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Benefit Plans and Other Postretirement Benefits - Narrative (Details)
$ in Millions
12 Months Ended
Dec. 31, 2023
USD ($)
benefitPlan
Dec. 31, 2022
USD ($)
Nov. 01, 2023
Benefit Plans and Other Postretirement Benefits      
Number of qualified pension plans | benefitPlan 3    
STP      
Benefit Plans and Other Postretirement Benefits      
Ownership percentage 44.00%   44.00%
Pension Benefits      
Benefit Plans and Other Postretirement Benefits      
Expects to contribute to the pension plans $ 43    
Actuarial gain (loss) (22) $ 289  
Pension Benefits | GenOn      
Benefit Plans and Other Postretirement Benefits      
Expects to contribute to the pension plans $ 23