XML 202 R149.htm IDEA: XBRL DOCUMENT
v3.25.0.1

PROPERTY, PLANT, AND EQUIPMENT - Ownership and Investment in Jointly-Owned Facilities (Details) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 USD ($) mi
Alabama Power |
Other Ownership Interests [Line Items] |
Percent Ownership | 14.00%
Alabama Power | Plant Greene County (natural gas) Units 1 and 2 |
Other Ownership Interests [Line Items] |
Percent Ownership | 60.00%
Plant in Service | $ 192
Accumulated Depreciation | 140
CWIP | $ 1
Alabama Power | Plant Miller (coal) Units 1 and 2 |
Other Ownership Interests [Line Items] |
Percent Ownership | 91.80%
Plant in Service | $ 2,180
Accumulated Depreciation | 829
CWIP | 7
Georgia Power | Plant Hatch (nuclear) Units 1 and 2 |
Other Ownership Interests [Line Items] |
Plant in Service | 1,464
Accumulated Depreciation | 604
CWIP | $ 66
Georgia Power | Plant Vogtle (nuclear) Units 1 and 2 |
Other Ownership Interests [Line Items] |
Percent Ownership | 45.70%
Plant in Service | $ 3,621
Accumulated Depreciation | 2,342
CWIP | $ 162
Georgia Power | Plant Vogtle (nuclear) Units 3 and 4 |
Other Ownership Interests [Line Items] |
Percent Ownership | 45.70%
Plant in Service | $ 7,953
Accumulated Depreciation | 119
CWIP | $ 45
Georgia Power | Plant Scherer (coal) Units 1 and 2 |
Other Ownership Interests [Line Items] |
Percent Ownership | 8.40%
Plant in Service | $ 289
Accumulated Depreciation | 140
CWIP | $ 4
Georgia Power | Plant Scherer (coal) Unit 3 |
Other Ownership Interests [Line Items] |
Percent Ownership | 75.00%
Plant in Service | $ 1,316
Accumulated Depreciation | 720
CWIP | $ 22
Georgia Power | Rocky Mountain (pumped storage) |
Other Ownership Interests [Line Items] |
Percent Ownership | 25.40%
Plant in Service | $ 182
Accumulated Depreciation | 160
CWIP | $ 6
Mississippi Power | Plant Greene County (natural gas) Units 1 and 2 |
Other Ownership Interests [Line Items] |
Percent Ownership | 40.00%
Plant in Service | $ 125
Accumulated Depreciation | 88
CWIP | $ 2
Mississippi Power | Plant Daniel (coal) Units 1 and 2 |
Other Ownership Interests [Line Items] |
Percent Ownership | 50.00%
Plant in Service | $ 791
Accumulated Depreciation | 286
CWIP | $ 3
Southern Company Gas | Dalton Pipeline (natural gas pipeline) |
Other Ownership Interests [Line Items] |
Percent Ownership | 50.00%
Plant in Service | $ 271
Accumulated Depreciation | 32
CWIP | $ 1
Pipeline infrastructure (miles) | mi | 115
Agreement to lease undivided ownership (percent) | 50.00%
Future minimum payments receivable | $ 26

X
- Definition Jointly Owned Utility Plant, Future Minimum Payments Receivable + References No definition available. + Details
Name: | so_JointlyOwnedUtilityPlantFutureMinimumPaymentsReceivable
Namespace Prefix: | so_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Pipeline Infrastructure + References No definition available. + Details
Name: | so_PipelineInfrastructure
Namespace Prefix: | so_
Data Type: | dtr-types1:lengthItemType
Balance Type: | na
Period Type: | instant

X
- Definition Undivided Ownership Interest To Be Leased + References No definition available. + Details
Name: | so_UndividedOwnershipInterestToBeLeased
Namespace Prefix: | so_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The period end amount owned by the reporting utility of a jointly owned utility plant in service. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 360 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479070/980-360-S99-1 + Details
Name: | us-gaap_JointlyOwnedUtilityPlantGrossOwnershipAmountOfPlantInService
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The period end amount of construction work in progress at a jointly owned electricity generation plant. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 360 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479070/980-360-S99-1 + Details
Name: | us-gaap_JointlyOwnedUtilityPlantOwnershipAmountOfConstructionWorkInProgress
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The period end amount of accumulated depreciation in a jointly owned electricity generation plant. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 360 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479070/980-360-S99-1 + Details
Name: | us-gaap_JointlyOwnedUtilityPlantOwnershipAmountOfPlantAccumulatedDepreciation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The proportionate share of interest (percent) in a jointly owned utility plant. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 360 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 10.C) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479070/980-360-S99-1 + Details
Name: | us-gaap_JointlyOwnedUtilityPlantProportionateOwnershipShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
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_OtherOwnershipInterestsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=so_GreeneCountyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=so_PlantMillerCoalUnitsOneAndTwoMember
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: | us-gaap_JointlyOwnedUtilityPlantAxis=so_PlantHatchNuclearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=so_PlantVogtleNuclearUnitsOneAndTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=so_PlantVogtleNuclearUnitsThreeAndFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=so_PlantSchererCoalUnitsOneAndTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=so_PlantSchererUnitThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=so_RockyMountainPumpedStorageMember
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: | us-gaap_JointlyOwnedUtilityPlantAxis=so_PlantDanielUnitsOneAndTwoMember
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: |

X
- Details
Name: | us-gaap_JointlyOwnedUtilityPlantAxis=so_DaltonPipelineNaturalGasPipelineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |