XML 196 R154.htm IDEA: XBRL DOCUMENT
v3.24.0.1

PROPERTY, PLANT, AND EQUIPMENT - Depreciation and Amortization (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2023 | Dec. 31, 2022
Property, Plant and Equipment [Line Items] |  |
Accumulated depreciation | $ 37,725 | $ 35,297
Utility plant in service |  |
Property, Plant and Equipment [Line Items] |  |
Accumulated depreciation | 36,600 | 34,300
Other plant in service |  |
Property, Plant and Equipment [Line Items] |  |
Accumulated depreciation | $ 1,100 | 1,000
Other plant in service | Maximum |  |
Property, Plant and Equipment [Line Items] |  |
Depreciation period of original cost | 30 years |
Southern Company Gas |  |
Property, Plant and Equipment [Line Items] |  |
Accumulated depreciation | $ 5,534 | 5,276
Southern Company Gas | Utility plant in service |  |
Property, Plant and Equipment [Line Items] |  |
Accumulated depreciation | 5,300 | 5,100
Southern Company Gas | Other plant in service |  |
Property, Plant and Equipment [Line Items] |  |
Accumulated depreciation | $ 210 | $ 184
Southern Company Gas | Transportation equipment | Minimum |  |
Property, Plant and Equipment [Line Items] |  |
Depreciation period of original cost | 5 years |
Southern Company Gas | Transportation equipment | Maximum |  |
Property, Plant and Equipment [Line Items] |  |
Depreciation period of original cost | 12 years |
Southern Company Gas | Storage facilities | Minimum |  |
Property, Plant and Equipment [Line Items] |  |
Depreciation period of original cost | 30 years |
Southern Company Gas | Storage facilities | Maximum |  |
Property, Plant and Equipment [Line Items] |  |
Depreciation period of original cost | 75 years |
Southern Company Gas | Other assets | Maximum |  |
Property, Plant and Equipment [Line Items] |  |
Depreciation period of original cost | 75 years |

X
- Definition Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(8)(b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(14)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-1 + Details
Name: | us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
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_PropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of other property, plant and equipment (PPE) owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=so_UtilityPlantInServiceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_OtherPlantInServiceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
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_PropertyPlantAndEquipmentByTypeAxis=us-gaap_TransportationEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=so_StorageFacilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_OtherAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |