Consolidated Statements of Changes in Shareholders Equity (Unaudited) - USD ($) shares in Thousands, $ in Millions	Total	Correcting Adjustment [Member]	Common Stock [Member]	Common Stock [Member] Correcting Adjustment [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]	Commonwealth Edison Co [Member]	Commonwealth Edison Co [Member] Common Stock [Member]	Commonwealth Edison Co [Member] Retained Earnings [Member]	Commonwealth Edison Co [Member] Other Paid-in-Capital [Member]	PECO Energy Co [Member]	PECO Energy Co [Member] Common Stock [Member]	PECO Energy Co [Member] Retained Earnings [Member]	Baltimore Gas and Electric Company [Member]	Baltimore Gas and Electric Company [Member] Common Stock [Member]	Baltimore Gas and Electric Company [Member] Retained Earnings [Member]	Pepco Holdings LLC [Member]	Pepco Holdings LLC [Member] Retained Earnings [Member]	Pepco Holdings LLC [Member] Membership Interest [Member]	Pepco Holdings LLC [Member] Retained Earnings, Unappropriated [Member]	Potomac Electric Power Company [Member]	Potomac Electric Power Company [Member] Common Stock [Member]	Potomac Electric Power Company [Member] Retained Earnings [Member]	Delmarva Power and Light Company [Member]	Delmarva Power and Light Company [Member] Common Stock [Member]	Delmarva Power and Light Company [Member] Retained Earnings [Member]	Atlantic City Electric Company [Member]	Atlantic City Electric Company [Member] Common Stock [Member]	Atlantic City Electric Company [Member] Retained Earnings [Member]
Beginning balance (in shares) at Dec. 31, 2020	977,466
Beginning balance at Dec. 31, 2020	$ 34,868		$ 19,373		$ (123)	$ 16,735	$ (3,400)	$ 2,283
Beginning Balance at Dec. 31, 2020									$ 11,329	$ 1,588	$ 1,456	$ 8,285	$ 4,533	$ 3,014	$ 1,519	$ 4,197	$ 2,318	$ 1,879					$ 3,203	$ 2,058	$ 1,145	$ 1,676	$ 1,089	$ 587	$ 1,398	$ 1,271	$ 127
Beginning Balance at Dec. 31, 2020																			$ 10,044	$ (68)	$ 10,112
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (264)					(289)		25	197		197		167		167	209		209	128	128			59		59	56		56	14		14
Long -Term Incentive Plan Activity (shares)	640
Long-Term Incentive Plan Activity		$ 5		$ 5
Employee stock purchase plan issuances (shares)	902
Employee stock purchase plan issuances	$ 34		34
Changes in equity of noncontrolling interests	$ (10)							(10)
Common Stock, Dividends, Per Share, Declared	$ 0.38
Common stock dividends	$ (374)					(374)			(127)		(127)		(85)		(85)	(74)		(74)					(28)		(28)	(40)		(40)	(14)		(14)
Other comprehensive income (loss), net of income taxes	$ 54						54
Distributions to member																			(81)	(81)
Contributions from parent									198			198							560		560		138	138		120	120		303	303
Ending balance (in shares) at Mar. 31, 2021	979,008
Ending balance at Mar. 31, 2021	$ 34,313		19,412		(123)	16,072	(3,346)	2,298
Ending Balance at Mar. 31, 2021									11,597	1,588	1,526	8,483	4,615	3,014	1,601	4,332	2,318	2,014					3,372	2,196	1,176	1,812	1,209	603	1,701	1,574	127
Ending Balance at Mar. 31, 2021																			10,651	(21)	10,672
Beginning balance (in shares) at Dec. 31, 2020	977,466
Beginning balance at Dec. 31, 2020	$ 34,868		19,373		(123)	16,735	(3,400)	2,283
Beginning Balance at Dec. 31, 2020									11,329	1,588	1,456	8,285	4,533	3,014	1,519	4,197	2,318	1,879					3,203	2,058	1,145	1,676	1,089	587	1,398	1,271	127
Beginning Balance at Dec. 31, 2020																			10,044	(68)	10,112
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	211								390				271			254			269				134			86			51
Other comprehensive income (loss), net of income taxes	$ 111						111
Ending balance (in shares) at Jun. 30, 2021	979,665
Ending balance at Jun. 30, 2021	$ 34,500		19,454		(123)	16,098	(3,289)	2,360
Ending Balance at Jun. 30, 2021									11,860	1,588	1,592	8,680	5,030	3,409	1,621	4,305	2,318	1,987					3,352	2,196	1,156	1,819	1,209	610	1,523	1,574	(51)
Ending Balance at Jun. 30, 2021																			10,459		10,672	$ (213)
Beginning balance (in shares) at Mar. 31, 2021	979,008
Beginning balance at Mar. 31, 2021	$ 34,313		19,412		(123)	16,072	(3,346)	2,298
Beginning Balance at Mar. 31, 2021									11,597	1,588	1,526	8,483	4,615	3,014	1,601	4,332	2,318	2,014					3,372	2,196	1,176	1,812	1,209	603	1,701	1,574	127
Beginning Balance at Mar. 31, 2021																			10,651	(21)	10,672
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 476					401		75	192		192		104		104	45		45	141	141			75		75	30		30	37		37
Long -Term Incentive Plan Activity (shares)	237
Long-Term Incentive Plan Activity	$ 24		24
Employee stock purchase plan issuances (shares)		420
Employee stock purchase plan issuances	18		18
Changes in equity of noncontrolling interests	$ (13)							(13)
