Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Retained earnings/Undistributed earnings (losses)	$ 4,161				$ 4,161		$ 16,942
Deferred income taxes and unamortized investment tax credits	11,240				11,240		10,611
Net income (loss)	465	$ 598	$ 476	$ (264)	1,063	$ 211
Atlantic City Electric Company [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Retained earnings/Undistributed earnings (losses)	(16)				(16)		(15)
Deferred income taxes and unamortized investment tax credits	695				695		682
Net income (loss)	11	26	37	14	37	51
Pepco Holdings LLC [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Retained earnings/Undistributed earnings (losses)	(375)				(375)		(210)
Deferred income taxes and unamortized investment tax credits	2,752				2,752		$ 2,675
Net income (loss)	$ 100	$ 130	$ 141	$ 128	$ 230	$ 269