208 35 17 3 163 — PPA capacity revenues 109 25 13 1 81 — Non-PPA revenues 53 3 1 89 68 — Total wholesale electric revenues 370 63 31 93 312 — Other natural gas revenues Wholesale gas services 444 — — — — 444 Gas marketing services 55 — — — — 55 Other natural gas revenues 12 — — — — 12 Total natural gas revenues 511 — — — — 511 Other revenues 238 37 95 4 3 — Total revenue from contracts with customers 5,222 1,490 2,069 310 315 1,068 Other revenue sources (a) 1,050 23 48 3 195 795 Other adjustments (b) (1,174 ) — — — — (1,174 ) Total operating revenues $ 5,098 $ 1,513 $ 2,117 $ 313 $ 510 $ 689 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Six Months Ended June 30, 2019 Operating revenues Retail electric revenues Residential $ 2,818 $ 1,151 $ 1,539 $ 128 $ — $ — Commercial 2,390 790 1,463 137 — — Industrial 1,474 707 623 144 — — Other 44 13 25 6 — — Total retail electric revenues 6,726 2,661 3,650 415 — — Natural gas distribution revenues Residential 830 — — — — 830 Commercial 235 — — — — 235 Transportation 469 — — — — 469 Industrial 22 — — — — 22 Other 161 — — — — 161 Total natural gas distribution revenues 1,717 — — — — 1,717 Wholesale electric revenues PPA energy revenues 398 67 28 5 314 — PPA capacity revenues 217 52 27 2 163 — Non-PPA revenues 108 62 3 164 109 — Total wholesale electric revenues 723 181 58 171 586 — Other natural gas revenues Wholesale gas services 1,165 — — — — 1,165 Gas marketing services 276 — — — — 276 Other natural gas revenues 22 — — — — 22 Total natural gas revenues 1,463 — — — — 1,463 Other revenues 502 83 186 10 6 — Total revenue from contracts with customers 11,131 2,925 3,894 596 592 3,180 Other revenue sources (a) 2,413 (4 ) 57 4 361 2,017 Other adjustments (b) (3,034 ) — — — — (3,034 ) Total operating revenues $ 10,510 $ 2,921 $ 3,951 $ 600 $ 953 $ 2,163 (a) Other revenue sources primarily relate to revenues from customers accounted for as derivatives and leases, as well as alternative revenue programs at Southern Company Gas and other cost recovery mechanisms at the traditional electric operating companies. (b) Other adjustments relate to the cost of Southern Company Gas' energy and risk management activities. Wholesale gas services revenues are presented net of the related costs of those activities on the statement of income. See Note (L) under " Southern Company Gas " for additional information on the components of wholesale gas services' operating revenues.
Contract with Customer, Asset and Liability and Revenue Recognized	The following table reflects the closing balances of receivables, contract assets, and contract liabilities related to revenues from contracts with customers at June 30, 2020 and December 31, 2019 : Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Accounts Receivables As of June 30, 2020 $ 2,283 $ 592 $ 796 $ 84 $ 115 $ 523 As of December 31, 2019 2,413 586 688 79 97 749 Contract Assets As of June 30, 2020 $ 103 $ — $ 54 $ 1 $ — $ — As of December 31, 2019 117 — 69 — — — Contract Liabilities As of June 30, 2020 $ 57 $ 6 $ 23 $ — $ 1 $ 2 As of December 31, 2019 52 10 13 — 1 1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	Revenue from contracts with customers related to these performance obligations remaining at June 30, 2020 are expected to be recognized as follows: 2020 (remaining) 2021 2022 2023 2024 2025 and Thereafter (in millions) Southern Company $ 319 $ 432 $ 362 $ 339 $ 319 $ 3,062 Alabama Power 12 33 31 24 7 5 Georgia Power 37 70 39 34 23 62 Southern Power 156 290 292 282 290 3,013
Summary of Lease Income	Lease income for the three and six months ended June 30, 2020 and 2019 is as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) For the Three Months Ended June 30, 2020 Lease income - interest income on sales-type leases $ 3 $ — $ — $ 3 $ — $ — Lease income - operating leases 47 6 15 — 21 9 Variable lease income 126 — — — 136 — Total lease income $ 176 $ 6 $ 15 $ 3 $ 157 $ 9 For the Six Months Ended June 30, 2020 Lease income - interest income on sales-type leases $ 6 $ — $ — $ 5 $ — $ — Lease income - operating leases 97 13 30 — 45 17 Variable lease income 200 — — — 215 — Total lease income $ 303 $ 13 $ 30 $ 5 $ 260 $ 17 For the Three Months Ended June 30, 2019 Lease income - interest income on sales-type leases $ 2 $ — $ — $ 2 $ — $ — Lease income - operating leases 67 7 19 — 44 9 Variable lease income 115 — — — 129 — Total lease income $ 184 $ 7 $ 19 $ 2 $ 173 $ 9 For the Six Months Ended June 30, 2019 Lease income - interest income on sales-type leases $ 5 $ — $ — $ 5 $ — $ — Lease income - operating leases 139 13 39 — 90 17 Variable lease income 182 — — — 204 — Total lease income $ 326 $ 13 $ 39 $ 5 $ 294 $ 17

CONSOLIDATED ENTITIES AND EQU_2

CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS (Tables)	6 Months Ended
	Jun. 30, 2020
Regulated Operations [Abstract]
Equity Method Investments	Selected financial information of SNG for the three and six months ended June 30, 2020 and 2019 is as follows: Income Statement Information Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 (in millions) Revenues $ 149 $ 155 $ 307 $ 321 Operating income 78 86 176 192 Net income 55 64 130 148 The carrying amounts of Southern Company Gas' equity method investments as of June 30, 2020 and December 31, 2019 and related income from those investments for the three and six months ended June 30, 2020 and 2019 were as follows: Investment Balance June 30, 2020 December 31, 2019 (a) (in millions) SNG (b) $ 1,189 $ 1,137 PennEast Pipeline (c) 87 82 Other 32 32 Total $ 1,308 $ 1,251 (a) Excludes investments in Atlantic Coast Pipeline and Pivotal JAX LNG classified as held for sale at December 31, 2019. See Note 15 to the financial statements under "Assets Held for Sale" in Item 8 of the Form 10-K for additional information. (b) Increase primarily relates to a capital contribution, partially offset by the continued amortization of deferred tax assets established upon acquisition. (c) See Note (C) under "Other Matters – Southern Company Gas" for additional information on the PennEast Pipeline.
Schedule of Other Nonoperating Income, by Component	Earnings from Equity Method Investments Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 (in millions) SNG $ 28 $ 32 $ 65 $ 74 Atlantic Coast Pipeline (a)(b) — 3 3 6 PennEast Pipeline (a) 1 1 3 3 Other 1 (5 ) 1 (3 ) Total $ 30 $ 31 $ 72 $ 80 (a) Amounts primarily result from AFUDC equity recorded by the project entity. (b) On March 24, 2020, Southern Company Gas completed the sale of its interest in Atlantic Coast Pipeline. See Note (K) under "Southern Company Gas" for additional information.

FINANCING (Tables)

FINANCING (Tables)	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Credit Arrangements by Company	At June 30, 2020 , committed credit arrangements with banks were as follows: Expires Company 2020 2021 2022 2023 2024 Total Unused Due within One Year (in millions) Southern Company parent $ — $ — $ — $ — $ 2,000 $ 2,000 $ 1,999 $ — Alabama Power 3 — 525 — 800 1,328 1,328 3 Georgia Power — — — — 1,750 1,750 1,733 — Mississippi Power — — 150 125 — 275 250 — Southern Power (a) — — — — 600 600 590 — Southern Company Gas (b) — — — — 1,750 1,750 1,745 — SEGCO — 30 — — — 30 30 30 Southern Company $ 3 $ 30 $ 675 $ 125 $ 6,900 $ 7,733 $ 7,675 $ 33 (a) Does not include Southern Power Company's $120 million and $60 million continuing letter of credit facilities for standby letters of credit expiring in 2021 and 2023, respectively, of which $19 million and $60 million , respectively, was unused at June 30, 2020 . Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities. (b) Southern Company Gas, as the parent entity, guarantees the obligations of Southern Company Gas Capital, which is the borrower of $1.25 billion of this arrangement. Southern Company Gas' committed credit arrangement also includes $500 million for which Nicor Gas is the borrower and which is restricted for working capital needs of Nicor Gas. Pursuant to this multi-year credit arrangement, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted.
Shares Used to Compute Diluted Earnings Per Share	Shares used to compute diluted earnings per share were as follows: Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 (in millions) As reported shares 1,058 1,044 1,057 1,041 Effect of stock-based compensation 5 8 7 8 Effect of equity units — — 1 — Diluted shares 1,063 1,052 1,065 1,049

RETIREMENT BENEFITS (Tables)

RETIREMENT BENEFITS (Tables)	6 Months Ended
	Jun. 30, 2020
Retirement Benefits [Abstract]
Pension Plans and Postretirement Plans	Components of the net periodic benefit costs for the three and six months ended June 30, 2020 and 2019 are presented in the following tables. Three Months Ended June 30, 2020 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Pension Plans Service cost $ 94 $ 22 $ 24 $ 4 $ 2 $ 8 Interest cost 108 25 34 5 2 7 Expected return on plan assets (275 ) (66 ) (87 ) (12 ) (3 ) (20 ) Amortization: Prior service costs — — 1 — — — Regulatory asset — — — — — 4 Net (gain)/loss 67 18 21 3 — 3 Net periodic pension cost (income) $ (6 ) $ (1 ) $ (7 ) $ — $ 1 $ 2 Postretirement Benefits Service cost $ 6 $ 1 $ 2 $ 1 $ — $ 1 Interest cost 14 3 5 1 — 4 Expected return on plan assets (18 ) (7 ) (6 ) (1 ) — (2 ) Amortization: Prior service costs (1 ) — — — — — Regulatory asset — — — — — 1 Net (gain)/loss — — — — — (1 ) Net periodic postretirement benefit cost $ 1 $ (3 ) $ 1 $ 1 $ — $ 3 Six Months Ended June 30, 2020 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Pension Plans Service cost $ 188 $ 44 $ 48 $ 8 $ 4 $ 16 Interest cost 216 50 67 10 3 15 Expected return on plan assets (550 ) (132 ) (174 ) (25 ) (6 ) (39 ) Amortization: Prior service costs 1 — 1 — — (1 ) Regulatory asset — — — — — 8 Net (gain)/loss 134 36 43 6 1 5 Net periodic pension cost (income) $ (11 ) $ (2 ) $ (15 ) $ (1 ) $ 2 $ 4 Six Months Ended June 30, 2020 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Postretirement Benefits Service cost $ 11 $ 3 $ 3 $ 1 $ — $ 1 Interest cost 27 6 10 1 — 6 Expected return on plan assets (36 ) (14 ) (13 ) (1 ) — (4 ) Amortization: Prior service costs (1 ) — — — — — Regulatory asset — — — — — 3 Net (gain)/loss 1 — 1 — — (2 ) Net periodic postretirement benefit cost $ 2 $ (5 ) $ 1 $ 1 $ — $ 4 Three Months Ended June 30, 2019 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Pension Plans Service cost $ 73 $ 17 $ 18 $ 3 $ 1 $ 6 Interest cost 123 29 39 5 2 9 Expected return on plan assets (221 ) (52 ) (73 ) (10 ) (3 ) (15 ) Amortization: Prior service costs 1 1 1 — — — Regulatory asset — — — — — 4 Net (gain)/loss 30 9 11 2 — — Net periodic pension cost (income) $ 6 $ 4 $ (4 ) $ — $ — $ 4 Postretirement Benefits Service cost $ 4 $ 1 $ 1 $ — $ — $ — Interest cost 17 4 6 1 — 3 Expected return on plan assets (17 ) (7 ) (6 ) (1 ) — (1 ) Amortization: Prior service costs 1 1 — — — — Regulatory asset — — — — — 1 Net (gain)/loss — — — — — (1 ) Net periodic postretirement benefit cost $ 5 $ (1 ) $ 1 $ — $ — $ 2 Six Months Ended June 30, 2019 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Pension Plans Service cost $ 146 $ 34 $ 37 $ 6 $ 3 $ 12 Interest cost 246 57 78 11 3 18 Expected return on plan assets (442 ) (103 ) (146 ) (20 ) (5 ) (30 ) Amortization: Prior service costs 1 1 1 — — (1 ) Regulatory asset — — — — — 7 Net (gain)/loss 60 18 22 3 — 1 Net periodic pension cost (income) $ 11 $ 7 $ (8 ) $ — $ 1 $ 7 Postretirement Benefits Service cost $ 9 $ 2 $ 2 $ — $ — $ 1 Interest cost 34 8 13 2 — 5 Expected return on plan assets (33 ) (13 ) (12 ) (1 ) — (3 ) Amortization: Prior service costs 2 2 — — — — Regulatory asset — — — — — 3 Net (gain)/loss (1 ) — — — — (2 ) Net periodic postretirement benefit cost $ 11 $ (1 ) $ 3 $ 1 $ — $ 4

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	As of June 30, 2020 , assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using: As of June 30, 2020: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 388 $ 181 $ 143 $ — $ 712 Interest rate derivatives — 23 — — 23 Investments in trusts: (b)(c) Domestic equity 703 128 — — 831 Foreign equity 65 202 — — 267 U.S. Treasury and government agency securities — 268 — — 268 Municipal bonds — 106 — — 106 Pooled funds – fixed income — 16 — — 16 Corporate bonds 19 369 — — 388 Mortgage and asset backed securities — 75 — — 75 Private equity — — — 61 61 Other 26 3 — — 29 Cash equivalents 1,315 13 — — 1,328 Other investments 9 21 — — 30 Total $ 2,525 $ 1,405 $ 143 $ 61 $ 4,134 Liabilities: Energy-related derivatives (a) $ 468 $ 187 $ 63 $ — $ 718 Interest rate derivatives — 23 — — 23 Foreign currency derivatives — 49 — — 49 Contingent consideration — — 19 — 19 Total $ 468 $ 259 $ 82 $ — $ 809 Fair Value Measurements Using: As of June 30, 2020: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 11 $ — $ — $ 11 Nuclear decommissioning trusts: (b) Domestic equity 442 117 — — 559 Foreign equity 65 59 — — 124 U.S. Treasury and government agency securities — 22 — — 22 Municipal bonds — 1 — — 1 Corporate bonds 19 155 — — 174 Mortgage and asset backed securities — 28 — — 28 Private equity — — — 61 61 Other 8 — — — 8 Cash equivalents 692 13 — — 705 Other investments — 21 — — 21 Total $ 1,226 $ 427 $ — $ 61 $ 1,714 Liabilities: Energy-related derivatives $ — $ 19 $ — $ — $ 19 Georgia Power Assets: Energy-related derivatives $ — $ 10 $ — $ — $ 10 Nuclear decommissioning trusts: (b)(c) Domestic equity 261 1 — — 262 Foreign equity — 141 — — 141 U.S. Treasury and government agency securities — 246 — — 246 Municipal bonds — 105 — — 105 Corporate bonds — 214 — — 214 Mortgage and asset backed securities — 47 — — 47 Other 18 3 — — 21 Cash equivalents 349 — — — 349 Total $ 628 $ 767 $ — $ — $ 1,395 Liabilities: Energy-related derivatives $ — $ 40 $ — $ — $ 40 Fair Value Measurements Using: As of June 30, 2020: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Net Asset Value as a Practical Expedient (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 6 $ — $ — $ 6 Liabilities: Energy-related derivatives $ — $ 22 $ — $ — $ 22 Southern Power Assets: Energy-related derivatives $ — $ 2 $ — $ — $ 2 Liabilities: Energy-related derivatives $ — $ 3 $ — $ — $ 3 Foreign currency derivatives — 49 — — 49 Contingent consideration — — 19 — 19 Total $ — $ 52 $ 19 $ — $ 71 Southern Company Gas Assets: Energy-related derivatives (a) $ 388 $ 152 $ 143 $ — $ 683 Non-qualified deferred compensation trusts: Domestic equity — 10 — — 10 Foreign equity — 2 — — 2 Pooled funds – fixed income — 16 — — 16 Cash equivalents and restricted cash 40 — — — 40 Total $ 428 $ 180 $ 143 $ — $ 751 Liabilities: Energy-related derivatives (a) $ 468 $ 103 $ 63 $ — $ 634 Interest rate derivatives — 23 — — 23 Total $ 468 $ 126 $ 63 $ — $ 657 (a) Energy-related derivatives exclude cash collateral of $114 million . (b) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information. (c) Includes investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. As of June 30, 2020 , approximately $45 million of the fair market value of Georgia Power's nuclear decommissioning trust funds' securities were on loan to creditors under the funds' managers' securities lending program. See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information.
Schedule of Increase (Decrease) In Fair Value Of Funds	The fair value of the funds, including reinvested interest and dividends and excluding the funds' expenses, increased (decreased) by the amounts shown in the table below for the three and six months ended June 30, 2020 and 2019 . The changes were recorded as a change to the regulatory assets and liabilities related to AROs for Georgia Power and Alabama Power, respectively. Fair value increases (decreases) Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 (in millions) Southern Company $ 223 $ 75 $ (23 ) $ 227 Alabama Power 124 38 (42 ) 125 Georgia Power 99 37 19 102
Financial Instruments for Which Carrying Amount Did Not Equal Fair Value	As of June 30, 2020 , other financial instruments for which the carrying amount did not equal fair value were as follows: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (*) (in millions) Long-term debt, including securities due within one year: Carrying amount $ 46,513 $ 8,519 $ 12,720 $ 1,404 $ 4,097 $ 5,827 Fair value 53,079 10,008 15,092 1,571 4,423 6,817 (*) The long-term debt of Southern Company Gas is recorded at amortized cost, including the fair value adjustments at the effective date of the 2016 merger with Southern Company. Southern Company Gas amortizes the fair value adjustments over the lives of the respective bonds.
Fair Value of Commodity Derivative Contracts that Include a Significant Unobservable Component	The following table includes transfers to Level 3, which represent the fair value of Southern Company Gas' commodity derivative contracts that include a significant unobservable component for the first time during the period. Three Months Ended June 30, 2020 Six Months Ended June 30, 2020 (in millions) Beginning balance $ 76 $ 14 Transfers to Level 3 — 70 Transfers from Level 3 — (3 ) Instruments realized or otherwise settled during period (6 ) (7 ) Changes in fair value 10 6 Ending balance $ 80 $ 80

