CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS - SPC Noncontrolling Interests and VIEs Narrative (Details) $ in Millions	2 Months Ended	12 Months Ended
	Feb. 15, 2023 USD ($)	Dec. 31, 2022 USD ($) investor	Dec. 31, 2019	Dec. 31, 2018 investor	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Redeemable Noncontrolling Interest [Line Items]
Assets		$ 134,891			$ 127,534	$ 122,935
Liabilities		100,359			94,967
Equity investments in unconsolidated subsidiaries		1,443			1,282
Southern Power
Redeemable Noncontrolling Interest [Line Items]
Assets		13,081			13,390
Liabilities		6,165			6,792
Equity investments in unconsolidated subsidiaries		49			86
Proceeds from sale of equity method investments		$ 38
Southern Power | Subsequent Event
Redeemable Noncontrolling Interest [Line Items]
Proceeds from sale of equity method investments	$ 50
Southern Power | SP Solar Holdings I, LP
Redeemable Noncontrolling Interest [Line Items]
Sale of equity interest in limited partnership			33.00%
Wholly Owned Subsidiary Of Southern Power | Southern Power | SP Solar Holdings I, LP
Redeemable Noncontrolling Interest [Line Items]
Ownership interest			66.00%
Wholly Owned Subsidiary Of Southern Power | Southern Power | SP Wind
Redeemable Noncontrolling Interest [Line Items]
Ownership interest				100.00%
SP Solar Holdings I, LP | Southern Power
Redeemable Noncontrolling Interest [Line Items]
Distribution made to limited partner, cash distributions paid, percentage		67.00%
SP Solar Holdings I, LP | Global Atlantic
Redeemable Noncontrolling Interest [Line Items]
Distribution made to limited partner, cash distributions paid, percentage		33.00%
SP Wind | Southern Power
Redeemable Noncontrolling Interest [Line Items]
Distribution made to limited partner, cash distributions paid, percentage		60.00%
Number of financial investors | investor		3		3
SP Wind | Financial Investors
Redeemable Noncontrolling Interest [Line Items]
Distribution made to limited partner, cash distributions paid, percentage		40.00%
General Partner | Wholly Owned Subsidiary Of Southern Power | Southern Power | SP Solar Holdings I, LP
Redeemable Noncontrolling Interest [Line Items]
Ownership interest			1.00%
Variable Interest Entity, Primary Beneficiary | SP Solar Holdings I, LP | Southern Power
Redeemable Noncontrolling Interest [Line Items]
Assets		$ 5,900			6,100
Liabilities		400
Noncontrolling interests related to other partners' interest		1,100
Variable Interest Entity, Primary Beneficiary | SP Wind | Southern Power
Redeemable Noncontrolling Interest [Line Items]
Assets		2,200			2,300
Liabilities		169			130
Noncontrolling interests related to other partners' interest		39			41
Variable Interest Entity, Primary Beneficiary | Other Variable Interest Entities | Southern Power
Redeemable Noncontrolling Interest [Line Items]
Assets		1,800			1,900
Liabilities		200			300
Noncontrolling interests related to other partners' interest		$ 800			$ 900