Commitments and Contingencies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) mGPSite
Commitments and Contingencies [Line Items]
Deferred Prosecution Payment	$ 200.0
Commonwealth Edison Co
Commitments and Contingencies [Line Items]
Sites under study/remediation | mGPSite	17
Deferred Prosecution Payment	$ 200.0
Loss Contingency Accrual	46.2
Customer Refund Liability, Current	38.0
Commonwealth Edison Co | Accrual For MGP Investigation And Remediation [Member]
Commitments and Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Period Increase (Decrease)	25.0
Commonwealth Edison Co | Illinois Chamber of Commerce
Commitments and Contingencies [Line Items]
Customer Refund Liability, Current	$ 31.0
PECO Energy Co
Commitments and Contingencies [Line Items]
Sites under study/remediation | mGPSite	6
Baltimore Gas and Electric Company
Commitments and Contingencies [Line Items]
Sites under study/remediation | mGPSite	4
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual	0.48
Potomac Electric Power Company
Commitments and Contingencies [Line Items]
Environmental Liability - Anacostia	$ 47.0
Environmental Liability - Buzzard Point	$ 10.0
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual	0.48
Delmarva Power & Light Company
Commitments and Contingencies [Line Items]
Sites under study/remediation | mGPSite	1
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual	0.48
Atlantic City Electric Company
Commitments and Contingencies [Line Items]
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual	0.48
Atlantic City Electric Company | Minimum
Commitments and Contingencies [Line Items]
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual	0.30
Exelon Business Services Co Affiliate
Commitments and Contingencies [Line Items]
Deferred Prosecution Agreement Liability, Current	$ 173.0
Insurers' Settlement Payment	40.0
Settling Shareholders' Attorney Fees	$ 10.0