DERIVATIVES (Tables)

DERIVATIVES (Tables)	6 Months Ended
	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Energy-Related Derivatives	At June 30, 2020 , the net volume of energy-related derivative contracts for natural gas positions, together with the longest hedge date over which the respective entity is hedging its exposure to the variability in future cash flows for forecasted transactions and the longest non-hedge date for derivatives not designated as hedges, were as follows: Net Purchased mmBtu Longest Hedge Date Longest Non-Hedge Date (in millions) Southern Company (*) 944 2024 2031 Alabama Power 85 2024 — Georgia Power 152 2023 — Mississippi Power 91 2024 — Southern Power 15 2022 2021 Southern Company Gas (*) 601 2022 2031 (*) Southern Company Gas' derivative instruments include both long and short natural gas positions. A long position is a contract to purchase natural gas and a short position is a contract to sell natural gas. Southern Company Gas' volume represents the net of long natural gas positions of 4.6 billion mmBtu and short natural gas positions of 4.0 billion mmBtu as of June 30, 2020 , which is also included in Southern Company's total volume.
Schedule of Interest Rate Derivatives	At June 30, 2020 , the following interest rate derivatives were outstanding: Notional Amount Interest Rate Received Weighted Average Interest Rate Paid Hedge Maturity Date Fair Value Gain (Loss) at June 30, 2020 (in millions) (in millions) Cash Flow Hedges of Forecasted Debt Southern Company Gas $ 200 3-month LIBOR 1.81% September 2030 $ (23 ) Cash Flow Hedges of Existing Debt Mississippi Power 60 1-month LIBOR 0.58% December 2021 — Fair Value Hedges of Existing Debt Southern Company parent 1,500 2.35% 1-month LIBOR + 0.87% July 2021 23 Southern Company $ 1,760 $ —
Schedule of Foreign Currency Derivatives	At June 30, 2020 , the following foreign currency derivatives were outstanding: Pay Notional Pay Rate Receive Notional Receive Rate Hedge Fair Value Gain (Loss) at June 30, 2020 (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 677 2.95% € 600 1.00% June 2022 $ (18 ) Southern Power 564 3.78% 500 1.85% June 2026 (31 ) Total $ 1,241 € 1,100 $ (49 )
Fair Value of Energy-Related Derivatives and Interest Rate Derivatives	The fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows: As of June 30, 2020 As of December 31, 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Southern Company Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 19 $ 64 $ 3 $ 70 Other deferred charges and assets/Other deferred credits and liabilities 13 28 6 44 Total derivatives designated as hedging instruments for regulatory purposes $ 32 $ 92 $ 9 $ 114 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities $ 3 $ 6 $ 1 $ 6 Interest rate derivatives: Other current assets/Other current liabilities 12 23 2 23 Other deferred charges and assets/Other deferred credits and liabilities 10 — — 1 Foreign currency derivatives: Other current assets/Other current liabilities — 24 — 24 Other deferred charges and assets/Other deferred credits and liabilities — 25 16 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 25 $ 78 $ 19 $ 54 Derivatives not designated as hedging instruments Energy-related derivatives: Other current assets/Other current liabilities $ 361 $ 367 $ 461 $ 358 Other deferred charges and assets/Other deferred credits and liabilities 316 253 207 225 Total derivatives not designated as hedging instruments $ 677 $ 620 $ 668 $ 583 Gross amounts recognized $ 734 $ 790 $ 696 $ 751 Gross amounts offset (a) (520 ) (634 ) (463 ) (562 ) Net amounts recognized in the Balance Sheets (b) $ 214 $ 156 $ 233 $ 189 As of June 30, 2020 As of December 31, 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Alabama Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 7 $ 12 $ 2 $ 14 Other deferred charges and assets/Other deferred credits and liabilities 4 7 2 10 Total derivatives designated as hedging instruments for regulatory purposes $ 11 $ 19 $ 4 $ 24 Gross amounts recognized $ 11 $ 19 $ 4 $ 24 Gross amounts offset (8 ) (8 ) (2 ) (2 ) Net amounts recognized in the Balance Sheets $ 3 $ 11 $ 2 $ 22 Georgia Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 5 $ 28 $ 1 $ 32 Other deferred charges and assets/Other deferred credits and liabilities 5 12 3 21 Total derivatives designated as hedging instruments for regulatory purposes $ 10 $ 40 $ 4 $ 53 Derivatives designated as hedging instruments in cash flow and fair value hedges Interest rate derivatives: Other current assets/Other current liabilities $ — $ — $ — $ 17 Total derivatives designated as hedging instruments in cash flow and fair value hedges $ — $ — $ — $ 17 Gross amounts recognized $ 10 $ 40 $ 4 $ 70 Gross amounts offset (10 ) (10 ) (3 ) (3 ) Net amounts recognized in the Balance Sheets $ — $ 30 $ 1 $ 67 As of June 30, 2020 As of December 31, 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Mississippi Power Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Other current assets/Other current liabilities $ 3 $ 13 $ — $ 15 Other deferred charges and assets/Other deferred credits and liabilities 3 9 1 12 Total derivatives designated as hedging instruments for regulatory purposes $ 6 $ 22 $ 1 $ 27 Gross amounts recognized $ 6 $ 22 $ 1 $ 27 Gross amounts offset (6 ) (6 ) (1 ) (1 ) Net amounts recognized in the Balance Sheets $ — $ 16 $ — $ 26 Southern Power Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities $ 2 $ 3 $ 1 $ 2 Foreign currency derivatives: Other current assets/Other current liabilities — 24 — 24 Other deferred charges and assets/Other deferred credits and liabilities — 25 16 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 2 $ 52 $ 17 $ 26 Derivatives not designated as hedging instruments Energy-related derivatives: Other current assets/Other current liabilities $ — $ — $ 2 $ 1 Total derivatives not designated as hedging instruments $ — $ — $ 2 $ 1 Gross amounts recognized $ 2 $ 52 $ 19 $ 27 Gross amounts offset (1 ) (1 ) — — Net amounts recognized in the Balance Sheets $ 1 $ 51 $ 19 $ 27 As of June 30, 2020 As of December 31, 2019 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Southern Company Gas Derivatives designated as hedging instruments for regulatory purposes Energy-related derivatives: Assets from risk management activities/Liabilities from risk management activities-current $ 4 $ 11 $ — $ 9 Other deferred charges and assets/Other deferred credits and liabilities 1 — — 1 Total derivatives designated as hedging instruments for regulatory purposes $ 5 $ 11 $ — $ 10 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Assets from risk management activities/Liabilities from risk management activities-current $ 1 $ 3 $ — $ 4 Interest rate derivatives: Assets from risk management activities/Liabilities from risk management activities-current — 23 2 — Total derivatives designated as hedging instruments in cash flow and fair value hedges $ 1 $ 26 $ 2 $ 4 Derivatives not designated as hedging instruments Energy-related derivatives: Assets from risk management activities/Liabilities from risk management activities-current $ 361 $ 367 $ 459 $ 357 Other deferred charges and assets/Other deferred credits and liabilities 316 253 207 225 Total derivatives not designated as hedging instruments $ 677 $ 620 $ 666 $ 582 Gross amounts of recognized $ 683 $ 657 $ 668 $ 596 Gross amounts offset (a) (495 ) (609 ) (456 ) (555 ) Net amounts recognized in the Balance Sheets (b) $ 188 $ 48 $ 212 $ 41 (a) Gross amounts offset include cash collateral held on deposit in broker margin accounts of $114 million and $99 million as of June 30, 2020 and December 31, 2019 , respectively. (b) Net amounts of derivative instruments outstanding exclude premium and intrinsic value associated with weather derivatives of $4 million as of December 31, 2019 .
Pre-tax Effects of Unrealized Derivative Gains (Losses) Arising from Energy-Related Derivative Instruments	At June 30, 2020 and December 31, 2019 , the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows: Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet Derivative Category and Balance Sheet Location Southern Company (*) Alabama Power Georgia Power Mississippi Power Southern Company Gas (*) (in millions) At June 30, 2020: Energy-related derivatives: Other regulatory assets, current $ (42 ) $ (8 ) $ (23 ) $ (10 ) $ (1 ) Other regulatory assets, deferred (16 ) (3 ) (7 ) (6 ) — Other regulatory liabilities, current 10 3 — — 7 Total energy-related derivative gains (losses) $ (48 ) $ (8 ) $ (30 ) $ (16 ) $ 6 At December 31, 2019: Energy-related derivatives: Other regulatory assets, current $ (63 ) $ (14 ) $ (31 ) $ (15 ) $ (3 ) Other regulatory assets, deferred (37 ) (8 ) (18 ) (11 ) — Other regulatory liabilities, current 6 2 — — 4 Total energy-related derivative gains (losses) $ (94 ) $ (20 ) $ (49 ) $ (26 ) $ 1 (*) Fair value gains and losses recorded in regulatory assets and liabilities include cash collateral held on deposit in broker margin accounts of $12 million and $11 million at June 30, 2020 and December 31, 2019, respectively.
Pre-tax Effects of Interest Rate Derivatives, Designated as Cash Flow Hedging Instruments	For the three and six months ended June 30, 2020 and 2019 , the pre-tax effects of cash flow hedge accounting on accumulated OCI were as follows: Gain (Loss) Recognized in OCI on Derivative For the Three Months Ended June 30, For the Six Months Ended June 30, 2020 2019 2020 2019 (in millions) (in millions) Southern Company Energy-related derivatives $ (2 ) $ (6 ) $ (6 ) $ (6 ) Interest rate derivatives (1 ) (37 ) (28 ) (37 ) Foreign currency derivatives 17 (1 ) (65 ) (39 ) Total $ 14 $ (44 ) $ (99 ) $ (82 ) Georgia Power Interest rate derivatives $ — $ (37 ) $ (3 ) $ (37 ) Southern Power Energy-related derivatives $ (2 ) $ (2 ) $ (2 ) $ (2 ) Foreign currency derivatives $ 17 $ (1 ) (65 ) (39 ) Total $ 15 $ (3 ) $ (67 ) $ (41 ) Southern Company Gas Energy-related derivatives $ — $ (4 ) $ (4 ) $ (4 ) Interest rate derivatives (1 ) — (25 ) — Total $ (1 ) $ (4 ) $ (29 ) $ (4 )
Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location	For the three and six months ended June 30, 2020 and 2019 , the pre-tax effects of cash flow and fair value hedge accounting on income were as follows: Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships For the Three Months Ended June 30, For the Six Months Ended June 30, 2020 2019 2020 2019 (in millions) (in millions) Southern Company Total cost of natural gas $ 144 $ 191 $ 583 $ 877 Gain (loss) on energy-related cash flow hedges (a) (1 ) — (8 ) — Total depreciation and amortization 873 755 1,730 1,506 Gain (loss) on energy-related cash flow hedges (a) (1 ) (1 ) (2 ) (4 ) Total interest expense, net of amounts capitalized (444 ) (429 ) (900 ) (859 ) Gain (loss) on interest rate cash flow hedges (a) (6 ) (5 ) (13 ) (9 ) Gain (loss) on foreign currency cash flow hedges (a) (6 ) (6 ) (12 ) (12 ) Gain (loss) on interest rate fair value hedges (b) 1 19 30 33 Total other income (expense), net 101 99 204 176 Gain (loss) on foreign currency cash flow hedges (a)(c) 27 16 (4 ) (8 ) Southern Power Total depreciation and amortization $ 121 $ 119 $ 239 $ 237 Gain (loss) on energy-related cash flow hedges (a) (1 ) (1 ) (2 ) (4 ) Total interest expense, net of amounts capitalized (38 ) (41 ) (77 ) (84 ) Gain (loss) on foreign currency cash flow hedges (a) (6 ) (6 ) (12 ) (12 ) Total other income (expense), net 1 40 4 41 Gain (loss) on foreign currency cash flow hedges (a)(c) 27 16 (4 ) (8 ) (a) Reclassified from accumulated OCI into earnings. (b) For fair value hedges, changes in the fair value of the derivative contracts are generally equal to changes in the fair value of the underlying debt and have no material impact on income. (c) The reclassification from accumulated OCI into other income (expense), net completely offsets currency gains and losses arising from changes in the U.S. currency exchange rates used to record the euro-denominated notes.
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location	As of June 30, 2020 and December 31, 2019 , the following amounts were recorded on the balance sheets related to cumulative basis adjustments for fair value hedges: Carrying Amount of the Hedged Item Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item Balance Sheet Location of Hedged Items As of June 30, 2020 As of December 31, 2019 As of June 30, 2020 As of December 31, 2019 (in millions) (in millions) Southern Company Securities due within one year $ — $ (599 ) $ — $ — Long-term debt (1,517 ) (1,494 ) (20 ) 3
Pre-tax Effect of Interest Rate and Energy Related Derivatives	For the three and six months ended June 30, 2020 and 2019 , the pre-tax effects of energy-related derivatives not designated as hedging instruments on the statements of income of Southern Company and Southern Company Gas were as follows: Gain (Loss) Three Months Ended June 30, Six Months Ended June 30, Derivatives in Non-Designated Hedging Relationships Statements of Income Location 2020 2019 2020 2019 (in millions) (in millions) Energy-related derivatives: Natural gas revenues (*) $ 14 $ 50 $ 84 $ 83 Cost of natural gas 5 (5 ) 13 3 Total derivatives in non-designated hedging relationships $ 19 $ 45 $ 97 $ 86 (*) Excludes immaterial gains (losses) recorded in natural gas revenues associated with weather derivatives for all periods presented.

