Segment Information - Reconciliation to Consolidated Financial Statements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total operating revenues	$ 6,043	$ 5,563
Income taxes	63	134
Net income (loss):	658	669
Total assets	103,211		$ 101,546
Pepco Holdings LLC
Segment Reporting Information [Line Items]
Total operating revenues	1,606	1,536
Income taxes	40	34
Net income (loss):	168	155
Total assets	27,535		26,903
Related Party
Segment Reporting Information [Line Items]
Interest expense, net	6	6
Related Party | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues from affiliates	3	3
Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	6,043	5,563
Depreciation and amortization	879	860
Operating expenses	4,931	4,457
Interest expense, net	468	412
Income taxes	63	134
Net income (loss):	658	669
Capital expenditures	1,767	1,881
Total assets	103,211		101,546
Operating Segment | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	0	0
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total operating revenues	(468)	(446)
Depreciation and amortization	0	0
Operating expenses	(475)	(447)
Interest expense, net	0	0
Income taxes	0	0
Net income (loss):	0	0
Capital expenditures	0	0
Total assets	(4,392)		(4,337)
Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Total operating revenues	(111)	(103)
Depreciation and amortization	0	0
Operating expenses	(110)	(103)
Interest expense, net	0	0
Income taxes	0	0
Net income (loss):	0	0
Capital expenditures	0	0
Total assets	(312)		(41)
Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	(466)	(445)
Intersegment Eliminations | Related Party | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues from affiliates	(111)	(103)
Commonwealth Edison Co | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	2,095	1,667
Depreciation and amortization	362	338
Operating expenses	1,781	1,256
Interest expense, net	122	117
Income taxes	19	71
Net income (loss):	193	241
Capital expenditures	594	617
Total assets	43,132		42,827
Commonwealth Edison Co | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2	3
PECO Energy Co | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	1,054	1,112
Depreciation and amortization	104	98
Operating expenses	851	902
Interest expense, net	55	48
Income taxes	10	4
Net income (loss):	149	166
Capital expenditures	361	335
Total assets	16,116		15,595
PECO Energy Co | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2	2
Baltimore Gas and Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	1,297	1,257
Depreciation and amortization	150	167
Operating expenses	967	964
Interest expense, net	50	44
Income taxes	24	52
Net income (loss):	264	200
Capital expenditures	324	350
Total assets	14,444		14,184
Baltimore Gas and Electric Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2	3
Pepco Holdings LLC | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	1,606	1,536
Depreciation and amortization	246	241
Operating expenses	1,335	1,297
Interest expense, net	90	76
Income taxes	40	34
Net income (loss):	168	155
Capital expenditures	453	561
Total assets	27,535		26,903
Pepco Holdings LLC | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	3	3
Potomac Electric Power Company | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	759	710
Depreciation and amortization	107	108
Operating expenses	640	610
Interest expense, net	45	39
Income taxes	14	12
Net income (loss):	75	65
Capital expenditures	229	264
Total assets	11,585		11,194
Potomac Electric Power Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2	1
Delmarva Power and Light Company | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	491	474
Depreciation and amortization	61	60
Operating expenses	391	388
Interest expense, net	22	17
Income taxes	17	12
Net income (loss):	66	60
Capital expenditures	134	134
Total assets	6,291		5,966
Delmarva Power and Light Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2	2
Atlantic City Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Total operating revenues	358	353
Depreciation and amortization	74	67
Operating expenses	303	298
Interest expense, net	20	16
Income taxes	11	11
Net income (loss):	29	33
Capital expenditures	89	161
Total assets	5,253		5,157
Atlantic City Electric Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	1	1
Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total operating revenues	459	437
Depreciation and amortization	17	16
Operating expenses	472	485
Interest expense, net	151	127
Income taxes	(30)	(27)
Net income (loss):	(116)	(93)
Capital expenditures	35	18
Total assets	6,376		6,374
Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Total operating revenues	109	102
Depreciation and amortization	4	6
Operating expenses	111	104
Interest expense, net	3	4
Income taxes	(2)	(1)
Net income (loss):	(2)	(3)
Capital expenditures	1	2
Total assets	4,718		$ 4,627
Corporate and Other | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	457	434
Corporate and Other | Intersegment Eliminations | Related Party | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues from affiliates	109	102
Rate-regulated electric revenues
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	5,198	4,462
Rate-regulated electric revenues | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	1,485	1,371
Rate-regulated electric revenues | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	5,284	4,707
Rate-regulated electric revenues | Intersegment Eliminations
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	(6)	(5)
Rate-regulated electric revenues | Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	(4)	(4)
Rate-regulated electric revenues | Commonwealth Edison Co | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	2,095	1,667
Rate-regulated electric revenues | PECO Energy Co | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	782	795
Rate-regulated electric revenues | Baltimore Gas and Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	881	814
Rate-regulated electric revenues | Pepco Holdings LLC | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	1,532	1,436
Rate-regulated electric revenues | Potomac Electric Power Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	759	710
Rate-regulated electric revenues | Delmarva Power and Light Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	419	377
Rate-regulated electric revenues | Atlantic City Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	358	353
Rate-regulated electric revenues | Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated electric revenues | Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	739	822
Rate-regulated natural gas revenues | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	72	97
Rate-regulated natural gas revenues | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	759	856
Rate-regulated natural gas revenues | Intersegment Eliminations
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	(1)	(1)
Rate-regulated natural gas revenues | Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Commonwealth Edison Co | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | PECO Energy Co | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	272	317
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	416	443
Rate-regulated natural gas revenues | Pepco Holdings LLC | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	72	97
Rate-regulated natural gas revenues | Potomac Electric Power Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Delmarva Power and Light Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	72	97
Rate-regulated natural gas revenues | Atlantic City Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Shared service and other revenues | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Shared service and other revenues | Intersegment Eliminations
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	(461)	(440)
Shared service and other revenues | Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	(107)	(99)
Shared service and other revenues | Commonwealth Edison Co | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Shared service and other revenues | PECO Energy Co | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Shared service and other revenues | Baltimore Gas and Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Shared service and other revenues | Pepco Holdings LLC | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	2	3
Shared service and other revenues | Potomac Electric Power Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Shared service and other revenues | Delmarva Power and Light Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Shared service and other revenues | Atlantic City Electric Company | Operating Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	0	0
Shared service and other revenues | Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	459	437
Shared service and other revenues | Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Electric and natural gas operating revenues	$ 109	$ 102