Related Party Transactions - Utility Registrants' expense with Generation (Details) - Exelon Generation Co L L C $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($)
Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Operating revenues from affiliates	$ 59
PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Operating revenues from affiliates	33
Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Operating revenues from affiliates	18
Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Operating revenues from affiliates	51
Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Operating revenues from affiliates	39
Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Operating revenues from affiliates	10
Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Operating revenues from affiliates	$ 2