ACQUISITIONS AND DISPOSITIONS (

ACQUISITIONS AND DISPOSITIONS (Tables)	6 Months Ended
	Jun. 30, 2020
Business Combinations [Abstract]
Schedule of Asset Acquisitions	During the six months ended June 30, 2020 , Southern Power acquired a controlling interest in the wind facility listed below. Acquisition-related costs were expensed as incurred and were not material. Project Facility Resource Seller Approximate Nameplate Capacity ( MW ) Location Southern Power Ownership Percentage COD PPA Contract Period Beech Ridge II Wind Invenergy Renewables LLC 56 Greenbrier County, West Virginia 100% of Class A (*) May 2020 12 years (*) In May 2020, Southern Power purchased 100% of the Class A membership interests and now owns the controlling interest in the project, with the Class B member, Invenergy Renewables LLC, owning the noncontrolling interest.
Schedule of Construction Projects	Project Facility Resource Approximate Nameplate Capacity ( MW ) Location Actual/Expected COD PPA Contract Period Projects Completed During the Six Months Ended June 30, 2020 Reading (a) Wind 200 Osage and Lyon Counties, KS May 2020 12 years Projects Under Construction as of June 30, 2020 Skookumchuck (b) Wind 136 Lewis and Thurston Counties, WA Fourth quarter 2020 20 years Garland Solar Storage (c) Battery energy storage system 88 Kern County, CA Second quarter 2021 20 years Tranquillity Solar Storage (c) Battery energy storage system 72 Fresno County, CA Second quarter 2021 20 years (a) In 2018, Southern Power purchased 100% of the membership interests of the Reading facility pursuant to a joint development arrangement. At the time the facility was placed in service, Southern Power recorded an operating lease right-of-use asset and an operating lease liability, each in the amount of $24 million . In June 2020, Southern Power completed a tax equity transaction whereby it received $156 million and now owns 100% of the Class B membership interests. (b) In October 2019, Southern Power purchased 100% of the membership interests of the Skookumchuck facility pursuant to a joint development arrangement. Southern Power expects to complete a tax equity transaction upon commercial operation and retain the Class B membership interests. Shortly after commercial operation, Southern Power may sell a noncontrolling interest in these Class B membership interests to another partner. The ultimate outcome of these matters cannot be determined at this time. (c) Prior to commercial operation, Southern Power may enter into one or more partnerships, in which case it would ultimately own less than 100% of the Class B membership interests, but would retain ownership of the controlling interest. The PPAs for these facilities are pending approval from the California Public Utilities Commission. The ultimate outcome of these matters cannot be determined at this time.
Disposal Groups, Including Discontinued Operations	Plants Nacogdoches (sold in June 2019) and Mankato represented individually significant components of Southern Power; therefore, pre-tax income for these components for the three months ended June 30, 2019 and the six months ended June 30, 2020 and 2019 is presented below: Three Months Ended June 30, 2019 Six Months Ended June 30, 2020 2019 (in millions) Southern Power's earnings before income taxes: (*) Plant Nacogdoches $ 9 N/A $ 16 Plant Mankato $ 6 $ 2 $ 8 (*) Earnings before income taxes for components reflect the cessation of depreciation and amortization on the long-lived assets being sold upon classification as held for sale in November 2018 and April 2019 for Plant Mankato and Plant Nacogdoches, respectively.

SEGMENT AND RELATED INFORMATI_2

SEGMENT AND RELATED INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Financial Data for Business Segments	Financial data for business segments and products and services for the three and six months ended June 30, 2020 and 2019 was as follows: Electric Utilities Traditional Electric Operating Companies Southern Power Eliminations Total Southern Company Gas All Other Eliminations Consolidated (in millions) Three Months Ended June 30, 2020 Operating revenues $ 3,539 $ 439 $ (94 ) $ 3,884 $ 636 $ 135 $ (35 ) $ 4,620 Segment net income (loss) (a)(b)(c) 645 63 — 708 71 (177 ) 10 612 Six Months Ended June 30, 2020 Operating revenues $ 6,946 $ 814 $ (181 ) $ 7,579 $ 1,885 $ 248 $ (74 ) $ 9,638 Segment net income (loss) (a)(b)(c)(d) 1,287 138 — 1,425 346 (299 ) 8 1,480 At June 30, 2020 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 263 $ — $ 5,280 Total assets 83,158 13,557 (713 ) 96,002 21,500 3,325 (1,096 ) 119,731 Three Months Ended June 30, 2019 Operating revenues $ 3,899 $ 510 $ (119 ) $ 4,290 $ 689 $ 186 $ (67 ) $ 5,098 Segment net income (loss) (a)(e)(f) 782 174 — 956 106 (154 ) (9 ) 899 Six Months Ended June 30, 2019 Operating revenues $ 7,343 $ 953 $ (211 ) $ 8,085 $ 2,163 $ 368 $ (106 ) $ 10,510 Segment net income (loss) (a)(e)(f) 1,346 230 — 1,576 376 1,041 (11 ) 2,982 At December 31, 2019 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 263 $ — $ 5,280 Total assets 81,063 14,300 (713 ) 94,650 21,687 3,511 (1,148 ) 118,700 (a) Attributable to Southern Company. (b) Segment net income (loss) for the traditional electric operating companies includes a pre-tax charge of $149 million ( $111 million after tax) related to Plant Vogtle Units 3 and 4 for the three and six months ended June 30, 2020. See Note (B) under "Georgia Power – Nuclear Construction " for additional information. (c) Segment net income (loss) for the "All Other" column includes a pre-tax impairment charge of $154 million ( $74 million after tax) related to a leveraged lease investment for the three and six months ended June 30, 2020. See Note (C) under "Other Matters – Southern Company" for additional information. (d) Segment net income (loss) for Southern Power includes a $39 million pre-tax gain ( $23 million gain after tax) on the sale of Plant Mankato for the six months ended June 30, 2020 . See Note (K) under " Southern Power " for additional information. (e) Segment net income (loss) for the "All Other" column includes the preliminary pre-tax gain associated with the sale of Gulf Power of $2.5 billion ( $1.3 billion after tax) for the six months ended June 30, 2019, of which $(15) million ( $(11) million after tax) was recorded in the three months ended June 30, 2019, as well as a goodwill impairment charge of $32 million for the three and six months ended June 30, 2019 in contemplation of the sale of one of PowerSecure's business units. See Note 15 to the financial statements in Item 8 of the Form 10-K under " Southern Company" for additional information. (f) Segment net income (loss) for Southern Power includes a $23 million pre-tax gain ( $88 million gain after tax) on the sale of Plant Nacogdoches for the three and six months ended June 30, 2019. See Note 15 to the financial statements in Item 8 of the Form 10-K under "Southern Power – Sale of Natural Gas and Biomass Plants" for additional information. Business segment financial data for the three and six months ended June 30, 2020 and 2019 was as follows: Gas Distribution Operations Gas Pipeline Investments Wholesale Gas Services (*) Gas Marketing Services Total All Other Eliminations Consolidated (in millions) Three Months Ended June 30, 2020 Operating revenues $ 587 $ 8 $ (19 ) $ 56 $ 632 $ 8 $ (4 ) $ 636 Segment net income (loss) 74 21 (23 ) 5 77 (6 ) — 71 Six Months Ended June 30, 2020 Operating revenues $ 1,607 $ 16 $ 32 $ 233 $ 1,888 $ 16 $ (19 ) $ 1,885 Segment net income (loss) 238 51 — 62 351 (5 ) — 346 Total assets at June 30, 2020 18,276 1,617 637 1,480 22,010 10,645 (11,155 ) 21,500 Three Months Ended June 30, 2019 Operating revenues $ 568 $ 8 $ 48 $ 58 $ 682 $ 13 $ (6 ) $ 689 Segment net income (loss) 58 25 23 (3 ) 103 3 — 106 Six Months Ended June 30, 2019 Operating revenues $ 1,740 $ 16 $ 134 $ 287 $ 2,177 $ 24 $ (38 ) $ 2,163 Segment net income (loss) 191 57 70 58 376 — — 376 Total assets at December 31, 2019 18,204 1,678 850 1,496 22,228 10,759 (11,300 ) 21,687 (*) The revenues for wholesale gas services are netted with costs associated with its energy and risk management activities. A reconciliation of operating revenues and intercompany revenues is shown in the following table. Third Party Gross Revenues Intercompany Revenues Total Gross Revenues Less Gross Gas Costs Operating Revenues (in millions) Three Months Ended June 30, 2020 $ 854 $ 18 $ 872 $ 891 $ (19 ) Three Months Ended June 30, 2019 1,223 63 1,286 1,238 48 Six Months Ended June 30, 2020 $ 2,039 $ 47 $ 2,086 $ 2,054 $ 32 Six Months Ended June 30, 2019 3,148 151 3,299 3,165 134
Financial Data for Products and Services	Electric Utilities' Revenues Retail Wholesale Other Total (in millions) Three Months Ended June 30, 2020 $ 3,182 $ 472 $ 230 $ 3,884 Three Months Ended June 30, 2019 3,540 542 208 4,290 Six Months Ended June 30, 2020 $ 6,260 $ 889 $ 430 $ 7,579 Six Months Ended June 30, 2019 6,623 1,041 421 8,085 Southern Company Gas' Revenues Gas Wholesale Gas Services (*) Gas Other Total (in millions) Three Months Ended June 30, 2020 $ 583 $ (19 ) $ 56 $ 16 $ 636 Three Months Ended June 30, 2019 563 48 58 20 689 Six Months Ended June 30, 2020 $ 1,596 $ 32 $ 233 $ 24 $ 1,885 Six Months Ended June 30, 2019 1,724 134 287 18 2,163 (*) The revenues for wholesale gas services are netted with costs associated with its energy and risk management activities. See "Southern Company Gas" herein for additional information.

INTRODUCTION - Narrative (Detai

INTRODUCTION - Narrative (Details) $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2020USD ($)facility	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Goodwill	$ 5,280		$ 5,280		$ 5,280
SOUTHERN Co GAS
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Goodwill	5,015		5,015		$ 5,015
Inventory decrement		$ 7		$ 10
ALABAMA POWER CO
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Asset retirement obligation, period increase	$ 462
Number of facilities, closure designs completed | facility	1
PowerSecure
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Goodwill	$ 263		$ 263
Maximum | Natural Gas Generating Facility | SOUTHERN POWER CO
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, useful life			50 years		45 years

INTRODUCTION - Goodwill (Detail

INTRODUCTION - Goodwill (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill	$ 5,280	$ 5,280
SOUTHERN Co GAS
Goodwill [Line Items]
Goodwill	5,015	$ 5,015
SOUTHERN Co GAS | Gas Distribution Operations
Goodwill [Line Items]
Goodwill	4,034
SOUTHERN Co GAS | Gas Marketing Services
Goodwill [Line Items]
Goodwill	$ 981

INTRODUCTION - Other Intangible

INTRODUCTION - Other Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Other intangible assets subject to amortization:
Gross Carrying Amount	$ 740	$ 741
Accumulated Amortization	(304)	(280)
Other Intangible Assets, Net	436	461
Other intangible assets not subject to amortization:
Federal Communications Commission licenses	75	75
Total other intangible assets
Gross Carrying Amount	815	816
Accumulated Amortization	(304)	(280)
Other Intangible Assets, Net	511	536
Customer relationships
Other intangible assets subject to amortization:
Gross Carrying Amount	212	212
Accumulated Amortization	(126)	(116)
Other Intangible Assets, Net	86	96
Total other intangible assets
Accumulated Amortization	(126)	(116)
Trade names
Other intangible assets subject to amortization:
Gross Carrying Amount	64	64
Accumulated Amortization	(28)	(25)
Other Intangible Assets, Net	36	39
Total other intangible assets
Accumulated Amortization	(28)	(25)
Storage and transportation contracts
Other intangible assets subject to amortization:
Gross Carrying Amount	64	64
Accumulated Amortization	(63)	(62)
Other Intangible Assets, Net	1	2
Total other intangible assets
Accumulated Amortization	(63)	(62)
PPA fair value adjustments
Other intangible assets subject to amortization:
Gross Carrying Amount	390	390
Accumulated Amortization	(79)	(69)
Other Intangible Assets, Net	311	321
Total other intangible assets
Accumulated Amortization	(79)	(69)
Other
Other intangible assets subject to amortization:
Gross Carrying Amount	10	11
Accumulated Amortization	(8)	(8)
Other Intangible Assets, Net	2	3
Total other intangible assets
Accumulated Amortization	(8)	(8)
SOUTHERN POWER CO
Other intangible assets subject to amortization:
Accumulated Amortization	(79)	(69)
Total other intangible assets
Accumulated Amortization	(79)	(69)
SOUTHERN POWER CO | PPA fair value adjustments
Other intangible assets subject to amortization:
Gross Carrying Amount	390	390
Accumulated Amortization	(79)	(69)
Other Intangible Assets, Net	311	321
Total other intangible assets
Accumulated Amortization	(79)	(69)
SOUTHERN Co GAS
Other intangible assets subject to amortization:
Gross Carrying Amount	246	246
Accumulated Amortization	(186)	(176)
Other Intangible Assets, Net	60	70
Total other intangible assets
Accumulated Amortization	(186)	(176)
Other Intangible Assets, Net	60	70
SOUTHERN Co GAS | Customer relationships
Other intangible assets subject to amortization:
Gross Carrying Amount	156	156
Accumulated Amortization	(112)	(104)
Other Intangible Assets, Net	44	52
Total other intangible assets
Accumulated Amortization	(112)	(104)
SOUTHERN Co GAS | Trade names
Other intangible assets subject to amortization:
Gross Carrying Amount	26	26
Accumulated Amortization	(11)	(10)
Other Intangible Assets, Net	15	16
Total other intangible assets
Accumulated Amortization	(11)	(10)
SOUTHERN Co GAS | Storage and transportation contracts
Other intangible assets subject to amortization:
Gross Carrying Amount	64	64
Accumulated Amortization	(63)	(62)
Other Intangible Assets, Net	1	2
Total other intangible assets
Accumulated Amortization	$ (63)	$ (62)

INTRODUCTION - Other Intangib_2

INTRODUCTION - Other Intangible Assets, Amortization (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 13	$ 25
Decrease in operating revenues	5	11
SOUTHERN POWER CO
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	5	10
SOUTHERN Co GAS
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	5	10
Gas Marketing Services | SOUTHERN Co GAS
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	5	9
Wholesale Gas Services | SOUTHERN Co GAS
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 0	$ 1

INTRODUCTION - Restricted Cash

INTRODUCTION - Restricted Cash (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 1,879	$ 1,975
Restricted cash:
Total cash, cash equivalents, and restricted cash	1,885	1,978	$ 1,386	$ 1,519
Other accounts and notes receivable
Restricted cash:
Restricted cash	0	3
Other current assets
Restricted cash:
Restricted cash	4	0
Other deferred charges and assets
Restricted cash:
Restricted cash	2	0
SOUTHERN POWER CO
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	154	279
Restricted cash:
Total cash, cash equivalents, and restricted cash	156	279	370	181
SOUTHERN POWER CO | Other accounts and notes receivable
Restricted cash:
Restricted cash	0
SOUTHERN POWER CO | Other current assets
Restricted cash:
Restricted cash	0
SOUTHERN POWER CO | Other deferred charges and assets
Restricted cash:
Restricted cash	2
SOUTHERN Co GAS
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	120	46
Restricted cash:
Total cash, cash equivalents, and restricted cash	124	49	$ 60	$ 70
SOUTHERN Co GAS | Other accounts and notes receivable
Restricted cash:
Restricted cash	0	3
SOUTHERN Co GAS | Other current assets
Restricted cash:
Restricted cash	4	0
SOUTHERN Co GAS | Other deferred charges and assets
Restricted cash:
Restricted cash	$ 0	$ 0

INTRODUCTION - Asset Retirement

INTRODUCTION - Asset Retirement Obligations (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at December 31, 2019	$ 9,786
Liabilities incurred	15
Liabilities settled	(193)
Accretion	204
Cash flow revisions	462
Balance at June 30, 2020	10,274
ALABAMA POWER CO
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at December 31, 2019	3,540
Liabilities incurred	0
Liabilities settled	(100)
Accretion	74
Cash flow revisions	462
Balance at June 30, 2020	$ 3,976

REGULATORY MATTERS - Cost Recov

REGULATORY MATTERS - Cost Recovery Clauses (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
ALABAMA POWER CO | Other regulatory liabilities, current
Loss Contingencies [Line Items]
Rate CNP Compliance	$ 25	$ 55
Retail Energy Cost Recovery	22	32
Natural Disaster Reserve	16	37
ALABAMA POWER CO | Other regulatory liabilities, deferred
Loss Contingencies [Line Items]
Rate CNP Compliance	0	7
Retail Energy Cost Recovery	93	17
Natural Disaster Reserve	96	113
ALABAMA POWER CO | Deferred under recovered regulatory clause revenues
Loss Contingencies [Line Items]
Rate CNP PPA	41	40
GEORGIA POWER CO | Other current liabilities
Loss Contingencies [Line Items]
Fuel Cost Recovery	109	0
GEORGIA POWER CO | Other deferred credits and liabilities
Loss Contingencies [Line Items]
Fuel Cost Recovery	95	73
MISSISSIPPI POWER CO | Other regulatory liabilities, deferred
Loss Contingencies [Line Items]
Property Damage Reserve	50	54
MISSISSIPPI POWER CO | Over recovered regulatory clause liabilities
Loss Contingencies [Line Items]
Fuel Cost Recovery	22	23
MISSISSIPPI POWER CO | Other regulatory assets
Loss Contingencies [Line Items]
Ad Valorem Tax	11	47
MISSISSIPPI POWER CO | Other regulatory assets, deferred
Loss Contingencies [Line Items]
Ad Valorem Tax	39	0
SOUTHERN Co GAS | Other regulatory liabilities
Loss Contingencies [Line Items]
Natural Gas Cost Recovery	$ 100	$ 74

