Segment Information - Reconciliation to Consolidated Financial Statements (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total operating revenues	$ 5,980			$ 4,845			$ 16,360	$ 14,412
Income (loss) from continuing operations before income taxes:	767			768			1,985	1,978
Income taxes	67			92			274	356
Net income (loss):	700	$ 343	$ 669	676	$ 465	$ 598	1,711	1,739
Net income (loss) from continuing operations:	700			676			1,711	1,622
Capital expenditures							5,540	5,179
Total assets	99,259						99,259		$ 95,349
Pepco Holdings LLC
Segment Reporting Information [Line Items]
Total operating revenues	1,773			1,598			4,615	4,223
Income (loss) from continuing operations before income taxes:	281			291			593	528
Income taxes	49			2			103	10
Net income (loss):	232	$ 103	$ 155	289	$ 100	$ 130	490	518
Capital expenditures							1,510	1,174
Total assets	26,656						26,656		26,082
Related Party
Segment Reporting Information [Line Items]
Interest expense, net	6			6			18	19
Related Party | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2			3			7	9
Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	5,980			4,845			16,360	14,412
Depreciation and amortization	890			825			2,616	2,472
Operating expenses	4,857			3,834			13,429	11,804
Interest expense, net	437			365			1,277	1,063
Income (loss) from continuing operations before income taxes:	767			768			1,985	1,978
Income taxes	67			92			274	356
Net income (loss) from continuing operations:	700			676			1,711	1,622
Capital expenditures	1,855			1,672			5,540	4,952
Total assets	99,259						99,259		95,349
Operating Segment | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	0			0			0	6
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total operating revenues	(475)			(396)			(1,370)	(1,376)
Depreciation and amortization	0			0			0	0
Operating expenses	(478)			(380)			(1,367)	(1,288)
Interest expense, net	0			0			(4)	0
Income (loss) from continuing operations before income taxes:	(16)			0			(21)	(42)
Income taxes	0			0			1	(9)
Net income (loss) from continuing operations:	(15)			(1)			(22)	(33)
Capital expenditures	0			0			0	0
Total assets	(4,172)						(4,172)		(4,260)
Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Total operating revenues	(104)			(94)			(314)	(290)
Depreciation and amortization	0			0			0	0
Operating expenses	(103)			(95)			(314)	(290)
Interest expense, net	(1)			1			2	1
Income (loss) from continuing operations before income taxes:	(1)			0			0	0
Income taxes	0			0			0	0
Net income (loss):	0			0			0	0
Capital expenditures	0			0			0	0
Total assets	(74)						(74)		(33)
Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	(458)			(393)			(1,343)	(1,377)
Intersegment Eliminations | Related Party | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues from affiliates	(104)			(94)			(313)	(290)
Commonwealth Edison Co | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	2,268			1,378			5,836	4,536
Depreciation and amortization	357			333			1,045	982
Operating expenses	1,738			913			4,472	3,357
Interest expense, net	119			104			357	308
Income (loss) from continuing operations before income taxes:	427			375			1,057	909
Income taxes	94			84			235	203
Net income (loss) from continuing operations:	333			291			822	706
Capital expenditures	664			593			1,926	1,801
Total assets	42,042						42,042		39,661
Commonwealth Edison Co | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	9			6			14	14
PECO Energy Co | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	1,037			1,014			2,977	2,877
Depreciation and amortization	100			92			297	277
Operating expenses	847			798			2,436	2,230
Interest expense, net	52			45			149	129
Income (loss) from continuing operations before income taxes:	149			179			418	541
Income taxes	3			44			8	67
Net income (loss) from continuing operations:	146			135			410	474
Capital expenditures	361			333			1,068	991
Total assets	15,259						15,259		14,502
PECO Energy Co | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2			3			6	5
Baltimore Gas and Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	932			870			2,986	2,810
Depreciation and amortization	161			148			487	470
Operating expenses	835			810			2,503	2,446
Interest expense, net	47			39			135	110
Income (loss) from continuing operations before income taxes:	56			26			362	270
Income taxes	11			(7)			76	3
Net income (loss) from continuing operations:	45			33			286	267
Capital expenditures	330			340			986	918
Total assets	13,649						13,649		13,350
Baltimore Gas and Electric Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2			3			6	13
Pepco Holdings LLC | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	1,773			1,598			4,615	4,223
Depreciation and amortization	257			238			741	697
Operating expenses	1,440			1,254			3,864	3,535
Interest expense, net	80			72			238	216
Income (loss) from continuing operations before income taxes:	281			291			593	528
Income taxes	49			2			103	10
Net income (loss):	232			289			490	518
Net income (loss) from continuing operations:	232			289			490	518
Capital expenditures	488			398			1,510	1,174
Total assets	26,656						26,656		26,082
Pepco Holdings LLC | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2			3			7	9
Potomac Electric Power Company | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	822			724			2,174	1,919
Depreciation and amortization	112			99			329	312
Operating expenses	658			555			1,810	1,588
Interest expense, net	41			37			122	111
Income (loss) from continuing operations before income taxes:	141			146			292	259
Income taxes	21			1			43	(2)
Net income (loss):	120			145			249	261
Capital expenditures	227			193			710	595
Total assets	11,061						11,061		10,657
Potomac Electric Power Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	1			2			5	4
Delmarva Power and Light Company | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	450			412			1,273	1,176
Depreciation and amortization	62			59			182	172
Operating expenses	386			345			1,079	999
Interest expense, net	18			16			53	48
Income (loss) from continuing operations before income taxes:	51			54			153	138
Income taxes	8			2			25	8
Net income (loss):	43			52			128	130
Capital expenditures	158			100			416	294
Total assets	5,870						5,870		5,802
Delmarva Power and Light Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2			1			5	5
Atlantic City Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	502			462			1,172	1,120
Depreciation and amortization	77			74			212	192
