Income Taxes - Schedule of Carryforwards and Corresponding Valuation Allowances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	$ 264
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	5,629
Deferred taxes on state tax attributes (net of federal taxes)	341
Valuation allowance on state tax attributes (net of federal taxes)	$ 73
Operating loss carryforwards, expiration date	Dec. 31, 2035
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	$ 264
Operating Loss Carryforwards	130
Deferred taxes on Federal net operating loss	27
Domestic Tax Authority | General Business Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards	281
Commonwealth Edison Co
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	118
Commonwealth Edison Co | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	0
Deferred taxes on state tax attributes (net of federal taxes)	0
Valuation allowance on state tax attributes (net of federal taxes)	0
Commonwealth Edison Co | Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	118
Operating Loss Carryforwards	0
Deferred taxes on Federal net operating loss	0
Commonwealth Edison Co | Domestic Tax Authority | General Business Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards	0
PECO Energy Co
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	82
PECO Energy Co | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	1,286
Deferred taxes on state tax attributes (net of federal taxes)	51
Valuation allowance on state tax attributes (net of federal taxes)	$ 4
Operating loss carryforwards, expiration date	Dec. 31, 2032
PECO Energy Co | Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	$ 82
Operating Loss Carryforwards	0
Deferred taxes on Federal net operating loss	0
PECO Energy Co | Domestic Tax Authority | General Business Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards	0
Baltimore Gas and Electric Company
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	55
Baltimore Gas and Electric Company | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	1,187
Deferred taxes on state tax attributes (net of federal taxes)	77
Valuation allowance on state tax attributes (net of federal taxes)	$ 0
Operating loss carryforwards, expiration date	Dec. 31, 2033
Baltimore Gas and Electric Company | Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	$ 55
Operating Loss Carryforwards	0
Deferred taxes on Federal net operating loss	0
Baltimore Gas and Electric Company | Domestic Tax Authority | General Business Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards	0
Pepco Holdings LLC
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	0
Pepco Holdings LLC | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	1,509
Deferred taxes on state tax attributes (net of federal taxes)	104
Valuation allowance on state tax attributes (net of federal taxes)	$ 32
Operating loss carryforwards, expiration date	Dec. 31, 2029
Pepco Holdings LLC | Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	$ 0
Operating Loss Carryforwards	0
Deferred taxes on Federal net operating loss	0
Pepco Holdings LLC | Domestic Tax Authority | General Business Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards	0
Potomac Electric Power Company
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	0
Potomac Electric Power Company | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	0
Deferred taxes on state tax attributes (net of federal taxes)	0
Valuation allowance on state tax attributes (net of federal taxes)	0
Potomac Electric Power Company | Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	0
Operating Loss Carryforwards	0
Deferred taxes on Federal net operating loss	0
Potomac Electric Power Company | Domestic Tax Authority | General Business Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards	0
Delmarva Power & Light Company
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	2
Valuation allowance on state tax attributes (net of federal taxes)		$ 31
Delmarva Power & Light Company | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	743
Deferred taxes on state tax attributes (net of federal taxes)	50
Valuation allowance on state tax attributes (net of federal taxes)	$ 32
Operating loss carryforwards, expiration date	Dec. 31, 2035
Delmarva Power & Light Company | Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	$ 2
Operating Loss Carryforwards	0
Deferred taxes on Federal net operating loss	0
Delmarva Power & Light Company | Domestic Tax Authority | General Business Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards	0
Atlantic City Electric Company
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	11
Atlantic City Electric Company | State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	736
Deferred taxes on state tax attributes (net of federal taxes)	52
Valuation allowance on state tax attributes (net of federal taxes)	$ 0
Operating loss carryforwards, expiration date	Dec. 31, 2031
Atlantic City Electric Company | Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Corporate Alternative Minimum Tax	$ 11
Operating Loss Carryforwards	0
Deferred taxes on Federal net operating loss	0
Atlantic City Electric Company | Domestic Tax Authority | General Business Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards	$ 0