Revenue from Contracts with Customers - Contract Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Contract Liabilities [Roll Forward]
Beginning Balance - Contract Liabilities	$ 109	$ 118
Contract with Customer, Liability, Revenue Recognized	(8)	(9)
Ending Balance - Contract Liabilities	101	109
Pepco Holdings LLC [Member]
Contract Liabilities [Roll Forward]
Beginning Balance - Contract Liabilities	109	118
Contract with Customer, Liability, Revenue Recognized	(8)	(9)
Ending Balance - Contract Liabilities	101	109
Potomac Electric Power Company [Member]
Contract Liabilities [Roll Forward]
Beginning Balance - Contract Liabilities	87	94
Contract with Customer, Liability, Revenue Recognized	(6)	(7)
Ending Balance - Contract Liabilities	81	87
Delmarva Power & Light Company [Member]
Contract Liabilities [Roll Forward]
Beginning Balance - Contract Liabilities	11	12
Contract with Customer, Liability, Revenue Recognized	(1)	(1)
Ending Balance - Contract Liabilities	10	11
Atlantic City Electric Company [Member]
Contract Liabilities [Roll Forward]
Beginning Balance - Contract Liabilities	11	12
Contract with Customer, Liability, Revenue Recognized	(1)	(1)
Ending Balance - Contract Liabilities	$ 10	$ 11