v3.25.0.1
PROPERTY, PLANT, AND EQUIPMENT - Additional Information (Narrative) (Details) - USD ($)
$ in Millions
 1 Months Ended 12 Months Ended
Feb. 13, 2025
Oct. 25, 2024
Jan. 01, 2024
Jan. 01, 2023
Jun. 30, 2023
May 31, 2023
Dec. 31, 2024
Dec. 31, 2022
Dec. 31, 2023
Property, Plant and Equipment [Line Items]                  
Regulatory asset amortization period             4 years    
Less: Accumulated depreciation             $ 40,126   $ 37,725
Utility plant in service                  
Property, Plant and Equipment [Line Items]                  
Less: Accumulated depreciation             38,900   36,600
Other plant in service                  
Property, Plant and Equipment [Line Items]                  
Less: Accumulated depreciation             $ 1,200   1,100
Maximum | Other plant in service                  
Property, Plant and Equipment [Line Items]                  
Depreciation period of original cost             40 years    
Alabama Power                  
Property, Plant and Equipment [Line Items]                  
Requested rate increase (decrease), amount         $ 78        
Less: Accumulated depreciation             $ 11,741   11,131
Georgia Power                  
Property, Plant and Equipment [Line Items]                  
Requested rate increase (decrease), amount           $ 1,100   $ 14,000  
Less: Accumulated depreciation             14,806   13,955
Southern Company Gas                  
Property, Plant and Equipment [Line Items]                  
Requested rate increase (decrease), amount     $ 53 $ 53          
Less: Accumulated depreciation             5,887   5,534
Southern Company Gas | Utility plant in service                  
Property, Plant and Equipment [Line Items]                  
Less: Accumulated depreciation             5,600   5,300
Southern Company Gas | Other plant in service                  
Property, Plant and Equipment [Line Items]                  
Less: Accumulated depreciation             $ 252   210
Southern Company Gas | Maximum | Transportation equipment                  
Property, Plant and Equipment [Line Items]                  
Depreciation period of original cost             10 years    
Southern Company Gas | Maximum | Storage facilities                  
Property, Plant and Equipment [Line Items]                  
Depreciation period of original cost             40 years    
Southern Company Gas | Maximum | Other assets                  
Property, Plant and Equipment [Line Items]                  
Depreciation period of original cost             78 years    
Southern Company Gas | Minimum | Transportation equipment                  
Property, Plant and Equipment [Line Items]                  
Depreciation period of original cost             5 years    
Southern Company Gas | Minimum | Storage facilities                  
Property, Plant and Equipment [Line Items]                  
Depreciation period of original cost             5 years    
Mississippi Power                  
Property, Plant and Equipment [Line Items]                  
Requested rate increase (decrease), amount   $ 11              
Less: Accumulated depreciation             $ 1,833   $ 1,792
Mississippi Power | Subsequent Event                  
Property, Plant and Equipment [Line Items]                  
Requested rate increase (decrease), amount $ 8                
Mississippi Power | Chevron Products Company [Member]                  
Property, Plant and Equipment [Line Items]                  
Net book value of co-generation assets             $ 139    
Plant Farley | Alabama Power | Nuclear Outage                  
Property, Plant and Equipment [Line Items]                  
Regulatory asset amortization period             18 months    
Plant Hatch Units 1 and 2 | Georgia Power | Nuclear Outage | Maximum                  
Property, Plant and Equipment [Line Items]                  
Regulatory asset amortization period             24 months    
Plant Vogtle Nuclear Units One , Two, and Three | Georgia Power | Nuclear Outage                  
Property, Plant and Equipment [Line Items]                  
Regulatory asset amortization period             18 months