Segment Information - Electric and Gas Revenue by Customer Class (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue, Major Customer [Line Items]
Total operating revenues	$ 6,043	$ 5,563
Operating Segment
Revenue, Major Customer [Line Items]
Total operating revenues	6,043	5,563
Operating Segment | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	0	0
Commonwealth Edison Co
Revenue, Major Customer [Line Items]
Total operating revenues	2,095	1,667
Commonwealth Edison Co | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	2	3
Commonwealth Edison Co | Regulated Operation
Revenue, Major Customer [Line Items]
Total operating revenues	2,076	1,508
Commonwealth Edison Co | Other Regulated Revenue
Revenue, Major Customer [Line Items]
Total operating revenues	19	159
PECO Energy Co
Revenue, Major Customer [Line Items]
Total operating revenues	1,054	1,112
PECO Energy Co | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	2	2
PECO Energy Co | Regulated Operation
Revenue, Major Customer [Line Items]
Total operating revenues	1,056	1,111
PECO Energy Co | Other Regulated Revenue
Revenue, Major Customer [Line Items]
Total operating revenues	(2)	1
Baltimore Gas and Electric Company
Revenue, Major Customer [Line Items]
Total operating revenues	1,297	1,257
Baltimore Gas and Electric Company | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	2	3
Baltimore Gas and Electric Company | Regulated Operation
Revenue, Major Customer [Line Items]
Total operating revenues	1,251	1,186
Baltimore Gas and Electric Company | Other Regulated Revenue
Revenue, Major Customer [Line Items]
Total operating revenues	46	71
Pepco Holdings LLC
Revenue, Major Customer [Line Items]
Total operating revenues	1,606	1,536
Pepco Holdings LLC | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	3	3
Pepco Holdings LLC | Regulated Operation
Revenue, Major Customer [Line Items]
Total operating revenues	1,557	1,467
Pepco Holdings LLC | Other Regulated Revenue
Revenue, Major Customer [Line Items]
Total operating revenues	49	69
Potomac Electric Power Company
Revenue, Major Customer [Line Items]
Total operating revenues	759	710
Potomac Electric Power Company | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	2	1
Potomac Electric Power Company | Regulated Operation
Revenue, Major Customer [Line Items]
Total operating revenues	728	668
Potomac Electric Power Company | Other Regulated Revenue
Revenue, Major Customer [Line Items]
Total operating revenues	31	42
Delmarva Power and Light Company
Revenue, Major Customer [Line Items]
Total operating revenues	491	474
Delmarva Power and Light Company | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	2	2
Delmarva Power and Light Company | Regulated Operation
Revenue, Major Customer [Line Items]
Total operating revenues	486	464
Delmarva Power and Light Company | Other Regulated Revenue
Revenue, Major Customer [Line Items]
Total operating revenues	5	10
Atlantic City Electric Company
Revenue, Major Customer [Line Items]
Total operating revenues	358	353
Atlantic City Electric Company | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	1	1
Atlantic City Electric Company | Regulated Operation
Revenue, Major Customer [Line Items]
Total operating revenues	345	336
Atlantic City Electric Company | Other Regulated Revenue
Revenue, Major Customer [Line Items]
Total operating revenues	13	17
Rate-regulated electric revenues
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	5,198	4,462
Rate-regulated electric revenues | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	5,284	4,707
Rate-regulated electric revenues | Commonwealth Edison Co
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	2,074	1,511
Rate-regulated electric revenues | Commonwealth Edison Co | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	2,076	1,508
Rate-regulated electric revenues | Commonwealth Edison Co | Regulated Operation | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	2	3
Rate-regulated electric revenues | Commonwealth Edison Co | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	6
Rate-regulated electric revenues | Commonwealth Edison Co | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	918	836
Rate-regulated electric revenues | Commonwealth Edison Co | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	594	361
Rate-regulated electric revenues | Commonwealth Edison Co | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	320	84
Rate-regulated electric revenues | Commonwealth Edison Co | Regulated Operation | Public authorities & electric railroads
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	17	10
Rate-regulated electric revenues | Commonwealth Edison Co | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	227	217
Rate-regulated electric revenues | PECO Energy Co
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	782	798
Rate-regulated electric revenues | PECO Energy Co | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	784	795
Rate-regulated electric revenues | PECO Energy Co | Regulated Operation | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	2	1
Rate-regulated electric revenues | PECO Energy Co | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	4
Rate-regulated electric revenues | PECO Energy Co | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	520	519
Rate-regulated electric revenues | PECO Energy Co | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	126	135
Rate-regulated electric revenues | PECO Energy Co | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	57	65
Rate-regulated electric revenues | PECO Energy Co | Regulated Operation | Public authorities & electric railroads
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	7	8
Rate-regulated electric revenues | PECO Energy Co | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	74	68
Rate-regulated electric revenues | Baltimore Gas and Electric Company
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	857	780
Rate-regulated electric revenues | Baltimore Gas and Electric Company | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	856	778
Rate-regulated electric revenues | Baltimore Gas and Electric Company | Regulated Operation | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	1	2
