Related Party Transactions - Operating Revenues and Purchased Power and Fuel From Affiliates (Details) - Exelon Generation Co L L C - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 59	$ 376
PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	33	196
Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	18	236
Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	51	366
Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	39	270
Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	10	79
Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 2	$ 17