<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>290</ContextCount>
  <ElementCount>436</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>99</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>75000 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>75010 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>75020 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>75030 - Statement - Consolidated Statements Of Comprehensive (Loss)/ Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/StatementConsolidatedStatementsOfComprehensiveLossIncome</Role>
      <ShortName>Consolidated Statements Of Comprehensive (Loss)/ Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>75050 - Statement - Consolidated Statements Of Changes In Shareholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/StatementConsolidatedStatementsOfChangesInShareholdersEquity</Role>
      <ShortName>Consolidated Statements Of Changes In Shareholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>75060 - Statement - Consolidated Statements Of Changes In Shareholders' Equity (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/StatementConsolidatedStatementsOfChangesInShareholdersEquityParentheticals</Role>
      <ShortName>Consolidated Statements Of Changes In Shareholders' Equity (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>75070 - Statement - Consolidated Statements Of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements Of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>75080 - Disclosure - Cybersecurity Risk Management, Strategy and Governance</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureCybersecurityRiskManagementStrategyAndGovernance</Role>
      <ShortName>Cybersecurity Risk Management, Strategy and Governance</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>995410 - Disclosure - Pay vs Performance Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/PvpDisclosure</Role>
      <ShortName>Pay vs Performance Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995447 - Disclosure - Insider Trading Policies and Procedures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc</Role>
      <ShortName>Insider Trading Policies and Procedures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995457 - Disclosure - Organization And Principal Activities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/OrganizationAndPrincipalActivities</Role>
      <ShortName>Organization And Principal Activities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995467 - Disclosure - Summary Of Principal Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/SummaryOfPrincipalAccountingPolicies</Role>
      <ShortName>Summary Of Principal Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995477 - Disclosure - Revenue From Contracts With Customers</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RevenueFromContractsWithCustomers</Role>
      <ShortName>Revenue From Contracts With Customers</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995487 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995497 - Disclosure - Inventories</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/Inventories</Role>
      <ShortName>Inventories</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995507 - Disclosure - Prepayments and Other Current Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/PrepaymentsAndOtherCurrentAssets</Role>
      <ShortName>Prepayments and Other Current Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995517 - Disclosure - Property and Equipment, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/PropertyAndEquipmentNet</Role>
      <ShortName>Property and Equipment, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995527 - Disclosure - Other Non-Current Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/OtherNonCurrentAssets</Role>
      <ShortName>Other Non-Current Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995537 - Disclosure - Short-Term Borrowings</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ShortTermBorrowings</Role>
      <ShortName>Short-Term Borrowings</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995557 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995567 - Disclosure - Accrued Expenses And Other Current Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/AccruedExpensesAndOtherCurrentLiabilities</Role>
      <ShortName>Accrued Expenses And Other Current Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995577 - Disclosure - Ordinary Shares</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/OrdinaryShares</Role>
      <ShortName>Ordinary Shares</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995587 - Disclosure - Share Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ShareBasedCompensation</Role>
      <ShortName>Share Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995597 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995617 - Disclosure - Redeemable Noncontrolling Interests</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RedeemableNoncontrollingInterests</Role>
      <ShortName>Redeemable Noncontrolling Interests</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995627 - Disclosure - Net (Loss) /Earnings Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureNetLossEarningsPerShare1</Role>
      <ShortName>Net (Loss) /Earnings Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995637 - Disclosure - Statutory Reserves</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/StatutoryReserves</Role>
      <ShortName>Statutory Reserves</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995647 - Disclosure - Restricted Net Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RestrictedNetAssets</Role>
