<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.2.0.727</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>203</ContextCount>
  <ElementCount>309</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>71</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>8</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>001 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>002 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/CondensedConsolidatedBalanceSheetsUnaudited</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>003 - Statement - CONSOLIDATED BALANCE SHEETS (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/Consolidatedbalancesheetsparentheticals</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>004 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/CondensedConsolidatedStatementsOfOperationsUnaudited</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>005 - Statement - CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (DEFICIT)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/ConsolidatedStatementOfStockholdersEquityDeficit</Role>
      <ShortName>CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (DEFICIT)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>006 - Statement - CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (DEFICIT) (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/ConsolidatedStatementOfStockholdersEquityDeficitParentheticals</Role>
      <ShortName>CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (DEFICIT) (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>007 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/CondensedConsolidatedStatementsOfCashFlowsUnaudited</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>008 - Disclosure - Business, Liquidity and Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Business, Liquidity and Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>009 - Disclosure - Stockholders' Equity (Deficit)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockholdersEquity</Role>
      <ShortName>Stockholders' Equity (Deficit)</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>010 - Disclosure - Stock Incentive Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockIncentivePlans</Role>
      <ShortName>Stock Incentive Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>011 - Disclosure - Intellectual Property and Collaborative Agreements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/IntellectualPropertyAndCollaborativeAgreements</Role>
      <ShortName>Intellectual Property and Collaborative Agreements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>012 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>013 - Disclosure - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/SubsequentEvents</Role>
      <ShortName>Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>014 - Disclosure - Intangible assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/IntangibleAssets</Role>
      <ShortName>Intangible assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>015 - Disclosure - Accrued Expenses</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/AccruedExpenses</Role>
      <ShortName>Accrued Expenses</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>016 - Disclosure - Restructuring Charges</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/RestructuringCharges</Role>
      <ShortName>Restructuring Charges</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>017 - Disclosure - Notes Payable</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.marinabiotech.com/role/NotesPayable</Role>
      <ShortName>Notes Payable</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>018 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>019 - Disclosure - Business, Liquidity and Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Business, Liquidity and Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>19</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>020 - Disclosure - Business, Liquidity and Summary of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Business, Liquidity and Summary of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>20</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>021 - Disclosure - Stockholders' Equity (Deficit) (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockholdersEquityTables</Role>
      <ShortName>Stockholders' Equity (Deficit) (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockholdersEquity</ParentRole>
      <Position>21</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>022 - Disclosure - Stock Incentive Plans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockIncentivePlansTables</Role>
      <ShortName>Stock Incentive Plans (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockIncentivePlans</ParentRole>
      <Position>22</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>023 - Disclosure - Accrued Expenses (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/AccruedExpensesTables</Role>
      <ShortName>Accrued Expenses (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/AccruedExpenses</ParentRole>
      <Position>23</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>024 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/IncomeTaxes</ParentRole>
      <Position>24</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>025 - Disclosure - Business, Liquidity and Summary of Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesDetails</Role>
      <ShortName>Business, Liquidity and Summary of Significant Accounting Policies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>25</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>026 - Disclosure - Business, Liquidity and Summary of Significant Accounting Policies (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesDetails1</Role>
      <ShortName>Business, Liquidity and Summary of Significant Accounting Policies (Details 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>26</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>027 - Disclosure - Business, Liquidity and Summary of Significant Accounting Policies (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesDetails2</Role>
      <ShortName>Business, Liquidity and Summary of Significant Accounting Policies (Details 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>27</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>028 - Disclosure - Business, Liquidity and Summary of Significant Accounting Policies (Details 3)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesDetails3</Role>
      <ShortName>Business, Liquidity and Summary of Significant Accounting Policies (Details 3)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>28</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>029 - Disclosure - Business, Liquidity and Summary of Significant Accounting Policies (Details 4)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesDetails4</Role>
      <ShortName>Business, Liquidity and Summary of Significant Accounting Policies (Details 4)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>29</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>030 - Disclosure - Business, Liquidity and Summary of Significant Accounting Policies (Detail Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesDetailTextuals</Role>
      <ShortName>Business, Liquidity and Summary of Significant Accounting Policies (Detail Textuals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/BusinessLiquidityAndSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>30</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>031 - Disclosure - Stockholders' Equity (Deficit) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockholdersEquityDetails</Role>
      <ShortName>Stockholders' Equity (Deficit) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockholdersEquityTables</ParentRole>
      <Position>31</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>032 - Disclosure - Stockholders' Equity (Deficit) (Preferred Stock) (Detail Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockholdersEquityPreferredStockDetailTextuals</Role>
      <ShortName>Stockholders' Equity (Deficit) (Preferred Stock) (Detail Textuals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockholdersEquityTables</ParentRole>
