Related Party Transactions - Operating Revenues and Purchased Power and Fuel From Affiliates (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)
PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Agreement Term	10 years
Exelon Generation Co L L C | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 59
Exelon Generation Co L L C | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	33
Exelon Generation Co L L C | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	18
Exelon Generation Co L L C | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	51
Exelon Generation Co L L C | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	39
Exelon Generation Co L L C | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	10
Exelon Generation Co L L C | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 2