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CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS - SPC Noncontrolling Interests and VIEs Narrative (Details) $ in Millions | 2 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | ---
Feb. 16, 2022 USD ($) | Dec. 31, 2021 USD ($) investor | Dec. 31, 2018 investor | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($)
Redeemable Noncontrolling Interest [Line Items] |  |  |  |  |
Assets |  | $ 127,534 |  | $ 122,935 | $ 118,700
Liabilities |  | 94,967 |  | 90,410 |
Equity investments in unconsolidated subsidiaries |  | 1,282 |  | 1,362 |
Southern Power |  |  |  |  |
Redeemable Noncontrolling Interest [Line Items] |  |  |  |  |
Assets |  | 13,390 |  | 13,235 |
Liabilities |  | 6,792 |  | 6,604 |
Equity investments in unconsolidated subsidiaries |  | $ 86 |  | 19 |
Southern Power | Subsequent Event |  |  |  |  |
Redeemable Noncontrolling Interest [Line Items] |  |  |  |  |
Proceeds from sale of equity method investments | $ 31 |  |  |  |
Southern Power | SP Solar Holdings I, LP |  |  |  |  |
Redeemable Noncontrolling Interest [Line Items] |  |  |  |  |
Sale of equity interest in limited partnership |  |  | 33.00% |  |
Southern Power | SP Wind |  |  |  |  |
Redeemable Noncontrolling Interest [Line Items] |  |  |  |  |
Sale of equity interest in limited partnership |  |  | 100.00% |  |
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 |  | $ 6,100 |  |  |
Liabilities |  | 408 |  | 387 |
Noncontrolling interests related to other partners' interest |  | 1,100 |  |  |
Variable Interest Entity, Primary Beneficiary | SP Wind | Southern Power |  |  |  |  |
Redeemable Noncontrolling Interest [Line Items] |  |  |  |  |
Assets |  | 2,300 |  | 2,400 |
Liabilities |  | 130 |  | 138 |
Noncontrolling interests related to other partners' interest |  | 41 |  | 43 |
Variable Interest Entity, Primary Beneficiary | Other Variable Interest Entities | Southern Power |  |  |  |  |
Redeemable Noncontrolling Interest [Line Items] |  |  |  |  |
Assets |  | 1,900 |  | 1,100 |
Liabilities |  | 263 |  | 110 |
Noncontrolling interests related to other partners' interest |  | $ 886 |  | $ 454 |

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