Rate-regulated electric revenues | Baltimore Gas and Electric Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	2	4
Rate-regulated electric revenues | Baltimore Gas and Electric Company | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	534	434
Rate-regulated electric revenues | Baltimore Gas and Electric Company | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	90	92
Rate-regulated electric revenues | Baltimore Gas and Electric Company | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	132	149
Rate-regulated electric revenues | Baltimore Gas and Electric Company | Regulated Operation | Public authorities & electric railroads
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	7	7
Rate-regulated electric revenues | Baltimore Gas and Electric Company | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	93	96
Rate-regulated electric revenues | Pepco Holdings LLC
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	1,485	1,371
Rate-regulated electric revenues | Pepco Holdings LLC | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	1,485	1,370
Rate-regulated electric revenues | Pepco Holdings LLC | Regulated Operation | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	3	3
Rate-regulated electric revenues | Pepco Holdings LLC | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	3	4
Rate-regulated electric revenues | Pepco Holdings LLC | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	775	639
Rate-regulated electric revenues | Pepco Holdings LLC | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	158	160
Rate-regulated electric revenues | Pepco Holdings LLC | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	340	378
Rate-regulated electric revenues | Pepco Holdings LLC | Regulated Operation | Public authorities & electric railroads
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	20	17
Rate-regulated electric revenues | Pepco Holdings LLC | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	192	176
Rate-regulated electric revenues | Potomac Electric Power Company
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	728	670
Rate-regulated electric revenues | Potomac Electric Power Company | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	728	668
Rate-regulated electric revenues | Potomac Electric Power Company | Regulated Operation | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	2	1
Rate-regulated electric revenues | Potomac Electric Power Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	2	3
Rate-regulated electric revenues | Potomac Electric Power Company | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	345	283
Rate-regulated electric revenues | Potomac Electric Power Company | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	46	39
Rate-regulated electric revenues | Potomac Electric Power Company | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	262	282
Rate-regulated electric revenues | Potomac Electric Power Company | Regulated Operation | Public authorities & electric railroads
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	11	8
Rate-regulated electric revenues | Potomac Electric Power Company | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	64	56
Rate-regulated electric revenues | Delmarva Power and Light Company
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	413	366
Rate-regulated electric revenues | Delmarva Power and Light Company | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	414	367
Rate-regulated electric revenues | Delmarva Power and Light Company | Regulated Operation | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	2	2
Rate-regulated electric revenues | Delmarva Power and Light Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	1	1
Rate-regulated electric revenues | Delmarva Power and Light Company | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	256	210
Rate-regulated electric revenues | Delmarva Power and Light Company | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	62	62
Rate-regulated electric revenues | Delmarva Power and Light Company | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	29	33
Rate-regulated electric revenues | Delmarva Power and Light Company | Regulated Operation | Public authorities & electric railroads
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	4	4
Rate-regulated electric revenues | Delmarva Power and Light Company | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	63	58
Rate-regulated electric revenues | Atlantic City Electric Company
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	344	335
Rate-regulated electric revenues | Atlantic City Electric Company | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	345	336
Rate-regulated electric revenues | Atlantic City Electric Company | Regulated Operation | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	1	1
Rate-regulated electric revenues | Atlantic City Electric Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated electric revenues | Atlantic City Electric Company | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	174	146
Rate-regulated electric revenues | Atlantic City Electric Company | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	50	59
Rate-regulated electric revenues | Atlantic City Electric Company | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	49	63
Rate-regulated electric revenues | Atlantic City Electric Company | Regulated Operation | Public authorities & electric railroads
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	5	5
Rate-regulated electric revenues | Atlantic City Electric Company | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	67	63
Rate-regulated natural gas revenues
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	739	822
Rate-regulated natural gas revenues | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	759	856
Rate-regulated natural gas revenues | Commonwealth Edison Co | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Commonwealth Edison Co | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Commonwealth Edison Co | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Commonwealth Edison Co | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Commonwealth Edison Co | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Commonwealth Edison Co | Regulated Operation | Transportation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Commonwealth Edison Co | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | PECO Energy Co
