<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.25.2</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>248</ContextCount>
  <ElementCount>272</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>71</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>9</UnitCount>
  <MyReports>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-document-and-entity-information</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>001 - Statement - Consolidated Balance Sheets (Current Period Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-consolidated-balance-sheets-current-period-unaudited</Role>
      <ShortName>Consolidated Balance Sheets (Current Period Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>002 - Statement - Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-consolidated-balance-sheets-current-period-unaudited-parentheticals</Role>
      <ShortName>Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>003 - Statement - Consolidated Statements of Operations (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-consolidated-statements-of-operations-unaudited</Role>
      <ShortName>Consolidated Statements of Operations (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>004 - Statement - Consolidated Statements of Stockholders' Equity (Deficit) (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-consolidated-statements-of-stockholders-equity-deficit-unaudited-</Role>
      <ShortName>Consolidated Statements of Stockholders' Equity (Deficit) (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>005 - Statement - Consolidated Statements of Cash Flows (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-consolidated-statements-of-cash-flows-unaudited</Role>
      <ShortName>Consolidated Statements of Cash Flows (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>006 - Disclosure - Note 1 - Organization</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-1-organization</Role>
      <ShortName>Note 1 - Organization</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>007 - Disclosure - Note 2 - Principles of Consolidation and Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-2-principles-of-consolidation-and-significant-accounting-policies</Role>
      <ShortName>Note 2 - Principles of Consolidation and Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>008 - Disclosure - Note 3 - Related-Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-3-relatedparty-transactions</Role>
      <ShortName>Note 3 - Related-Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>009 - Disclosure - Note 4 - Revenue and Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-4-revenue-and-segment-information</Role>
      <ShortName>Note 4 - Revenue and Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>010 - Disclosure - Note 5 - Prepaid Expenses and Other Current Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-5-prepaid-expenses-and-other-current-assets</Role>
      <ShortName>Note 5 - Prepaid Expenses and Other Current Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>011 - Disclosure - Note 6 - Inventory</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-6-inventory</Role>
      <ShortName>Note 6 - Inventory</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>012 - Disclosure - Note 7 - Property, Plant and Equipment, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-7-property-plant-and-equipment-net</Role>
      <ShortName>Note 7 - Property, Plant and Equipment, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>013 - Disclosure - Note 8 - Accrued Expenses and Other Current Liabilities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-8-accrued-expenses-and-other-current-liabilities</Role>
      <ShortName>Note 8 - Accrued Expenses and Other Current Liabilities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>014 - Disclosure - Note 9 - Third-party Long-term Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-9-thirdparty-longterm-debt</Role>
      <ShortName>Note 9 - Third-party Long-term Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>015 - Disclosure - Note 10 - AROs</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-10-aros</Role>
      <ShortName>Note 10 - AROs</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>016 - Disclosure - Note 11 - Lease Obligations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-11-lease-obligations</Role>
      <ShortName>Note 11 - Lease Obligations</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>017 - Disclosure - Note 12 - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-12-income-taxes</Role>
      <ShortName>Note 12 - Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>018 - Disclosure - Note 13 - Earnings and Dividends Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-13-earnings-and-dividends-per-share</Role>
      <ShortName>Note 13 - Earnings and Dividends Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>019 - Disclosure - Note 14 - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-14-commitments-and-contingencies</Role>
      <ShortName>Note 14 - Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>020 - Disclosure - Note 15 - Subsequent Events</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-15-subsequent-events</Role>
      <ShortName>Note 15 - Subsequent Events</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995445 - Disclosure - Insider Trading Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements</Role>
      <ShortName>Insider Trading Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995467 - Disclosure - Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-significant-accounting-policies-policies</Role>
      <ShortName>Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-2-principles-of-consolidation-and-significant-accounting-policies</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995468 - Disclosure - Note 2 - Principles of Consolidation and Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-2-principles-of-consolidation-and-significant-accounting-policies-tables</Role>
      <ShortName>Note 2 - Principles of Consolidation and Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-2-principles-of-consolidation-and-significant-accounting-policies</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995469 - Disclosure - Note 3 - Related-Party Transactions (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-3-relatedparty-transactions-tables</Role>
      <ShortName>Note 3 - Related-Party Transactions (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-3-relatedparty-transactions</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995470 - Disclosure - Note 4 - Revenue and Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-4-revenue-and-segment-information-tables</Role>
      <ShortName>Note 4 - Revenue and Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-4-revenue-and-segment-information</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995471 - Disclosure - Note 5 - Prepaid Expenses and Other Current Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-5-prepaid-expenses-and-other-current-assets-tables</Role>
      <ShortName>Note 5 - Prepaid Expenses and Other Current Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-5-prepaid-expenses-and-other-current-assets</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995472 - Disclosure - Note 6 - Inventory (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-6-inventory-tables</Role>
      <ShortName>Note 6 - Inventory (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-6-inventory</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995473 - Disclosure - Note 7 - Property, Plant and Equipment, Net (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-7-property-plant-and-equipment-net-tables</Role>
      <ShortName>Note 7 - Property, Plant and Equipment, Net (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-7-property-plant-and-equipment-net</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995474 - Disclosure - Note 8 - Accrued Expenses and Other Current Liabilities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-8-accrued-expenses-and-other-current-liabilities-tables</Role>
      <ShortName>Note 8 - Accrued Expenses and Other Current Liabilities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-8-accrued-expenses-and-other-current-liabilities</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995475 - Disclosure - Note 9 - Third-party Long-term Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-9-thirdparty-longterm-debt-tables</Role>
