Commitments and Contingencies - Narrative (Details) $ in Millions	1 Months Ended
	Nov. 30, 2020 USD ($)	Jun. 30, 2023 USD ($) MGPSite
Commonwealth Edison Co [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Mgp Site Contingency Monitoring Count | MGPSite		19
Deferred Prosecution Agreement Payments	$ 200.0
Loss Contingency Accrual		$ 46.2
Customer Refund Liability, Current		38.0
Commonwealth Edison Co [Member] | Illinois Chamber of Commerce
Commitments And Contingencies Additional Narrative Information [Line Items]
Customer Refund Liability, Current		$ 31.0
PECO Energy Co [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Mgp Site Contingency Monitoring Count | MGPSite		6
Baltimore Gas and Electric Company [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Mgp Site Contingency Monitoring Count | MGPSite		4
Delmarva Power and Light Company [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Mgp Site Contingency Count | MGPSite		1
Exelon Business Services Co Affiliate [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Deferred Prosecution Agreement Liability, Current		$ 173.0
Insurers' Settlement Payment		40.0
Settling Shareholders' Attorney Fees		$ 10.0