      <Position>32</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>033 - Disclosure - Stockholders' Equity (Deficit) (Common Stock) (Detail Textuals 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockholdersEquityCommonStockDetailTextuals1</Role>
      <ShortName>Stockholders' Equity (Deficit) (Common Stock) (Detail Textuals 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockholdersEquityTables</ParentRole>
      <Position>33</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>034 - Disclosure - Stockholders' Equity (Deficit) (Warrants) (Detail Textuals 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockholdersEquityWarrantsDetailTextuals2</Role>
      <ShortName>Stockholders' Equity (Deficit) (Warrants) (Detail Textuals 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockholdersEquityTables</ParentRole>
      <Position>34</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>035 - Disclosure - Stock Incentive Plans (Stock-Based Compensation Expense) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockIncentivePlansStockBasedCompensationExpenseDetails</Role>
      <ShortName>Stock Incentive Plans (Stock-Based Compensation Expense) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockIncentivePlansTables</ParentRole>
      <Position>35</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>036 - Disclosure - Stock Incentive Plans (Stock Option Activity) (Detail 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockIncentivePlansStockOptionActivityDetail1</Role>
      <ShortName>Stock Incentive Plans (Stock Option Activity) (Detail 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockIncentivePlansTables</ParentRole>
      <Position>36</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>037 - Disclosure - Stock Incentive Plans (Stock options outstanding) (Details 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockIncentivePlansStockOptionsOutstandingDetails2</Role>
      <ShortName>Stock Incentive Plans (Stock options outstanding) (Details 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockIncentivePlansTables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>038 - Disclosure - Stock Incentive Plans (Detail Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/StockIncentivePlansDetailTextuals</Role>
      <ShortName>Stock Incentive Plans (Detail Textuals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockIncentivePlansTables</ParentRole>
      <Position>38</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>039 - Disclosure - Stock Incentive Plans (Detail Textuals 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/Stockincentiveplansdetailtextuals1</Role>
      <ShortName>Stock Incentive Plans (Detail Textuals 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockIncentivePlansTables</ParentRole>
      <Position>39</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>040 - Disclosure - Stock Incentive Plans (Details Textuals 2)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/Stockincentiveplansdetailstextuals2</Role>
      <ShortName>Stock Incentive Plans (Details Textuals 2)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/StockIncentivePlansTables</ParentRole>
      <Position>40</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>041 - Disclosure - Intellectual Property and Collaborative Agreements (Detail Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/IntellectualPropertyAndCollaborativeAgreementsDetailTextuals</Role>
      <ShortName>Intellectual Property and Collaborative Agreements (Detail Textuals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/IntellectualPropertyAndCollaborativeAgreements</ParentRole>
      <Position>41</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>042 - Disclosure - Intellectual Property and Collaborative Agreements (Detail Textuals 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/IntellectualPropertyAndCollaborativeAgreementsDetailTextuals1</Role>
      <ShortName>Intellectual Property and Collaborative Agreements (Detail Textuals 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/IntellectualPropertyAndCollaborativeAgreements</ParentRole>
      <Position>42</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>043 - Disclosure - Commitments and Contingencies (Detail Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/CommitmentsAndContingenciesDetails</Role>
      <ShortName>Commitments and Contingencies (Detail Textuals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/CommitmentsAndContingencies</ParentRole>
      <Position>43</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>044 - Disclosure - Subsequent Events (Detail Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/SubsequentEventsDetailTextuals</Role>
      <ShortName>Subsequent Events (Detail Textuals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/SubsequentEvents</ParentRole>
      <Position>44</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>045 - Disclosure - Intangible assets (Detail Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/IntangibleAssetsDetailTextuals</Role>
      <ShortName>Intangible assets (Detail Textuals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/IntangibleAssets</ParentRole>
      <Position>45</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>046 - Disclosure - Intangible assets (Detail Textuals 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/IntangibleAssetsDetailTextuals1</Role>
      <ShortName>Intangible assets (Detail Textuals 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/IntangibleAssets</ParentRole>
      <Position>46</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>047 - Disclosure - Accrued Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/AccruedExpensesDetails</Role>
      <ShortName>Accrued Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/AccruedExpensesTables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>048 - Disclosure - Restructuring Charges (Detail Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/RestructuringChargesDetailTextuals</Role>
      <ShortName>Restructuring Charges (Detail Textuals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/RestructuringCharges</ParentRole>
      <Position>48</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>049 - Disclosure - Notes Payable (Detail Textuals)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://www.marinabiotech.com/role/NotesPayableDetailTextuals</Role>
      <ShortName>Notes Payable (Detail Textuals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/NotesPayable</ParentRole>
      <Position>49</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>050 - Disclosure - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/IncomeTaxesDetails</Role>
      <ShortName>Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/IncomeTaxesTables</ParentRole>
      <Position>50</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>051 - Disclosure - Income Taxes (Detail Textuals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.marinabiotech.com/role/IncomeTaxesDetailTextuals</Role>
      <ShortName>Income Taxes (Detail Textuals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.marinabiotech.com/role/IncomeTaxesTables</ParentRole>
      <Position>51</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="Info">In ''CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited)'', column(s) 3, 5, 6 are contained in other reports, so were removed by flow through suppression.</Log>
    <Log type="Info">In ''CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (DEFICIT) (Parentheticals)'', column(s) 3 are contained in other reports, so were removed by flow through suppression.</Log>
    <Log type="Info">In ''CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited)'', column(s) 1, 2 are contained in other reports, so were removed by flow through suppression.</Log>
  </Logs>
  <InputFiles>
    <File>mrna-20150630.xml</File>
    <File>mrna-20150630_cal.xml</File>
    <File>mrna-20150630_def.xml</File>
    <File>mrna-20150630_lab.xml</File>
    <File>mrna-20150630_pre.xml</File>
    <File>mrna-20150630.xsd</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies/>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>

