v3.26.1
Fair Value Measurements (Details) - EBP 002 - USD ($)
Dec. 31, 2025
Dec. 31, 2024
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value $ 10,110,935,773 $ 9,167,476,568
Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value 4,031,752,808 3,823,328,815
Level 1 | Southern Company Common Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value 3,133,901,439 3,064,813,002
Level 1 | Money Market Fund    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value 4,453,394 2,011,460
Level 1 | Self-Directed Investments    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value 893,397,975 756,504,353
Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value 43,666,599 41,146,530
Level 2 | Self-Directed Investments    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value 43,666,599 41,146,530
Total    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value 4,075,419,407 3,864,475,345
Total | Southern Company Common Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value 3,133,901,439 3,064,813,002
Total | Money Market Fund    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value 4,453,394 2,011,460
Total | Self-Directed Investments    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value 937,064,574 797,650,883
Fair Value Measured at Net Asset Value Per Share | Common Collective Trusts    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments, at fair value $ 6,035,516,366 $ 5,303,001,223