REGULATORY MATTERS - Alabama Po

REGULATORY MATTERS - Alabama Power (Details) - ALABAMA POWER CO $ in Millions	Jun. 09, 2020USD ($)MW
Public Utilities, General Disclosures [Line Items]
Approved additional generating capacity, purchases (in MWs)	240
Approved additional generating capacity, demand-side management and distributed energy resource programs (in MWs)	200
Additional generating capacity (in MWs)	400
Plant Barry Unit 8
Public Utilities, General Disclosures [Line Items]
Approved additional generating capacity, construction (in MWs)	720
Costs incurred, percentage of estimated in-service costs	5.00%
Estimated in-service cost | $	$ 652

REGULATORY MATTERS - Georgia Po

REGULATORY MATTERS - Georgia Power (Details) - GEORGIA POWER CO - USD ($)	May 28, 2020	Sep. 30, 2020	Jun. 30, 2020
Public Utilities, General Disclosures [Line Items]
Incremental COVID-19 costs deferred			$ 34,000,000
Requested decrease in fuel billings	$ 740,000,000
Requested decrease in fuel billings, term	2 years
Adjustment to fuel cost recovery rate if under recovered fuel balance exceeds budget thereafter			$ 200,000,000
Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Requested decrease in fuel billings		$ 44,000,000

REGULATORY MATTERS - Nuclear Co

REGULATORY MATTERS - Nuclear Construction (Details) - GEORGIA POWER CO $ in Millions

Jan. 01, 2021

Aug. 18, 2020USD ($)

Jul. 31, 2020USD ($)

Jan. 01, 2020

Jan. 11, 2018USD ($)

Jan. 01, 2016

Apr. 30, 2020

Dec. 31, 2019USD ($)

Dec. 31, 2018appeal

Jun. 30, 2020USD ($)report

Jun. 30, 2020USD ($)report

Dec. 31, 2022USD ($)

Dec. 31, 2021USD ($)

Dec. 31, 2020USD ($)

Dec. 31, 2019USD ($)

Dec. 31, 2012utilityMW

Dec. 31, 2009USD ($)

Aug. 31, 2018

Jun. 30, 2018USD ($)

Dec. 31, 2013

Loss Contingencies [Line Items]

Additional construction capital costs

$ 3,300

Estimated in-service capital cost

$ 4,418

Financing costs collected, net of tax

$ 2,400

Decrease in NCCR tariff

$ 62

Amendment to estimated in-service capital cost

$ 5,680

Retail rate of return on common equity

10.95%

Number of appeals | appeal

2

Plant Vogtle Units 3 And 4

Loss Contingencies [Line Items]

Proportionate ownership share

45.70%

45.70%

Number of construction units approved | utility

2

Electric generating capacity in mega watts under consortium agreement | MW

1,100

Construction costs incurred

$ 2,400

Construction contingency estimate

$ 194

194

$ 366

Construction contingency estimate, amount in excess of original estimate

34

34

Construction contingency estimate, additional amount

115

115

Estimated loss on Plant Vogtle Units 3 and 4

149

149

Estimated loss on plants under construction, after tax

111

111

Expected percentage of positions eliminated

20.00%

Base project capital cost forecast, monthly

50

Monthly AFUDC

10

Percentage of ownership interest required for voting for continuing construction

90.00%

Production tax credits, aggregate purchase price, maximum

300

Preliminary estimated cost to complete

8,500

$ 8,500

Remaining share of construction costs, agreement to pay, percentage

100.00%

Percentage of costs, disallowed for recovery

6.00%

Costs disallowed for recovery, period

6 months

Public utilities, extension project schedule, term

1 year

Cost settlement agreement revised forecast, net of payments

$ 7,300

$ 7,300

Public utilities, approved return on equity percentage

8.30%

10.00%

Public utilities, approved return on equity, monthly percentage decrease

0.10%

Return on equity reduction, negative impact on earnings

$ 75

Plant Vogtle Units 3 And 4 | Scenario, Forecast

Loss Contingencies [Line Items]

Construction costs incurred

$ 3,000

Public utilities, approved return on equity percentage

5.30%

Return on equity reduction, negative impact on earnings

$ 200

$ 255

$ 145

Plant Vogtle Units 3 And 4 | Vogtle Owners

Loss Contingencies [Line Items]

Period of notice required in the event letters of credit are not renewed

30 days

Twenty First Construction Monitoring Report | Plant Vogtle Units 3 And 4

Loss Contingencies [Line Items]

Number of approved construction management reports | report

21

21

Requested capital construction costs

$ 6,700

Guarantor obligations

$ 1,700

1,700

Customer refund

188

Twenty Second Construction Monitoring Report | Plant Vogtle Units 3 And 4 | Scenario, Forecast

Loss Contingencies [Line Items]

Requested capital construction costs

$ 674

Twenty Third Construction Monitoring Report | Plant Vogtle Units 3 And 4 | Scenario, Forecast

Loss Contingencies [Line Items]

Requested capital construction costs

$ 701

Minimum | COVID-19

Loss Contingencies [Line Items]

Estimate of possible loss

70

70

Maximum | COVID-19

Loss Contingencies [Line Items]

Estimate of possible loss

115

115

Category I | Plant Vogtle Units 3 And 4

Loss Contingencies [Line Items]

Preliminary estimated cost to complete

$ 8,400

8,400

Additional construction capital costs, threshold

$ 800

Category II | Plant Vogtle Units 3 And 4

Loss Contingencies [Line Items]

Percentage of construction costs, responsibility to pay

55.70%

Additional construction capital costs

$ 80

Category II | Plant Vogtle Units 3 And 4 | Vogtle Owners

Loss Contingencies [Line Items]

Percentage of construction costs, responsibility to pay

44.30%

Category II | Minimum | Plant Vogtle Units 3 And 4

Loss Contingencies [Line Items]

Additional construction capital costs, threshold

$ 800

Category II | Maximum | Plant Vogtle Units 3 And 4

Loss Contingencies [Line Items]

Additional construction capital costs, threshold

$ 1,600

Category III | Plant Vogtle Units 3 And 4

Loss Contingencies [Line Items]

Percentage of construction costs, responsibility to pay

65.70%

Additional construction capital costs

$ 100

Category III | Plant Vogtle Units 3 And 4 | Vogtle Owners

Loss Contingencies [Line Items]

Percentage of construction costs, responsibility to pay

34.30%

Category III | Maximum | Plant Vogtle Units 3 And 4

Loss Contingencies [Line Items]

Additional construction capital costs, threshold

$ 2,100

REGULATORY MATTERS - Nuclear _2

REGULATORY MATTERS - Nuclear Construction Cost and Schedule (Details) - GEORGIA POWER CO - Plant Vogtle Units 3 And 4 $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)
Loss Contingencies [Line Items]
Base project capital cost forecast	$ 8,400
Construction contingency estimate	100
Total project capital cost forecast	8,500
Net investment as of September 30, 2019	(6,600)
Remaining estimate to complete	1,900
Expected capitalized costs	260
Capitalized interest accrued	$ 52

REGULATORY MATTERS - Mississipp

REGULATORY MATTERS - Mississippi Power (Details) - MISSISSIPPI POWER CO - USD ($) $ in Millions	Jun. 25, 2020	Mar. 17, 2020	Jun. 30, 2020
Loss Contingencies [Line Items]
Increase (decrease) in retail rates	$ 2	$ (16.7)
Decrease in retail rates, percentage		1.85%
Base rate case filing, measurement input, average equity ratio		53.00%
Base rate case filing, measurement input, maximum equity ratio		55.00%
Base rate case filing, measurement input, return on investment		7.57%
Regulatory asset, amortization period		4 years
Regulatory liability, amortization period		3 years
Annual base rate adjustment, increase in depreciation		$ 10
Annual base rate adjustment, compensation costs excluded		$ 3.9
Incremental COVID-19 costs deferred			$ 2

REGULATORY MATTERS - Southern C

REGULATORY MATTERS - Southern Company Gas (Details) - USD ($) $ in Millions	Jul. 01, 2020	Jun. 01, 2020	Jun. 30, 2020
Nicor Gas
Loss Contingencies [Line Items]
Requested rate increase		$ 49.6
Requested rate increase, projected test year, period		12 months
Requested return on equity percentage		10.35%
Requested equity ratio percentage		54.00%
Subsequent Event | Atlanta Gas Light
Loss Contingencies [Line Items]
Requested rate increase	$ 37.6
Requested rate increase, projected test year, period	12 months
Maximum base rate	5.00%
COVID-19 | Nicor Gas
Loss Contingencies [Line Items]
Regulatory assets			$ 12
COVID-19 | Virginia Natural Gas
Loss Contingencies [Line Items]
Regulatory assets			$ 1

CONTINGENCIES - General Litigat

CONTINGENCIES - General Litigation Matters (Details) - Pending Litigation $ in Millions	1 Months Ended				12 Months Ended
	Sep. 30, 2019USD ($)	Mar. 31, 2019plaintiff	Nov. 30, 2018USD ($)defendantplaintiff	May 31, 2018USD ($)agreement	Dec. 31, 2018	Dec. 31, 2017claim
Putative Securities Class Action
Loss Contingencies [Line Items]
Increase in the purported class period						1 day
Shareholder Derivative Lawsuits
Loss Contingencies [Line Items]
Pending number of claims | claim						2
Stay period					30 days
MISSISSIPPI POWER CO | Martin Product Sales, LLC Litigation
Loss Contingencies [Line Items]
Number of agreements | agreement				2
Damages sought by litigation				$ 143
Compensatory damages sought by litigation	$ 5
Punitive damages sought by litigation	$ 50
MISSISSIPPI POWER CO | Purported Violations Of Mississippi Consumer Protection Act
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff		4	10
Number of defendants | defendant			3
Underpayment of refunds			$ 23.5

CONTINGENCIES - Environmental R

CONTINGENCIES - Environmental Remediation (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
GEORGIA POWER CO
Loss Contingencies [Line Items]
Environmental remediation liability, current and former sites	$ 14	$ 15
SOUTHERN Co GAS
Loss Contingencies [Line Items]
Environmental remediation liability, current and former sites	$ 253	$ 269

CONTINGENCIES - Other Matters (

CONTINGENCIES - Other Matters (Details) - USD ($) $ in Millions

Apr. 24, 2020

Apr. 23, 2020

Feb. 20, 2020

Dec. 31, 2019

Jun. 30, 2020

Jun. 30, 2019

Jun. 30, 2020

Jun. 30, 2019

Dec. 31, 2025

Dec. 31, 2024

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2020

Dec. 31, 2018

Loss Contingencies [Line Items]

Leveraged lease investments impairment loss

$ 154

$ 0

$ 154

$ 0

Liabilities incurred

15

MISSISSIPPI POWER CO

Loss Contingencies [Line Items]

Firm transportation agreement, term

15 years

MISSISSIPPI POWER CO | Kemper IGCC

Loss Contingencies [Line Items]

Government grants received

$ 387

MISSISSIPPI POWER CO | Scenario, Forecast | Kemper IGCC

Loss Contingencies [Line Items]

Liabilities incurred

$ 5

Asset retirement obligation, expected cost

$ 6

GULF POWER CO | Plant Daniel Units 1 And 2

Loss Contingencies [Line Items]

Undivided ownership interest to be restructured

50.00%

Undivided ownership interest, ownership interest in individual unit

100.00%

100.00%

Minimum | MISSISSIPPI POWER CO | Scenario, Forecast | Kemper IGCC

Loss Contingencies [Line Items]

Liabilities incurred

$ 11

$ 11

$ 11

$ 11

$ 16

Maximum | MISSISSIPPI POWER CO | Scenario, Forecast | Kemper IGCC

Loss Contingencies [Line Items]

Liabilities incurred

$ 13

$ 13

$ 13

$ 13

PennEast Pipelines

Loss Contingencies [Line Items]

Construction contingency, extension request, term

2 years

PennEast Pipelines | SOUTHERN Co GAS

Loss Contingencies [Line Items]

Construction contingency estimate

300

300

All Other

Loss Contingencies [Line Items]

Leveraged lease investments impairment loss

154

154

Leveraged lease investments impairment loss, net of tax

$ 74

$ 74

REVENUE FROM CONTRACTS WITH C_3

REVENUE FROM CONTRACTS WITH CUSTOMERS AND LEASE INCOME - Disaggregate Revenue Sources (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Operating revenues	$ 4,765	$ 5,222	$ 10,053	$ 11,131
Revenues	4,620	5,098	9,638	10,510
Total retail electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	3,198	3,546	6,417	6,726
Residential
Disaggregation of Revenue [Line Items]
Operating revenues	1,430	1,491	2,801	2,818
Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	1,103	1,264	2,247	2,390
Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	642	766	1,323	1,474
Other
Disaggregation of Revenue [Line Items]
Operating revenues	23	25	46	44
Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Operating revenues	585	557	1,584	1,717
Residential
Disaggregation of Revenue [Line Items]
Operating revenues	239	229	736	830
Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	58	65	188	235
Transportation
Disaggregation of Revenue [Line Items]
Operating revenues	234	213	499	469
Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	5	5	17	22
Other
Disaggregation of Revenue [Line Items]
Operating revenues	49	45	144	161
Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	325	370	639	723
PPA energy revenues
Disaggregation of Revenue [Line Items]
Operating revenues	167	208	326	398
PPA capacity revenues
Disaggregation of Revenue [Line Items]
Operating revenues	108	109	213	217
Non-PPA revenues
Disaggregation of Revenue [Line Items]
Operating revenues	50	53	100	108
Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	406	511	972	1,463
Wholesale gas services
Disaggregation of Revenue [Line Items]
Operating revenues	341	444	737	1,165
Gas marketing services
Disaggregation of Revenue [Line Items]
Operating revenues	57	55	220	276
Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	8	12	15	22
Other revenues
Disaggregation of Revenue [Line Items]
Operating revenues	251	238	441	502
Other revenue sources
Disaggregation of Revenue [Line Items]
Other	728	1,050	1,599	2,413
Other adjustments
Disaggregation of Revenue [Line Items]
Other	(873)	(1,174)	(2,014)	(3,034)
ALABAMA POWER CO
Disaggregation of Revenue [Line Items]
Operating revenues	1,312	1,490	2,663	2,925
Revenues	1,365	1,513	2,716	2,921
ALABAMA POWER CO | Total retail electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	1,210	1,390	2,454	2,661
ALABAMA POWER CO | Residential
Disaggregation of Revenue [Line Items]
Operating revenues	549	592	1,103	1,151
ALABAMA POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	353	422	717	790
ALABAMA POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	302	369	623	707
ALABAMA POWER CO | Other
Disaggregation of Revenue [Line Items]
Operating revenues	6	7	11	13
ALABAMA POWER CO | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
ALABAMA POWER CO | Residential
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
ALABAMA POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
ALABAMA POWER CO | Transportation
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
ALABAMA POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
ALABAMA POWER CO | Other
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
ALABAMA POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	58	63	131	181
ALABAMA POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Operating revenues	28	35	55	67
ALABAMA POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Operating revenues	25	25	52	52
ALABAMA POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Operating revenues	5	3	24	62
ALABAMA POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
ALABAMA POWER CO | Wholesale gas services
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
ALABAMA POWER CO | Gas marketing services
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
ALABAMA POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
ALABAMA POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Operating revenues	44	37	78	83
ALABAMA POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other	53	23	53	(4)
ALABAMA POWER CO | Other adjustments
Disaggregation of Revenue [Line Items]
Other	0	0	0	0
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Operating revenues	1,935	2,069	3,830	3,894
Revenues	1,928	2,117	3,754	3,951
GEORGIA POWER CO | Total retail electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	1,794	1,943	3,572	3,650
GEORGIA POWER CO | Residential
Disaggregation of Revenue [Line Items]
Operating revenues	817	831	1,577	1,539
GEORGIA POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	689	770	1,409	1,463
GEORGIA POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	273	327	555	623
GEORGIA POWER CO | Other
Disaggregation of Revenue [Line Items]
Operating revenues	15	15	31	25
GEORGIA POWER CO | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
GEORGIA POWER CO | Residential
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
GEORGIA POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
GEORGIA POWER CO | Transportation
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
GEORGIA POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
GEORGIA POWER CO | Other
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
GEORGIA POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	22	31	44	58
GEORGIA POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Operating revenues	7	17	15	28
GEORGIA POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Operating revenues	13	13	25	27
GEORGIA POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Operating revenues	2	1	4	3
GEORGIA POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
GEORGIA POWER CO | Wholesale gas services
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
GEORGIA POWER CO | Gas marketing services
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
GEORGIA POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
GEORGIA POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Operating revenues	119	95	214	186
GEORGIA POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other	(7)	48	(76)	57
GEORGIA POWER CO | Other adjustments
Disaggregation of Revenue [Line Items]
Other	0	0	0	0
MISSISSIPPI POWER CO
Disaggregation of Revenue [Line Items]
Operating revenues	276	310	552	596
Revenues	283	313	559	600
MISSISSIPPI POWER CO | Total retail electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	194	213	391	415
MISSISSIPPI POWER CO | Residential
Disaggregation of Revenue [Line Items]
Operating revenues	64	68	121	128
MISSISSIPPI POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	61	72	121	137
MISSISSIPPI POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	67	70	145	144
MISSISSIPPI POWER CO | Other
Disaggregation of Revenue [Line Items]
Operating revenues	2	3	4	6
MISSISSIPPI POWER CO | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
MISSISSIPPI POWER CO | Residential
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
MISSISSIPPI POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
MISSISSIPPI POWER CO | Transportation
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
MISSISSIPPI POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
MISSISSIPPI POWER CO | Other
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
MISSISSIPPI POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	76	93	148	171
MISSISSIPPI POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Operating revenues	2	3	4	5
MISSISSIPPI POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Operating revenues	1	1	2	2
MISSISSIPPI POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Operating revenues	73	89	142	164
MISSISSIPPI POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
MISSISSIPPI POWER CO | Wholesale gas services
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
MISSISSIPPI POWER CO | Gas marketing services
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
MISSISSIPPI POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
MISSISSIPPI POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Operating revenues	6	4	13	10
MISSISSIPPI POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other	7	3	7	4
MISSISSIPPI POWER CO | Other adjustments
Disaggregation of Revenue [Line Items]
Other	0	0	0	0
SOUTHERN POWER CO
Disaggregation of Revenue [Line Items]
Operating revenues	268	315	519	592
Revenues	439	510	814	953
SOUTHERN POWER CO | Total retail electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Residential
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Other
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Residential
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Transportation
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Other
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	264	312	512	586
SOUTHERN POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Operating revenues	134	163	259	314
SOUTHERN POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Operating revenues	71	81	136	163
SOUTHERN POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Operating revenues	59	68	117	109
SOUTHERN POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Wholesale gas services
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Gas marketing services
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Operating revenues	4	3	7	6
SOUTHERN POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other	171	195	295	361
SOUTHERN POWER CO | Other adjustments
Disaggregation of Revenue [Line Items]
Other	0	0	0	0
SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Operating revenues	991	1,068	2,556	3,180
Revenues	636	689	1,885	2,163
SOUTHERN Co GAS | Total retail electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN Co GAS | Residential
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN Co GAS | Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN Co GAS | Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN Co GAS | Other
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN Co GAS | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Operating revenues	585	557	1,584	1,717
SOUTHERN Co GAS | Residential
Disaggregation of Revenue [Line Items]
Operating revenues	239	229	736	830
SOUTHERN Co GAS | Commercial
Disaggregation of Revenue [Line Items]
Operating revenues	58	65	188	235
SOUTHERN Co GAS | Transportation
Disaggregation of Revenue [Line Items]
Operating revenues	234	213	499	469
SOUTHERN Co GAS | Industrial
Disaggregation of Revenue [Line Items]
Operating revenues	5	5	17	22
SOUTHERN Co GAS | Other
Disaggregation of Revenue [Line Items]
Operating revenues	49	45	144	161
SOUTHERN Co GAS | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN Co GAS | PPA energy revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN Co GAS | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN Co GAS | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN Co GAS | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	406	511	972	1,463
SOUTHERN Co GAS | Wholesale gas services
Disaggregation of Revenue [Line Items]
Operating revenues	341	444	737	1,165
SOUTHERN Co GAS | Gas marketing services
Disaggregation of Revenue [Line Items]
Operating revenues	57	55	220	276
SOUTHERN Co GAS | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Operating revenues	8	12	15	22
SOUTHERN Co GAS | Other revenues
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
SOUTHERN Co GAS | Other revenue sources
Disaggregation of Revenue [Line Items]
Other	518	795	1,343	2,017
SOUTHERN Co GAS | Other adjustments
Disaggregation of Revenue [Line Items]
Other	$ (873)	$ (1,174)	$ (2,014)	$ (3,034)

