v3.26.1
Retirement Benefits - Defined Contribution Savings Plans (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Defined Benefit Plan Disclosure [Line Items]        
Savings Plan Employer Contributions $ 32 $ 30 $ 64 $ 56
Commonwealth Edison Co        
Defined Benefit Plan Disclosure [Line Items]        
Savings Plan Employer Contributions 13 12 24 22
PECO Energy Co        
Defined Benefit Plan Disclosure [Line Items]        
Savings Plan Employer Contributions 5 4 9 8
Baltimore Gas and Electric Company        
Defined Benefit Plan Disclosure [Line Items]        
Savings Plan Employer Contributions 3 3 6 6
Pepco Holdings LLC        
Defined Benefit Plan Disclosure [Line Items]        
Savings Plan Employer Contributions 7 5 12 10
Potomac Electric Power Company        
Defined Benefit Plan Disclosure [Line Items]        
Savings Plan Employer Contributions 2 2 3 3
Delmarva Power and Light Company        
Defined Benefit Plan Disclosure [Line Items]        
Savings Plan Employer Contributions 1 1 2 2
Atlantic City Electric Company        
Defined Benefit Plan Disclosure [Line Items]        
Savings Plan Employer Contributions $ 1 $ 0 $ 2 $ 1