Operating expenses	394			353			971	947
Interest expense, net	19			17			52	49
Income (loss) from continuing operations before income taxes:	94			95			162	133
Income taxes	23			1			40	2
Net income (loss):	71			94			122	131
Capital expenditures	101			105			376	284
Total assets	5,155						5,155		4,979
Atlantic City Electric Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	0			0			1	2
Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total operating revenues	445			381			1,316	1,342
Depreciation and amortization	15			14			46	46
Operating expenses	475			439			1,521	1,524
Interest expense, net	139			105			402	300
Income (loss) from continuing operations before income taxes:	(130)			(103)			(424)	(228)
Income taxes	(90)			(31)			(149)	82
Net income (loss) from continuing operations:	(41)			(71)			(275)	(310)
Capital expenditures	12			8			50	68
Total assets	5,825						5,825		6,014
Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Total operating revenues	103			94			310	298
Depreciation and amortization	6			6			18	21
Operating expenses	105			96			318	291
Interest expense, net	3			1			9	7
Income (loss) from continuing operations before income taxes:	(4)			(4)			(14)	(2)
Income taxes	(3)			(2)			(5)	2
Net income (loss):	(2)			(2)			(9)	(4)
Capital expenditures	2			0			8	1
Total assets	4,644						4,644		$ 4,677
Corporate and Other | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	443			378			1,310	1,342
Corporate and Other | Intersegment Eliminations | Related Party | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues from affiliates	103			94			309	288
Rate-regulated electric revenues
Segment Reporting Information [Line Items]
Electric operating revenues	5,684			4,557			14,579	12,972
Rate-regulated electric revenues | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric operating revenues	1,762			1,568			4,399	4,090
Rate-regulated electric revenues | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	5,793			4,621			15,056	13,082
Rate-regulated electric revenues | Intersegment Eliminations
Segment Reporting Information [Line Items]
Electric operating revenues	(28)			(12)			(45)	(24)
Rate-regulated electric revenues | Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric operating revenues	(3)			(3)			(11)	0
Rate-regulated electric revenues | Commonwealth Edison Co | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	2,268			1,378			5,836	4,536
Rate-regulated electric revenues | PECO Energy Co | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	970			941			2,484	2,390
Rate-regulated electric revenues | Baltimore Gas and Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	836			757			2,322	2,122
Rate-regulated electric revenues | Pepco Holdings LLC | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	1,747			1,557			4,459	4,058
Rate-regulated electric revenues | Potomac Electric Power Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	822			724			2,174	1,919
Rate-regulated electric revenues | Delmarva Power and Light Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	426			374			1,123	1,019
Rate-regulated electric revenues | Atlantic City Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	502			462			1,172	1,120
Rate-regulated electric revenues | Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Rate-regulated electric revenues | Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			1	0
Rate-regulated natural gas revenues
Segment Reporting Information [Line Items]
Electric operating revenues	188			224			1,268	1,348
Rate-regulated natural gas revenues | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric operating revenues	24			38			150	157
Rate-regulated natural gas revenues | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	187			224			1,304	1,330
Rate-regulated natural gas revenues | Intersegment Eliminations
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			(3)	(2)
Rate-regulated natural gas revenues | Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Rate-regulated natural gas revenues | Commonwealth Edison Co | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Rate-regulated natural gas revenues | PECO Energy Co | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	67			73			493	487
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	96			113			664	688
Rate-regulated natural gas revenues | Pepco Holdings LLC | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	24			38			150	157
Rate-regulated natural gas revenues | Potomac Electric Power Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Rate-regulated natural gas revenues | Delmarva Power and Light Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	24			38			150	157
Rate-regulated natural gas revenues | Atlantic City Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Rate-regulated natural gas revenues | Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Rate-regulated natural gas revenues | Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Shared service and other revenues | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Shared service and other revenues | Intersegment Eliminations
Segment Reporting Information [Line Items]
Electric operating revenues	(447)			(384)			(1,322)	(1,350)
Shared service and other revenues | Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric operating revenues	(101)			(91)			(303)	(290)
Shared service and other revenues | Commonwealth Edison Co | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Shared service and other revenues | PECO Energy Co | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Shared service and other revenues | Baltimore Gas and Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Shared service and other revenues | Pepco Holdings LLC | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	2			3			6	8
Shared service and other revenues | Potomac Electric Power Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Shared service and other revenues | Delmarva Power and Light Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Shared service and other revenues | Atlantic City Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric operating revenues	0			0			0	0
Shared service and other revenues | Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Electric operating revenues	445			381			1,316	1,342
Shared service and other revenues | Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric operating revenues	$ 103			$ 94			$ 309	$ 298