REVENUE FROM CONTRACTS WITH C_4

REVENUE FROM CONTRACTS WITH CUSTOMERS AND LEASE INCOME - Contract Balances (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Accounts Receivables	$ 2,283	$ 2,413
Contract Assets	103	117
Contract Liabilities	57	52
ALABAMA POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivables	592	586
Contract Assets	0	0
Contract Liabilities	6	10
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivables	796	688
Contract Assets	54	69
Contract Liabilities	23	13
MISSISSIPPI POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivables	84	79
Contract Assets	1	0
Contract Liabilities	0	0
SOUTHERN POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivables	115	97
Contract Assets	0	0
Contract Liabilities	1	1
SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Accounts Receivables	523	749
Contract Assets	0	0
Contract Liabilities	$ 2	$ 1

REVENUE FROM CONTRACTS WITH C_5

REVENUE FROM CONTRACTS WITH CUSTOMERS AND LEASE INCOME - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Contract assets	$ 103	$ 103	$ 117
Contract liabilities	57	57	52
Revenue from contracts with customers recognized	11	21
Unregulated Distributed Generation
Disaggregation of Revenue [Line Items]
Contract assets	41	41	40
Contract liabilities	26	$ 26	28
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Revenue, performance obligation, description of timing		Georgia Power had contract assets primarily related to unregulated service agreements, where payment is contingent on project completion, and fixed retail customer bill programs, where the payment is contingent upon Georgia Power's continued performance and the customer's continued participation in the program over a one-year contract term. Contract liabilities for Georgia Power relate to cash collections recognized in advance of revenue for certain unregulated service agreements. Alabama Power had contract liabilities for outstanding performance obligations primarily related to extended service agreements.
Contract assets	54	$ 54	69
Contract liabilities	$ 23	$ 23	$ 13

REVENUE FROM CONTRACTS WITH C_6

REVENUE FROM CONTRACTS WITH CUSTOMERS AND LEASE INCOME - Performance Obligations (Details) $ in Millions	Jun. 30, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 319
Performance obligation, expected timing of satisfaction	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 432
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 362
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 339
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 319
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 3,062
Performance obligation, expected timing of satisfaction
ALABAMA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 12
Performance obligation, expected timing of satisfaction	6 months
ALABAMA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 33
Performance obligation, expected timing of satisfaction	1 year
ALABAMA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 31
Performance obligation, expected timing of satisfaction	1 year
ALABAMA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 24
Performance obligation, expected timing of satisfaction	1 year
ALABAMA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 7
Performance obligation, expected timing of satisfaction	1 year
ALABAMA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 5
Performance obligation, expected timing of satisfaction
GEORGIA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 37
Performance obligation, expected timing of satisfaction	6 months
GEORGIA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 70
Performance obligation, expected timing of satisfaction	1 year
GEORGIA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 39
Performance obligation, expected timing of satisfaction	1 year
GEORGIA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 34
Performance obligation, expected timing of satisfaction	1 year
GEORGIA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 23
Performance obligation, expected timing of satisfaction	1 year
GEORGIA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 62
Performance obligation, expected timing of satisfaction
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 156
Performance obligation, expected timing of satisfaction	6 months
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 290
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 292
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 282
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 290
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 3,013
Performance obligation, expected timing of satisfaction

REVENUE FROM CONTRACTS WITH C_7

REVENUE FROM CONTRACTS WITH CUSTOMERS AND LEASE INCOME - Summary of Lease Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	$ 3	$ 2	$ 6	$ 5
Lease income - operating leases	47	67	97	139
Variable lease income	126	115	200	182
Total lease income	176	184	303	326
ALABAMA POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0	0	0
Lease income - operating leases	6	7	13	13
Variable lease income	0	0	0	0
Total lease income	6	7	13	13
GEORGIA POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0	0	0
Lease income - operating leases	15	19	30	39
Variable lease income	0	0	0	0
Total lease income	15	19	30	39
MISSISSIPPI POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	3	2	5	5
Lease income - operating leases	0	0	0	0
Variable lease income	0	0	0	0
Total lease income	3	2	5	5
SOUTHERN POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0	0	0
Lease income - operating leases	21	44	45	90
Variable lease income	136	129	215	204
Total lease income	157	173	260	294
SOUTHERN Co GAS
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0	0	0
Lease income - operating leases	9	9	17	17
Variable lease income	0	0	0	0
Total lease income	$ 9	$ 9	$ 17	$ 17

CONSOLIDATED ENTITIES AND EQU_3

CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS - Narrative (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)investor	Dec. 31, 2019USD ($)
Schedule of Equity Method Investments [Line Items]
Assets	$ 119,731	$ 118,700
Liabilities	87,479	86,650
Equity method investments	379	391
SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	13,557	14,300
Liabilities	6,898	7,678
Equity method investments	19	28
SOUTHERN Co GAS
Schedule of Equity Method Investments [Line Items]
Assets	21,500	21,687
Liabilities	11,731	12,181
Equity method investments	$ 20	20
SP Solar Holdings I, LP | SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Distribution made to limited partner, cash distributions paid, percentage	67.00%
SP Solar Holdings I, LP | Global Atlantic
Schedule of Equity Method Investments [Line Items]
Distribution made to limited partner, cash distributions paid, percentage	33.00%
Variable Interest Entity, Primary Beneficiary | SP Solar Holdings I, LP | SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	$ 6,200	6,400
Liabilities	381	381
Noncontrolling interests related to other partners' interests	1,100	1,100
Variable Interest Entity, Primary Beneficiary | SP Wind | SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	2,400	2,500
Liabilities	125	128
Noncontrolling interests related to other partners' interests	$ 44	45
Distribution made to limited partner, cash distributions paid, percentage	60.00%
Number of financial investors | investor	3
Variable Interest Entity, Primary Beneficiary | SP Wind | Financial Investors
Schedule of Equity Method Investments [Line Items]
Distribution made to limited partner, cash distributions paid, percentage	40.00%
Variable Interest Entity, Primary Beneficiary | Other Variable Interest Entities | SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	$ 1,500	1,100
Liabilities	160	104
Noncontrolling interests related to other partners' interests	$ 557	$ 409

CONSOLIDATED ENTITIES AND EQU_4

CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS - Balance Sheet Equity Method Investment Carrying Amount (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 1,363	$ 1,303
SOUTHERN Co GAS
Schedule of Equity Method Investments [Line Items]
Investment Balance	1,308	1,251
SOUTHERN Co GAS | SNG
Schedule of Equity Method Investments [Line Items]
Investment Balance	1,189	1,137
SOUTHERN Co GAS | PennEast Pipeline
Schedule of Equity Method Investments [Line Items]
Investment Balance	87	82
SOUTHERN Co GAS | Other
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 32	$ 32

CONSOLIDATED ENTITIES AND EQU_5

CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS - Income Statement Equity Method Investment Carrying Amount (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Equity Method Investments [Line Items]
Earnings from Equity Method Investments	$ 30	$ 33	$ 72	$ 81
SOUTHERN Co GAS
Schedule of Equity Method Investments [Line Items]
Earnings from Equity Method Investments	30	31	72	80
SOUTHERN Co GAS | SNG
Schedule of Equity Method Investments [Line Items]
Earnings from Equity Method Investments	28	32	65	74
SOUTHERN Co GAS | Atlantic Coast Pipeline
Schedule of Equity Method Investments [Line Items]
Earnings from Equity Method Investments	0	3	3	6
SOUTHERN Co GAS | PennEast Pipeline
Schedule of Equity Method Investments [Line Items]
Earnings from Equity Method Investments	1	1	3	3
SOUTHERN Co GAS | Other
Schedule of Equity Method Investments [Line Items]
Earnings from Equity Method Investments	$ 1	$ (5)	$ 1	$ (3)

CONSOLIDATED ENTITIES AND EQU_6

CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS - Investment in SNG (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Equity Method Investments [Line Items]
Revenues	$ 4,620	$ 5,098	$ 9,638	$ 10,510
Operating income	1,058	1,342	2,321	5,033
Net income	621	931	1,461	2,989
Equity Method Investment | SNG
Schedule of Equity Method Investments [Line Items]
Revenues	149	155	307	321
Operating income	78	86	176	192
Net income	$ 55	$ 64	$ 130	$ 148

FINANCING - Schedule of Credit

FINANCING - Schedule of Credit Arrangements (Details)	Jun. 30, 2020USD ($)
Line of Credit Facility [Line Items]
Expires, 2020	$ 3,000,000
Expires, 2021	30,000,000
Expires, 2022	675,000,000
Expires, 2023	125,000,000
Expires, 2024	6,900,000,000
Total	7,733,000,000
Unused	7,675,000,000
Due within One Year	33,000,000
Southern Company
Line of Credit Facility [Line Items]
Expires, 2020	0
Expires, 2021	0
Expires, 2022	0
Expires, 2023	0
Expires, 2024	2,000,000,000
Total	2,000,000,000
Unused	1,999,000,000
Due within One Year	0
ALABAMA POWER CO
Line of Credit Facility [Line Items]
Expires, 2020	3,000,000
Expires, 2021	0
Expires, 2022	525,000,000
Expires, 2023	0
Expires, 2024	800,000,000
Total	1,328,000,000
Unused	1,328,000,000
Due within One Year	3,000,000
GEORGIA POWER CO
Line of Credit Facility [Line Items]
Expires, 2020	0
Expires, 2021	0
Expires, 2022	0
Expires, 2023	0
Expires, 2024	1,750,000,000
Total	1,750,000,000
Unused	1,733,000,000
Due within One Year	0
MISSISSIPPI POWER CO
Line of Credit Facility [Line Items]
Expires, 2020	0
Expires, 2021	0
Expires, 2022	150,000,000
Expires, 2023	125,000,000
Expires, 2024	0
Total	275,000,000
Unused	250,000,000
Due within One Year	0
SOUTHERN POWER CO
Line of Credit Facility [Line Items]
Expires, 2020	0
Expires, 2021	0
Expires, 2022	0
Expires, 2023	0
Expires, 2024	600,000,000
Total	600,000,000
Unused	590,000,000
Due within One Year	0
SOUTHERN POWER CO | Standby Letters of Credit
Line of Credit Facility [Line Items]
Expires, 2021	120,000,000
Expires, 2024	60,000,000
Unused, 2021	19,000,000
Unused, 2023	60,000,000
SOUTHERN Co GAS
Line of Credit Facility [Line Items]
Expires, 2020	0
Expires, 2021	0
Expires, 2022	0
Expires, 2023	0
Expires, 2024	1,750,000,000
Total	1,750,000,000
Unused	1,745,000,000
Due within One Year	0
SEGCO
Line of Credit Facility [Line Items]
Expires, 2020	0
Expires, 2021	30,000,000
Expires, 2022	0
Expires, 2023	0
Expires, 2024	0
Total	30,000,000
Unused	30,000,000
Due within One Year	30,000,000
Southern Company Gas Capital
Line of Credit Facility [Line Items]
Total	1,250,000,000
Nicor Gas
Line of Credit Facility [Line Items]
Total	$ 500,000,000

FINANCING - Narrative (Details)

FINANCING - Narrative (Details) $ in Millions	Jun. 30, 2020USD ($)
Debt Instrument [Line Items]
Line of credit expiring in 2023	$ 125
Variable rate pollution control revenue bonds outstanding	1,400
MISSISSIPPI POWER CO
Debt Instrument [Line Items]
Line of credit expiring in 2023	125
Variable rate pollution control revenue bonds outstanding	34
ALABAMA POWER CO
Debt Instrument [Line Items]
Line of credit expiring in 2023	0
Variable rate pollution control revenue bonds outstanding	854
GEORGIA POWER CO
Debt Instrument [Line Items]
Line of credit expiring in 2023	0
Variable rate pollution control revenue bonds outstanding	550
Fixed rate pollution control revenue bonds outstanding	$ 257

FINANCING - Shares Used to Comp

FINANCING - Shares Used to Compute Diluted Earnings Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Debt Disclosure [Abstract]
As reported shares (in shares)	1,058,000,000	1,044,000,000	1,057,000,000	1,041,000,000
Effect of stock-based compensation (in shares)	5,000,000	8,000,000	7,000,000	8,000,000
Effect of equity units (in shares)	0	0	1,000,000	0
Diluted shares (in shares)	1,063,000,000	1,052,000,000	1,065,000,000	1,049,000,000
Antidilutive securities excluded from computation of earnings per share (in shares)		0		0

