DISTRICT OF COLUMBIA DISTRICT OF COLUMBIA Baltimore Gas and Electric Company [Member] Baltimore Gas and Electric Company [Member] Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line Two Entity Address, Address Line Two Entity File Number Entity File Number Legal Entity [Axis] Legal Entity [Axis] Cover page. Cover [Abstract] Title of 12(b) Security Title of 12(b) Security Local Phone Number Local Phone Number Soliciting Material Soliciting Material Entity Address, Address Line One Entity Address, Address Line One Potomac Electric Power Company [Member] Potomac Electric Power Company [Member] Potomac Electric Power Company [Member] PECO Energy Co [Member] PECO Energy Co [Member] PECO Energy Co [Member] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Entity Address, State or Province Entity Address, State or Province Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Written Communications Written Communications VIRGINIA VIRGINIA Trading Symbol Trading Symbol Geographical [Domain] Geographical [Domain] City Area Code City Area Code Document Information [Table] Document Information [Table] Delmarva Power and Light Company [Member] Delmarva Power and Light Company [Member] Delmarva Power and Light Company [Member] Pepco Holdings LLC [Member] Pepco Holdings LLC [Member] Pepco Holdings LLC [Member] Commonwealth Edison Co [Member] Commonwealth Edison Co [Member] Commonwealth Edison Co [Member] Document Period End Date Document Period End Date Amendment Flag Amendment Flag Pre-commencement Issuer Tender Offer Pre-commencement Issuer Tender Offer Entity Address, City or Town Entity Address, City or Town Document [Domain] Document [Domain] Entity [Domain] Entity [Domain] Security Exchange Name Security Exchange Name Document Information, Document [Axis] Document Information, Document [Axis] Document Information [Line Items] Document Information [Line Items] Geographical [Axis] Geographical [Axis] Document Type Document Type Atlantic City Electric Company [Member] Atlantic City Electric Company [Member] Atlantic City Electric Company [Member] Pre-commencement Tender Offer Pre-commencement Tender Offer Entity Central Index Key Entity Central Index Key DELAWARE DELAWARE Entity Emerging Growth Company Entity Emerging Growth Company