Regulatory Matters - Annual Electric Transmission Fillings (Details) - USD ($) $ in Millions	Apr. 29, 2022	Apr. 27, 2022
Commonwealth Edison Co [Member] \| 2022 Transmission Formula Rate Annual Update [Domain]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount	$ 24
Annual Reconciliation Increase	(24)
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount	$ 0
Public Utilities, Approved Equity Capital Structure, Percentage	8.11%
Public Utilities, Approved Return on Equity, Percentage	11.50%
Cap on Equity Component of Rate of Return on Common Equity in Federal Energy Regulatory Committee Complaint	55.00%
Basis points for Transmission Formula Rate	50
Baltimore Gas and Electric Company [Member] \| 2022 Transmission Formula Rate Annual Update [Domain]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 25
Annual Reconciliation Increase		(4)
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount		$ 16
Public Utilities, Approved Equity Capital Structure, Percentage		7.30%
Public Utilities, Approved Return on Equity, Percentage		10.50%
Basis points for Transmission Formula Rate		50
Baltimore Gas and Electric Company [Member] \| 2022 Transmission Formula Rate Revenue Reduction
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount		$ 5

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