INCOME TAXES (Details)

INCOME TAXES (Details)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	9.30%	33.50%
GEORGIA POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	4.00%	21.70%
MISSISSIPPI POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	10.60%	14.00%
SOUTHERN POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	10.50%	(35.50%)
SOUTHERN Co GAS
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	21.50%	18.00%

RETIREMENT BENEFITS (Details)

RETIREMENT BENEFITS (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Amortization:
Net (gain)/loss
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected future employer contributions, remainder of fiscal year	$ 0		$ 0
Pension Plans and Postretirement Plans
Service cost	94,000,000	73,000,000	188,000,000	$ 146,000,000
Interest cost	108,000,000	123,000,000	216,000,000	246,000,000
Expected return on plan assets	(275,000,000)	(221,000,000)	(550,000,000)	(442,000,000)
Amortization:
Prior service costs	0	1,000,000	1,000,000	1,000,000
Regulatory asset	0	0	0	0
Net (gain)/loss	67,000,000	30,000,000	134,000,000	60,000,000
Net periodic pension cost (income)	(6,000,000)	6,000,000	(11,000,000)	11,000,000
Pension Plans | ALABAMA POWER CO
Pension Plans and Postretirement Plans
Service cost	22,000,000	17,000,000	44,000,000	34,000,000
Interest cost	25,000,000	29,000,000	50,000,000	57,000,000
Expected return on plan assets	(66,000,000)	(52,000,000)	(132,000,000)	(103,000,000)
Amortization:
Prior service costs	0	1,000,000	0	1,000,000
Regulatory asset	0	0	0	0
Net (gain)/loss	18,000,000	9,000,000	36,000,000	18,000,000
Net periodic pension cost (income)	(1,000,000)	4,000,000	(2,000,000)	7,000,000
Pension Plans | GEORGIA POWER CO
Pension Plans and Postretirement Plans
Service cost	24,000,000	18,000,000	48,000,000	37,000,000
Interest cost	34,000,000	39,000,000	67,000,000	78,000,000
Expected return on plan assets	(87,000,000)	(73,000,000)	(174,000,000)	(146,000,000)
Amortization:
Prior service costs	1,000,000	1,000,000	1,000,000	1,000,000
Regulatory asset	0	0	0	0
Net (gain)/loss	21,000,000	11,000,000	43,000,000	22,000,000
Net periodic pension cost (income)	(7,000,000)	(4,000,000)	(15,000,000)	(8,000,000)
Pension Plans | MISSISSIPPI POWER CO
Pension Plans and Postretirement Plans
Service cost	4,000,000	3,000,000	8,000,000	6,000,000
Interest cost	5,000,000	5,000,000	10,000,000	11,000,000
Expected return on plan assets	(12,000,000)	(10,000,000)	(25,000,000)	(20,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain)/loss	3,000,000	2,000,000	6,000,000	3,000,000
Net periodic pension cost (income)	0	0	(1,000,000)	0
Pension Plans | SOUTHERN POWER CO
Pension Plans and Postretirement Plans
Service cost	2,000,000	1,000,000	4,000,000	3,000,000
Interest cost	2,000,000	2,000,000	3,000,000	3,000,000
Expected return on plan assets	(3,000,000)	(3,000,000)	(6,000,000)	(5,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain)/loss	0	0	1,000,000	0
Net periodic pension cost (income)	1,000,000	0	2,000,000	1,000,000
Pension Plans | SOUTHERN Co GAS
Pension Plans and Postretirement Plans
Service cost	8,000,000	6,000,000	16,000,000	12,000,000
Interest cost	7,000,000	9,000,000	15,000,000	18,000,000
Expected return on plan assets	(20,000,000)	(15,000,000)	(39,000,000)	(30,000,000)
Amortization:
Prior service costs	0	0	(1,000,000)	(1,000,000)
Regulatory asset	4,000,000	4,000,000	8,000,000	7,000,000
Net (gain)/loss	3,000,000	0	5,000,000	1,000,000
Net periodic pension cost (income)	2,000,000	4,000,000	4,000,000	7,000,000
Postretirement Benefits
Pension Plans and Postretirement Plans
Service cost	6,000,000	4,000,000	11,000,000	9,000,000
Interest cost	14,000,000	17,000,000	27,000,000	34,000,000
Expected return on plan assets	(18,000,000)	(17,000,000)	(36,000,000)	(33,000,000)
Amortization:
Prior service costs	(1,000,000)	1,000,000	(1,000,000)	2,000,000
Regulatory asset	0	0	0	0
Net (gain)/loss	0	0	1,000,000	(1,000,000)
Net periodic pension cost (income)	1,000,000	5,000,000	2,000,000	11,000,000
Postretirement Benefits | ALABAMA POWER CO
Pension Plans and Postretirement Plans
Service cost	1,000,000	1,000,000	3,000,000	2,000,000
Interest cost	3,000,000	4,000,000	6,000,000	8,000,000
Expected return on plan assets	(7,000,000)	(7,000,000)	(14,000,000)	(13,000,000)
Amortization:
Prior service costs	0	1,000,000	0	2,000,000
Regulatory asset	0	0	0	0
Net (gain)/loss	0	0	0	0
Net periodic pension cost (income)	(3,000,000)	(1,000,000)	(5,000,000)	(1,000,000)
Postretirement Benefits | GEORGIA POWER CO
Pension Plans and Postretirement Plans
Service cost	2,000,000	1,000,000	3,000,000	2,000,000
Interest cost	5,000,000	6,000,000	10,000,000	13,000,000
Expected return on plan assets	(6,000,000)	(6,000,000)	(13,000,000)	(12,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain)/loss	0	0	1,000,000	0
Net periodic pension cost (income)	1,000,000	1,000,000	1,000,000	3,000,000
Postretirement Benefits | MISSISSIPPI POWER CO
Pension Plans and Postretirement Plans
Service cost	1,000,000	0	1,000,000	0
Interest cost	1,000,000	1,000,000	1,000,000	2,000,000
Expected return on plan assets	(1,000,000)	(1,000,000)	(1,000,000)	(1,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain)/loss	0	0	0	0
Net periodic pension cost (income)	1,000,000	0	1,000,000	1,000,000
Postretirement Benefits | SOUTHERN POWER CO
Pension Plans and Postretirement Plans
Service cost	0	0	0	0
Interest cost	0	0	0	0
Expected return on plan assets	0	0	0	0
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain)/loss	0	0	0	0
Net periodic pension cost (income)	0	0	0	0
Postretirement Benefits | SOUTHERN Co GAS
Pension Plans and Postretirement Plans
Service cost	1,000,000	0	1,000,000	1,000,000
Interest cost	4,000,000	3,000,000	6,000,000	5,000,000
Expected return on plan assets	(2,000,000)	(1,000,000)	(4,000,000)	(3,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	1,000,000	1,000,000	3,000,000	3,000,000
Net (gain)/loss	(1,000,000)	(1,000,000)	(2,000,000)	(2,000,000)
Net periodic pension cost (income)	$ 3,000,000	$ 2,000,000	$ 4,000,000	$ 4,000,000

FAIR VALUE MEASUREMENTS - Asset

FAIR VALUE MEASUREMENTS - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Assets:
Derivatives	$ 214	$ 233
Liabilities:
Derivatives	156	189
Collateral already posted, aggregate fair value	114
ALABAMA POWER CO
Assets:
Derivatives	3	2
Liabilities:
Derivatives	11	22
GEORGIA POWER CO
Assets:
Derivatives	0	1
Investments in trusts	45
Liabilities:
Derivatives	30	67
MISSISSIPPI POWER CO
Assets:
Derivatives	0	0
Liabilities:
Derivatives	16	26
SOUTHERN POWER CO
Assets:
Derivatives	1	19
Liabilities:
Derivatives	51	27
SOUTHERN Co GAS
Assets:
Derivatives	188	212
Liabilities:
Derivatives	48	41
Total
Collateral already posted, aggregate fair value	114	$ 99
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	1,328
Other investments	30
Total	4,134
Liabilities:
Contingent consideration	19
Total	809
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	1,315
Other investments	9
Total	2,525
Liabilities:
Contingent consideration	0
Total	468
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	13
Other investments	21
Total	1,405
Liabilities:
Contingent consideration	0
Total	259
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0
Other investments	0
Total	143
Liabilities:
Contingent consideration	19
Total	82
Fair Value, Measurements, Recurring | Net Asset Value as a Practical Expedient (NAV)
Assets:
Total	61
Fair Value, Measurements, Recurring | Energy-related derivatives
Assets:
Derivatives	712
Liabilities:
Derivatives	718
Fair Value, Measurements, Recurring | Energy-related derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	388
Liabilities:
Derivatives	468
Fair Value, Measurements, Recurring | Energy-related derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	181
Liabilities:
Derivatives	187
Fair Value, Measurements, Recurring | Energy-related derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	143
Liabilities:
Derivatives	63
Fair Value, Measurements, Recurring | Interest rate derivatives
Assets:
Derivatives	23
Liabilities:
Derivatives	23
Fair Value, Measurements, Recurring | Interest rate derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | Interest rate derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	23
Liabilities:
Derivatives	23
Fair Value, Measurements, Recurring | Interest rate derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | Foreign currency derivatives
Liabilities:
Derivatives	49
Fair Value, Measurements, Recurring | Foreign currency derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | Foreign currency derivatives | Significant Other Observable Inputs (Level 2)
Liabilities:
Derivatives	49
Fair Value, Measurements, Recurring | Foreign currency derivatives | Significant Unobservable Inputs (Level 3)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | Domestic equity
Assets:
Investments in trusts	831
Fair Value, Measurements, Recurring | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	703
Fair Value, Measurements, Recurring | Domestic equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	128
Fair Value, Measurements, Recurring | Domestic equity | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Foreign equity
Assets:
Investments in trusts	267
Fair Value, Measurements, Recurring | Foreign equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	65
Fair Value, Measurements, Recurring | Foreign equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	202
Fair Value, Measurements, Recurring | Foreign equity | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | U.S. Treasury and government agency securities
Assets:
Investments in trusts	268
Fair Value, Measurements, Recurring | U.S. Treasury and government agency securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | U.S. Treasury and government agency securities | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	268
Fair Value, Measurements, Recurring | U.S. Treasury and government agency securities | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Municipal bonds
Assets:
Investments in trusts	106
Fair Value, Measurements, Recurring | Municipal bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Municipal bonds | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	106
Fair Value, Measurements, Recurring | Municipal bonds | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Pooled funds – fixed income
Assets:
Investments in trusts	16
Fair Value, Measurements, Recurring | Pooled funds – fixed income | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Pooled funds – fixed income | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	16
Fair Value, Measurements, Recurring | Pooled funds – fixed income | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Corporate bonds
Assets:
Investments in trusts	388
Fair Value, Measurements, Recurring | Corporate bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	19
Fair Value, Measurements, Recurring | Corporate bonds | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	369
Fair Value, Measurements, Recurring | Corporate bonds | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Mortgage and asset backed securities
Assets:
Investments in trusts	75
Fair Value, Measurements, Recurring | Mortgage and asset backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Mortgage and asset backed securities | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	75
Fair Value, Measurements, Recurring | Mortgage and asset backed securities | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Private equity
Assets:
Investments in trusts	61
Fair Value, Measurements, Recurring | Private equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Private equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Private equity | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Private equity | Net Asset Value as a Practical Expedient (NAV)
Assets:
Investments in trusts	61
Fair Value, Measurements, Recurring | Other
Assets:
Investments in trusts	29
Fair Value, Measurements, Recurring | Other | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	26
Fair Value, Measurements, Recurring | Other | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	3
Fair Value, Measurements, Recurring | Other | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO
Assets:
Cash equivalents	705
Other investments	21
Total	1,714
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	692
Other investments	0
Total	1,226
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	13
Other investments	21
Total	427
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0
Other investments	0
Total	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Net Asset Value as a Practical Expedient (NAV)
Assets:
Total	61
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Energy-related derivatives
Assets:
Derivatives	11
Liabilities:
Derivatives	19
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Energy-related derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Energy-related derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	11
Liabilities:
Derivatives	19
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Energy-related derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Domestic equity
Assets:
Investments in trusts	559
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	442
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Domestic equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	117
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Domestic equity | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Foreign equity
Assets:
Investments in trusts	124
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Foreign equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	65
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Foreign equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	59
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Foreign equity | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | U.S. Treasury and government agency securities
Assets:
Investments in trusts	22
Fair Value, Measurements, Recurring | ALABAMA POWER CO | U.S. Treasury and government agency securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | U.S. Treasury and government agency securities | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	22
Fair Value, Measurements, Recurring | ALABAMA POWER CO | U.S. Treasury and government agency securities | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Municipal bonds
Assets:
Investments in trusts	1
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Municipal bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Municipal bonds | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	1
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Municipal bonds | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Corporate bonds
Assets:
Investments in trusts	174
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Corporate bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	19
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Corporate bonds | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	155
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Corporate bonds | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Mortgage and asset backed securities
Assets:
Investments in trusts	28
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Mortgage and asset backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Mortgage and asset backed securities | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	28
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Mortgage and asset backed securities | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Private equity
Assets:
Investments in trusts	61
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Private equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Private equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Private equity | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Private equity | Net Asset Value as a Practical Expedient (NAV)
Assets:
Investments in trusts	61
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Other
Assets:
Investments in trusts	8
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Other | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	8
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Other | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Other | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO
Assets:
Cash equivalents	349
Total	1,395
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	349
Total	628
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	0
Total	767
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0
Total	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Energy-related derivatives
Assets:
Derivatives	10
Liabilities:
Derivatives	40
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Energy-related derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Energy-related derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	10
Liabilities:
Derivatives	40
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Energy-related derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Domestic equity
Assets:
Investments in trusts	262
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	261
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Domestic equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	1
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Domestic equity | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Foreign equity
Assets:
Investments in trusts	141
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Foreign equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Foreign equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	141
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Foreign equity | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | U.S. Treasury and government agency securities
Assets:
Investments in trusts	246
Fair Value, Measurements, Recurring | GEORGIA POWER CO | U.S. Treasury and government agency securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | U.S. Treasury and government agency securities | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	246
Fair Value, Measurements, Recurring | GEORGIA POWER CO | U.S. Treasury and government agency securities | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Municipal bonds
Assets:
Investments in trusts	105
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Municipal bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Municipal bonds | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	105
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Municipal bonds | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Corporate bonds
Assets:
Investments in trusts	214
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Corporate bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Corporate bonds | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	214
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Corporate bonds | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Mortgage and asset backed securities
Assets:
Investments in trusts	47
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Mortgage and asset backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Mortgage and asset backed securities | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	47
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Mortgage and asset backed securities | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Other
Assets:
Investments in trusts	21
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Other | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	18
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Other | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	3
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Other | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | MISSISSIPPI POWER CO | Energy-related derivatives
Assets:
Derivatives	6
Liabilities:
Derivatives	22
Fair Value, Measurements, Recurring | MISSISSIPPI POWER CO | Energy-related derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | MISSISSIPPI POWER CO | Energy-related derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	6
Liabilities:
Derivatives	22
Fair Value, Measurements, Recurring | MISSISSIPPI POWER CO | Energy-related derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN POWER CO
Liabilities:
Contingent consideration	19
Total	71
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Contingent consideration	0
Total	0
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Significant Other Observable Inputs (Level 2)
Liabilities:
Contingent consideration	0
Total	52
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Significant Unobservable Inputs (Level 3)
Liabilities:
Contingent consideration	19
Total	19
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Energy-related derivatives
Assets:
Derivatives	2
Liabilities:
Derivatives	3
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Energy-related derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Energy-related derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	2
Liabilities:
Derivatives	3
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Energy-related derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Foreign currency derivatives
Liabilities:
Derivatives	49
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Foreign currency derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Foreign currency derivatives | Significant Other Observable Inputs (Level 2)
Liabilities:
Derivatives	49
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Foreign currency derivatives | Significant Unobservable Inputs (Level 3)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS
Assets:
Cash equivalents	40
Total	751
Liabilities:
Total	657
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	40
Total	428
Liabilities:
Total	468
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	0
Total	180
Liabilities:
Total	126
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0
Total	143
Liabilities:
Total	63
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives
Assets:
Derivatives	683
Liabilities:
Derivatives	634
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	388
Liabilities:
Derivatives	468
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	152
Liabilities:
Derivatives	103
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	143
Liabilities:
Derivatives	63
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives
Liabilities:
Derivatives	23
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives | Significant Other Observable Inputs (Level 2)
Liabilities:
Derivatives	23
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives | Significant Unobservable Inputs (Level 3)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Domestic equity
Assets:
Non-qualified deferred compensation trusts	10
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Domestic equity | Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	10
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Domestic equity | Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Foreign equity
Assets:
Non-qualified deferred compensation trusts	2
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Foreign equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Foreign equity | Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	2
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Foreign equity | Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Pooled funds – fixed income
Assets:
Non-qualified deferred compensation trusts	16
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Pooled funds – fixed income | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Pooled funds – fixed income | Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	16
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Pooled funds – fixed income | Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	$ 0

