Segment Information - Reconciliation to Consolidated Financial Statements (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Revenues	$ 4,818		$ 4,239		$ 10,380	$ 9,566
Income (Loss) before income taxes	416		511		1,218	1,209
Income taxes	73		46		206	263
Net income (loss)	343	$ 669	465	$ 598	1,012	1,063
Capital expenditures					3,685	3,507
Assets	98,080				98,080		$ 95,349
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	343		465		1,012	946
Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues	1,305		1,221		2,841	2,626
Income (Loss) before income taxes	123		101		312	238
Income taxes	20		1		54	8
Net income (loss)	103	$ 155	100	$ 130	258	230
Capital expenditures					1,022	776
Assets	26,241				26,241		26,082
Related Party
Segment Reporting Information [Line Items]
Interest Expense, Other	6		6		12	13
Related Party | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues from Related Parties	2		2		4	6
Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	4,818		4,239		10,380	9,566
Depreciation and Amortization	866		830		1,727	1,647
Operating Expenses	4,114		3,543		8,571	7,971
Interest Expense, Other	427		358		840	697
Income (Loss) before income taxes	416		511		1,218	1,209
Income taxes	73		46		206	263
Capital expenditures	1,804		1,585		3,685	3,280
Assets	98,080				98,080		95,349
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	343		465		1,012	946
Operating Segment [Member] | Related Party
Segment Reporting Information [Line Items]
Revenues from Related Parties	0		0		0	6
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(447)		(393)		(893)	(982)
Depreciation and Amortization	0		1		2	0
Operating Expenses	(442)		(378)		(889)	(909)
Interest Expense, Other	0		1		(2)	0
Income (Loss) before income taxes	(6)		(1)		(5)	(45)
Income taxes	0		0		0	(12)
Capital expenditures	0		0		0	0
Assets	(4,450)				(4,450)		(4,260)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(6)		(1)		(4)	(33)
Intersegment Eliminations [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues	(108)		(99)		(210)	(195)
Depreciation and Amortization	0		0		0	0
Operating Expenses	(108)		(99)		(210)	(195)
Interest Expense, Other	0		0		0	(1)
Income (Loss) before income taxes	1		0		0	0
Income taxes	0		0		0	0
Net income (loss)	1		0		0	0
Capital expenditures	0		0		0	0
Assets	(243)				(243)		(33)
Intersegment Eliminations [Member] | Related Party
Segment Reporting Information [Line Items]
Revenues from Related Parties	(440)		(393)		(884)	(981)
Intersegment Eliminations [Member] | Related Party | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues from Related Parties	(107)		(101)		(209)	(196)
Commonwealth Edison Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,901		1,425		3,568	3,158
Depreciation and Amortization	350		328		688	649
Operating Expenses	1,478		1,039		2,734	2,444
Interest Expense, Other	120		104		237	204
Income (Loss) before income taxes	320		293		631	534
Income taxes	71		66		142	119
Capital expenditures	645		591		1,262	1,208
Assets	41,672				41,672		39,661
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	249		227		489	415
Commonwealth Edison Co [Member] | Intersegment Eliminations [Member] | Related Party
Segment Reporting Information [Line Items]
Revenues from Related Parties	2		3		5	8
PECO Energy Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	828		816		1,940	1,863
Depreciation and Amortization	99		93		197	185
Operating Expenses	687		639		1,590	1,432
Interest Expense, Other	48		43		97	84
Income (Loss) before income taxes	99		142		268	363
Income taxes	2		9		5	24
Capital expenditures	372		314		707	658
Assets	15,207				15,207		14,502
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	97		133		263	339
PECO Energy Co [Member] | Intersegment Eliminations [Member] | Related Party
Segment Reporting Information [Line Items]
Revenues from Related Parties	2		1		4	2
Baltimore Gas and Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	797		786		2,053	1,940
Depreciation and Amortization	158		152		325	322
Operating Expenses	704		717		1,667	1,636
Interest Expense, Other	44		36		88	71
Income (Loss) before income taxes	54		38		306	244
Income taxes	12		1		65	10
Capital expenditures	306		275		656	578
Assets	13,488				13,488		13,350
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	42		37		241	234
Baltimore Gas and Electric Company [Member] | Intersegment Eliminations [Member] | Related Party
Segment Reporting Information [Line Items]
Revenues from Related Parties	2		3		4	10
Pepco Holdings LLC [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,305		1,221		2,841	2,626
Depreciation and Amortization	243		240		484	459
Operating Expenses	1,126		1,066		2,423	2,282
Interest Expense, Other	81		73		157	143
Income (Loss) before income taxes	123		101		312	238
Income taxes	20		1		54	8
Net income (loss)	103		100		258	230
Capital expenditures	461		367		1,022	776
Assets	26,241				26,241		26,082
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	103		100		258	230
Pepco Holdings LLC [Member] | Intersegment Eliminations [Member] | Related Party
Segment Reporting Information [Line Items]
Revenues from Related Parties	2		2		4	6
Potomac Electric Power Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	642		581		1,351	1,195
Depreciation and Amortization	109		105		216	213
Operating Expenses	541		487		1,151	1,034
Interest Expense, Other	43		38		81	74
Income (Loss) before income taxes	74		69		152	113
Income taxes	10		(1)		22	(3)
Net income (loss)	64		70		130	116
Capital expenditures	219		184		483	402
Assets	10,838				10,838		10,657
Potomac Electric Power Company [Member] | Intersegment Eliminations [Member] | Related Party
Segment Reporting Information [Line Items]
Revenues from Related Parties	2		2		3	2
Delmarva Power and Light Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	349		332		823	763
Depreciation and Amortization	60		56		121	113
Operating Expenses	305		296		693	653
Interest Expense, Other	18		17		36	33
Income (Loss) before income taxes	30		23		102	83
Income taxes	5		2		17	6
Net income (loss)	25		21		85	77
Capital expenditures	124		91		258	194
Assets	5,823				5,823		5,802
Delmarva Power and Light Company [Member] | Intersegment Eliminations [Member] | Related Party
Segment Reporting Information [Line Items]
Revenues from Related Parties	2		2		3	3
Atlantic City Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	317		309		670	658
Depreciation and Amortization	68		72		135	118
Operating Expenses	280		283		577	593