      <ShortName>Restricted Net Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995657 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995667 - Disclosure - Parent Company Only Condensed Financial Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ParentCompanyOnlyCondensedFinancialInformation</Role>
      <ShortName>Parent Company Only Condensed Financial Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995677 - Disclosure - Subsequent Event</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureSubsequentEvent</Role>
      <ShortName>Subsequent Event</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995687 - Disclosure - Summary Of Principal Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/SummaryOfPrincipalAccountingPoliciesPolicies</Role>
      <ShortName>Summary Of Principal Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/SummaryOfPrincipalAccountingPolicies</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995697 - Disclosure - Organization And Principal Activities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/OrganizationAndPrincipalActivitiesTables</Role>
      <ShortName>Organization And Principal Activities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/OrganizationAndPrincipalActivities</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995707 - Disclosure - Summary Of Principal Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureSummaryOfPrincipalAccountingPoliciesTables</Role>
      <ShortName>Summary Of Principal Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/SummaryOfPrincipalAccountingPolicies</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995717 - Disclosure - Revenue From Contracts With Customers (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RevenueFromContractsWithCustomersTables</Role>
      <ShortName>Revenue From Contracts With Customers (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/RevenueFromContractsWithCustomers</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995727 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/FairValueMeasurements</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995737 - Disclosure - Inventories  (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/InventoriesTables</Role>
      <ShortName>Inventories  (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/Inventories</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995747 - Disclosure - Prepayments and Other Current Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/PrepaymentsAndOtherCurrentAssetsTables</Role>
      <ShortName>Prepayments and Other Current Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/PrepaymentsAndOtherCurrentAssets</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995757 - Disclosure - Property and Equipment, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/PropertyAndEquipmentNetTables</Role>
      <ShortName>Property and Equipment, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/PropertyAndEquipmentNet</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995767 - Disclosure - Other Non-Current Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/OtherNonCurrentAssetsTables</Role>
      <ShortName>Other Non-Current Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/OtherNonCurrentAssets</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995777 - Disclosure - Short-Term Borrowings (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureShorttermBorrowingsTables</Role>
      <ShortName>Short-Term Borrowings (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/ShortTermBorrowings</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>995797 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/Leases</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>995807 - Disclosure - Accrued Expenses And Other Current Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/AccruedExpensesAndOtherCurrentLiabilitiesTables</Role>
      <ShortName>Accrued Expenses And Other Current Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/AccruedExpensesAndOtherCurrentLiabilities</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>995817 - Disclosure - Share Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ShareBasedCompensationTables</Role>
      <ShortName>Share Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/ShareBasedCompensation</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>995827 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/IncomeTaxes</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>995857 - Disclosure - Redeemable Noncontrolling Interests (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RedeemableNoncontrollingInterestsTables</Role>
      <ShortName>Redeemable Noncontrolling Interests (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/RedeemableNoncontrollingInterests</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>995867 - Disclosure - Net (Loss)/ Earnings Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureNetLossEarningsPerShareTables</Role>
      <ShortName>Net (Loss)/ Earnings Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/DisclosureNetLossEarningsPerShare1</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>995877 - Disclosure - Commitments And Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments And Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>995887 - Disclosure - Parent Company Only Condensed Financial Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ParentCompanyOnlyCondensedFinancialInformationTables</Role>
      <ShortName>Parent Company Only Condensed Financial Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/ParentCompanyOnlyCondensedFinancialInformation</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>995907 - Disclosure - Organization And Principal Activities - Summary of Group's Major Subsidiaries (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/OrganizationAndPrincipalActivitiesSummaryOfGroupsMajorSubsidiariesDetail</Role>
