Debt and Credit Agreements - Summary of Credit Facility Agreements at Minority and Community Banks (Details) - Community and Minority Facilities - Community and Minority Facilities - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	$ 140	$ 140
Outstanding letters of credit	10	10
Commonwealth Edison Co
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	40	40
Outstanding letters of credit	7	7
PECO Energy Co
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	40	40
Outstanding letters of credit	1	1
Baltimore Gas and Electric Company
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	15	15
Outstanding letters of credit	2	2
Pepco Holdings LLC
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	45	45
Outstanding letters of credit	0	0
Potomac Electric Power Company
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	15	15
Outstanding letters of credit	0	0
Delmarva Power & Light Company
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	15	15
Outstanding letters of credit	0	0
Atlantic City Electric Company
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	15	15
Outstanding letters of credit	$ 0	$ 0