Debt and Credit Agreements (All Registrants) - Commercial Paper Borrowings (Details) - Commercial Paper - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Short-term Debt [Line Items]
Commercial paper	$ 820	$ 1,938
Short-term debt, weighted average interest rate, at point in time	5.44%	4.77%
Corporate
Short-term Debt [Line Items]
Commercial paper	$ 311	$ 449
Commonwealth Edison Co
Short-term Debt [Line Items]
Commercial paper	$ 277	$ 427
Short-term debt, weighted average interest rate, at point in time	5.42%	4.71%
PECO Energy Co
Short-term Debt [Line Items]
Commercial paper	$ 0	$ 239
Short-term debt, weighted average interest rate, at point in time	0.00%	4.71%
Baltimore Gas and Electric Company
Short-term Debt [Line Items]
Commercial paper	$ 59	$ 409
Short-term debt, weighted average interest rate, at point in time	5.43%	4.81%
Pepco Holdings LLC
Short-term Debt [Line Items]
Commercial paper	$ 173	$ 414
Short-term debt, weighted average interest rate, at point in time	5.47%	4.78%
Potomac Electric Power Company
Short-term Debt [Line Items]
Commercial paper	$ 0	$ 299
Short-term debt, weighted average interest rate, at point in time	0.00%	4.79%
Delmarva Power and Light Company
Short-term Debt [Line Items]
Commercial paper	$ 0	$ 115
Short-term debt, weighted average interest rate, at point in time	0.00%	4.76%
Atlantic City Electric Company
Short-term Debt [Line Items]
Commercial paper	$ 173	$ 0
Short-term debt, weighted average interest rate, at point in time	5.47%	0.00%