Regulatory Matters - Energy Efficiency Formula Rate (Details) - Commonwealth Edison Co $ in Millions		12 Months Ended
May 23, 2025 USD ($) basisPoint	Dec. 31, 2024
ComEd 2025 Energy Efficiency Formula Rate
Schedule of Energy Efficiency Formula Rate Updates [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount	$ 24
Public Utilities Requested Rate Increase (Decrease), Prior Year Annual Reconciliation	(4)
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount	$ 20
Public Utilities, Requested Equity Capital Structure, Percentage	7.24%
Requested Return on Equity, Percentage	10.21%
ComEd 2025 Energy Efficiency Formula Rate \| 2025
Schedule of Energy Efficiency Formula Rate Updates [Line Items]
Basis points for ComEd's Revenue Requirement \| basisPoint	580
ComEd 2024 Energy Efficiency Formula Rate
Schedule of Energy Efficiency Formula Rate Updates [Line Items]
Public Utilities, Approved Equity Capital Structure, Percentage		7.51%
Public Utilities, Approved Return on Equity, Percentage		10.75%

- Definition

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.

+ References

No definition available.

+ Details

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- Definition

Amount of public utility's requested rate increase (decrease) with regulatory agency, prior year annual reconciliation.

+ References

No definition available.

+ Details

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- Definition

Schedule of Energy Efficiency Formula Rate Updates [Line Items]

+ References

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- Definition

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

+ References

No definition available.

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- Definition

Percentage of public utility's approved return on equity.

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

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

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No definition available.

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- Definition

Percentage of public utility's requested return on equity.

+ References

No definition available.

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