XML 89 R45.htm IDEA: XBRL DOCUMENT v3.22.0.1
Consolidated Statements of Income - GAS (Parenthetical) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Southern Company Gas      
Excise taxes collected $ 122 $ 107 $ 117