Supplemental Financial Information - Summary of Other Income (Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other, Net [Abstract]
AFUDC—Equity	$ 150	$ 136	$ 104
Non-service net periodic benefit cost	63	91	53
Unrealized Gain (Loss) on Investments	(16)	(160)	186
Commonwealth Edison Co [Member]
Other, Net [Abstract]
AFUDC—Equity	35	34	29
Non-service net periodic benefit cost	0	0	0
PECO Energy Co [Member]
Other, Net [Abstract]
AFUDC—Equity	31	26	17
Non-service net periodic benefit cost	0	0	0
Baltimore Gas and Electric Company [Member]
Other, Net [Abstract]
AFUDC—Equity	21	27	22
Non-service net periodic benefit cost	0	0	0
Pepco Holdings LLC [Member]
Other, Net [Abstract]
AFUDC—Equity	63	49	36
Non-service net periodic benefit cost	0	0	0
Potomac Electric Power Company [Member]
Other, Net [Abstract]
AFUDC—Equity	48	40	28
Non-service net periodic benefit cost	0	0	0
Delmarva Power & Light Company [Member]
Other, Net [Abstract]
AFUDC—Equity	7	6	4
Non-service net periodic benefit cost	0	0	0
Atlantic City Electric Company [Member]
Other, Net [Abstract]
AFUDC—Equity	8	3	4
Non-service net periodic benefit cost	$ 0	$ 0	$ 0