<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.2.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>2472</ContextCount>
  <ElementCount>456</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>192</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>8</UnitCount>
  <MyReports>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0000002 - Statement - Consolidated Statements of Operations and Comprehensive Income (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/ConsolidatedStatementsofOperationsandComprehensiveIncomeUnaudited</Role>
      <ShortName>Consolidated Statements of Operations and Comprehensive Income (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>0000003 - Statement - Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/ConsolidatedStatementsofCashFlowsUnaudited</Role>
      <ShortName>Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>0000004 - Statement - Consolidated Balance Sheets (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/ConsolidatedBalanceSheetsUnaudited</Role>
      <ShortName>Consolidated Balance Sheets (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>0000005 - Statement - Consolidated Statements of Changes in Shareholders Equity (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/ConsolidatedStatementsofChangesinShareholdersEquityUnaudited</Role>
      <ShortName>Consolidated Statements of Changes in Shareholders Equity (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>0000006 - Disclosure - Significant Accounting Policies (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SignificantAccountingPoliciesAllRegistrants</Role>
      <ShortName>Significant Accounting Policies (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>0000007 - Disclosure - Discontinued Operations (Exelon)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DiscontinuedOperationsExelon</Role>
      <ShortName>Discontinued Operations (Exelon)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>0000008 - Disclosure - Regulatory Matters (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RegulatoryMattersAllRegistrants</Role>
      <ShortName>Regulatory Matters (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>0000009 - Disclosure - Revenue from Contracts with Customers (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RevenuefromContractswithCustomersAllRegistrants</Role>
      <ShortName>Revenue from Contracts with Customers (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>0000010 - Disclosure - Segment Information (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SegmentInformationAllRegistrants</Role>
      <ShortName>Segment Information (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>0000011 - Disclosure - Accounts Receivable (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/AccountsReceivableAllRegistrants</Role>
      <ShortName>Accounts Receivable (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>0000012 - Disclosure - Asset Impairments (Exelon and BGE)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/AssetImpairmentsExelonandBGE</Role>
      <ShortName>Asset Impairments (Exelon and BGE)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>0000013 - Disclosure - Income Taxes (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/IncomeTaxesAllRegistrants</Role>
      <ShortName>Income Taxes (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>0000014 - Disclosure - Retirement Benefits (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RetirementBenefitsAllRegistrants</Role>
      <ShortName>Retirement Benefits (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>0000015 - Disclosure - Derivative Financial Instruments (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DerivativeFinancialInstrumentsAllRegistrants</Role>
      <ShortName>Derivative Financial Instruments (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>0000016 - Disclosure - Debt and Credit Agreements (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DebtandCreditAgreementsAllRegistrants</Role>
      <ShortName>Debt and Credit Agreements (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>0000017 - Disclosure - Fair Value of Financial Assets and Liabilities (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/FairValueofFinancialAssetsandLiabilitiesAllRegistrants</Role>
      <ShortName>Fair Value of Financial Assets and Liabilities (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>0000018 - Disclosure - Commitments and Contingencies (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/CommitmentsandContingenciesAllRegistrants</Role>
      <ShortName>Commitments and Contingencies (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>0000019 - Disclosure - Shareholders' Equity (Exelon)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/ShareholdersEquityExelon</Role>
      <ShortName>Shareholders' Equity (Exelon)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>0000020 - Disclosure - Changes in Accumulated Other Comprehensive Income (Exelon)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/ChangesinAccumulatedOtherComprehensiveIncomeExelon</Role>
