Supplemental Financial Information - Taxes Other Than Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Supplemental Statement of Operations Information [Line Items]
Utility taxes	$ 287	$ 269	$ 816	$ 765
Property	132	119	381	341
Payroll	38	34	108	101
Commonwealth Edison Co
Supplemental Statement of Operations Information [Line Items]
Utility taxes	93	85	264	244
Property	20	9	40	27
Payroll	12	9	29	26
PECO Energy Co
Supplemental Statement of Operations Information [Line Items]
Utility taxes	62	58	171	156
Property	5	6	15	15
Payroll	5	4	14	14
Baltimore Gas and Electric Company
Supplemental Statement of Operations Information [Line Items]
Utility taxes	29	27	92	85
Property	67	61	193	175
Payroll	4	5	13	14
Pepco Holdings LLC
Supplemental Statement of Operations Information [Line Items]
Utility taxes	103	99	288	280
Property	39	43	132	123
Payroll	8	8	25	22
Potomac Electric Power Company
Supplemental Statement of Operations Information [Line Items]
Utility taxes	94	91	260	255
Property	32	29	92	84
Payroll	2	2	5	5
Delmarva Power and Light Company
Supplemental Statement of Operations Information [Line Items]
Utility taxes	8	7	25	22
Property	7	13	37	37
Payroll	1	1	3	3
Atlantic City Electric Company
Supplemental Statement of Operations Information [Line Items]
Utility taxes	1	1	3	3
Property	0	1	2	2
Payroll	$ 1	$ 1	$ 3	$ 2

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- Definition

Amount of labor-related expenses classified as other.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(4))
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- Definition

A tax based on the assessed value of real estate by the local government. The tax is usually based on the value of property (including the land).

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 720
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
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Amount of operating expense for taxes other than income taxes of regulated operation.

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-Section S99
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