Commitments and Contingencies - Schedule of Accruals for Environmental Matters (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	$ 382	$ 403
Commonwealth Edison Co
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	280	285
PECO Energy Co
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	29	29
Baltimore Gas and Electric Company
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	14	13
Pepco Holdings LLC
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	58	75
Potomac Electric Power Company
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	56	73
Delmarva Power and Light Company
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	1	1
Atlantic City Electric Company
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	1	1
Environmental Remediation
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	317	322
Environmental Remediation \| Commonwealth Edison Co
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	280	284
Environmental Remediation \| PECO Energy Co
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	27	28
Environmental Remediation \| Baltimore Gas and Electric Company
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	10	10
Environmental Remediation \| Pepco Holdings LLC
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	0	0
Environmental Remediation \| Potomac Electric Power Company
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	0	0
Environmental Remediation \| Delmarva Power and Light Company
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	0	0
Environmental Remediation \| Atlantic City Electric Company
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	$ 0	$ 0