Debt and Credit Agreements - Summary of Bank Commitments, Credit Facility Borrowings and Available Capacity (Details) - USD ($) $ in Millions	Feb. 01, 2022	Dec. 31, 2023	Jan. 31, 2022
Revolving Credit Facility
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity		$ 4,000
Long-term line of credit/facility draws		0
Outstanding letters of credit		19
Actual available capacity		3,981
To support additional commercial paper		2,357
Corporate, Non-Segment | Revolving Credit Facility
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 900	900	$ 600
Outstanding letters of credit		3
Actual available capacity		370
Credit facility, term	5 years
Commonwealth Edison Co
Short-term Debt [Line Items]
Credit facility, term	5 years
Commonwealth Edison Co | Revolving Credit Facility
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,000	1,000
Long-term line of credit/facility draws		0
Outstanding letters of credit		10
Actual available capacity		990
To support additional commercial paper		788
PECO Energy Co
Short-term Debt [Line Items]
Credit facility, term	5 years
PECO Energy Co | Revolving Credit Facility
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 600	600
Long-term line of credit/facility draws		0
Outstanding letters of credit		0
Actual available capacity		600
To support additional commercial paper		435
Baltimore Gas and Electric Company
Short-term Debt [Line Items]
Credit facility, term	5 years
Baltimore Gas and Electric Company | Revolving Credit Facility
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 600	600
Long-term line of credit/facility draws		0
Outstanding letters of credit		6
Actual available capacity		594
To support additional commercial paper		258
Pepco Holdings LLC | Revolving Credit Facility
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity		900
Long-term line of credit/facility draws		0
Outstanding letters of credit		0
Actual available capacity		900
To support additional commercial paper		506
Potomac Electric Power Company
Short-term Debt [Line Items]
Credit facility, term	5 years
Potomac Electric Power Company | Revolving Credit Facility
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 300	300
Long-term line of credit/facility draws		0
Outstanding letters of credit		0
Actual available capacity		300
To support additional commercial paper		168
Delmarva Power & Light Company
Short-term Debt [Line Items]
Credit facility, term	5 years
Delmarva Power & Light Company | Revolving Credit Facility
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 300	300
Long-term line of credit/facility draws		0
Outstanding letters of credit		0
Actual available capacity		300
To support additional commercial paper		237
Atlantic City Electric Company
Short-term Debt [Line Items]
Credit facility, term	5 years
Atlantic City Electric Company | Revolving Credit Facility
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 300	300
Long-term line of credit/facility draws		0
Outstanding letters of credit		0
Actual available capacity		300
To support additional commercial paper		$ 101