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	272	316
Rate-regulated natural gas revenues | PECO Energy Co | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	272	316
Rate-regulated natural gas revenues | PECO Energy Co | Regulated Operation | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates		1
Rate-regulated natural gas revenues | PECO Energy Co | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	1
Rate-regulated natural gas revenues | PECO Energy Co | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	193	223
Rate-regulated natural gas revenues | PECO Energy Co | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	64	75
Rate-regulated natural gas revenues | PECO Energy Co | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	1
Rate-regulated natural gas revenues | PECO Energy Co | Regulated Operation | Transportation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	8	8
Rate-regulated natural gas revenues | PECO Energy Co | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	7	9
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	395	409
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	395	408
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company | Regulated Operation | Related Party
Revenue, Major Customer [Line Items]
Operating revenues from affiliates	1	1
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	1	2
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	271	278
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	47	41
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	72	70
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company | Regulated Operation | Transportation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Baltimore Gas and Electric Company | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	5	19
Rate-regulated natural gas revenues | Pepco Holdings LLC
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	72	97
Rate-regulated natural gas revenues | Pepco Holdings LLC | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	72	97
Rate-regulated natural gas revenues | Pepco Holdings LLC | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Pepco Holdings LLC | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	46	60
Rate-regulated natural gas revenues | Pepco Holdings LLC | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	17	26
Rate-regulated natural gas revenues | Pepco Holdings LLC | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	2	1
Rate-regulated natural gas revenues | Pepco Holdings LLC | Regulated Operation | Transportation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	5	4
Rate-regulated natural gas revenues | Pepco Holdings LLC | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	2	6
Rate-regulated natural gas revenues | Potomac Electric Power Company | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Potomac Electric Power Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Potomac Electric Power Company | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Potomac Electric Power Company | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Potomac Electric Power Company | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Potomac Electric Power Company | Regulated Operation | Transportation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Potomac Electric Power Company | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Delmarva Power and Light Company
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	72	97
Rate-regulated natural gas revenues | Delmarva Power and Light Company | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	72	97
Rate-regulated natural gas revenues | Delmarva Power and Light Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Delmarva Power and Light Company | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	46	60
Rate-regulated natural gas revenues | Delmarva Power and Light Company | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	17	26
Rate-regulated natural gas revenues | Delmarva Power and Light Company | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	2	1
Rate-regulated natural gas revenues | Delmarva Power and Light Company | Regulated Operation | Transportation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	5	4
Rate-regulated natural gas revenues | Delmarva Power and Light Company | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	2	6
Rate-regulated natural gas revenues | Atlantic City Electric Company | Regulated Operation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Atlantic City Electric Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Atlantic City Electric Company | Regulated Operation | Residential
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Atlantic City Electric Company | Regulated Operation | Small commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Atlantic City Electric Company | Regulated Operation | Large commercial & industrial
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Atlantic City Electric Company | Regulated Operation | Transportation
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Rate-regulated natural gas revenues | Atlantic City Electric Company | Regulated Operation | Other
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	0	0
Alternative revenue programs | Commonwealth Edison Co | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	19	153
Alternative revenue programs | PECO Energy Co | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	(2)	(4)
Alternative revenue programs | Baltimore Gas and Electric Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	43	65
Alternative revenue programs | Pepco Holdings LLC | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	46	65
Alternative revenue programs | Potomac Electric Power Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	29	39
Alternative revenue programs | Delmarva Power and Light Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	4	9
Alternative revenue programs | Atlantic City Electric Company | Regulated Operation | Operating Segment
Revenue, Major Customer [Line Items]
Electric and natural gas operating revenues	$ 13	$ 17