Common Stock, Dividends, Per Share, Declared	$ 0.38
Common stock dividends	$ (375)					(375)			(126)		(126)		(84)		(84)	(72)		(72)					(95)		(95)	(23)		(23)	(215)		(215)
Other comprehensive income (loss), net of income taxes	$ 57						57
Distributions to member																			(333)	(333)
Contributions from parent									197			197	395	395
Ending balance (in shares) at Jun. 30, 2021	979,665
Ending balance at Jun. 30, 2021	$ 34,500		19,454		(123)	16,098	(3,289)	2,360
Ending Balance at Jun. 30, 2021									11,860	1,588	1,592	8,680	5,030	3,409	1,621	4,305	2,318	1,987					3,352	2,196	1,156	1,819	1,209	610	1,523	1,574	(51)
Ending Balance at Jun. 30, 2021																			10,459		10,672	(213)
Beginning balance (in shares) at Dec. 31, 2021	981,291
Beginning balance at Dec. 31, 2021	$ 34,795		20,324		(123)	16,942	(2,750)	402
Beginning Balance at Dec. 31, 2021	34,393								12,355	1,588	1,691	9,076	5,112	3,428	1,684	4,570	2,575	1,995					3,475	2,302	1,173	1,777	1,209	568	1,575	1,590	(15)
Beginning Balance at Dec. 31, 2021																			10,585	(210)	10,795
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 598					597		1	188		188		206		206	198		198	130	130			46		46	56		56	26		26
Long -Term Incentive Plan Activity (shares)	540
Long-Term Incentive Plan Activity	$ (13)		(13)
Employee stock purchase plan issuances (shares)	211
Employee stock purchase plan issuances	$ 9		9
Changes in equity of noncontrolling interests	(7)							(7)
Distribution of Constellation	$ (11,573)		(21)			(13,179)	2,023	(396)
Common Stock, Dividends, Per Share, Declared	$ 0.34
Common stock dividends	$ (332)					(332)			(144)		(144)		(100)		(100)	(76)		(76)					(42)		(42)	(41)		(41)	(19)		(19)
Other comprehensive income (loss), net of income taxes	$ 14						14
Distributions to member																			(102)	(102)
Contributions from parent									167			167	227	227					704		704		387	387		144	144		173	173
Ending balance (in shares) at Mar. 31, 2022	982,042
Ending balance at Mar. 31, 2022	$ 23,491		20,299		(123)	4,028	(713)	0
Ending Balance at Mar. 31, 2022									12,566	1,588	1,735	9,243	5,445	3,655	1,790	4,692	2,575	2,117					3,866	2,689	1,177	1,936	1,353	583	1,755	1,763	(8)
Ending Balance at Mar. 31, 2022																			11,317	(182)	11,499
Beginning balance (in shares) at Dec. 31, 2021	981,291
Beginning balance at Dec. 31, 2021	$ 34,795		20,324		(123)	16,942	(2,750)	402
Beginning Balance at Dec. 31, 2021	34,393								12,355	1,588	1,691	9,076	5,112	3,428	1,684	4,570	2,575	1,995					3,475	2,302	1,173	1,777	1,209	568	1,575	1,590	(15)
Beginning Balance at Dec. 31, 2021																			10,585	(210)	10,795
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,063								415				339			234			230				116			77			37
Other comprehensive income (loss), net of income taxes	$ 26						26
Ending balance (in shares) at Jun. 30, 2022	982,305
Ending balance at Jun. 30, 2022	$ 23,656		20,319		(123)	4,161	(701)	0
Ending Balance at Jun. 30, 2022	$ 23,656								12,816	1,588	1,817	9,411	5,478	3,655	1,823	4,840	2,761	2,079					3,678	2,689	989	1,942	1,353	589	1,747	1,763	(16)
Ending Balance at Jun. 30, 2022																			11,124		11,499	(375)
Beginning balance (in shares) at Mar. 31, 2022	982,042
Beginning balance at Mar. 31, 2022	$ 23,491		20,299		(123)	4,028	(713)	0
Beginning Balance at Mar. 31, 2022									12,566	1,588	1,735	9,243	5,445	3,655	1,790	4,692	2,575	2,117					3,866	2,689	1,177	1,936	1,353	583	1,755	1,763	(8)
Beginning Balance at Mar. 31, 2022																			11,317	(182)	11,499
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 465					465		0	227		227		133		133	37		37	100	100			70		70	21		21	11		11
Long -Term Incentive Plan Activity (shares)	21
Long-Term Incentive Plan Activity	$ 10		10
Employee stock purchase plan issuances (shares)	242
Employee stock purchase plan issuances	$ 10		10
Changes in equity of noncontrolling interests	$ 0							0
Common Stock, Dividends, Per Share, Declared	$ 0.34
Common stock dividends	$ (332)					(332)			(145)		(145)		(100)		(100)	(75)		(75)					(258)		(258)	(15)		(15)	(19)		(19)
Other comprehensive income (loss), net of income taxes	$ 12						12
Distributions to member																			(293)	$ (293)
Contributions from parent									168			168				186	186
Ending balance (in shares) at Jun. 30, 2022	982,305
Ending balance at Jun. 30, 2022	$ 23,656		$ 20,319		$ (123)	$ 4,161	$ (701)	$ 0
Ending Balance at Jun. 30, 2022	$ 23,656								$ 12,816	$ 1,588	$ 1,817	$ 9,411	$ 5,478	$ 3,655	$ 1,823	$ 4,840	$ 2,761	$ 2,079					$ 3,678	$ 2,689	$ 989	$ 1,942	$ 1,353	$ 589	$ 1,747	$ 1,763	$ (16)
Ending Balance at Jun. 30, 2022																			$ 11,124		$ 11,499	$ (375)