Segment Information - Reconciliation to Consolidated Financial Statements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Total operating revenues	$ 21,727	$ 19,078	$ 17,938
Income taxes	374	349	38
Net income	2,328	2,171	1,829
Total assets	101,546	95,349
Pepco Holdings LLC
Segment Reporting Information [Line Items]
Total operating revenues	6,026	5,565	5,041
Operating revenues from affiliates	9	10	13
Income taxes	116	9	42
Net income	590	608	561
Total assets	26,903	26,082
Pepco Holdings LLC | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	9	10	13
Operating Segments
Segment Reporting Information [Line Items]
Total operating revenues	21,727	19,078	17,938
Depreciation and amortization	3,506	3,325	3,033
Operating expenses	17,714	15,761	15,256
Interest expense, net	1,729	1,447	1,289
Income taxes	374	349	38
Net income	2,328	2,054	1,616
Capital expenditures	7,411	6,921	6,640
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Income taxes	(212)	(21)	(48)
Net income	2,328	2,170	1,706
Total assets	43,632	40,578
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total operating revenues	(1,823)	(1,869)	(2,261)
Depreciation and amortization	0	0	1
Operating expenses	(1,820)	(1,762)	(1,587)
Interest expense, net	0	(3)	(1)
Income taxes	(2)	(11)	(161)
Net income	(20)	(34)	(443)
Capital expenditures	0	0	0
Total assets	(4,337)	(4,260)
Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	0	6	57
Intersegment Eliminations | Related Party | Intersubsegment Eliminations
Segment Reporting Information [Line Items]
Operating revenues from affiliates	(1,793)	(1,865)	(2,252)
Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Total operating revenues	(431)	(383)	(380)
Depreciation and amortization	0	0	0
Operating expenses	(431)	(383)	(381)
Interest expense, net	0	1	0
Income taxes	0	0	0
Net income	0	0	0
Capital expenditures	0	0	0
Total assets	(41)	(33)
Intersegment Eliminations | Pepco Holdings LLC | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	(432)	(383)	(381)
Commonwealth Edison Co | Operating Segments
Segment Reporting Information [Line Items]
Total operating revenues	7,844	5,761	6,406
Depreciation and amortization	1,403	1,323	1,205
Operating expenses	6,038	4,218	5,151
Interest expense, net	477	414	389
Income taxes	314	264	172
Net income	1,090	917	742
Capital expenditures	2,576	2,506	2,387
Total assets	42,827	39,661
Commonwealth Edison Co | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	16	16	41
PECO Energy Co | Operating Segments
Segment Reporting Information [Line Items]
Total operating revenues	3,894	3,903	3,198
Depreciation and amortization	397	373	348
Operating expenses	3,146	3,102	2,547
Interest expense, net	201	177	161
Income taxes	20	79	12
Net income	563	576	504
Capital expenditures	1,426	1,349	1,240
Total assets	15,595	14,502
PECO Energy Co | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	9	7	21
Baltimore Gas and Electric Company | Operating Segments
Segment Reporting Information [Line Items]
Total operating revenues	4,027	3,895	3,341
Depreciation and amortization	654	630	591
Operating expenses	3,245	3,376	2,860
Interest expense, net	182	152	138
Income taxes	133	8	(35)
Net income	485	380	408
Capital expenditures	1,367	1,262	1,226
Total assets	14,184	13,350
Baltimore Gas and Electric Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	9	15	31
Pepco Holdings LLC | Operating Segments
Segment Reporting Information [Line Items]
Total operating revenues	6,026	5,565	5,041
Depreciation and amortization	990	938	821
Operating expenses	5,114	4,734	4,240
Interest expense, net	323	292	267
Income taxes	116	9	42
Net income	590	608	561
Capital expenditures	1,988	1,709	1,720
Total assets	26,903	26,082
Pepco Holdings LLC | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	9	10	13
Potomac Electric Power Company | Operating Segments
Segment Reporting Information [Line Items]
Total operating revenues	2,824	2,531	2,274
Depreciation and amortization	441	417	403
Operating expenses	2,377	2,140	1,871
Interest expense, net	165	150	140
Income taxes	51	(9)	15
Net income	306	305	296
Capital expenditures	957	874	843
Total assets	11,194	10,657
Potomac Electric Power Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	9	5	5
Delmarva Power & Light Company | Operating Segments
Segment Reporting Information [Line Items]
Total operating revenues	1,688	1,595	1,380
Depreciation and amortization	244	232	210
Operating expenses	1,420	1,359	1,161
Interest expense, net	74	66	61
Income taxes	35	14	42
Net income	177	169	128
Capital expenditures	562	430	429
Total assets	5,966	5,802
Delmarva Power & Light Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	8	6	7
Atlantic City Electric Company | Operating Segments
Segment Reporting Information [Line Items]
Total operating revenues	1,522	1,431	1,388
Depreciation and amortization	283	261	179
Operating expenses	1,314	1,225	1,201
Interest expense, net	72	66	58
Income taxes	36	3	(13)
Net income	120	148	146
Capital expenditures	460	398	445
Total assets	5,157	4,979
Atlantic City Electric Company | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	2	2	2
Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total operating revenues	1,759	1,823	2,213
