Commitments and Contingencies - Schedule of Commercial Commitments (Details) $ in Millions	Mar. 31, 2023 USD ($)
Other Commitments [Line Items]
Other Commitment	$ 631
Other Commitment, to be Paid, Remainder of Fiscal Year	207
Other Commitment, to be Paid, Year One	22
Other Commitment, to be Paid, Year Two	6
Other Commitment, to be Paid, Year Three	5
Other Commitment, to be Paid, Year Four	4
Other Commitment, to be Paid, Year Five and Beyond	387
Guarantor Obligations, Maximum Exposure, Undiscounted	65
Letters of Credit
Other Commitments [Line Items]
Other Commitment	19
Other Commitment, to be Paid, Remainder of Fiscal Year	17
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
Surety Bonds
Other Commitments [Line Items]
Other Commitment	205
Other Commitment, to be Paid, Remainder of Fiscal Year	190
Other Commitment, to be Paid, Year One	15
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	0
Other Commitment, to be Paid, Year Five and Beyond	378
Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	29
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	5
Other Commitment, to be Paid, Year Two	6
Other Commitment, to be Paid, Year Three	5
Other Commitment, to be Paid, Year Four	4
Other Commitment, to be Paid, Year Five and Beyond	9
Commonwealth Edison Co [Member]
Other Commitments [Line Items]
Other Commitment	259
Other Commitment, to be Paid, Remainder of Fiscal Year	52
Other Commitment, to be Paid, Year One	7
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 [Member] | Letters of Credit
Other Commitments [Line Items]
Other Commitment	12
Other Commitment, to be Paid, Remainder of Fiscal Year	10
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 [Member] | Surety Bonds
Other Commitments [Line Items]
Other Commitment	47
Other Commitment, to be Paid, Remainder of Fiscal Year	42
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
Commonwealth Edison Co [Member] | 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 [Member]
Other Commitments [Line Items]
Other Commitment	181
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	178
PECO Energy Co [Member] | 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 [Member] | 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	0
Other Commitment, to be Paid, Year Five and Beyond	178
PECO Energy Co [Member] | Standby Letters of Credit
Other Commitments [Line Items]
Other Commitment	1
Other Commitment, to be Paid, Remainder of Fiscal Year	1
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, after Year Five	0
Baltimore Gas and Electric Company [Member]
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
Baltimore Gas and Electric Company [Member] | Letters of Credit
Other Commitments [Line Items]
Other Commitment	2
Other Commitment, to be Paid, Remainder of Fiscal Year	2
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 [Member] | 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 [Member]
Other Commitments [Line Items]
Other Commitment	124
Other Commitment, to be Paid, Remainder of Fiscal Year	90
Other Commitment, to be Paid, Year One	10
Other Commitment, to be Paid, Year Two	6
Other Commitment, to be Paid, Year Three	5
Other Commitment, to be Paid, Year Four	4
Other Commitment, to be Paid, Year Five and Beyond	9
Guarantor Obligations, Maximum Exposure, Undiscounted	65
Pepco Holdings LLC [Member] | Surety Bonds
Other Commitments [Line Items]
Other Commitment	95
Other Commitment, to be Paid, Remainder of Fiscal Year	90
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 [Member] | Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	29
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	5
Other Commitment, to be Paid, Year Two	6
Other Commitment, to be Paid, Year Three	5
Other Commitment, to be Paid, Year Four	4
Other Commitment, to be Paid, Year Five and Beyond	9
Potomac Electric Power Company [Member]
Other Commitments [Line Items]
Other Commitment	94
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	2
Other Commitment, to be Paid, Year Four	1
Other Commitment, to be Paid, Year Five and Beyond	3
Guarantor Obligations, Maximum Exposure, Undiscounted	21
Potomac Electric Power Company [Member] | Surety Bonds
Other Commitments [Line Items]
Other Commitment	84
Other Commitment, to be Paid, Remainder of Fiscal Year	84
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
Potomac Electric Power Company [Member] | 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	2
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	1
Other Commitment, to be Paid, Year Five and Beyond	3
Delmarva Power and Light Company [Member]
Other Commitments [Line Items]
Other Commitment	18
Other Commitment, to be Paid, Remainder of Fiscal Year	2
Other Commitment, to be Paid, Year One	6
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	4
Guarantor Obligations, Maximum Exposure, Undiscounted	27
Delmarva Power and Light Company [Member] | Surety Bonds
Other Commitments [Line Items]
Other Commitment	6
Other Commitment, to be Paid, Remainder of Fiscal Year	2
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	0
Other Commitment, to be Paid, Year Five and Beyond	0
Delmarva Power and Light Company [Member] | Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	12
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	2
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	4
Atlantic City Electric Company [Member]
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	2
Other Commitment, to be Paid, Year Three	1
Other Commitment, to be Paid, Year Four	1
Other Commitment, to be Paid, Year Five and Beyond	2
Guarantor Obligations, Maximum Exposure, Undiscounted	17
Atlantic City Electric Company [Member] | 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 [Member] | 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	2
Other Commitment, to be Paid, Year Three	1
Other Commitment, to be Paid, Year Four	1
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