<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>200</ContextCount>
  <ElementCount>278</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>33</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>12</UnitCount>
  <MyReports>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001002 - Statement - Consolidated Balance Sheets (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/ConsolidatedBalanceSheetsUnaudited</Role>
      <ShortName>Consolidated Balance Sheets (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1002003 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1003004 - Statement - Consolidated Statements of Operations and Comprehensive Loss (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/ConsolidatedStatementsofOperationsandComprehensiveLossUnaudited</Role>
      <ShortName>Consolidated Statements of Operations and Comprehensive Loss (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1004005 - Statement - Consolidated Statements of Stockholders' Equity (Deficit)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/ConsolidatedStatementsofStockholdersEquityDeficit</Role>
      <ShortName>Consolidated Statements of Stockholders' Equity (Deficit)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1005006 - Statement - Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/ConsolidatedStatementsofCashFlowsUnaudited</Role>
      <ShortName>Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>2101101 - Disclosure - The Business and Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/TheBusinessandSummaryofSignificantAccountingPolicies</Role>
      <ShortName>The Business and Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2108102 - Disclosure - Investments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/Investments</Role>
      <ShortName>Investments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2113103 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2119104 - Disclosure - Equity Transactions and Share-based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/EquityTransactionsandSharebasedCompensation</Role>
      <ShortName>Equity Transactions and Share-based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2123105 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2125106 - Disclosure - Significant Agreements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/SignificantAgreements</Role>
      <ShortName>Significant Agreements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2127107 - Disclosure - Restructuring Costs</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/RestructuringCosts</Role>
      <ShortName>Restructuring Costs</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2132108 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2202201 - Disclosure - The Business and Summary of Significant Accounting Policies (Policy)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/TheBusinessandSummaryofSignificantAccountingPoliciesPolicy</Role>
      <ShortName>The Business and Summary of Significant Accounting Policies (Policy)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.chimerix.com/role/TheBusinessandSummaryofSignificantAccountingPolicies</ParentRole>
      <Position>15</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2303301 - Disclosure - The Business and Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/TheBusinessandSummaryofSignificantAccountingPoliciesTables</Role>
      <ShortName>The Business and Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.chimerix.com/role/TheBusinessandSummaryofSignificantAccountingPolicies</ParentRole>
      <Position>16</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2309302 - Disclosure - Investments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/InvestmentsTables</Role>
      <ShortName>Investments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.chimerix.com/role/Investments</ParentRole>
      <Position>17</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2314303 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/CommitmentsandContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.chimerix.com/role/CommitmentsandContingencies</ParentRole>
      <Position>18</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2320304 - Disclosure - Equity Transactions and Share-based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/EquityTransactionsandSharebasedCompensationTables</Role>
      <ShortName>Equity Transactions and Share-based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.chimerix.com/role/EquityTransactionsandSharebasedCompensation</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2328305 - Disclosure - Restructuring Costs (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/RestructuringCostsTables</Role>
      <ShortName>Restructuring Costs (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.chimerix.com/role/RestructuringCosts</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2404401 - Disclosure - The Business and Summary of Significant Accounting Policies - Description of Business (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/TheBusinessandSummaryofSignificantAccountingPoliciesDescriptionofBusinessDetails</Role>
      <ShortName>The Business and Summary of Significant Accounting Policies - Description of Business (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2405402 - Disclosure - The Business and Summary of Significant Accounting Policies - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/TheBusinessandSummaryofSignificantAccountingPoliciesAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails</Role>
      <ShortName>The Business and Summary of Significant Accounting Policies - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2406403 - Disclosure - The Business and Summary of Significant Accounting Policies - Schedule of Accrued Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/TheBusinessandSummaryofSignificantAccountingPoliciesScheduleofAccruedLiabilitiesDetails</Role>
      <ShortName>The Business and Summary of Significant Accounting Policies - Schedule of Accrued Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2407404 - Disclosure - The Business and Summary of Significant Accounting Policies - Revenue Recognition (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/TheBusinessandSummaryofSignificantAccountingPoliciesRevenueRecognitionDetails</Role>
      <ShortName>The Business and Summary of Significant Accounting Policies - Revenue Recognition (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2410405 - Disclosure - Investments - Summary of Available-for-Sale securities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/InvestmentsSummaryofAvailableforSalesecuritiesDetails</Role>
      <ShortName>Investments - Summary of Available-for-Sale securities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2411406 - Disclosure - Investments - Summary of Investments with Unrealized Losses, Aggregated by Investment Type and the Length of Time (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/InvestmentsSummaryofInvestmentswithUnrealizedLossesAggregatedbyInvestmentTypeandtheLengthofTimeDetails</Role>
      <ShortName>Investments - Summary of Investments with Unrealized Losses, Aggregated by Investment Type and the Length of Time (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>26</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2412407 - Disclosure - Investments - Schedule of Investment Maturity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/InvestmentsScheduleofInvestmentMaturityDetails</Role>
      <ShortName>Investments - Schedule of Investment Maturity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2415408 - Disclosure - Commitments and Contingencies - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/CommitmentsandContingenciesNarrativeDetails</Role>
      <ShortName>Commitments and Contingencies - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2416409 - Disclosure - Commitments and Contingencies - Operating Lease Right-of-Use Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/CommitmentsandContingenciesOperatingLeaseRightofUseAssetsandLiabilitiesDetails</Role>
      <ShortName>Commitments and Contingencies - Operating Lease Right-of-Use Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2417410 - Disclosure - Commitments and Contingencies - Maturity Analysis of Operating Lease Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/CommitmentsandContingenciesMaturityAnalysisofOperatingLeaseLiabilitiesDetails</Role>
      <ShortName>Commitments and Contingencies - Maturity Analysis of Operating Lease Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2418411 - Disclosure - Commitments and Contingencies - Minimum Sublease Rentals (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/CommitmentsandContingenciesMinimumSubleaseRentalsDetails</Role>
      <ShortName>Commitments and Contingencies - Minimum Sublease Rentals (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2421412 - Disclosure - Equity Transactions and Share-based Compensation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/EquityTransactionsandSharebasedCompensationDetails</Role>
      <ShortName>Equity Transactions and Share-based Compensation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.chimerix.com/role/EquityTransactionsandSharebasedCompensationTables</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2422413 - Disclosure - Equity Transactions and Share-based Compensation - Schedule of Share-based Compensation Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/EquityTransactionsandSharebasedCompensationScheduleofSharebasedCompensationExpenseDetails</Role>
      <ShortName>Equity Transactions and Share-based Compensation - Schedule of Share-based Compensation Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2424414 - Disclosure - Income Taxes - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/IncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2426415 - Disclosure - Significant Agreements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/SignificantAgreementsDetails</Role>
      <ShortName>Significant Agreements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.chimerix.com/role/SignificantAgreements</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2429416 - Disclosure - Restructuring Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/RestructuringCostsDetails</Role>
      <ShortName>Restructuring Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.chimerix.com/role/RestructuringCostsTables</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2430417 - Disclosure - Restructuring Costs - Summary of Restructuring Charges (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/RestructuringCostsSummaryofRestructuringChargesDetails</Role>
      <ShortName>Restructuring Costs - Summary of Restructuring Charges (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="cmrx-20200930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2431418 - Disclosure - Restructuring Costs - Accrual Activity for Restructuring Accrual (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.chimerix.com/role/RestructuringCostsAccrualActivityforRestructuringAccrualDetails</Role>
      <ShortName>Restructuring Costs - Accrual Activity for Restructuring Accrual (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</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-Q" original="cmrx-20200930.htm">cmrx-20200930.htm</File>
    <File>a20200930cmrxex-101.htm</File>
    <File>a20200930cmrxex-102.htm</File>
    <File>a20200930cmrxex-103.htm</File>
    <File>a20200930cmrxex-104.htm</File>
    <File>a20200930cmrxex-311.htm</File>
    <File>a20200930cmrxex-312.htm</File>
    <File>a20200930cmrxex-321.htm</File>
    <File>a20200930cmrxex-322.htm</File>
    <File>cmrx-20200930.xsd</File>
    <File>cmrx-20200930_cal.xml</File>
    <File>cmrx-20200930_def.xml</File>
    <File>cmrx-20200930_lab.xml</File>
    <File>cmrx-20200930_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/us-gaap/2020-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2020-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
