Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net income (loss)	$ 376	$ 621	$ 1,482	$ 1,461
Qualifying hedges:
Changes in fair value, net of tax	14	10	(16)	(75)
Reclassification adjustment for amounts included in net income, net of tax	(5)	(9)	50	29
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	3	3	6	3
Total other comprehensive income (loss)	12	4	40	(43)
Comprehensive Income (Loss)	388	625	1,522	1,418
Dividends on preferred stock of subsidiaries	4	4	7	7
Comprehensive income (loss) attributable to noncontrolling interests	0	5	(33)	(26)
Comprehensive Income (Loss) Attributable to Parent	384	616	1,548	1,437
ALABAMA POWER CO
Net income (loss)	335	302	697	585
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 (Loss)	336	303	699	587
Dividends on preferred stock of subsidiaries	4	4	7	7
GEORGIA POWER CO
Net income (loss)	143	308	494	638
Qualifying hedges:
Changes in fair value, net of tax	0	0	0	(2)
Reclassification adjustment for amounts included in net income, net of tax	1	2	3	3
Pension and other postretirement benefit plans:
Total other comprehensive income (loss)	1	2	3	1
Comprehensive Income (Loss)	144	310	497	639
MISSISSIPPI POWER CO
Net income (loss)	38	39	83	71
Qualifying hedges:
Changes in fair value, net of tax	0	0	0	(1)
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	1	0
Comprehensive Income (Loss)	38	39	84	71
SOUTHERN POWER CO
Net income (loss)	36	68	100	112
Qualifying hedges:
Changes in fair value, net of tax	6	11	(26)	(50)
Reclassification adjustment for amounts included in net income, net of tax	(9)	(15)	38	13
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	0	1	1	1
Total other comprehensive income (loss)	(3)	(3)	13	(36)
Comprehensive Income (Loss)	33	65	113	76
Comprehensive income (loss) attributable to noncontrolling interests	0	5	(33)	(26)
Comprehensive Income (Loss) Attributable to Parent	33	60	146	102
SOUTHERN Co GAS
Net income (loss)	(65)	71	333	346
Qualifying hedges:
Changes in fair value, net of tax	8	(1)	9	(21)
Reclassification adjustment for amounts included in net income, net of tax	0	1	3	6
Pension and other postretirement benefit plans:
Total other comprehensive income (loss)	8	0	12	(15)
Comprehensive Income (Loss)	$ (57)	$ 71	$ 345	$ 331