Debt and Credit Agreements - Summary of Revolving Credit Agreements (Details) - USD ($) $ in Millions	Dec. 31, 2022	Feb. 01, 2022	Jan. 31, 2022	Dec. 31, 2021
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 4,000
Letters of Credit Outstanding, Amount	8
Revolving Credit Facility [Member] | Commonwealth Edison Co [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,000	$ 1,000
Letters of Credit Outstanding, Amount	5
Revolving Credit Facility [Member] | Commonwealth Edison Co [Member] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end		1.00%
Revolving Credit Facility [Member] | PECO Energy Co [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	600	$ 600
Letters of Credit Outstanding, Amount	0
Revolving Credit Facility [Member] | PECO Energy Co [Member] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end		0.90%
Revolving Credit Facility [Member] | Baltimore Gas and Electric Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	600	$ 600
Letters of Credit Outstanding, Amount	0
Revolving Credit Facility [Member] | Baltimore Gas and Electric Company [Member] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end		0.90%
Revolving Credit Facility [Member] | Potomac Electric Power Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	300	$ 300
Letters of Credit Outstanding, Amount	0
Revolving Credit Facility [Member] | Potomac Electric Power Company [Member] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end		1.075%
Revolving Credit Facility [Member] | Delmarva Power & Light Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	300	$ 300
Letters of Credit Outstanding, Amount	0
Revolving Credit Facility [Member] | Delmarva Power & Light Company [Member] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end		1.00%
Revolving Credit Facility [Member] | Atlantic City Electric Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	300	$ 300
Letters of Credit Outstanding, Amount	0
Revolving Credit Facility [Member] | Atlantic City Electric Company [Member] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end		1.075%
Revolving Credit Facility [Member] | Pepco Holdings LLC [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	900
Letters of Credit Outstanding, Amount	0
Community and Minority Facilities [Member] | Community and Minority Facilities [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	140			$ 98
Letters of Credit Outstanding, Amount	10			8
Community and Minority Facilities [Member] | Commonwealth Edison Co [Member] | Community and Minority Facilities [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	40			33
Letters of Credit Outstanding, Amount	7			5
Community and Minority Facilities [Member] | PECO Energy Co [Member] | Community and Minority Facilities [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	40			33
Letters of Credit Outstanding, Amount	1			1
Community and Minority Facilities [Member] | Baltimore Gas and Electric Company [Member] | Community and Minority Facilities [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	15			8
Letters of Credit Outstanding, Amount	2			2
Community and Minority Facilities [Member] | Potomac Electric Power Company [Member] | Community and Minority Facilities [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	15			8
Letters of Credit Outstanding, Amount	0			0
Community and Minority Facilities [Member] | Delmarva Power & Light Company [Member] | Community and Minority Facilities [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	15			8
Letters of Credit Outstanding, Amount	0			0
Community and Minority Facilities [Member] | Atlantic City Electric Company [Member] | Community and Minority Facilities [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	15			8
Letters of Credit Outstanding, Amount	0			0
Community and Minority Facilities [Member] | Pepco Holdings LLC [Member] | Community and Minority Facilities [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	45			24
Letters of Credit Outstanding, Amount	0			$ 0
Corporate, Non-Segment [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	900	$ 900	$ 600
Letters of Credit Outstanding, Amount	$ 3
Corporate, Non-Segment [Member] | Revolving Credit Facility [Member] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end		1.275%