      <ShortName>Organization And Principal Activities - Summary of Group's Major Subsidiaries (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>995917 - Disclosure - Summary Of Principal Accounting Policies - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/SummaryOfPrincipalAccountingPoliciesAdditionalInformationDetail</Role>
      <ShortName>Summary Of Principal Accounting Policies - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>995927 - Disclosure - Summary Of Principal Accounting Policies - Schedule of Property and equipment, net (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/SummaryOfPrincipalAccountingPoliciesScheduleOfPropertyAndEquipmentNetDetail</Role>
      <ShortName>Summary Of Principal Accounting Policies - Schedule of Property and equipment, net (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>995937 - Disclosure - Revenue From Contracts With Customers -Summary Of Contract With Customer Asset And Liability (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RevenueFromContractsWithCustomersSummaryOfContractWithCustomerAssetAndLiabilityDetail</Role>
      <ShortName>Revenue From Contracts With Customers -Summary Of Contract With Customer Asset And Liability (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>995947 - Disclosure - Revenue From Contracts With Customers - Additional Informational (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RevenueFromContractsWithCustomersAdditionalInformationalDetail</Role>
      <ShortName>Revenue From Contracts With Customers - Additional Informational (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>995957 - Disclosure - Fair Value Measurements - Summary Of Fair Value Assets Measured On Recurring Basis (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/FairValueMeasurementsSummaryOfFairValueAssetsMeasuredOnRecurringBasisDetail</Role>
      <ShortName>Fair Value Measurements - Summary Of Fair Value Assets Measured On Recurring Basis (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>995967 - Disclosure - Fair Value Measurements - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetail</Role>
      <ShortName>Fair Value Measurements - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>995977 - Disclosure - Inventories - Summary Of Schedule Of Inventory Current (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/InventoriesSummaryOfScheduleOfInventoryCurrentDetail</Role>
      <ShortName>Inventories - Summary Of Schedule Of Inventory Current (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>995987 - Disclosure - Prepayments and Other Current Assets - Summary of Other Current Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/PrepaymentsAndOtherCurrentAssetsSummaryOfOtherCurrentAssetsDetail</Role>
      <ShortName>Prepayments and Other Current Assets - Summary of Other Current Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>995997 - Disclosure - Property and Equipment, Net - Schedule of Property and Equipment, Net (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/PropertyAndEquipmentNetScheduleOfPropertyAndEquipmentNetDetail</Role>
      <ShortName>Property and Equipment, Net - Schedule of Property and Equipment, Net (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>996007 - Disclosure - Property and Equipment, Net - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/PropertyAndEquipmentNetAdditionalInformationDetail</Role>
      <ShortName>Property and Equipment, Net - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>996017 - Disclosure - Property and Equipment, Net - Schedule of Depreciation Included in Consolidated Statements of Income and Comprehensive Income (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/PropertyAndEquipmentNetScheduleOfDepreciationIncludedInConsolidatedStatementsOfIncomeAndComprehensiveIncomeDetail</Role>
      <ShortName>Property and Equipment, Net - Schedule of Depreciation Included in Consolidated Statements of Income and Comprehensive Income (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>996027 - Disclosure - Other Non-Current Assets - Summary of Other Non-Current Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/OtherNonCurrentAssetsSummaryOfOtherNonCurrentAssetsDetail</Role>
      <ShortName>Other Non-Current Assets - Summary of Other Non-Current Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>996047 - Disclosure - Short-Term Borrowings - Schedule of Short-term Debt (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ShortTermBorrowingsScheduleOfShortTermDebtDetail</Role>
      <ShortName>Short-Term Borrowings - Schedule of Short-term Debt (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>996057 - Disclosure - Short-Term Borrowings - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ShortTermBorrowingsAdditionalInformationDetail</Role>
      <ShortName>Short-Term Borrowings - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>996067 - Disclosure - Short-Term Borrowings - Schedule of Group's Outstanding Obligations Under the Reversed Factoring Arrangements (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureShorttermBorrowingsScheduleOfGroupsOutstandingObligationsUnderTheReversedFactoringArrangementsDetail</Role>
      <ShortName>Short-Term Borrowings - Schedule of Group's Outstanding Obligations Under the Reversed Factoring Arrangements (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>996077 - Disclosure - Leases - Summary of Supplemental Information Related to Operating Lease (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/LeasesSummaryOfSupplementalInformationRelatedToOperatingLeaseDetail</Role>
      <ShortName>Leases - Summary of Supplemental Information Related to Operating Lease (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>996087 - Disclosure - Leases - Summary of Lease Cost (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/LeasesSummaryOfLeaseCostDetail</Role>
      <ShortName>Leases - Summary of Lease Cost (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>996097 - Disclosure - Leases - Summary of Maturity of Operating Lease Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/LeasesSummaryOfMaturityOfOperatingLeaseLiabilitiesDetail</Role>
      <ShortName>Leases - Summary of Maturity of Operating Lease Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>996117 - Disclosure - Accrued Expenses And Other Current Liabilities - Summary of Accrued Liabilities And Other Liabilities Current (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/AccruedExpensesAndOtherCurrentLiabilitiesSummaryOfAccruedLiabilitiesAndOtherLiabilitiesCurrentDetail</Role>
      <ShortName>Accrued Expenses And Other Current Liabilities - Summary of Accrued Liabilities And Other Liabilities Current (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>996127 - Disclosure - Ordinary Shares - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/OrdinarySharesAdditionalInformationDetail</Role>
      <ShortName>Ordinary Shares - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>996137 - Disclosure - Share Based Compensation - Summary of Option Activities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ShareBasedCompensationSummaryOfOptionActivitiesDetail</Role>
      <ShortName>Share Based Compensation - Summary of Option Activities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>996147 - Disclosure - Share Based Compensation - Summary of Assumptions Used to Value the Share Options (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureShareBasedCompensationSummaryOfAssumptionsUsedToValueTheShareOptionsDetail</Role>
      <ShortName>Share Based Compensation - Summary of Assumptions Used to Value the Share Options (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>996157 - Disclosure - Share Based Compensation - Summary of Recognized Share Based Compensation Expenses (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureShareBasedCompensationSummaryOfRecognizedShareBasedCompensationExpensesDetail</Role>
      <ShortName>Share Based Compensation - Summary of Recognized Share Based Compensation Expenses (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>996167 - Disclosure - Share Based Compensation - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ShareBasedCompensationAdditionalInformationDetail</Role>
      <ShortName>Share Based Compensation - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>996177 - Disclosure - Income Taxes - Schedule Of Components Of Income Tax Expense Benefit (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/IncomeTaxesScheduleOfComponentsOfIncomeTaxExpenseBenefitDetail</Role>
      <ShortName>Income Taxes - Schedule Of Components Of Income Tax Expense Benefit (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>996187 - Disclosure - Income Taxes - Schedule of Loss Before Income Taxes By Jurisdiction (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/IncomeTaxesScheduleOfLossBeforeIncomeTaxesByJurisdictionDetail</Role>
      <ShortName>Income Taxes - Schedule of Loss Before Income Taxes By Jurisdiction (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>996197 - Disclosure - Income Taxes - Schedule of Reconciliations of The Income Tax Expenses (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/IncomeTaxesScheduleOfReconciliationsOfTheIncomeTaxExpensesDetail</Role>
      <ShortName>Income Taxes - Schedule of Reconciliations of The Income Tax Expenses (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>996207 - Disclosure - Income Taxes - Schedule of Deferred Tax Assets And Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/IncomeTaxesScheduleOfDeferredTaxAssetsAndLiabilitiesDetail</Role>
      <ShortName>Income Taxes - Schedule of Deferred Tax Assets And Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>996217 - Disclosure - Income Taxes - Schedule of Unrecognized Tax Benefits (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/IncomeTaxesScheduleOfUnrecognizedTaxBenefitsDetail</Role>
      <ShortName>Income Taxes - Schedule of Unrecognized Tax Benefits (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R80.htm</HtmlFileName>
      <LongName>996227 - Disclosure - Income Taxes - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/IncomeTaxesAdditionalInformationDetail</Role>
      <ShortName>Income Taxes - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>80</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R81.htm</HtmlFileName>
      <LongName>996247 - Disclosure - Related Party Transactions and Balances  - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RelatedPartyTransactionsAndBalancesAdditionalInformationDetail</Role>
      <ShortName>Related Party Transactions and Balances  - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>81</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R82.htm</HtmlFileName>
      <LongName>996257 - Disclosure - Redeemable Noncontrolling Interests - Summary Of  Redeemable Noncontrolling Interests (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RedeemableNoncontrollingInterestsSummaryOfRedeemableNoncontrollingInterestsDetail</Role>
      <ShortName>Redeemable Noncontrolling Interests - Summary Of  Redeemable Noncontrolling Interests (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>82</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R83.htm</HtmlFileName>
