XML 191 R149.htm IDEA: XBRL DOCUMENT
v3.24.0.1

REVENUE FROM CONTRACTS WITH CUSTOMERS - Performance Obligations (Details) $ in Millions | Dec. 31, 2023 USD ($)
--- | ---
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 | $ 940
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 | $ 552
Expected timing of satisfaction | 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 338
Expected timing of satisfaction | 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 332
Expected timing of satisfaction | 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 323
Expected timing of satisfaction | 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 2,045
Expected timing of satisfaction |
Alabama Power | 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
Expected timing of satisfaction | 1 year
Alabama Power | 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 | $ 9
Expected timing of satisfaction | 1 year
Alabama Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 0
Expected timing of satisfaction | 1 year
Alabama Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 0
Expected timing of satisfaction | 1 year
Alabama Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 0
Expected timing of satisfaction | 1 year
Alabama Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 0
Expected timing of satisfaction |
Georgia Power | 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 | $ 73
Expected timing of satisfaction | 1 year
Georgia Power | 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 | $ 41
Expected timing of satisfaction | 1 year
Georgia Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 14
Expected timing of satisfaction | 1 year
Georgia Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 15
Expected timing of satisfaction | 1 year
Georgia Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 15
Expected timing of satisfaction | 1 year
Georgia Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 9
Expected timing of satisfaction |
Mississippi Power | 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 | $ 60
Mississippi Power | 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 | 63
Mississippi Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | 66
Mississippi Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | 69
Mississippi Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | 73
Mississippi Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | 0
Southern Power | 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 | $ 379
Expected timing of satisfaction | 1 year
Southern Power | 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 | $ 301
Expected timing of satisfaction | 1 year
Southern Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 299
Expected timing of satisfaction | 1 year
Southern Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 306
Expected timing of satisfaction | 1 year
Southern Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 297
Expected timing of satisfaction | 1 year
Southern Power | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 2,041
Expected timing of satisfaction |
Southern Company Gas | 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 | $ 26
Expected timing of satisfaction | 1 year
Southern Company Gas | 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 | $ 0
Expected timing of satisfaction | 1 year
Southern Company Gas | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 0
Expected timing of satisfaction | 1 year
Southern Company Gas | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 0
Expected timing of satisfaction | 1 year
Southern Company Gas | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 0
Expected timing of satisfaction | 1 year
Southern Company Gas | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] |
Revenue, remaining performance obligation | $ 0
Expected timing of satisfaction |

X
- Definition Amount of transaction price allocated to performance obligation that has not been recognized as revenue. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -SubTopic 10 -Topic 606 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479806/606-10-50-13 + Details
Name: | us-gaap_RevenueRemainingPerformanceObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period in which remaining performance obligation is expected to be recognized as revenue, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b)(1) -SubTopic 10 -Topic 606 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479806/606-10-50-13 + Details
Name: | us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis=2024-01-01
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis=2025-01-01
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis=2026-01-01
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis=2027-01-01
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis=2028-01-01
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis=2029-01-01
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=so_AlabamaPowerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=so_GeorgiaPowerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=so_MississippiPowerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=so_SouthernPowerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=so_SouthernCompanyGasMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |