Maximum basis points that can be added to the average rate on 30-year treasury notes, to determine the allowed ROE for ComEd's revenue requirement.

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Schedule of Energy Efficiency Formula Rate Updates [Line Items]

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Percentage of public utility's approved equity to capital, including debt and equity.

No definition available.

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Amount of public utility's approved rate increase (decrease) by regulatory agency.

No definition available.

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Percentage of public utility's approved return on equity.

No definition available.

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Percentage of public utility's requested equity to capital, including debt and equity.

No definition available.

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Amount of public utility's requested rate increase (decrease) with regulatory agency.

No definition available.

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Regulatory Matters - Energy Efficiency Formula Rate (Details) - ComEd 2022 Energy Efficiency Formula Rate [Domain] - Commonwealth Edison Co [Member] - USD ($) $ in Millions			12 Months Ended
	Oct. 27, 2022	May 25, 2022	Dec. 31, 2021
Schedule of Energy Efficiency Formula Rate Updates [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 50
Approved Revenue Requirement Increase (Decrease)	$ 50
Public Utilities, Requested Equity Capital Structure, Percentage	5.94%
Basis points for ComEd's Revenue Requirement	580
Public Utilities, Approved Return on Equity, Percentage	7.85%
2021
Schedule of Energy Efficiency Formula Rate Updates [Line Items]
Approved Revenue Requirement Increase (Decrease)	$ (16)
Public Utilities, Approved Equity Capital Structure, Percentage			5.52%
Public Utilities, Approved Return on Equity, Percentage			6.99%