FAIR VALUE MEASUREMENTS - Sched

FAIR VALUE MEASUREMENTS - Schedule of Increase (Decrease) In Fair Value Of Funds (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	$ 223	$ 75	$ (23)	$ 227
ALABAMA POWER CO
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	124	38	(42)	125
GEORGIA POWER CO
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	$ 99	$ 37	$ 19	$ 102

FAIR VALUE MEASUREMENTS - Narra

FAIR VALUE MEASUREMENTS - Narrative (Details) $ in Millions	Jun. 30, 2020USD ($)$ / MMBTU
ALABAMA POWER CO | Private equity
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value	$ 61
Unfunded commitments	72
SOUTHERN Co GAS | Significant Unobservable Inputs (Level 3) | Energy-related derivatives
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of derivatives	$ 80
SOUTHERN Co GAS | Significant Unobservable Inputs (Level 3) | Energy-related derivatives | Forward Price | Valuation, Market Approach | Minimum
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Measurement input (usd per mmbtu) | $ / MMBTU	(0.91)
SOUTHERN Co GAS | Significant Unobservable Inputs (Level 3) | Energy-related derivatives | Forward Price | Valuation, Market Approach | Maximum
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Measurement input (usd per mmbtu) | $ / MMBTU	0.99

FAIR VALUE MEASUREMENTS - Finan

FAIR VALUE MEASUREMENTS - Financial Instruments for which Carrying Amount did not Equal Fair Value (Details) $ in Millions	Jun. 30, 2020USD ($)
Long-term debt, including securities due within one year:
Carrying amount	$ 46,513
Fair value	53,079
ALABAMA POWER CO
Long-term debt, including securities due within one year:
Carrying amount	8,519
Fair value	10,008
GEORGIA POWER CO
Long-term debt, including securities due within one year:
Carrying amount	12,720
Fair value	15,092
MISSISSIPPI POWER CO
Long-term debt, including securities due within one year:
Carrying amount	1,404
Fair value	1,571
SOUTHERN POWER CO
Long-term debt, including securities due within one year:
Carrying amount	4,097
Fair value	4,423
SOUTHERN Co GAS
Long-term debt, including securities due within one year:
Carrying amount	5,827
Fair value	$ 6,817

FAIR VALUE MEASUREMENTS - Fair

FAIR VALUE MEASUREMENTS - Fair Value of Commodity Derivative Contracts that Include a Significant Unobservable Component (Details) - SOUTHERN Co GAS - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 76	$ 14
Transfers to Level 3	0	70
Transfers from Level 3	0	(3)
Instruments realized or otherwise settled during period	(6)	(7)
Changes in fair value	10	6
Ending balance	$ 80	$ 80

DERIVATIVES - Energy-Related De

DERIVATIVES - Energy-Related Derivatives (Details) - Energy-related, Natural Gas MMBTU in Millions	Jun. 30, 2020MMBTU
Energy-related derivative contracts
Net Purchased mmBtu	944
ALABAMA POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	85
GEORGIA POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	152
MISSISSIPPI POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	91
SOUTHERN POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	15
SOUTHERN Co GAS
Energy-related derivative contracts
Net Purchased mmBtu	601
SOUTHERN Co GAS | Derivatives not designated as hedging instruments | Long
Energy-related derivative contracts
Derivative nonmonetary notional amount net long short position volume	4,600
SOUTHERN Co GAS | Derivatives not designated as hedging instruments | Short
Energy-related derivative contracts
Derivative nonmonetary notional amount net long short position volume	4,000

DERIVATIVES - Narrative (Detail

DERIVATIVES - Narrative (Details) MWh in Millions, MMBTU in Millions	6 Months Ended
	Jun. 30, 2020USD ($)MWhMMBTU	Dec. 31, 2019USD ($)
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU	16
Cash flow hedge gain (loss) to be reclassified within twelve months | $	$ (25,000,000)
Collateral already posted, aggregate fair value | $	$ 114,000,000
ALABAMA POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU	4
GEORGIA POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU	5
MISSISSIPPI POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU	2
SOUTHERN POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU	5
Parent Company and Southern Power
Derivative [Line Items]
Foreign currency cash flow hedge gain (loss) to be reclassified during next 12 months | $	$ (24,000,000)
Registrants | Derivative Counterparties
Derivative [Line Items]
Collateral already posted, aggregate fair value | $	0
SOUTHERN Co GAS
Derivative [Line Items]
Collateral already posted, aggregate fair value | $	$ 114,000,000	$ 99,000,000
Public Utilities, Inventory, Power Position | SOUTHERN POWER CO
Derivative [Line Items]
Net Purchased mmBtu | MWh	1

DERIVATIVES - Interest Rate Der

DERIVATIVES - Interest Rate Derivatives (Details) - Interest rate derivatives $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)
Derivative [Line Items]
Notional Amount	$ 1,760
Fair Value Gain (Loss) at June 30, 2020	0
SOUTHERN Co GAS | Cash Flow Hedges of Forecasted Debt
Derivative [Line Items]
Notional Amount	$ 200
Weighted Average Interest Rate Paid	1.81%
Fair Value Gain (Loss) at June 30, 2020	$ (23)
MISSISSIPPI POWER CO | Cash Flow Hedges of Existing Debt
Derivative [Line Items]
Notional Amount	$ 60
Weighted Average Interest Rate Paid	0.58%
Fair Value Gain (Loss) at June 30, 2020	$ 0
Southern Company | Fair Value Hedges of Existing Debt
Derivative [Line Items]
Notional Amount	$ 1,500
Interest Rate Received	2.35%
Fair Value Gain (Loss) at June 30, 2020	$ 23
London Interbank Offered Rate (LIBOR) | Southern Company | Fair Value Hedges of Existing Debt
Derivative [Line Items]
Weighted Average Interest Rate Paid	0.87%

DERIVATIVES - Foreign Currency

DERIVATIVES - Foreign Currency Derivatives (Details) - 6 months ended Jun. 30, 2020 - Cash Flow Hedges of Forecasted Debt - Foreign currency derivatives € in Millions, $ in Millions	USD ($)	EUR (€)
Derivative [Line Items]
Pay Notional	$ 1,241
Receive Notional | €		€ 1,100
Fair Value Gain (Loss) at June 30, 2020	(49)
SOUTHERN POWER CO | June 2022
Derivative [Line Items]
Pay Notional	$ 677
Pay Rate	2.95%
Receive Notional | €		600
Receive Rate	1.00%
Fair Value Gain (Loss) at June 30, 2020	$ (18)
SOUTHERN POWER CO | June 2026
Derivative [Line Items]
Pay Notional	$ 564
Pay Rate	3.78%
Receive Notional | €		€ 500
Receive Rate	1.85%
Fair Value Gain (Loss) at June 30, 2020	$ (31)

DERIVATIVES - Derivative Financ

DERIVATIVES - Derivative Financial Statement Presentation and Amounts With Balance Sheet Offsetting (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivatives, assets	$ 734	$ 696
Derivatives, liabilities	790	751
Derivative asset, Gross amounts offset	(520)	(463)
Derivative liability, Gross amounts offset	(634)	(562)
Derivative asset	214	233
Derivative liability	156	189
Collateral already posted, aggregate fair value	114
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivatives, assets	677	668
Derivatives, liabilities	620	583
Derivatives not designated as hedging instruments | Energy-related derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	361	461
Derivatives not designated as hedging instruments | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	367	358
Derivatives not designated as hedging instruments | Energy-related derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	316	207
Derivatives not designated as hedging instruments | Energy-related derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	253	225
Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivatives, assets	32	9
Derivatives, liabilities	92	114
Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	19	3
Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	64	70
Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	13	6
Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	28	44
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivatives, assets	25	19
Derivatives, liabilities	78	54
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	3	1
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	6	6
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Interest rate derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	12	2
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Interest rate derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	23	23
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Interest rate derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	10	0
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Interest rate derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	1
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Foreign currency derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Foreign currency derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	24	24
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Foreign currency derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	16
Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Foreign currency derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	25	0
ALABAMA POWER CO
Derivatives, Fair Value [Line Items]
Derivatives, assets	11	4
Derivatives, liabilities	19	24
Derivative asset, Gross amounts offset	(8)	(2)
Derivative liability, Gross amounts offset	(8)	(2)
Derivative asset	3	2
Derivative liability	11	22
ALABAMA POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivatives, assets	11	4
Derivatives, liabilities	19	24
ALABAMA POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	7	2
ALABAMA POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	12	14
ALABAMA POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	4	2
ALABAMA POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	7	10
GEORGIA POWER CO
Derivatives, Fair Value [Line Items]
Derivatives, assets	10	4
Derivatives, liabilities	40	70
Derivative asset, Gross amounts offset	(10)	(3)
Derivative liability, Gross amounts offset	(10)	(3)
Derivative asset	0	1
Derivative liability	30	67
GEORGIA POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivatives, assets	10	4
Derivatives, liabilities	40	53
GEORGIA POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	5	1
GEORGIA POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	28	32
GEORGIA POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	5	3
GEORGIA POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	12	21
GEORGIA POWER CO | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
Derivatives, liabilities	0	17
GEORGIA POWER CO | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Interest rate derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
GEORGIA POWER CO | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Interest rate derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	17
MISSISSIPPI POWER CO
Derivatives, Fair Value [Line Items]
Derivatives, assets	6	1
Derivatives, liabilities	22	27
Derivative asset, Gross amounts offset	(6)	(1)
Derivative liability, Gross amounts offset	(6)	(1)
Derivative asset	0	0
Derivative liability	16	26
MISSISSIPPI POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivatives, assets	6	1
Derivatives, liabilities	22	27
MISSISSIPPI POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	3	0
MISSISSIPPI POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	13	15
MISSISSIPPI POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	3	1
MISSISSIPPI POWER CO | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	9	12
SOUTHERN POWER CO
Derivatives, Fair Value [Line Items]
Derivatives, assets	2	19
Derivatives, liabilities	52	27
Derivative asset, Gross amounts offset	(1)	0
Derivative liability, Gross amounts offset	(1)	0
Derivative asset	1	19
Derivative liability	51	27
SOUTHERN POWER CO | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	2
Derivatives, liabilities	0	1
SOUTHERN POWER CO | Derivatives not designated as hedging instruments | Energy-related derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	2
SOUTHERN POWER CO | Derivatives not designated as hedging instruments | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	1
SOUTHERN POWER CO | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivatives, assets	2	17
Derivatives, liabilities	52	26
SOUTHERN POWER CO | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	2	1
SOUTHERN POWER CO | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	3	2
SOUTHERN POWER CO | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Foreign currency derivatives | Other current assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	0
SOUTHERN POWER CO | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Foreign currency derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	24	24
SOUTHERN POWER CO | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Foreign currency derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	16
SOUTHERN POWER CO | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Foreign currency derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	25	0
SOUTHERN Co GAS
Derivatives, Fair Value [Line Items]
Derivatives, assets	683	668
Derivatives, liabilities	657	596
Derivative asset, Gross amounts offset	(495)	(456)
Derivative liability, Gross amounts offset	(609)	(555)
Derivative asset	188	212
Derivative liability	48	41
Collateral already posted, aggregate fair value	114	99
Weather derivative premium		4
SOUTHERN Co GAS | Energy-related derivatives
Derivatives, Fair Value [Line Items]
Collateral already posted, aggregate fair value	12	11
SOUTHERN Co GAS | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivatives, assets	677	666
Derivatives, liabilities	620	582
SOUTHERN Co GAS | Derivatives not designated as hedging instruments | Energy-related derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	316	207
SOUTHERN Co GAS | Derivatives not designated as hedging instruments | Energy-related derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	253	225
SOUTHERN Co GAS | Derivatives not designated as hedging instruments | Energy-related derivatives | Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivatives, assets	361	459
SOUTHERN Co GAS | Derivatives not designated as hedging instruments | Energy-related derivatives | Liabilities from risk management activities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	367	357
SOUTHERN Co GAS | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivatives, assets	5	0
Derivatives, liabilities	11	10
SOUTHERN Co GAS | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivatives, assets	1	0
SOUTHERN Co GAS | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	0	1
SOUTHERN Co GAS | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivatives, assets	4	0
SOUTHERN Co GAS | Derivatives designated as hedging instruments for regulatory purposes | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Liabilities from risk management activities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	11	9
SOUTHERN Co GAS | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivatives, assets	1	2
Derivatives, liabilities	26	4
SOUTHERN Co GAS | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivatives, assets	1	0
SOUTHERN Co GAS | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Liabilities from risk management activities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	3	4
SOUTHERN Co GAS | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Interest rate derivatives | Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivatives, assets	0	2
SOUTHERN Co GAS | Derivatives designated as hedging instruments in cash flow and fair value hedges | Derivatives designated as hedging instruments for regulatory purposes | Interest rate derivatives | Liabilities from risk management activities
Derivatives, Fair Value [Line Items]
Derivatives, liabilities	$ 23	$ 0

DERIVATIVES - Pre-tax Effects o

DERIVATIVES - Pre-tax Effects of Derivatives Designated as Cash Flow Hedging Instruments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Collateral already posted, aggregate fair value	$ 114		$ 114
Gain (Loss) Recognized in OCI on Derivative	14	$ (44)	(99)	$ (82)
SOUTHERN Co GAS
Derivative Instruments, Gain (Loss) [Line Items]
Collateral already posted, aggregate fair value	114		114		$ 99
Gain (Loss) Recognized in OCI on Derivative	(1)	(4)	(29)	(4)
SOUTHERN POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	15	(3)	(67)	(41)
Energy-related derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(48)		(48)		(94)
Gain (Loss) Recognized in OCI on Derivative	(2)	(6)	(6)	(6)
Energy-related derivatives | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(42)		(42)		(63)
Energy-related derivatives | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(16)		(16)		(37)
Energy-related derivatives | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	10		10		6
Energy-related derivatives | ALABAMA POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(8)		(8)		(20)
Energy-related derivatives | ALABAMA POWER CO | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(8)		(8)		(14)
Energy-related derivatives | ALABAMA POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(3)		(3)		(8)
Energy-related derivatives | ALABAMA POWER CO | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	3		3		2
Energy-related derivatives | GEORGIA POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(30)		(30)		(49)
Energy-related derivatives | GEORGIA POWER CO | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(23)		(23)		(31)
Energy-related derivatives | GEORGIA POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(7)		(7)		(18)
Energy-related derivatives | GEORGIA POWER CO | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	0		0		0
Energy-related derivatives | MISSISSIPPI POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(16)		(16)		(26)
Energy-related derivatives | MISSISSIPPI POWER CO | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(10)		(10)		(15)
Energy-related derivatives | MISSISSIPPI POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(6)		(6)		(11)
Energy-related derivatives | MISSISSIPPI POWER CO | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	0		0		0
Energy-related derivatives | SOUTHERN Co GAS
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	6		6		1
Collateral already posted, aggregate fair value	12		12		11
Gain (Loss) Recognized in OCI on Derivative	0	(4)	(4)	(4)
Energy-related derivatives | SOUTHERN Co GAS | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(1)		(1)		(3)
Energy-related derivatives | SOUTHERN Co GAS | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	0		0		0
Energy-related derivatives | SOUTHERN Co GAS | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	7		7		$ 4
Energy-related derivatives | SOUTHERN POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	(2)	(2)	(2)	(2)
Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	(1)	(37)	(28)	(37)
Interest rate derivatives | GEORGIA POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	0	(37)	(3)	(37)
Interest rate derivatives | SOUTHERN Co GAS
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	(1)	0	(25)	0
Foreign currency derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	17	(1)	(65)	(39)
Foreign currency derivatives | SOUTHERN POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	$ 17	$ (1)	$ (65)	$ (39)

