Commitments and Contingencies - Schedule of Commercial Commitments (Details) $ in Millions	Mar. 31, 2024 USD ($)
Other Commitments [Line Items]
Other Commitment	$ 629
Other Commitment, to be Paid, Remainder of Fiscal Year	205
Other Commitment, to be Paid, Year One	24
Other Commitment, to be Paid, Year Two	5
Other Commitment, to be Paid, Year Three	4
Other Commitment, to be Paid, Year Four	84
Other Commitment, to be Paid, Year Five and Beyond	307
Guarantor Obligations, Maximum Exposure, Undiscounted	57
Letters of Credit
Other Commitments [Line Items]
Other Commitment	32
Other Commitment, to be Paid, Remainder of Fiscal Year	24
Other Commitment, to be Paid, Year One	8
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Surety Bonds
Other Commitments [Line Items]
Other Commitment	194
Other Commitment, to be Paid, Remainder of Fiscal Year	181
Other Commitment, to be Paid, Year One	13
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Financing trust guarantees
Other Commitments [Line Items]
Other Commitment	378
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	0
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	78
Other Commitment, to be Paid, Year Five and Beyond	300
Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	25
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	3
Other Commitment, to be Paid, Year Two	5
Other Commitment, to be Paid, Year Three	4
Other Commitment, to be Paid, Year Four	6
Other Commitment, to be Paid, Year Five and Beyond	7
Commonwealth Edison Co
Other Commitments [Line Items]
Other Commitment	253
Other Commitment, to be Paid, Remainder of Fiscal Year	48
Other Commitment, to be Paid, Year One	5
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	200
Commonwealth Edison Co | Letters of Credit
Other Commitments [Line Items]
Other Commitment	17
Other Commitment, to be Paid, Remainder of Fiscal Year	14
Other Commitment, to be Paid, Year One	3
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Commonwealth Edison Co | Surety Bonds
Other Commitments [Line Items]
Other Commitment	36
Other Commitment, to be Paid, Remainder of Fiscal Year	34
Other Commitment, to be Paid, Year One	2
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Commonwealth Edison Co | Financing trust guarantees
Other Commitments [Line Items]
Other Commitment	200
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	0
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	200
PECO Energy Co
Other Commitments [Line Items]
Other Commitment	183
Other Commitment, to be Paid, Remainder of Fiscal Year	1
Other Commitment, to be Paid, Year One	4
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	78
Other Commitment, to be Paid, Year Five and Beyond	100
PECO Energy Co | Letters of Credit
Other Commitments [Line Items]
Other Commitment	3
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	3
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
PECO Energy Co | Surety Bonds
Other Commitments [Line Items]
Other Commitment	2
Other Commitment, to be Paid, Remainder of Fiscal Year	1
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
PECO Energy Co | Financing trust guarantees
Other Commitments [Line Items]
Other Commitment	178
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	0
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	78
Other Commitment, to be Paid, Year Five and Beyond	100
Baltimore Gas and Electric Company
Other Commitments [Line Items]
Other Commitment	10
Other Commitment, to be Paid, Remainder of Fiscal Year	9
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Baltimore Gas and Electric Company | Letters of Credit
Other Commitments [Line Items]
Other Commitment	7
Other Commitment, to be Paid, Remainder of Fiscal Year	7
Other Commitment, to be Paid, Year One	0
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Baltimore Gas and Electric Company | Surety Bonds
Other Commitments [Line Items]
Other Commitment	3
Other Commitment, to be Paid, Remainder of Fiscal Year	2
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Pepco Holdings LLC
Other Commitments [Line Items]
Other Commitment	121
Other Commitment, to be Paid, Remainder of Fiscal Year	91
Other Commitment, to be Paid, Year One	8
Other Commitment, to be Paid, Year Two	5
Other Commitment, to be Paid, Year Three	4
Other Commitment, to be Paid, Year Four	6
Other Commitment, to be Paid, Year Five and Beyond	7
Guarantor Obligations, Maximum Exposure, Undiscounted	57
Pepco Holdings LLC | Surety Bonds
Other Commitments [Line Items]
Other Commitment	96
Other Commitment, to be Paid, Remainder of Fiscal Year	91
Other Commitment, to be Paid, Year One	5
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Pepco Holdings LLC | Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	25
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	3
Other Commitment, to be Paid, Year Two	5
Other Commitment, to be Paid, Year Three	4
Other Commitment, to be Paid, Year Four	6
Other Commitment, to be Paid, Year Five and Beyond	7
Potomac Electric Power Company
Other Commitments [Line Items]
Other Commitment	93
Other Commitment, to be Paid, Remainder of Fiscal Year	84
Other Commitment, to be Paid, Year One	2
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	1
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five and Beyond	2
Guarantor Obligations, Maximum Exposure, Undiscounted	19
Potomac Electric Power Company | Surety Bonds
Other Commitments [Line Items]
Other Commitment	85
Other Commitment, to be Paid, Remainder of Fiscal Year	84
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Potomac Electric Power Company | Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	8
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	1
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five and Beyond	2
Delmarva Power and Light Company
Other Commitments [Line Items]
Other Commitment	16
Other Commitment, to be Paid, Remainder of Fiscal Year	3
Other Commitment, to be Paid, Year One	4
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five and Beyond	3
Guarantor Obligations, Maximum Exposure, Undiscounted	22
Delmarva Power and Light Company | Surety Bonds
Other Commitments [Line Items]
Other Commitment	6
Other Commitment, to be Paid, Remainder of Fiscal Year	3
Other Commitment, to be Paid, Year One	3
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Delmarva Power and Light Company | Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	10
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five and Beyond	3
Atlantic City Electric Company
Other Commitments [Line Items]
Other Commitment	12
Other Commitment, to be Paid, Remainder of Fiscal Year	4
Other Commitment, to be Paid, Year One	2
Other Commitment, to be Paid, Year Two	1
Other Commitment, to be Paid, Year Three	1
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five and Beyond	2
Guarantor Obligations, Maximum Exposure, Undiscounted	16
Atlantic City Electric Company | Surety Bonds
Other Commitments [Line Items]
Other Commitment	5
Other Commitment, to be Paid, Remainder of Fiscal Year	4
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Atlantic City Electric Company | Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	7
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	1
Other Commitment, to be Paid, Year Three	1
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five and Beyond	$ 2
Minimum [Member] | Guaranteed lease residual values
Other Commitments [Line Items]
Lessor, Operating Lease, Term of Contract	1 year
Maximum [Member] | Guaranteed lease residual values
Other Commitments [Line Items]
Lessor, Operating Lease, Term of Contract	9 years