Interest Expense, Other	17		17		34	32
Income (Loss) before income taxes	24		11		68	38
Income taxes	6		0		17	1
Net income (loss)	18		11		51	37
Capital expenditures	114		92		275	179
Assets	5,088				5,088		4,979
Atlantic City Electric Company [Member] | Intersegment Eliminations [Member] | Related Party
Segment Reporting Information [Line Items]
Revenues from Related Parties	1		1		1	2
Corporate and Other [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenues	434		384		871	961
Depreciation and Amortization	16		16		31	32
Operating Expenses	561		460		1,046	1,086
Interest Expense, Other	134		101		263	195
Income (Loss) before income taxes	(174)		(62)		(294)	(125)
Income taxes	(32)		(31)		(60)	114
Capital expenditures	20		38		38	60
Assets	5,922				5,922		6,014
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(142)		(31)		(235)	(239)
Corporate and Other [Member] | Corporate, Non-Segment [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues	105		98		207	205
Depreciation and Amortization	6		7		12	15
Operating Expenses	108		99		212	197
Interest Expense, Other	3		1		6	5
Income (Loss) before income taxes	(6)		(2)		(10)	4
Income taxes	(1)		0		(2)	4
Net income (loss)	(5)		(2)		(8)	0
Capital expenditures	4		0		6	1
Assets	4,735				4,735		$ 4,677
Corporate and Other [Member] | Intersegment Eliminations [Member] | Related Party
Segment Reporting Information [Line Items]
Revenues from Related Parties	432		384		867	961
Corporate and Other [Member] | Intersegment Eliminations [Member] | Related Party | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues from Related Parties	104		98		206	195
Rate-regulated electric revenues [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,434		3,934		8,896	8,415
Rate-regulated electric revenues [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,265		1,199		2,637	2,522
Rate-regulated electric revenues [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,556		3,938		9,264	8,460
Rate-regulated electric revenues [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(10)		(6)		(14)	(14)
Rate-regulated electric revenues [Member] | Intersegment Eliminations [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(5)		(3)		(7)	5
Rate-regulated electric revenues [Member] | Commonwealth Edison Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,901		1,425		3,568	3,158
Rate-regulated electric revenues [Member] | PECO Energy Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	719		708		1,514	1,449
Rate-regulated electric revenues [Member] | Baltimore Gas and Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	672		629		1,485	1,366
Rate-regulated electric revenues [Member] | Pepco Holdings LLC [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,274		1,182		2,711	2,501
Rate-regulated electric revenues [Member] | Potomac Electric Power Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	642		581		1,351	1,195
Rate-regulated electric revenues [Member] | Delmarva Power and Light Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	320		295		697	643
Rate-regulated electric revenues [Member] | Atlantic City Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	317		309		670	658
Rate-regulated electric revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Rate-regulated electric revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Rate-regulated natural gas revenues [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	258		307		1,080	1,124
Rate-regulated natural gas revenues [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	29		37		126	120
Rate-regulated natural gas revenues [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	262		301		1,116	1,106
Rate-regulated natural gas revenues [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(1)		(1)		(4)	(2)
Rate-regulated natural gas revenues [Member] | Intersegment Eliminations [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Rate-regulated natural gas revenues [Member] | Commonwealth Edison Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Rate-regulated natural gas revenues [Member] | PECO Energy Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	109		108		426	414
Rate-regulated natural gas revenues [Member] | Baltimore Gas and Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	125		157		568	574
Rate-regulated natural gas revenues [Member] | Pepco Holdings LLC [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	29		37		126	120
Rate-regulated natural gas revenues [Member] | Potomac Electric Power Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Rate-regulated natural gas revenues [Member] | Delmarva Power and Light Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	29		37		126	120
Rate-regulated natural gas revenues [Member] | Atlantic City Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Rate-regulated natural gas revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Rate-regulated natural gas revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Shared service and other revenues [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Shared service and other revenues [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(436)		(386)		(875)	(966)
Shared service and other revenues [Member] | Intersegment Eliminations [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(103)		(96)		(203)	(200)
Shared service and other revenues [Member] | Commonwealth Edison Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Shared service and other revenues [Member] | PECO Energy Co [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Shared service and other revenues [Member] | Baltimore Gas and Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Shared service and other revenues [Member] | Pepco Holdings LLC [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2		2		4	5
Shared service and other revenues [Member] | Potomac Electric Power Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Shared service and other revenues [Member] | Delmarva Power and Light Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Shared service and other revenues [Member] | Atlantic City Electric Company [Member] | Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0		0		0	0
Shared service and other revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	434		384		871	961
Shared service and other revenues [Member] | Corporate and Other [Member] | Corporate, Non-Segment [Member] | Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 105		$ 98		$ 207	$ 205