Depreciation and amortization	62	61	67
Operating expenses	1,991	2,093	2,045
Interest expense, net	546	415	335
Income taxes	(207)	0	8
Net income	(380)	(393)	(156)
Capital expenditures	54	95	67
Total assets	6,374	6,014
Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Total operating revenues	423	391	379
Depreciation and amortization	22	28	29
Operating expenses	434	393	388
Interest expense, net	12	9	8
Income taxes	(6)	1	(2)
Net income	(13)	(14)	(9)
Capital expenditures	9	7	3
Total assets	4,627	4,677
Corporate and Other | Intersegment Eliminations | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	1,750	1,823	2,203
Corporate and Other | Intersegment Eliminations | Pepco Holdings LLC | Related Party
Segment Reporting Information [Line Items]
Operating revenues from affiliates	422	380	380
Electricity, US Regulated
Segment Reporting Information [Line Items]
Operating revenues	19,267	16,899	16,245
Electricity, US Regulated | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues	5,748	5,376	4,769
Electricity, US Regulated | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	19,916	17,083	16,395
Electricity, US Regulated | Intersegment Eliminations
Segment Reporting Information [Line Items]
Operating revenues	(51)	(31)	(35)
Electricity, US Regulated | Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues	(18)	(2)	(14)
Electricity, US Regulated | Commonwealth Edison Co | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	7,844	5,761	6,406
Electricity, US Regulated | PECO Energy Co | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	3,202	3,165	2,659
Electricity, US Regulated | Baltimore Gas and Electric Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	3,109	2,871	2,505
Electricity, US Regulated | Pepco Holdings LLC | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	5,812	5,317	4,860
Electricity, US Regulated | Potomac Electric Power Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	2,824	2,531	2,274
Electricity, US Regulated | Delmarva Power & Light Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	1,483	1,357	1,212
Electricity, US Regulated | Atlantic City Electric Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	1,522	1,431	1,388
Electricity, US Regulated | Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Electricity, US Regulated | Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues	1	0	0
Natural Gas, US Regulated
Segment Reporting Information [Line Items]
Operating revenues	1,764	2,018	1,522
Natural Gas, US Regulated | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues	205	238	168
Natural Gas, US Regulated | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	1,811	1,995	1,543
Natural Gas, US Regulated | Intersegment Eliminations
Segment Reporting Information [Line Items]
Operating revenues	(4)	(5)	0
Natural Gas, US Regulated | Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Natural Gas, US Regulated | Commonwealth Edison Co | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Natural Gas, US Regulated | PECO Energy Co | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	692	738	539
Natural Gas, US Regulated | Baltimore Gas and Electric Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	918	1,024	836
Natural Gas, US Regulated | Pepco Holdings LLC | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	205	238	168
Natural Gas, US Regulated | Potomac Electric Power Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Natural Gas, US Regulated | Delmarva Power & Light Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	205	238	168
Natural Gas, US Regulated | Atlantic City Electric Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Natural Gas, US Regulated | Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Natural Gas, US Regulated | Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Service, Other | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Service, Other | Intersegment Eliminations
Segment Reporting Information [Line Items]
Operating revenues	(1,768)	(1,833)	(2,226)
Service, Other | Intersegment Eliminations | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues	(413)	(381)	(366)
Service, Other | Commonwealth Edison Co | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Service, Other | PECO Energy Co | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Service, Other | Baltimore Gas and Electric Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Service, Other | Pepco Holdings LLC | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	9	10	13
Service, Other | Potomac Electric Power Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Service, Other | Delmarva Power & Light Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Service, Other | Atlantic City Electric Company | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	0	0	0
Service, Other | Corporate and Other | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Operating revenues	1,759	1,823	2,213
Service, Other | Corporate and Other | Corporate, Non-Segment | Pepco Holdings LLC
Segment Reporting Information [Line Items]
Operating revenues	$ 422	$ 391	$ 379