      <ShortName>Changes in Accumulated Other Comprehensive Income (Exelon)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>0000021 - Disclosure - Supplemental Financial Information (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SupplementalFinancialInformationAllRegistrants</Role>
      <ShortName>Supplemental Financial Information (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>0000022 - Disclosure - Related Party Transactions (All Registrants)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RelatedPartyTransactionsAllRegistrants</Role>
      <ShortName>Related Party Transactions (All Registrants)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>0000024 - Disclosure - Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SignificantAccountingPoliciesPolicies</Role>
      <ShortName>Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/SignificantAccountingPoliciesAllRegistrants</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>0000025 - Disclosure - Discontinued Operations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DiscontinuedOperationsTables</Role>
      <ShortName>Discontinued Operations (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/DiscontinuedOperationsExelon</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>0000026 - Disclosure - Regulatory Matters (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RegulatoryMattersTables</Role>
      <ShortName>Regulatory Matters (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/RegulatoryMattersAllRegistrants</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>0000027 - Disclosure - Revenue from Contracts with Customers (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RevenuefromContractswithCustomersTables</Role>
      <ShortName>Revenue from Contracts with Customers (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/RevenuefromContractswithCustomersAllRegistrants</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>0000028 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/SegmentInformationAllRegistrants</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>0000029 - Disclosure - Accounts Receivable (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/AccountsReceivableTables</Role>
      <ShortName>Accounts Receivable (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/AccountsReceivableAllRegistrants</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>0000031 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/IncomeTaxesAllRegistrants</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>0000032 - Disclosure - Retirement Benefits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RetirementBenefitsTables</Role>
      <ShortName>Retirement Benefits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/RetirementBenefitsAllRegistrants</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>0000033 - Disclosure - Debt and Credit Agreements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DebtandCreditAgreementsTables</Role>
      <ShortName>Debt and Credit Agreements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/DebtandCreditAgreementsAllRegistrants</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>0000034 - Disclosure - Fair Value of Financial Assets and Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/FairValueofFinancialAssetsandLiabilitiesTables</Role>
      <ShortName>Fair Value of Financial Assets and Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/FairValueofFinancialAssetsandLiabilitiesAllRegistrants</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>0000035 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/CommitmentsandContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/CommitmentsandContingenciesAllRegistrants</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>0000036 - Disclosure - Changes in Accumulated Other Comprehensive Income (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/ChangesinAccumulatedOtherComprehensiveIncomeTables</Role>
      <ShortName>Changes in Accumulated Other Comprehensive Income (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/ChangesinAccumulatedOtherComprehensiveIncomeExelon</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>0000037 - Disclosure - Supplemental Financial Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SupplementalFinancialInformationTables</Role>
      <ShortName>Supplemental Financial Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/SupplementalFinancialInformationAllRegistrants</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>0000038 - Disclosure - Related Party Transactions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RelatedPartyTransactionsTables</Role>
      <ShortName>Related Party Transactions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/RelatedPartyTransactionsAllRegistrants</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>0000039 - Disclosure - Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SignificantAccountingPoliciesDetails</Role>
      <ShortName>Significant Accounting Policies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.exeloncorp.com/role/SignificantAccountingPoliciesPolicies</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>0000040 - Disclosure - Discontinued Operations and Disposal Groups (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DiscontinuedOperationsandDisposalGroupsDetails</Role>
