Commitments and Contingencies - Schedule of Environmental Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	$ 409	$ 352
Commonwealth Edison Co [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	325	279
PECO Energy Co [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	25	22
Baltimore Gas and Electric Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	9	6
Pepco Holdings LLC [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	46	42
Potomac Electric Power Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	44	40
Delmarva Power & Light Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	1	1
Atlantic City Electric Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	1	1
Accrual For MGP Investigation And Remediation [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	355	303
Accrual For MGP Investigation And Remediation [Member] | Commonwealth Edison Co [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	324	279
Accrual For MGP Investigation And Remediation [Member] | PECO Energy Co [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	23	20
Accrual For MGP Investigation And Remediation [Member] | Baltimore Gas and Electric Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	8	4
Accrual For MGP Investigation And Remediation [Member] | Pepco Holdings LLC [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	0	0
Accrual For MGP Investigation And Remediation [Member] | Potomac Electric Power Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	0	0
Accrual For MGP Investigation And Remediation [Member] | Delmarva Power & Light Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	0	0
Accrual For MGP Investigation And Remediation [Member] | Atlantic City Electric Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	$ 0	$ 0