DERIVATIVES - Location and Amou

DERIVATIVES - Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative [Line Items]
Total cost of sales	$ 144	$ 191	$ 583	$ 877
Depreciation and amortization	873	755	1,730	1,506
Total interest expense, net of amounts capitalized	(444)	(429)	(900)	(859)
Total other income (expense), net	101	99	204	176
Cash Flow Hedging | Energy-related derivatives | Total cost of natural gas
Derivative [Line Items]
Gain (loss) on hedge	(1)	0	(8)	0
Cash Flow Hedging | Energy-related derivatives | Total depreciation and amortization
Derivative [Line Items]
Gain (loss) on hedge	(1)	(1)	(2)	(4)
Cash Flow Hedging | Interest rate derivatives | Total interest expense, net of amounts capitalized
Derivative [Line Items]
Gain (loss) on hedge	(6)	(5)	(13)	(9)
Cash Flow Hedging | Foreign currency derivatives | Total interest expense, net of amounts capitalized
Derivative [Line Items]
Gain (loss) on hedge	(6)	(6)	(12)	(12)
Cash Flow Hedging | Foreign currency derivatives | Total other income (expense), net
Derivative [Line Items]
Gain (loss) on hedge	27	16	(4)	(8)
Fair Value Hedging | Interest rate derivatives | Total interest expense, net of amounts capitalized
Derivative [Line Items]
Gain (loss) on hedge	1	19	30	33
SOUTHERN POWER CO
Derivative [Line Items]
Depreciation and amortization	121	119	239	237
Total interest expense, net of amounts capitalized	(38)	(41)	(77)	(84)
Total other income (expense), net	1	40	4	41
SOUTHERN POWER CO | Cash Flow Hedging | Energy-related derivatives | Total depreciation and amortization
Derivative [Line Items]
Gain (loss) on hedge	(1)	(1)	(2)	(4)
SOUTHERN POWER CO | Cash Flow Hedging | Foreign currency derivatives | Total interest expense, net of amounts capitalized
Derivative [Line Items]
Gain (loss) on hedge	(6)	(6)	(12)	(12)
SOUTHERN POWER CO | Cash Flow Hedging | Foreign currency derivatives | Total other income (expense), net
Derivative [Line Items]
Gain (loss) on hedge	$ 27	$ 16	$ (4)	$ (8)

DERIVATIVES - Cumulative Basis

DERIVATIVES - Cumulative Basis Adjustments for Fair Value Hedges (Details) - Fair Value Hedging - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Securities due within one year
Derivative [Line Items]
Carrying Amount of the Hedged Item	$ 0	$ (599)
Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item	0	0
Long-term debt
Derivative [Line Items]
Carrying Amount of the Hedged Item	(1,517)	(1,494)
Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item	$ (20)	$ 3

DERIVATIVES - Pre-tax Effects_2

DERIVATIVES - Pre-tax Effects of Derivatives Not Designated as Hedging (Details) - Derivatives not designated as hedging instruments - Energy-related derivatives - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 19	$ 45	$ 97	$ 86
Natural gas revenues
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	14	50	84	83
Cost of natural gas
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 5	$ (5)	$ 13	$ 3

ACQUISITIONS AND DISPOSITIONS -

ACQUISITIONS AND DISPOSITIONS - Schedule of Acquisition (Details) - SOUTHERN POWER CO - MW	1 Months Ended
	May 31, 2020	Mar. 31, 2020
Business Acquisition [Line Items]
Approximate nameplate capacity (in MWs)		300
Beech Ridge II
Business Acquisition [Line Items]
Approximate nameplate capacity (in MWs)	56
PPA Contract Period	12 years
Beech Ridge II | Beech Ridge II
Business Acquisition [Line Items]
Ownership percentage by parent	100.00%

ACQUISITIONS AND DISPOSITIONS_2

ACQUISITIONS AND DISPOSITIONS - Southern Power Narrative (Details) $ in Millions	Jan. 17, 2020USD ($)	Jun. 30, 2020USD ($)agreement	Jun. 30, 2019USD ($)	Mar. 31, 2020MW	Dec. 31, 2019USD ($)	May 31, 2019MW
Business Acquisition [Line Items]
Construction work in progress		$ 8,351			$ 7,880
Preliminary gain on sale		$ 35	$ 2,512
SOUTHERN POWER CO
Business Acquisition [Line Items]
Approximate nameplate capacity (in MWs) | MW				300
Business acquisition, number of Power Purchase Agreements | agreement		2
Construction work in progress		$ 314			$ 515
Preliminary gain on sale		39	$ 23
SOUTHERN POWER CO | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Mankato expansion
Business Acquisition [Line Items]
Approximate nameplate capacity (in MWs) | MW						385
Nacogdoches biomass-fueled facility	$ 663
Preliminary gain on sale	39
Preliminary gain on sale, net of tax	$ 23
SOUTHERN POWER CO | Series of Construction Projects
Business Acquisition [Line Items]
Construction work in progress		232
SOUTHERN POWER CO | Series of Construction Projects | Minimum
Business Acquisition [Line Items]
Estimated future construction payments		475
SOUTHERN POWER CO | Series of Construction Projects | Maximum
Business Acquisition [Line Items]
Estimated future construction payments		$ 545

ACQUISITIONS AND DISPOSITIONS_3

ACQUISITIONS AND DISPOSITIONS - Schedule of Construction Projects (Details) $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	May 31, 2020MW	Jun. 30, 2021MW	Dec. 31, 2020MW	Dec. 31, 2018USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020MW	Dec. 31, 2019USD ($)	Oct. 31, 2019
Business Acquisition [Line Items]
Operating lease ROU assets, net | $					$ 1,776		$ 1,800
SOUTHERN POWER CO
Business Acquisition [Line Items]
Approximate Nameplate Capacity (MW) | MW						300
Operating lease ROU assets, net | $					$ 397		$ 369
SOUTHERN POWER CO | Reading
Business Acquisition [Line Items]
Approximate Nameplate Capacity (MW) | MW	200
PPA Contract Period	12 years
SOUTHERN POWER CO | Reading | Reading
Business Acquisition [Line Items]
Ownership percentage by parent				100.00%
Operating lease ROU assets, net | $				$ 24
Operating lease obligations | $				24
Proceeds from tax equity transaction | $				$ 156
SOUTHERN POWER CO | Reading | Reading | Class B Membership Interest
Business Acquisition [Line Items]
Ownership percentage by parent				100.00%
SOUTHERN POWER CO | Skookumchuck | Skookumchuck
Business Acquisition [Line Items]
Ownership percentage by parent								100.00%
SOUTHERN POWER CO | Scenario, Forecast | Skookumchuck
Business Acquisition [Line Items]
Approximate Nameplate Capacity (MW) | MW			136
PPA Contract Period			20 years
SOUTHERN POWER CO | Scenario, Forecast | Garland Solar Storage
Business Acquisition [Line Items]
Approximate Nameplate Capacity (MW) | MW		88
PPA Contract Period		20 years
SOUTHERN POWER CO | Scenario, Forecast | Tranquillity Solar Storage
Business Acquisition [Line Items]
Approximate Nameplate Capacity (MW) | MW		72
PPA Contract Period		20 years

ACQUISITIONS AND DISPOSITIONS_4

ACQUISITIONS AND DISPOSITIONS - Pre-tax Profit (Details) - SOUTHERN POWER CO - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Plant Nacogdoches
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Earnings before income taxes	$ 9		$ 16
Plant Mankato
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Earnings before income taxes	$ 6	$ 2	$ 8

ACQUISITIONS AND DISPOSITIONS_5

ACQUISITIONS AND DISPOSITIONS - Southern Company Gas Narrative (Details) - SOUTHERN Co GAS $ in Millions	Mar. 24, 2020USD ($)payment
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Pivotal Home Solutions
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of businesses, net of cash divested	$ 178
Pivotal LNG and Atlantic Coast Pipeline
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of contingent milestone payments | payment	2
Contingent milestone payment, amount	$ 5

SEGMENT AND RELATED INFORMATI_3

SEGMENT AND RELATED INFORMATION - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)state	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)statesegment	Jun. 30, 2019USD ($)
Segment Reporting Information [Line Items]
Number of states in which entity operates | state	3		3
Operating revenues	$ 4,765	$ 5,222	$ 10,053	$ 11,131
Operating revenues	4,620	5,098	9,638	10,510
Natural gas
Segment Reporting Information [Line Items]
Operating revenues	636	689	1,885	2,163
SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	268	315	519	592
Operating revenues	439	510	814	953
SOUTHERN POWER CO | Wholesale revenues, affiliates
Segment Reporting Information [Line Items]
Operating revenues	92	117	178	204
SOUTHERN POWER CO | Traditional Electric Operating Companies | Wholesale revenues, affiliates
Segment Reporting Information [Line Items]
Operating revenues	$ 92	117	$ 178	204
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Number of states in which entity operates | state	4		4
Operating revenues	$ 991	1,068	$ 2,556	3,180
Operating revenues	636	689	$ 1,885	2,163
Number of reportable segments | segment			4
SOUTHERN Co GAS | Natural gas
Segment Reporting Information [Line Items]
Operating revenues	638	688	$ 1,878	2,163
SOUTHERN Co GAS | SOUTHERN POWER CO | Natural gas
Segment Reporting Information [Line Items]
Operating revenues	$ 3	$ 16	$ 13	$ 33
Southern Natural Gas Company, LLC | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Ownership percentage, equity method investment	50.00%		50.00%
PennEast Pipelines | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Ownership percentage, equity method investment	20.00%		20.00%
Dalton Pipeline | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Ownership percentage, equity method investment	50.00%		50.00%
Atlantic Coast Pipeline | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Ownership percentage, equity method investment	5.00%		5.00%

SEGMENT AND RELATED INFORMATI_4

SEGMENT AND RELATED INFORMATION - Financial Data for Business Segments (Details) $ in Millions	Jan. 17, 2020USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)business_unit	Jun. 30, 2020USD ($)business_unit	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Segment Reporting Information [Line Items]
Operating revenues		$ 4,620	$ 5,098	$ 9,638	$ 10,510
Segment net income (loss)		612	899	1,480	2,982
Goodwill		5,280		5,280		$ 5,280
Total assets		119,731		119,731		118,700
Leveraged lease investments impairment loss		154	0	154	0
Preliminary gain on sale				35	2,512
GEORGIA POWER CO
Segment Reporting Information [Line Items]
Operating revenues		1,928	2,117	3,754	3,951
Total assets		45,825		45,825		44,541
SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues		439	510	814	953
Segment net income (loss)		63	174	138	230
Total assets		13,557		13,557		14,300
Preliminary gain on sale				39	23
SOUTHERN POWER CO | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Plant Mankato
Segment Reporting Information [Line Items]
Gain on sale				39
Gain on sale, net of tax				23
Preliminary gain on sale	$ 39
Preliminary gain on sale, net of tax	$ 23
SOUTHERN POWER CO | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Plant Nacogdoches
Segment Reporting Information [Line Items]
Preliminary gain on sale			23	23
Preliminary gain on sale, net of tax			88	88
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		636	689	1,885	2,163
Segment net income (loss)		71	106	346	376
Goodwill		5,015		5,015		5,015
Total assets		21,500		21,500		21,687
Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues		3,884	4,290	7,579	8,085
Segment net income (loss)		708	956	1,425	1,576
Goodwill		2		2		2
Total assets		96,002		96,002		94,650
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		636	689	1,885	2,163
All Other
Segment Reporting Information [Line Items]
Leveraged lease investments impairment loss		154		154
Leveraged lease investments impairment loss, net of tax		74		$ 74
All Other | Disposal Group, Disposed of by Sale, Not Discontinued Operations | GULF POWER CO
Segment Reporting Information [Line Items]
Preliminary pre-tax gain on sale			(15)		2,500
Preliminary after-tax gain on sale			(11)		1,300
Impairment charges			$ 32		32
Number of business units contemplated for sale | business_unit			1	1
Gas Distribution Operations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Goodwill		4,034		$ 4,034
Wholesale Gas Services | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		(19)	$ 48	32	134
Gas Marketing Services | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Goodwill		981		981
Operating Segments | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		632	682	1,888	2,177
Segment net income (loss)		77	103	351	376
Total assets		22,010		22,010		22,228
Operating Segments | Traditional Electric Operating Companies | Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues		3,539	3,899	6,946	7,343
Segment net income (loss)		645	782	1,287	1,346
Goodwill		0		0		0
Total assets		83,158		83,158		81,063
Operating Segments | SOUTHERN POWER CO | Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues		439	510	814	953
Segment net income (loss)		63	174	138	230
Goodwill		2		2		2
Total assets		13,557		13,557		14,300
Operating Segments | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		636	689	1,885	2,163
Segment net income (loss)		71	106	346	376
Goodwill		5,015		5,015		5,015
Total assets		21,500		21,500		21,687
Operating Segments | All Other
Segment Reporting Information [Line Items]
Operating revenues		135	186	248	368
Segment net income (loss)		(177)	(154)	(299)	1,041
Goodwill		263		263		263
Total assets		3,325		3,325		3,511
Operating Segments | All Other | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		8	13	16	24
Segment net income (loss)		(6)	3	(5)	0
Total assets		10,645		10,645		10,759
Operating Segments | Gas Distribution Operations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		587	568	1,607	1,740
Segment net income (loss)		74	58	238	191
Total assets		18,276		18,276		18,204
Operating Segments | Gas Pipeline Investments | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		8	8	16	16
Segment net income (loss)		21	25	51	57
Total assets		1,617		1,617		1,678
Operating Segments | Wholesale Gas Services | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		(19)	48	32	134
Segment net income (loss)		(23)	23	0	70
Total assets		637		637		850
Operating Segments | Gas Marketing Services | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		56	58	233	287
Segment net income (loss)		5	(3)	62	58
Total assets		1,480		1,480		1,496
Eliminations
Segment Reporting Information [Line Items]
Operating revenues		(35)	(67)	(74)	(106)
Segment net income (loss)		10	(9)	8	(11)
Goodwill		0		0		0
Total assets		(1,096)		(1,096)		(1,148)
Eliminations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues		(4)	(6)	(19)	(38)
Segment net income (loss)		0	0	0	0
Total assets		(11,155)		(11,155)		(11,300)
Eliminations | Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues		(94)	(119)	(181)	(211)
Segment net income (loss)		0	$ 0	0	$ 0
Goodwill		0		0		0
Total assets		(713)		(713)		$ (713)
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO
Segment Reporting Information [Line Items]
Estimated loss on Plant Vogtle Units 3 and 4		149		149
Estimated loss on plants under construction, after tax		$ 111		$ 111

SEGMENT AND RELATED INFORMATI_5

SEGMENT AND RELATED INFORMATION - Financial Data for Products and Services (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Concentration Risk [Line Items]
Operating revenues	$ 4,620	$ 5,098	$ 9,638	$ 10,510
Less Gross Gas Costs	144	191	583	877
Retail
Concentration Risk [Line Items]
Operating revenues	3,182	3,540	6,260	6,623
Wholesale
Concentration Risk [Line Items]
Operating revenues	472	542	889	1,041
Other
Concentration Risk [Line Items]
Operating revenues	168	161	320	331
Electric Utilities' Revenues
Concentration Risk [Line Items]
Operating revenues	3,884	4,290	7,579	8,085
Electric Utilities' Revenues | Retail
Concentration Risk [Line Items]
Operating revenues	3,182	3,540	6,260	6,623
Electric Utilities' Revenues | Wholesale
Concentration Risk [Line Items]
Operating revenues	472	542	889	1,041
Electric Utilities' Revenues | Other
Concentration Risk [Line Items]
Operating revenues	230	208	430	421
Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	636	689	1,885	2,163
Southern Company Gas' Revenues | Gas Distribution Operations
Concentration Risk [Line Items]
Operating revenues	583	563	1,596	1,724
Southern Company Gas' Revenues | Wholesale Gas Services
Concentration Risk [Line Items]
Operating revenues	(19)	48	32	134
Southern Company Gas' Revenues | Gas Marketing Services
Concentration Risk [Line Items]
Operating revenues	56	58	233	287
Southern Company Gas' Revenues | Other
Concentration Risk [Line Items]
Operating revenues	16	20	24	18
Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	636	689	1,885	2,163
Southern Company Gas' Revenues | Wholesale Gas Services
Concentration Risk [Line Items]
Operating revenues	(19)	48	32	134
Less Gross Gas Costs	891	1,238	2,054	3,165
Third Party Gross Revenues | Southern Company Gas' Revenues | Wholesale Gas Services
Concentration Risk [Line Items]
Operating revenues	854	1,223	2,039	3,148
Intercompany Revenues | Southern Company Gas' Revenues | Wholesale Gas Services
Concentration Risk [Line Items]
Operating revenues	18	63	47	151
Total Gross Revenues | Southern Company Gas' Revenues | Wholesale Gas Services
Concentration Risk [Line Items]
Operating revenues	$ 872	$ 1,286	$ 2,086	$ 3,299