      <ShortName>Discontinued Operations and Disposal Groups (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>0000041 - Disclosure - Discontinued Operations and Disposal Groups (Details) - Income Statement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DiscontinuedOperationsandDisposalGroupsDetailsIncomeStatement</Role>
      <ShortName>Discontinued Operations and Disposal Groups (Details) - Income Statement</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>0000042 - Disclosure - Discontinued Operations and Disposal Groups (Details) - Balance Sheet</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DiscontinuedOperationsandDisposalGroupsDetailsBalanceSheet</Role>
      <ShortName>Discontinued Operations and Disposal Groups (Details) - Balance Sheet</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>0000043 - Disclosure - Discontinued Operations and Disposal Groups (Details) - Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DiscontinuedOperationsandDisposalGroupsDetailsCashFlows</Role>
      <ShortName>Discontinued Operations and Disposal Groups (Details) - Cash Flows</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>0000044 - Disclosure - Regulatory Matters - Schedule of Completed Rate Cases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RegulatoryMattersScheduleofCompletedRateCasesDetails</Role>
      <ShortName>Regulatory Matters - Schedule of Completed Rate Cases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>0000045 - Disclosure - Regulatory Matters - Schedule of Pending Rate Cases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RegulatoryMattersScheduleofPendingRateCasesDetails</Role>
      <ShortName>Regulatory Matters - Schedule of Pending Rate Cases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>0000046 - Disclosure - Regulatory Matters - Annual Electric Transmission Fillings (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RegulatoryMattersAnnualElectricTransmissionFillingsDetails</Role>
      <ShortName>Regulatory Matters - Annual Electric Transmission Fillings (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>0000047 - Disclosure - Regulatory Matters - Energy Efficiency Formula Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RegulatoryMattersEnergyEfficiencyFormulaRateDetails</Role>
      <ShortName>Regulatory Matters - Energy Efficiency Formula Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>0000048 - Disclosure - Regulatory Matters - Capitalized Ratemaking Amount Not Recognized (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RegulatoryMattersCapitalizedRatemakingAmountNotRecognizedDetails</Role>
      <ShortName>Regulatory Matters - Capitalized Ratemaking Amount Not Recognized (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>0000049 - Disclosure - Regulatory Matters - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RegulatoryMattersNarrativeDetails</Role>
      <ShortName>Regulatory Matters - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>0000050 - Disclosure - Revenue from Contracts with Customers - Change in Contract with Customer, Asset and Liability (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RevenuefromContractswithCustomersChangeinContractwithCustomerAssetandLiabilityDetails</Role>
      <ShortName>Revenue from Contracts with Customers - Change in Contract with Customer, Asset and Liability (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>0000051 - Disclosure - Revenue from Contract with Customer - Performance Obligations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RevenuefromContractwithCustomerPerformanceObligationsDetails</Role>
      <ShortName>Revenue from Contract with Customer - Performance Obligations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>0000052 - Disclosure - Segment Information - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SegmentInformationNarrativeDetails</Role>
      <ShortName>Segment Information - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>0000053 - Disclosure - Segment Information - Reconciliation to Consolidated Financial Statements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SegmentInformationReconciliationtoConsolidatedFinancialStatementsDetails</Role>
      <ShortName>Segment Information - Reconciliation to Consolidated Financial Statements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>0000054 - Disclosure - Segment Information - Electric and Gas Revenue by Customer Class (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SegmentInformationElectricandGasRevenuebyCustomerClassDetails</Role>
      <ShortName>Segment Information - Electric and Gas Revenue by Customer Class (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>0000055 - Disclosure - Accounts Receivable - Allowance for Credit Losses Rollforward (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/AccountsReceivableAllowanceforCreditLossesRollforwardDetails</Role>
