Income Taxes - Rollforward of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - Beginning Balance	$ 143	$ 125	$ 95
Unrecognized Tax Benefits, Period Increase (Decrease)	(1)	13	6
Increases based on tax positions related to current year	3	4	3
Increases based on tax positions prior to current year	3	4	26
Decreases based on tax positions prior to current year	0	(3)	(5)
Unrecognized tax benefits - Ending Balance	148	143	125
Income Taxes Receivable, Noncurrent	50
Pepco Holdings LLC [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - Beginning Balance	56	52	48
Unrecognized Tax Benefits, Period Increase (Decrease)	1	3	3
Increases based on tax positions related to current year	2	1	0
Increases based on tax positions prior to current year	0	0	1
Decreases based on tax positions prior to current year	0	0	0
Unrecognized tax benefits - Ending Balance	59	56	52
Atlantic City Electric Company [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - Beginning Balance	16	15	14
Unrecognized Tax Benefits, Period Increase (Decrease)	1	1	1
Increases based on tax positions related to current year	0	0	0
Increases based on tax positions prior to current year	0	0	0
Decreases based on tax positions prior to current year	0	0	0
Unrecognized tax benefits - Ending Balance	$ 17	$ 16	$ 15