v3.19.2
Introduction - Asset Retirement Obligations (Details)
$ in Millions
6 Months Ended
Jun. 30, 2019
USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]  
Balance at December 31, 2018 $ 9,394
Liabilities incurred 6
Liabilities settled (142)
Accretion 197
Cash flow revisions 452
Balance at June 30, 2019 9,907
ALABAMA POWER CO  
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]  
Balance at December 31, 2018 3,210
Liabilities incurred 0
Liabilities settled (43)
Accretion 70
Cash flow revisions 308
Balance at June 30, 2019 3,545
MISSISSIPPI POWER CO  
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]  
Balance at December 31, 2018 160
Liabilities incurred 0
Liabilities settled (17)
Accretion 2
Cash flow revisions 59
Balance at June 30, 2019 $ 204