      <ShortName>Accounts Receivable - Allowance for Credit Losses Rollforward (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>0000056 - Disclosure - Accounts Receivable - Unbilled Customer Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/AccountsReceivableUnbilledCustomerRevenueDetails</Role>
      <ShortName>Accounts Receivable - Unbilled Customer Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>0000057 - Disclosure - Accounts Receivable - Purchases and Sales of Accounts Receivable (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/AccountsReceivablePurchasesandSalesofAccountsReceivableDetail</Role>
      <ShortName>Accounts Receivable - Purchases and Sales of Accounts Receivable (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>0000058 - Disclosure - Asset Impairments - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/AssetImpairmentsNarrativeDetails</Role>
      <ShortName>Asset Impairments - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>0000059 - Disclosure - Income Taxes - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/IncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>0000060 - Disclosure - Income Taxes - Reconciliation to Effective Tax Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/IncomeTaxesReconciliationtoEffectiveTaxRateDetails</Role>
      <ShortName>Income Taxes - Reconciliation to Effective Tax Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>0000061 - Disclosure - Income Taxes - Unrecognized Tax Benefits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/IncomeTaxesUnrecognizedTaxBenefitsDetails</Role>
      <ShortName>Income Taxes - Unrecognized Tax Benefits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>0000062 - Disclosure - Income Taxes - Allocation of Tax Benefits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/IncomeTaxesAllocationofTaxBenefitsDetails</Role>
      <ShortName>Income Taxes - Allocation of Tax Benefits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>0000063 - Disclosure - Retirement Benefits - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RetirementBenefitsNarrativeDetails</Role>
      <ShortName>Retirement Benefits - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>0000064 - Disclosure - Retirement Benefits - Calculation of Net Periodic Benefit Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RetirementBenefitsCalculationofNetPeriodicBenefitCostDetails</Role>
      <ShortName>Retirement Benefits - Calculation of Net Periodic Benefit Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>0000065 - Disclosure - Retirement Benefits - Allocated Portion of Pension and Postretirement Benefit Plan Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RetirementBenefitsAllocatedPortionofPensionandPostretirementBenefitPlanCostsDetails</Role>
      <ShortName>Retirement Benefits - Allocated Portion of Pension and Postretirement Benefit Plan Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>0000066 - Disclosure - Retirement Benefits - Defined Contribution Savings Plans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RetirementBenefitsDefinedContributionSavingsPlansDetails</Role>
      <ShortName>Retirement Benefits - Defined Contribution Savings Plans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>0000067 - Disclosure - Derivative Financial Instruments - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DerivativeFinancialInstrumentsNarrativeDetails</Role>
      <ShortName>Derivative Financial Instruments - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>0000068 - Disclosure - Debt and Credit Agreements - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DebtandCreditAgreementsNarrativeDetails</Role>
      <ShortName>Debt and Credit Agreements - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>0000069 - Disclosure - Debt and Credit Agreements - Commercial Paper Borrowings (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DebtandCreditAgreementsCommercialPaperBorrowingsDetails</Role>
      <ShortName>Debt and Credit Agreements - Commercial Paper Borrowings (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>0000070 - Disclosure - Debt and Credit Agreements - Summary of Revolving Credit Agreements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DebtandCreditAgreementsSummaryofRevolvingCreditAgreementsDetails</Role>
      <ShortName>Debt and Credit Agreements - Summary of Revolving Credit Agreements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>0000071 - Disclosure - Debt and Credit Agreements - Issuance of Long-Term Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/DebtandCreditAgreementsIssuanceofLongTermDebtDetails</Role>
      <ShortName>Debt and Credit Agreements - Issuance of Long-Term Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>0000073 - Disclosure - Fair Value of Financial Assets and Liabilities - Fair Value of Financial Liabilities Recorded at Amortized Cost (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/FairValueofFinancialAssetsandLiabilitiesFairValueofFinancialLiabilitiesRecordedatAmortizedCostDetails</Role>
      <ShortName>Fair Value of Financial Assets and Liabilities - Fair Value of Financial Liabilities Recorded at Amortized Cost (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>0000074 - Disclosure - Fair Value of Financial Assets and Liabilities - Fair Value Measurements of Assets and Liabilities, Recurring and Nonrecurring (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/FairValueofFinancialAssetsandLiabilitiesFairValueMeasurementsofAssetsandLiabilitiesRecurringandNonrecurringDetails</Role>
