XML 307 R108.htm IDEA: XBRL DOCUMENT v3.24.3

Fair Value of Financial Assets and Liabilities - Fair Value Inputs Assets Quantitative Information (Details) - Fair Value, Inputs, Level 3 [Member] - Derivative [Member] - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$ (165,000,000)	$ (133,000,000)
Discounted Cash Flow [Member] | Minimum [Member]
Derivatives, Fair Value [Line Items]
Fair Value Inputs Forward Power Price	22.68	30.27
Discounted Cash Flow [Member] | Maximum [Member]
Derivatives, Fair Value [Line Items]
Fair Value Inputs Forward Power Price	55.35	73.71
Discounted Cash Flow [Member] | Arithmetic Average [Member]
Derivatives, Fair Value [Line Items]
Fair Value Inputs Forward Power Price	36.45	43.35
Commonwealth Edison Co
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$ (165,000,000)	$ (133,000,000)
Commonwealth Edison Co | Discounted Cash Flow [Member] | Minimum [Member]
Derivatives, Fair Value [Line Items]
Fair Value Inputs Forward Power Price	22.68	30.27
Commonwealth Edison Co | Discounted Cash Flow [Member] | Maximum [Member]
Derivatives, Fair Value [Line Items]
Fair Value Inputs Forward Power Price	55.35	73.71
Commonwealth Edison Co | Discounted Cash Flow [Member] | Arithmetic Average [Member]
Derivatives, Fair Value [Line Items]
Fair Value Inputs Forward Power Price	36.45	43.35

X

- Definition

Fair Value Inputs Forward Power Price

+ References

No definition available.

+ Details

Name:	exc_FairValueInputsForwardPowerPrice
Namespace Prefix:	exc_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 9
-SubTopic 20
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483444/210-20-55-9

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-SubTopic 20
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483466/210-20-50-3

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-SubTopic 20
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483444/210-20-55-10

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-8

+ Details

Name:	us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativesFairValueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_DerivativeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ValuationTechniqueAxis=us-gaap_IncomeApproachValuationTechniqueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_ArithmeticAverageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=exc_CommonwealthEdisonCoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: