<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.4</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>111</ContextCount>
  <ElementCount>276</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>31</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>7</UnitCount>
  <MyReports>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>100000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>100010 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>100030 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>100050 - Statement - Consolidated Statements of Operations and Comprehensive Loss</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_StatementConsolidatedStatementsOfOperationsAndComprehensiveLoss</Role>
      <ShortName>Consolidated Statements of Operations and Comprehensive Loss</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>100060 - Statement - Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_StatementConsolidatedStatementsOfRedeemableConvertiblePreferredStockAndStockholdersEquityDeficit</Role>
      <ShortName>Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>100070 - Statement - Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_StatementConsolidatedStatementsOfRedeemableConvertiblePreferredStockAndStockholdersEquityDeficitParenthetical</Role>
      <ShortName>Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>100080 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>100090 - Disclosure - Nature of Business and Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureNatureOfBusinessAndBasisOfPresentation</Role>
      <ShortName>Nature of Business and Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>100100 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>100110 - Disclosure - Cash, Cash Equivalents and Restricted Cash</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureCashCashEquivalentsAndRestrictedCash</Role>
      <ShortName>Cash, Cash Equivalents and Restricted Cash</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>100120 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureFairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>100130 - Disclosure - Property and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosurePropertyAndEquipment</Role>
      <ShortName>Property and Equipment</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>100140 - Disclosure - Accrued Expenses and Other Current Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureAccruedExpensesAndOtherCurrentLiabilities</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>100180 - Disclosure - Stockholders' Equity (Deficit)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficit</Role>
      <ShortName>Stockholders' Equity (Deficit)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>100190 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>100210 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureLeases1</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>100220 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>100240 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>18</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>100250 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>100260 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureFairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureFairValueMeasurements</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>100270 - Disclosure - Summary of Cash, Cash Equivalents and Restricted Cash (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureSummaryOfCashCashEquivalentsAndRestrictedCashTables</Role>
      <ShortName>Summary of Cash, Cash Equivalents and Restricted Cash (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>100280 - Disclosure - Property and Equipment (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosurePropertyAndEquipmentTables</Role>
      <ShortName>Property and Equipment (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosurePropertyAndEquipment</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>100290 - Disclosure - Accrued Expenses and Other Current Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureAccruedExpensesAndOtherCurrentLiabilitiesTables</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureAccruedExpensesAndOtherCurrentLiabilities</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>100300 - Disclosure - Stockholders' Equity (Deficit) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitTables</Role>
      <ShortName>Stockholders' Equity (Deficit) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficit</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>100310 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureIncomeTaxes</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>100320 - Disclosure - Net Loss Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureNetLossPerShareTables</Role>
      <ShortName>Net Loss Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>100330 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureLeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureLeases1</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>100340 - Disclosure - Nature of Business and Basis of Presentation - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureNatureOfBusinessAndBasisOfPresentationAdditionalInformationDetails</Role>
      <ShortName>Nature of Business and Basis of Presentation - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>100350 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>100360 - Disclosure - Summary of Significant Accounting Policies - Net loss per share (Details) - USD ($) $ in Thousands (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesNetLossPerShareDetailsUsdInThousandsDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Net loss per share (Details) - USD ($) $ in Thousands (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>100390 - Disclosure - Summary of Cash, Cash Equivalents and Restricted Cash -Additional information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureSummaryOfCashCashEquivalentsAndRestrictedCashAdditionalInformationDetails</Role>
      <ShortName>Summary of Cash, Cash Equivalents and Restricted Cash -Additional information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>100400 - Disclosure - Cash, Cash Equivalents and Restricted Cash (Additional Information) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureCashCashEquivalentsAndRestrictedCashAdditionalInformationDetails</Role>
      <ShortName>Cash, Cash Equivalents and Restricted Cash (Additional Information) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureCashCashEquivalentsAndRestrictedCash</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>100410 - Disclosure - Fair Value Measurements - Summary of Marketable Securities by Security Type (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfMarketableSecuritiesBySecurityTypeDetails</Role>
      <ShortName>Fair Value Measurements - Summary of Marketable Securities by Security Type (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>100420 - Disclosure - Fair Value Measurements - Summary of Assets Carried at Fair Value on Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfAssetsCarriedAtFairValueOnRecurringBasisDetails</Role>
      <ShortName>Fair Value Measurements - Summary of Assets Carried at Fair Value on Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>100430 - Disclosure - Fair Value Measurements - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetails</Role>
      <ShortName>Fair Value Measurements - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>100440 - Disclosure - Fair Value Measurements - Summary of Scheduled Maturity for Marketable Securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureFairValueMeasurementsSummaryOfScheduledMaturityForMarketableSecuritiesDetails</Role>
      <ShortName>Fair Value Measurements - Summary of Scheduled Maturity for Marketable Securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>100460 - Disclosure - Property and Equipment - Schedule of Property and Equipment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosurePropertyAndEquipmentScheduleOfPropertyAndEquipmentDetails</Role>
      <ShortName>Property and Equipment - Schedule of Property and Equipment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>100470 - Disclosure - Property and Equipment - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosurePropertyAndEquipmentAdditionalInformationDetails</Role>
      <ShortName>Property and Equipment - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>100480 - Disclosure - Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureAccruedExpensesAndOtherCurrentLiabilitiesScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesDetails</Role>
      <ShortName>Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>100500 - Disclosure - Convertible Preferred Stock - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureConvertiblePreferredStockAdditionalInformationDetails</Role>
      <ShortName>Convertible Preferred Stock - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>100510 - Disclosure - Equity - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureEquityAdditionalInformationDetails</Role>
      <ShortName>Equity - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>100520 - Disclosure - Stockholders' Equity (Deficit) - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitAdditionalInformationDetails</Role>
      <ShortName>Stockholders' Equity (Deficit) - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitTables</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>100530 - Disclosure - Stockholders' Equity (Deficit) - Summary of Assumptions Used to Determine Grant-Date Fair Value of Options Granted (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitSummaryOfAssumptionsUsedToDetermineGrantdateFairValueOfOptionsGrantedDetails</Role>
      <ShortName>Stockholders' Equity (Deficit) - Summary of Assumptions Used to Determine Grant-Date Fair Value of Options Granted (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>100540 - Disclosure - Stockholders' Equity (Deficit) - Summary of Stock Option Activity and Related Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitSummaryOfStockOptionActivityAndRelatedInformationDetails</Role>
      <ShortName>Stockholders' Equity (Deficit) - Summary of Stock Option Activity and Related Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>100550 - Disclosure - Stockholders' Equity (Deficit) - Summary of RSU Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitSummaryOfRsuActivityDetails</Role>
      <ShortName>Stockholders' Equity (Deficit) - Summary of RSU Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitTables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>100560 - Disclosure - Stockholders' Equity (Deficit) - Summary of Restricted Common Stock Award Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitSummaryOfRestrictedCommonStockAwardActivityDetails</Role>
      <ShortName>Stockholders' Equity (Deficit) - Summary of Restricted Common Stock Award Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitTables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>100570 - Disclosure - Stockholders' Equity (Deficit) - Summary of Stock-based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitSummaryOfStockbasedCompensationExpenseDetails</Role>
      <ShortName>Stockholders' Equity (Deficit) - Summary of Stock-based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureStockholdersEquityDeficitTables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>100580 - Disclosure - Income Taxes - Reconciliation of U.S. Federal Statutory Income Tax Rate to Effective Income Tax Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureIncomeTaxesReconciliationOfUSFederalStatutoryIncomeTaxRateToEffectiveIncomeTaxRateDetails</Role>
      <ShortName>Income Taxes - Reconciliation of U.S. Federal Statutory Income Tax Rate to Effective Income Tax Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>100590 - Disclosure - Income Taxes - Significant Components of Net Deferred Tax Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureIncomeTaxesSignificantComponentsOfNetDeferredTaxAssetsDetails</Role>
      <ShortName>Income Taxes - Significant Components of Net Deferred Tax Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>100600 - Disclosure - Income Taxes - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureIncomeTaxesAdditionalInformationDetails</Role>
      <ShortName>Income Taxes - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>100610 - Disclosure - Income Taxes - Schedule of Changes in Valuation Allowance (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureIncomeTaxesScheduleOfChangesInValuationAllowanceDetails</Role>
      <ShortName>Income Taxes - Schedule of Changes in Valuation Allowance (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>100620 - Disclosure - Net Loss Per Share - Calculation of Basic and Diluted Net Loss per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/Role_DisclosureNetLossPerShareCalculationOfBasicAndDilutedNetLossPerShareDetails</Role>
      <ShortName>Net Loss Per Share - Calculation of Basic and Diluted Net Loss per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>100630 - Disclosure - Leases - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureLeasesAdditionalInformationDetails</Role>
      <ShortName>Leases - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>100640 - Disclosure - Leases - Components of Lease Cost for the Sublease (Details) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureLeasesComponentsOfLeaseCostForTheSubleaseDetailsDetails</Role>
      <ShortName>Leases - Components of Lease Cost for the Sublease (Details) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>100650 - Disclosure - Leases - Supplemental Disclosure of Cash Flow Information Related to Leases for the Sublease (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureLeasesSupplementalDisclosureOfCashFlowInformationRelatedToLeasesForTheSubleaseDetails</Role>
      <ShortName>Leases - Supplemental Disclosure of Cash Flow Information Related to Leases for the Sublease (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>100660 - Disclosure - Leases - Schedule of Weighted Average Remaining Lease Term and Discount Rate for the Sublease (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureLeasesScheduleOfWeightedAverageRemainingLeaseTermAndDiscountRateForTheSubleaseDetails</Role>
      <ShortName>Leases - Schedule of Weighted Average Remaining Lease Term and Discount Rate for the Sublease (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="dyn-20221231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>100670 - Disclosure - Leases - Schedule of Future Minimum Lease Payments under Non-Cancelable Operating Leases for the Sublease (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.dyne-tx.com/20221231/taxonomy/role/DisclosureLeasesScheduleOfFutureMinimumLeasePaymentsUnderNoncancelableOperatingLeasesForTheSubleaseDetails</Role>
      <ShortName>Leases - Schedule of Future Minimum Lease Payments under Non-Cancelable Operating Leases for the Sublease (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</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: 1 fact(s) appearing in ix:hidden were eligible for transformation: dei:CurrentFiscalYearEndDate -  dyn-20221231.htm 8</Log>
  </Logs>
  <InputFiles>
    <File doctype="10-K" original="dyn-20221231.htm">dyn-20221231.htm</File>
    <File>dyn-20221231.xsd</File>
    <File>dyn-20221231_cal.xml</File>
    <File>dyn-20221231_def.xml</File>
    <File>dyn-20221231_lab.xml</File>
    <File>dyn-20221231_pre.xml</File>
    <File>dyn-ex21_1.htm</File>
    <File>dyn-ex23_1.htm</File>
    <File>dyn-ex31_1.htm</File>
    <File>dyn-ex31_2.htm</File>
    <File>dyn-ex32_1.htm</File>
    <File>dyn-ex32_2.htm</File>
    <File>dyn-ex3_2.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>img107152145_0.jpg</File>
    <File>img107152145_1.jpg</File>
    <File>img107152145_10.jpg</File>
    <File>img107152145_11.jpg</File>
    <File>img107152145_12.jpg</File>
    <File>img107152145_13.jpg</File>
    <File>img107152145_14.jpg</File>
    <File>img107152145_15.jpg</File>
    <File>img107152145_16.jpg</File>
    <File>img107152145_17.jpg</File>
    <File>img107152145_18.jpg</File>
    <File>img107152145_19.jpg</File>
    <File>img107152145_2.jpg</File>
    <File>img107152145_3.jpg</File>
    <File>img107152145_4.jpg</File>
    <File>img107152145_5.jpg</File>
    <File>img107152145_6.jpg</File>
    <File>img107152145_7.jpg</File>
    <File>img107152145_8.jpg</File>
    <File>img107152145_9.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="451">http://fasb.org/us-gaap/2022</BaseTaxonomy>
    <BaseTaxonomy items="39">http://xbrl.sec.gov/dei/2022</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