      <ShortName>Fair Value of Financial Assets and Liabilities - Fair Value Measurements of Assets and Liabilities, Recurring and Nonrecurring (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>0000075 - Disclosure - Fair Value of Financial Assets and Liabilities - Fair Value Assets Liabilities Measured On Recurring Basis Unobservable Input Reconciliation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/FairValueofFinancialAssetsandLiabilitiesFairValueAssetsLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationDetails</Role>
      <ShortName>Fair Value of Financial Assets and Liabilities - Fair Value Assets Liabilities Measured On Recurring Basis Unobservable Input Reconciliation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>0000076 - Disclosure - Fair Value of Financial Assets and Liabilities - Fair Value Inputs Assets Quantitative Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/FairValueofFinancialAssetsandLiabilitiesFairValueInputsAssetsQuantitativeInformationDetails</Role>
      <ShortName>Fair Value of Financial Assets and Liabilities - Fair Value Inputs Assets Quantitative Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>0000077 - Disclosure - Commitments and Contingencies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/CommitmentsandContingenciesNarrativeDetails</Role>
      <ShortName>Commitments and Contingencies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>0000078 - Disclosure - Commitments and Contingencies - Merger Commitment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/CommitmentsandContingenciesMergerCommitmentDetails</Role>
      <ShortName>Commitments and Contingencies - Merger Commitment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>0000079 - Disclosure - Commitments and Contingencies - Schedule of Commercial Commitments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/CommitmentsandContingenciesScheduleofCommercialCommitmentsDetails</Role>
      <ShortName>Commitments and Contingencies - Schedule of Commercial Commitments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>0000080 - Disclosure - Commitments and Contingencies - Schedule of Accruals for Environmental Matters (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/CommitmentsandContingenciesScheduleofAccrualsforEnvironmentalMattersDetails</Role>
      <ShortName>Commitments and Contingencies - Schedule of Accruals for Environmental Matters (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>0000081 - Disclosure - Shareholder's Equity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/ShareholdersEquityDetails</Role>
      <ShortName>Shareholder's Equity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>0000082 - Disclosure - Changes in Accumulated Other Comprehensive Income - Schedule of Changes in AOCI (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/ChangesinAccumulatedOtherComprehensiveIncomeScheduleofChangesinAOCIDetails</Role>
      <ShortName>Changes in Accumulated Other Comprehensive Income - Schedule of Changes in AOCI (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>0000083 - Disclosure - Changes in Accumulated Other Comprehensive Income - Income Taxes Allocated to Other Comprehensive Income (Loss) Components (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/ChangesinAccumulatedOtherComprehensiveIncomeIncomeTaxesAllocatedtoOtherComprehensiveIncomeLossComponentsDetails</Role>
      <ShortName>Changes in Accumulated Other Comprehensive Income - Income Taxes Allocated to Other Comprehensive Income (Loss) Components (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>0000084 - Disclosure - Supplemental Financial Information - Operations (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SupplementalFinancialInformationOperationsDetail</Role>
      <ShortName>Supplemental Financial Information - Operations (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>0000085 - Disclosure - Supplemental Financial Information - Taxes Other Than Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SupplementalFinancialInformationTaxesOtherThanIncomeTaxesDetails</Role>
      <ShortName>Supplemental Financial Information - Taxes Other Than Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>0000086 - Disclosure - Supplemental Financial Information - Cash Flow (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SupplementalFinancialInformationCashFlowDetails</Role>
      <ShortName>Supplemental Financial Information - Cash Flow (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>0000087 - Disclosure - Supplemental Financial Information - Balance Sheet (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/SupplementalFinancialInformationBalanceSheetDetails</Role>
      <ShortName>Supplemental Financial Information - Balance Sheet (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>84</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>0000088 - Disclosure - Related Party Transactions - Utility Registrants' expense with Generation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RelatedPartyTransactionsUtilityRegistrantsexpensewithGenerationDetails</Role>
