Debt and Credit Agreements (All Registrants) - Commercial Paper Borrowings (Details) - Commercial Paper - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Short-term Debt [Line Items]
Commercial paper	$ 1,307	$ 1,624
Short-term debt, weighted average interest rate, at point in time	5.53%	5.58%
Corporate
Short-term Debt [Line Items]
Commercial paper	$ 571	$ 527
Commonwealth Edison Co
Short-term Debt [Line Items]
Commercial paper	$ 330	$ 202
Short-term debt, weighted average interest rate, at point in time	5.43%	5.53%
PECO Energy Co
Short-term Debt [Line Items]
Commercial paper	$ 0	$ 165
Short-term debt, weighted average interest rate, at point in time	0.00%	5.57%
Baltimore Gas and Electric Company
Short-term Debt [Line Items]
Commercial paper	$ 406	$ 336
Short-term debt, weighted average interest rate, at point in time	5.57%	5.59%
Pepco Holdings LLC
Short-term Debt [Line Items]
Commercial paper	$ 0	$ 394
Short-term debt, weighted average interest rate, at point in time	0.00%	5.60%
Potomac Electric Power Company
Short-term Debt [Line Items]
Commercial paper	$ 0	$ 132
Short-term debt, weighted average interest rate, at point in time	0.00%	5.59%
Delmarva Power and Light Company
Short-term Debt [Line Items]
Commercial paper	$ 0	$ 63
Short-term debt, weighted average interest rate, at point in time	0.00%	5.60%
Atlantic City Electric Company
Short-term Debt [Line Items]
Commercial paper	$ 0	$ 199
Short-term debt, weighted average interest rate, at point in time	0.00%	5.60%