Debt and Credit Agreements - Summary of Credit Facility Agreements at Minority and Community Banks (Details) - Community and Minority Facilities [Member] - Community and Minority Facilities [Member] - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	$ 140	$ 98
Letters of Credit Outstanding, Amount	10	8
Commonwealth Edison Co [Member]
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	40	33
Letters of Credit Outstanding, Amount	7	5
PECO Energy Co [Member]
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	40	33
Letters of Credit Outstanding, Amount	1	1
Baltimore Gas and Electric Company [Member]
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	15	8
Letters of Credit Outstanding, Amount	2	2
Pepco Holdings LLC [Member]
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	45	24
Letters of Credit Outstanding, Amount	0	0
Potomac Electric Power Company [Member]
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	15	8
Letters of Credit Outstanding, Amount	0	0
Delmarva Power & Light Company [Member]
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	15	8
Letters of Credit Outstanding, Amount	0	0
Atlantic City Electric Company [Member]
Short-term Debt [Line Items]
Line of credit facility, current borrowing capacity	15	8
Letters of Credit Outstanding, Amount	$ 0	$ 0