XML 304 R105.htm IDEA: XBRL DOCUMENT
v3.24.3

Fair Value of Financial Assets and Liabilities - Fair Value of Financial Liabilities Recorded at Amortized Cost (Details) - USD ($) $ in Millions | Sep. 30, 2024 | Dec. 31, 2023
--- | --- | ---
Reported Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | $ 44,655 | $ 41,095
Reported Value Measurement [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 390 | 390
Estimate of Fair Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 41,579 | 37,246
Estimate of Fair Value Measurement [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 409 | 390
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 0 | 0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 37,642 | 33,804
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 0 | 0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 3,937 | 3,442
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 409 | 390
Long-term debt to financing trusts | 390 | 390
Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 390 | 390
Commonwealth Edison Co | Reported Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 12,028 | 11,486
Commonwealth Edison Co | Reported Value Measurement [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 206 | 205
Commonwealth Edison Co | Estimate of Fair Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 10,957 | 10,210
Commonwealth Edison Co | Estimate of Fair Value Measurement [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 215 | 208
Commonwealth Edison Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
Commonwealth Edison Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 0 | 0
Commonwealth Edison Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 10,957 | 10,210
Commonwealth Edison Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 0 | 0
Commonwealth Edison Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
Commonwealth Edison Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 215 | 208
Commonwealth Edison Co | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 206 | 205
PECO Energy Co | Reported Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 5,703 | 5,134
PECO Energy Co | Reported Value Measurement [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 184 | 184
PECO Energy Co | Estimate of Fair Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 5,156 | 4,562
PECO Energy Co | Estimate of Fair Value Measurement [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 194 | 182
PECO Energy Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
PECO Energy Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 0 | 0
PECO Energy Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 5,156 | 4,562
PECO Energy Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 0 | 0
PECO Energy Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
PECO Energy Co | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 194 | 182
PECO Energy Co | Related Party |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt to financing trusts | 184 | 184
Baltimore Gas and Electric Company | Reported Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 5,395 | 4,602
Baltimore Gas and Electric Company | Estimate of Fair Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 5,021 | 4,145
Baltimore Gas and Electric Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
Baltimore Gas and Electric Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 5,021 | 4,145
Baltimore Gas and Electric Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
Pepco Holdings LLC | Reported Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 9,135 | 8,648
Pepco Holdings LLC | Estimate of Fair Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 8,270 | 7,602
Pepco Holdings LLC | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
Pepco Holdings LLC | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 4,333 | 4,160
Pepco Holdings LLC | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 3,937 | 3,442
Potomac Electric Power Company | Reported Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 4,362 | 4,096
Potomac Electric Power Company | Estimate of Fair Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 4,272 | 3,911
Potomac Electric Power Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
Potomac Electric Power Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 2,638 | 2,311
Potomac Electric Power Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 1,634 | 1,600
Delmarva Power and Light Company | Reported Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 2,221 | 2,080
Delmarva Power and Light Company | Estimate of Fair Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 1,996 | 1,828
Delmarva Power and Light Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
Delmarva Power and Light Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 667 | 694
Delmarva Power and Light Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 1,329 | 1,134
Atlantic City Electric Company | Reported Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 1,935 | 1,833
Atlantic City Electric Company | Estimate of Fair Value Measurement [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 1,783 | 1,647
Atlantic City Electric Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 0 | 0
Atlantic City Electric Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | 809 | 939
Atlantic City Electric Company | Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Long-term debt (including amounts due within one year) | $ 974 | $ 708

X
- Definition Long-term debt to Financing Trusts + References No definition available. + Details
Name: | exc_LongTermDebtToFinancingTrusts
Namespace Prefix: | exc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2E -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69B -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69C -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1D -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-10 + Details
Name: | us-gaap_DebtInstrumentFairValue
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_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_RelatedPartyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
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: |

X
- Details
Name: | dei_LegalEntityAxis=exc_PecoEnergyCoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=exc_BaltimoreGasAndElectricCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=exc_PepcoHoldingsLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=exc_PotomacElectricPowerCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=exc_DelmarvaPowerandLightCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=exc_AtlanticCityElectricCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |