<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.22.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>226</ContextCount>
  <ElementCount>588</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>81</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>14</UnitCount>
  <MyReports>
    <Report instance="cdak-20211231.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.codiakbio.com/20211231/taxonomy/role/Role_DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>100010 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="cdak-20211231.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.codiakbio.com/20211231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>100060 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/StatementConsolidatedStatementsOfOperationsAndComprehensiveLoss</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>100070 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/StatementConsolidatedStatementsOfOperationsAndComprehensiveLossUnauditedParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>100080 - Statement - CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/StatementConsolidatedStatementsOfRedeemableConvertiblePreferredStockAndStockholdersEquityDeficit</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>100090 - Statement - CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/StatementConsolidatedStatementsOfRedeemableConvertiblePreferredStockAndStockholdersEquityDeficitParenthetical</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>100100 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>100110 - Disclosure - Nature of the Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureNatureOfBusiness</Role>
      <ShortName>Nature of the Business</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>100120 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies1</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>100130 - Disclosure - Derecognition of Business</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureDerecognitionOfBusiness1</Role>
      <ShortName>Derecognition of Business</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>100140 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureFairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>100150 - Disclosure - Investments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureInvestments</Role>
      <ShortName>Investments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>100160 - Disclosure - Prepaids and Other Current Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosurePrepaidsAndOtherCurrentAssets1</Role>
      <ShortName>Prepaids and Other Current Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>100170 - Disclosure - Property and Equipment, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosurePropertyAndEquipmentNet</Role>
      <ShortName>Property and Equipment, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>100180 - Disclosure - Restricted Cash</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureRestrictedCash</Role>
      <ShortName>Restricted Cash</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>100190 - Disclosure - Accrued Expenses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureAccruedExpenses</Role>
      <ShortName>Accrued Expenses</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>100200 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureLeases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>100210 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>100220 - Disclosure - Indebtedness</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureIndebtedness</Role>
      <ShortName>Indebtedness</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>100230 - Disclosure - Common Stock</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureCommonStock1</Role>
      <ShortName>Common Stock</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>100240 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureStockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>100250 - Disclosure - Collaborative Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureCollaborativeArrangements</Role>
      <ShortName>Collaborative Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>100260 - Disclosure - Other Significant Agreements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureOtherSignificantAgreements</Role>
      <ShortName>Other Significant Agreements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>100270 - Disclosure - 401(k) Plan</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Disclosure401kPlan</Role>
      <ShortName>401(k) Plan</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>100280 - Disclosure - Net Loss Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureNetLossPerShare</Role>
      <ShortName>Net Loss Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>100290 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureIncomeTaxes1</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>100300 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies1</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>100310 - Disclosure - Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies1</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>100320 - Disclosure - Derecognition of Business (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureDerecognitionOfBusinessTables</Role>
      <ShortName>Derecognition of Business (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureDerecognitionOfBusiness1</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>100330 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureFairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureFairValueMeasurements</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>100340 - Disclosure - Prepaids and Other Current Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosurePrepaidsAndOtherCurrentAssetsTables</Role>
      <ShortName>Prepaids and Other Current Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/DisclosurePrepaidsAndOtherCurrentAssets1</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>100350 - Disclosure - Property and Equipment, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosurePropertyAndEquipmentNetTables</Role>
      <ShortName>Property and Equipment, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosurePropertyAndEquipmentNet</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>100360 - Disclosure - Accrued Expenses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureAccruedExpensesTables</Role>
      <ShortName>Accrued Expenses (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureAccruedExpenses</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>100370 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureLeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureLeases</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>100380 - Disclosure - Indebtedness (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureIndebtednessTables</Role>
      <ShortName>Indebtedness (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureIndebtedness</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>100390 - Disclosure - Common Stock (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureCommonStockTables</Role>
      <ShortName>Common Stock (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureCommonStock1</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>100400 - Disclosure - Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureStockBasedCompensationTables</Role>
      <ShortName>Stock-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureStockBasedCompensation</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>100410 - Disclosure - Collaborative Arrangements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureCollaborativeArrangementsTables</Role>
      <ShortName>Collaborative Arrangements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureCollaborativeArrangements</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>100420 - Disclosure - Net Loss Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureNetLossPerShareTables</Role>
      <ShortName>Net Loss Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureNetLossPerShare</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>100430 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureIncomeTaxes1</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>100440 - Disclosure - Nature of the Business - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureNatureOfBusinessAdditionalInformationDetails</Role>
      <ShortName>Nature of the Business - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>100450 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>100460 - Disclosure - Summary of Significant Accounting Policies - Property and Equipment Estimated Useful Lives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPropertyAndEquipmentEstimatedUsefulLivesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies - Property and Equipment Estimated Useful Lives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>100470 - Disclosure - Derecognition of Business - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureDerecognitionOfBusinessAdditionalInformationDetails</Role>
      <ShortName>Derecognition of Business - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>100480 - Disclosure - Derecognition of Business - Summary of Calculation of Gain Recognized upon Derecognition of Group of Assets Transferred (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureDerecognitionOfBusinessSummaryOfCalculationOfGainRecognizedUponDerecognitionOfGroupOfAssetsTransferredDetails</Role>
      <ShortName>Derecognition of Business - Summary of Calculation of Gain Recognized upon Derecognition of Group of Assets Transferred (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>100490 - Disclosure - Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureFairValueMeasurementsAssetsMeasuredAtFairValueOnRecurringBasisDetails</Role>
      <ShortName>Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>100500 - Disclosure - Fair Value Measurements - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureFairValueMeasurementsAdditionalInformationDetails</Role>
      <ShortName>Fair Value Measurements - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>100510 - Disclosure - Investments - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureInvestmentsAdditionalInformationDetails</Role>
      <ShortName>Investments - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>100520 - Disclosure - Prepaids and Other Current Assets - Components of Prepaid and Other Current Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosurePrepaidsAndOtherCurrentAssetsComponentsOfPrepaidAndOtherCurrentAssetsDetails</Role>
      <ShortName>Prepaids and Other Current Assets - Components of Prepaid and Other Current Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>100530 - Disclosure - Property and Equipment, Net - Schedule of Property and Equipment, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentNetDetails</Role>
      <ShortName>Property and Equipment, Net - Schedule of Property and Equipment, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>100540 - Disclosure - Property and Equipment, Net - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosurePropertyAndEquipmentNetAdditionalInformationDetails</Role>
      <ShortName>Property and Equipment, Net - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>100550 - Disclosure - Restricted Cash - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureRestrictedCashAdditionalInformationDetails</Role>
      <ShortName>Restricted Cash - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>100560 - Disclosure - Accrued Expenses - Schedule of Accrued Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureAccruedExpensesScheduleOfAccruedExpensesDetails</Role>
      <ShortName>Accrued Expenses - Schedule of Accrued Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>100570 - Disclosure - Leases - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureLeasesAdditionalInformationDetails</Role>
      <ShortName>Leases - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>100580 - Disclosure - Leases - Components of Operating Lease Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureLeasesComponentsOfOperatingLeaseCostsDetails</Role>
      <ShortName>Leases - Components of Operating Lease Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>100590 - Disclosure - Leases - Summary of Additional Lease Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureLeasesSummaryOfAdditionalLeaseInformationDetails</Role>
      <ShortName>Leases - Summary of Additional Lease Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>100600 - Disclosure - Leases - Schedule of Undiscounted Cash Flows Used in Calculating the Operating Lease Liabilities and Amounts to be Received under the Sublease (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureLeasesScheduleOfUndiscountedCashFlowsUsedInCalculatingOperatingLeaseLiabilitiesAndAmountsToBeReceivedUnderSubleaseDetails</Role>
      <ShortName>Leases - Schedule of Undiscounted Cash Flows Used in Calculating the Operating Lease Liabilities and Amounts to be Received under the Sublease (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>100610 - Disclosure - Commitments and contingencies - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureCommitmentsAndContingenciesAdditionalInformationDetails</Role>
      <ShortName>Commitments and contingencies - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>100620 - Disclosure - Indebtedness - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureIndebtednessAdditionalInformationDetails</Role>
      <ShortName>Indebtedness - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>60</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>100630 - Disclosure - Indebtedness - Schedule of Future Principal Payments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureIndebtednessScheduleOfFuturePrincipalPaymentsDetails</Role>
      <ShortName>Indebtedness - Schedule of Future Principal Payments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>100640 - Disclosure - Common Stock - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureCommonStockAdditionalInformationDetails</Role>
      <ShortName>Common Stock - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>100650 - Disclosure - Common Stock - Shares of Common Stock Reserved for Future Issuance (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureCommonStockSharesOfCommonStockReservedForFutureIssuanceDetails</Role>
      <ShortName>Common Stock - Shares of Common Stock Reserved for Future Issuance (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>100660 - Disclosure - Stock-Based Compensation - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureStockBasedCompensationAdditionalInformationDetails</Role>
      <ShortName>Stock-Based Compensation - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>100670 - Disclosure - Stock-Based Compensation - Summary of Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureStockBasedCompensationSummaryOfStockOptionActivityDetails</Role>
      <ShortName>Stock-Based Compensation - Summary of Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>100680 - Disclosure - Stock-Based Compensation - Summary of Assumptions used in Black-Scholes Option Pricing Model (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureStockBasedCompensationSummaryOfAssumptionsUsedInBlackScholesOptionPricingModelDetails</Role>
      <ShortName>Stock-Based Compensation - Summary of Assumptions used in Black-Scholes Option Pricing Model (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>100690 - Disclosure - Stock-Based Compensation - Schedule of Components and Classification of Stock-Based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureStockBasedCompensationScheduleOfComponentsAndClassificationOfStockBasedCompensationExpenseDetails</Role>
      <ShortName>Stock-Based Compensation - Schedule of Components and Classification of Stock-Based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>100700 - Disclosure - Collaboration Agreements - Summary of Total Consolidated Net Revenue from Strategic Collaborators (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureCollaborationAgreementsSummaryOfTotalConsolidatedNetRevenueFromStrategicCollaboratorsDetails</Role>
      <ShortName>Collaboration Agreements - Summary of Total Consolidated Net Revenue from Strategic Collaborators (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>100710 - Disclosure - Collaboration Agreements - Schedule of Changes in Contract Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureCollaborationAgreementsScheduleOfChangesInContractAssetsAndLiabilitiesDetails</Role>
      <ShortName>Collaboration Agreements - Schedule of Changes in Contract Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>100720 - Disclosure - Collaboration Agreements - Schedule of Revenue Recognized (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureCollaborationAgreementsScheduleOfRevenueRecognizedDetails</Role>
      <ShortName>Collaboration Agreements - Schedule of Revenue Recognized (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>100730 - Disclosure - Collaboration Agreements - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureCollaborationAgreementsAdditionalInformationDetails</Role>
      <ShortName>Collaboration Agreements - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>100740 - Disclosure - Collaboration Agreements - Schedule of Transaction Price Allocated to Identified Performance Obligation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureCollaborationAgreementsScheduleOfTransactionPriceAllocatedToIdentifiedPerformanceObligationDetails</Role>
      <ShortName>Collaboration Agreements - Schedule of Transaction Price Allocated to Identified Performance Obligation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>72</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>100750 - Disclosure - Other Significant Agreements - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureOtherSignificantAgreementsAdditionalInformationDetails</Role>
      <ShortName>Other Significant Agreements - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>100760 - Disclosure - 401(k) Plan - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Disclosure401kPlanAdditionalInformationDetails</Role>
      <ShortName>401(k) Plan - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>74</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>100770 - Disclosure - Net Loss Per Share - Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/Role_DisclosureNetLossPerShareBasicAndDilutedNetLossPerShareAttributableToCommonStockholdersDetails</Role>
      <ShortName>Net Loss Per Share - Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>75</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R76.htm</HtmlFileName>
      <LongName>100780 - Disclosure - Net Loss Per Share - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureNetLossPerShareAdditionalInformationDetails</Role>
      <ShortName>Net Loss Per Share - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>76</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R77.htm</HtmlFileName>
      <LongName>100790 - Disclosure - Income Taxes - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetail</Role>
      <ShortName>Income Taxes - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>77</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R78.htm</HtmlFileName>
      <LongName>100800 - Disclosure - Income Taxes - Summary of Reconciliation of US Statutory Income Tax Rate to the Company's Effective Tax Rate (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureIncomeTaxesSummaryOfReconciliationOfUsStatutoryIncomeTaxRateToTheCompanysEffectiveTaxRateDetail</Role>
      <ShortName>Income Taxes - Summary of Reconciliation of US Statutory Income Tax Rate to the Company's Effective Tax Rate (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>78</Position>
    </Report>
    <Report instance="cdak-20211231.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R79.htm</HtmlFileName>
      <LongName>100810 - Disclosure - Income Taxes - Summary of Significant Components of Company's Deferred Tax Assets and Liabilities (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.codiakbio.com/20211231/taxonomy/role/DisclosureIncomeTaxesSummaryOfSignificantComponentsOfCompanysDeferredTaxAssetsAndLiabilitiesDetail</Role>
      <ShortName>Income Taxes - Summary of Significant Components of Company's Deferred Tax Assets and Liabilities (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>79</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="10-K" original="cdak-20211231.htm">cdak-20211231.htm</File>
    <File>cdak-20211231.xsd</File>
    <File>cdak-20211231_cal.xml</File>
    <File>cdak-20211231_def.xml</File>
    <File>cdak-20211231_lab.xml</File>
    <File>cdak-20211231_pre.xml</File>
    <File>cdak-ex10_18.htm</File>
    <File>cdak-ex10_19.htm</File>
    <File>cdak-ex10_20.htm</File>
    <File>cdak-ex10_4.htm</File>
    <File>cdak-ex21_1.htm</File>
    <File>cdak-ex23_1.htm</File>
    <File>cdak-ex31_1.htm</File>
    <File>cdak-ex31_2.htm</File>
    <File>cdak-ex32_1.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>img11753982_0.jpg</File>
    <File>img11753982_1.jpg</File>
    <File>img11753982_10.jpg</File>
    <File>img11753982_11.jpg</File>
    <File>img11753982_12.jpg</File>
    <File>img11753982_13.jpg</File>
    <File>img11753982_14.jpg</File>
    <File>img11753982_15.jpg</File>
    <File>img11753982_16.jpg</File>
    <File>img11753982_17.jpg</File>
    <File>img11753982_18.jpg</File>
    <File>img11753982_19.jpg</File>
    <File>img11753982_2.jpg</File>
    <File>img11753982_20.jpg</File>
    <File>img11753982_21.jpg</File>
    <File>img11753982_22.jpg</File>
    <File>img11753982_23.jpg</File>
    <File>img11753982_24.jpg</File>
    <File>img11753982_25.jpg</File>
    <File>img11753982_26.jpg</File>
    <File>img11753982_27.jpg</File>
    <File>img11753982_28.jpg</File>
    <File>img11753982_29.jpg</File>
    <File>img11753982_3.jpg</File>
    <File>img11753982_30.jpg</File>
    <File>img11753982_31.jpg</File>
    <File>img11753982_32.jpg</File>
    <File>img11753982_33.jpg</File>
    <File>img11753982_4.jpg</File>
    <File>img11753982_5.jpg</File>
    <File>img11753982_6.jpg</File>
    <File>img11753982_7.jpg</File>
    <File>img11753982_8.jpg</File>
    <File>img11753982_9.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="609">http://fasb.org/us-gaap/2021-01-31</BaseTaxonomy>
    <BaseTaxonomy items="40">http://xbrl.sec.gov/dei/2021q4</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