      <LongName>996267 - Disclosure - Redeemable Noncontrolling Interests - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RedeemableNoncontrollingInterestsAdditionalInformationDetail</Role>
      <ShortName>Redeemable Noncontrolling Interests - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>83</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R84.htm</HtmlFileName>
      <LongName>996277 - Disclosure - Net (Loss)/ Earnings Per Share - Summary of Basic and Diluted Net Loss Per Share (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureNetLossEarningsPerShareSummaryOfBasicAndDilutedNetLossPerShareDetail</Role>
      <ShortName>Net (Loss)/ Earnings Per Share - Summary of Basic and Diluted Net Loss Per Share (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/DisclosureNetLossEarningsPerShareTables</ParentRole>
      <Position>84</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R85.htm</HtmlFileName>
      <LongName>996287 - Disclosure - Net (Loss)/ Earnings Per Share - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureNetLossEarningsPerShareAdditionalInformationDetails</Role>
      <ShortName>Net (Loss)/ Earnings Per Share - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/DisclosureNetLossEarningsPerShareTables</ParentRole>
      <Position>85</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R86.htm</HtmlFileName>
      <LongName>996297 - Disclosure - Statutory Reserves - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/StatutoryReservesAdditionalInformationDetail</Role>
      <ShortName>Statutory Reserves - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>86</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R87.htm</HtmlFileName>
      <LongName>996307 - Disclosure - Restricted Net Assets - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/RestrictedNetAssetsAdditionalInformationDetail</Role>
      <ShortName>Restricted Net Assets - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>87</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R88.htm</HtmlFileName>
      <LongName>996327 - Disclosure - Commitments And Contingencies - Schedule of Outstanding Purchase Commitments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesScheduleOfOutstandingPurchaseCommitmentsDetails</Role>
      <ShortName>Commitments And Contingencies - Schedule of Outstanding Purchase Commitments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>88</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R89.htm</HtmlFileName>
      <LongName>996337 - Disclosure - Parent Company Only Condensed Financial Information - Condensed Balance Sheets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ParentCompanyOnlyCondensedFinancialInformationCondensedBalanceSheetsDetail</Role>
      <ShortName>Parent Company Only Condensed Financial Information - Condensed Balance Sheets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>89</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R90.htm</HtmlFileName>
      <LongName>996347 - Disclosure - Parent Company Only Condensed Financial Information - Condensed Statements of Comprehensive (Loss)/Income (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureParentCompanyOnlyCondensedFinancialInformationCondensedStatementsOfComprehensiveLossincomeDetail</Role>
      <ShortName>Parent Company Only Condensed Financial Information - Condensed Statements of Comprehensive (Loss)/Income (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>90</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R91.htm</HtmlFileName>
      <LongName>996357 - Disclosure - Parent Company Only Condensed Financial Information - Condensed Statements of Cash Flow (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/ParentCompanyOnlyCondensedFinancialInformationCondensedStatementsOfCashFlowDetail</Role>
      <ShortName>Parent Company Only Condensed Financial Information - Condensed Statements of Cash Flow (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>91</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R92.htm</HtmlFileName>
      <LongName>996367 - Disclosure - Parent Company Only Condensed Financial Information - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureParentCompanyOnlyCondensedFinancialInformationAdditionalInformationDetails</Role>
      <ShortName>Parent Company Only Condensed Financial Information - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>92</Position>
    </Report>
    <Report instance="ddl-20251231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R93.htm</HtmlFileName>
      <LongName>996377 - Disclosure - Subsequent Event (Additional Information) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.100.me/20251231/taxonomy/role/DisclosureSubsequentEventAdditionalInformationDetails</Role>
      <ShortName>Subsequent Event (Additional Information) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.100.me/20251231/taxonomy/role/DisclosureSubsequentEvent</ParentRole>
      <Position>93</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="20-F" isDefinitelyFs="true" isUsgaap="true" original="ddl-20251231.htm">ddl-20251231.htm</File>
    <File>ddl-20251231.xsd</File>
  </InputFiles>
  <SupplementalFiles>
    <File>img37851892_0.jpg</File>
    <File>img37851892_1.jpg</File>
    <File>img37851892_2.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="3">http://fasb.org/srt/2025</BaseTaxonomy>
    <BaseTaxonomy items="1345">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="11">http://xbrl.sec.gov/cyd/2025</BaseTaxonomy>
    <BaseTaxonomy items="92">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="1">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>false</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
