Intangible Assets - Schedule of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Mar. 24, 2016	Oct. 20, 2000
Goodwill [Line Items]
Goodwill Impairment Loss	$ 0	$ 0
Goodwill, Additions	0	0
Goodwill, Gross	8,613	8,613
Accumulated Impairment Loss	1,983	1,983
Carrying amount	6,630	6,630
Commonwealth Edison Co
Goodwill [Line Items]
Goodwill Impairment Loss	0	0
Goodwill, Additions	0	0
Goodwill, Gross	4,608	4,608
Accumulated Impairment Loss	1,983	1,983
Carrying amount	2,625	2,625		$ 2,600
Pepco Holdings LLC
Goodwill [Line Items]
Goodwill Impairment Loss	0	0
Goodwill, Additions	0	0
Goodwill, Gross	4,005	4,005
Accumulated Impairment Loss	0	0
Carrying amount	$ 4,005	$ 4,005	$ 4,000