Debt and Credit Agreements - Commercial Paper Borrowings (Details) - Commercial Paper [Member] - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Short-term Debt [Line Items]
Commercial Paper	$ 807	$ 1,938
Short-term Debt, Weighted Average Interest Rate, at Point in Time	5.12%	4.77%
Corporate [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 10	$ 449
Commonwealth Edison Co [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 409	$ 427
Short-term Debt, Weighted Average Interest Rate, at Point in Time	5.09%	4.71%
PECO Energy Co [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 145	$ 239
Short-term Debt, Weighted Average Interest Rate, at Point in Time	5.04%	4.71%
Baltimore Gas and Electric Company [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 243	$ 409
Short-term Debt, Weighted Average Interest Rate, at Point in Time	5.24%	4.81%
Pepco Holdings LLC [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 0	$ 414
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.00%	4.78%
Potomac Electric Power Company [Member]
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 [Member]
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 [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 0