      <ShortName>Related Party Transactions - Utility Registrants' expense with Generation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>85</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>0000089 - Disclosure - Related Party Transactions - BSC and PHISCO Service Companies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RelatedPartyTransactionsBSCandPHISCOServiceCompaniesDetails</Role>
      <ShortName>Related Party Transactions - BSC and PHISCO Service Companies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>0000090 - Disclosure - Related Party Transactions - Current Receivables From/Payables To Affiliates (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RelatedPartyTransactionsCurrentReceivablesFromPayablesToAffiliatesDetails</Role>
      <ShortName>Related Party Transactions - Current Receivables From/Payables To Affiliates (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="exc-20220930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>0000092 - Disclosure - Related Party Transactions - Long Term Debt to Financing Trusts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.exeloncorp.com/role/RelatedPartyTransactionsLongTermDebttoFinancingTrustsDetails</Role>
      <ShortName>Related Party Transactions - Long Term Debt to Financing Trusts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Warning">[ix-0514-Hidden-Fact-Eligible-For-Transform] WARN: 52 fact(s) appearing in ix:hidden were eligible for transformation: dei:DocumentPeriodEndDate, dei:Security12bTitle, us-gaap:DebtInstrumentFairValue, us-gaap:DueToAffiliateNoncurrent, us-gaap:RevenueFromRelatedParties, us-gaap:RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1 -  exc-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:PaymentsToAcquireAdditionalInterestInSubsidiaries has a value of -885000000 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:PaymentsToAcquireAdditionalInterestInSubsidiaries fact are: Context: i9aa8ef58e98f49ef837cc69fece55fdc_D20210101-20210930, Unit: usd, Rule Element Id: 2990. exc-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:StockIssuedDuringPeriodValueShareBasedCompensationGross has a value of -13000000 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:StockIssuedDuringPeriodValueShareBasedCompensationGross fact are: Context: i88013fa8194a4ccda4e8720b189dacc8_D20220101-20220331, Unit: usd, Rule Element Id: 3010. exc-20220930.htm 4</Log>
    <Log type="Warning">[dqc-0015-Negative-Values] Fact us-gaap:PaymentsToAcquireAdditionalInterestInSubsidiaries has a value of -885000000 which is less than zero. This element should not have a negative value. The preparer should consider if the value is input correctly for this assertion and, after considering the appropriateness of the input, if incorrect, input the amount as a positive (i.e., absolute) value and provide a negated label. The properties of this us-gaap:PaymentsToAcquireAdditionalInterestInSubsidiaries fact are: Context: i3a717da1f37b435184f50ce9e001356c_D20210701-20210930, Unit: usd, Rule Element Id: 2990. exc-20220930.htm 4</Log>
  </Logs>
  <InputFiles>
    <File doctype="10-Q" original="exc-20220930.htm">exc-20220930.htm</File>
    <File>exc-20220930.xsd</File>
    <File>exc-20220930_cal.xml</File>
    <File>exc-20220930_def.xml</File>
    <File>exc-20220930_lab.xml</File>
    <File>exc-20220930_pre.xml</File>
    <File>exc-ex3101_20220930q3.htm</File>
    <File>exc-ex3102_20220930q3.htm</File>
    <File>exc-ex3103_20220930q3.htm</File>
    <File>exc-ex3104_20220930q3.htm</File>
    <File>exc-ex3105_20220930q3.htm</File>
    <File>exc-ex3106_20220930q3.htm</File>
    <File>exc-ex3107_20220930q3.htm</File>
    <File>exc-ex3108_20220930q3.htm</File>
    <File>exc-ex3109_20220930q3.htm</File>
    <File>exc-ex3110_20220930q3.htm</File>
    <File>exc-ex3111_20220930q3.htm</File>
    <File>exc-ex3112_20220930q3.htm</File>
    <File>exc-ex3113_20220930q3.htm</File>
    <File>exc-ex3114_20220930q3.htm</File>
    <File>exc-ex3115_20220930q3.htm</File>
    <File>exc-ex3116_20220930q3.htm</File>
    <File>exc-ex3201_20220930q3.htm</File>
    <File>exc-ex3202_20220930q3.htm</File>
    <File>exc-ex3203_20220930q3.htm</File>
    <File>exc-ex3204_20220930q3.htm</File>
    <File>exc-ex3205_20220930q3.htm</File>
    <File>exc-ex3206_20220930q3.htm</File>
    <File>exc-ex3207_20220930q3.htm</File>
    <File>exc-ex3208_20220930q3.htm</File>
    <File>exc-ex3209_20220930q3.htm</File>
    <File>exc-ex3210_20220930q3.htm</File>
    <File>exc-ex3211_20220930q3.htm</File>
    <File>exc-ex3212_20220930q3.htm</File>
    <File>exc-ex3213_20220930q3.htm</File>
    <File>exc-ex3214_20220930q3.htm</File>
    <File>exc-ex3215_20220930q3.htm</File>
    <File>exc-ex3216_20220930q3.htm</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="2">http://fasb.org/srt/2022</BaseTaxonomy>
    <BaseTaxonomy items="6962">http://fasb.org/us-gaap/2022</BaseTaxonomy>
    <BaseTaxonomy items="140">http://xbrl.sec.gov/dei/2022</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
