Consolidated Statements of Cash Flows - SPC - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Activities:
Consolidated net income	$ 2,309	$ 3,103	$ 4,744
Adjustments to reconcile consolidated net income to net cash provided from operating activities —
Depreciation and amortization, total	3,973	3,905	3,331
Deferred income taxes	(49)	(241)	611
Utilization of federal investment tax credits	288	341	757
Amortization of investment tax credits	(84)	(84)	(181)
Pension and postretirement funding	0	(2)	(1,136)
Gain on dispositions, net	(176)	(66)	(2,588)
Other, net	86	(74)	115
Changes in certain current assets and liabilities —
-Receivables	(81)	(222)	630
-Other current assets	(170)	(161)	12
-Accrued taxes	(54)	242	117
-Other current liabilities	(49)	76	(73)
Net cash provided from operating activities	6,169	6,696	5,781
Investing Activities:
Business acquisitions, net of cash acquired	(345)	(81)	(50)
Property additions	(7,240)	(7,441)	(7,555)
Proceeds from dispositions	917	1,049	5,122
Payments pursuant to LTSAs	(188)	(211)	(234)
Other investing activities	74	(16)	(107)
Net cash used for investing activities	(7,353)	(7,030)	(3,392)
Financing Activities:
Increase (decrease) in notes payable, net	530		640
Increase (decrease) in notes payable, net		(1,096)
Proceeds —
Short-term borrowings	325	615	350
Redemptions and repurchases —
Short-term borrowings	(25)	(840)	(1,850)
Capital contributions from noncontrolling interests	501	363	196
Distributions to noncontrolling interests	(351)	(271)	(256)
Payment of common stock dividends	(2,777)	(2,685)	(2,570)
Other financing activities	(266)	(325)	(157)
Net cash provided from (used for) financing activities	1,945	(576)	(1,930)
Net Change in Cash, Cash Equivalents, and Restricted Cash	761	(910)	459
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year	1,068	1,978	1,519
Cash, Cash Equivalents, and Restricted Cash at End of Year	1,829	1,068	1,978
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	1,718	1,683	1,651
Income taxes, net	93	64	276
Noncash transactions —
Accrued property additions at year-end	866	989	932
Contributions from noncontrolling interests	89	12	80
Contributions of wind turbine equipment	82	17	26
Southern Power
Operating Activities:
Consolidated net income	167	207	329
Adjustments to reconcile consolidated net income to net cash provided from operating activities —
Depreciation and amortization, total	542	519	505
Deferred income taxes	55	(25)	(74)
Utilization of federal investment tax credits	288	340	734
Amortization of investment tax credits	(58)	(59)	(151)
Income taxes receivable, non-current	5	(20)	25
Pension and postretirement funding	0	0	(24)
Gain on dispositions, net	(41)	(39)	(24)
Loss on sales-type leases	40	0	0
Other, net	(6)	(5)	(6)
Changes in certain current assets and liabilities —
-Receivables	(44)	(4)	72
-Prepaid income taxes	(16)	20	39
-Other current assets	(14)	(30)	(8)
-Accrued taxes	(6)	11	6
-Other current liabilities	39	(14)	(38)
Net cash provided from operating activities	951	901	1,385
Investing Activities:
Business acquisitions, net of cash acquired	(345)	(81)	(50)
Property additions	(396)	(223)	(489)
Change in construction payables	(15)	31	7
Investments in unconsolidated subsidiaries	0	0	(116)
Proceeds from dispositions	24	666	572
Payments pursuant to LTSAs	(82)	(76)	(104)
Other investing activities	11	57	13
Net cash used for investing activities	(803)	374	(167)
Financing Activities:
Increase (decrease) in notes payable, net	36		449
Increase (decrease) in notes payable, net		(274)
Proceeds —
Senior notes	400	0	0
Short-term borrowings	0	0	100
Redemptions and repurchases —
Senior notes	(300)	(825)	(600)
Short-term borrowings	0	(100)	(100)
Capital contributions from parent company	8	6	64
Return of capital to parent company	(271)	0	(755)
Capital contributions from noncontrolling interests	501	363	196
Distributions to noncontrolling interests	(351)	(271)	(256)
Purchase of membership interests from noncontrolling interests	0	(60)	0
Payment of common stock dividends	(204)	(201)	(206)
Other financing activities	(14)	(10)	(12)
Net cash provided from (used for) financing activities	(195)	(1,372)	(1,120)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(47)	(97)	98
Cash, Cash Equivalents, and Restricted Cash at Beginning of Year	182	279	181
Cash, Cash Equivalents, and Restricted Cash at End of Year	135	182	279
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	140	147	167
Income taxes, net	(275)	(283)	(664)
Noncash transactions —
Accrued property additions at year-end	72	89	57
Contributions from noncontrolling interests	89	12	80
Contributions of wind turbine equipment	$ 82	$ 17	$ 26