      <ShortName>Note 9 - Third-party Long-term Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-9-thirdparty-longterm-debt</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995476 - Disclosure - Note 10 - AROs (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-10-aros-tables</Role>
      <ShortName>Note 10 - AROs (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-10-aros</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995477 - Disclosure - Note 11 - Lease Obligations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-11-lease-obligations-tables</Role>
      <ShortName>Note 11 - Lease Obligations (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-11-lease-obligations</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995478 - Disclosure - Note 12 - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-12-income-taxes-tables</Role>
      <ShortName>Note 12 - Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-12-income-taxes</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995479 - Disclosure - Note 13 - Earnings and Dividends Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-13-earnings-and-dividends-per-share-tables</Role>
      <ShortName>Note 13 - Earnings and Dividends Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-13-earnings-and-dividends-per-share</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995480 - Disclosure - Note 1 - Organization (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-1-organization-details-textual</Role>
      <ShortName>Note 1 - Organization (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-1-organization</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995481 - Disclosure - Note 2 - Principles of Consolidation and Significant Accounting Policies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-2-principles-of-consolidation-and-significant-accounting-policies-details-textual</Role>
      <ShortName>Note 2 - Principles of Consolidation and Significant Accounting Policies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-2-principles-of-consolidation-and-significant-accounting-policies-tables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995482 - Disclosure - Note 2 - Principles of Consolidation and Significant Accounting Policies - Cash, Cash Equivalents, and Restricted Cash (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-2-principles-of-consolidation-and-significant-accounting-policies-cash-cash-equivalents-and-restricted-cash-details</Role>
      <ShortName>Note 2 - Principles of Consolidation and Significant Accounting Policies - Cash, Cash Equivalents, and Restricted Cash (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995483 - Disclosure - Note 3 - Related-Party Transactions (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-3-relatedparty-transactions-details-textual</Role>
      <ShortName>Note 3 - Related-Party Transactions (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-3-relatedparty-transactions-tables</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995484 - Disclosure - Note 3 - Related-party Transactions - Related Party Debt Agreements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-3-relatedparty-transactions-related-party-debt-agreements-details</Role>
      <ShortName>Note 3 - Related-party Transactions - Related Party Debt Agreements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995485 - Disclosure - Note 3 - Related-party Transactions - Related Party Debt Agreements (Details) (Parentheticals)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-3-relatedparty-transactions-related-party-debt-agreements-details-parentheticals</Role>
      <ShortName>Note 3 - Related-party Transactions - Related Party Debt Agreements (Details) (Parentheticals)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>995486 - Disclosure - Note 3 - Related-party Transactions - Consolidated Balance Sheets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-3-relatedparty-transactions-consolidated-balance-sheets-details</Role>
      <ShortName>Note 3 - Related-party Transactions - Consolidated Balance Sheets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>995487 - Disclosure - Note 3 - Related-party Transactions - Related Party Long-term Debt Outstanding (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-3-relatedparty-transactions-related-party-longterm-debt-outstanding-details</Role>
      <ShortName>Note 3 - Related-party Transactions - Related Party Long-term Debt Outstanding (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>995488 - Disclosure - Note 3 - Related-party Transactions - Consolidated Statements of Operations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-3-relatedparty-transactions-consolidated-statements-of-operations-details</Role>
      <ShortName>Note 3 - Related-party Transactions - Consolidated Statements of Operations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>995489 - Disclosure - Note 4 - Revenue and Segment Information (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-4-revenue-and-segment-information-details-textual</Role>
      <ShortName>Note 4 - Revenue and Segment Information (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-4-revenue-and-segment-information-tables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>995490 - Disclosure - Note 4 - Revenue and Segment Information - Contract Balances (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-4-revenue-and-segment-information-contract-balances-details</Role>
      <ShortName>Note 4 - Revenue and Segment Information - Contract Balances (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>995491 - Disclosure - Note 4 - Revenue and Segment Information - Segment Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-4-revenue-and-segment-information-segment-information-details</Role>
      <ShortName>Note 4 - Revenue and Segment Information - Segment Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>995492 - Disclosure - Note 4 - Revenue and Segment Information - Capital Expenditures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-4-revenue-and-segment-information-capital-expenditures-details</Role>
      <ShortName>Note 4 - Revenue and Segment Information - Capital Expenditures (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>995493 - Disclosure - Note 4 - Revenue and Segment Information - Identifiable Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-4-revenue-and-segment-information-identifiable-assets-details</Role>
      <ShortName>Note 4 - Revenue and Segment Information - Identifiable Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>995494 - Disclosure - Note 5 - Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-5-prepaid-expenses-and-other-current-assets-schedule-of-prepaid-expenses-and-other-current-assets-details</Role>
      <ShortName>Note 5 - Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>995495 - Disclosure - Note 6 - Inventory (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-6-inventory-details-textual</Role>
      <ShortName>Note 6 - Inventory (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-6-inventory-tables</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>995496 - Disclosure - Note 6 - Inventory - Schedule of Inventory (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-6-inventory-schedule-of-inventory-details</Role>
      <ShortName>Note 6 - Inventory - Schedule of Inventory (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>995497 - Disclosure - Note 7 - Property, Plant and Equipment, Net - Property, Plant and Equipment, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-7-property-plant-and-equipment-net-property-plant-and-equipment-net-details</Role>
      <ShortName>Note 7 - Property, Plant and Equipment, Net - Property, Plant and Equipment, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>995498 - Disclosure - Note 8 - Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-8-accrued-expenses-and-other-current-liabilities-schedule-of-accrued-expenses-and-other-current-liabilities-details</Role>
      <ShortName>Note 8 - Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>995499 - Disclosure - Note 9 - Third-party Long-term Debt (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-9-thirdparty-longterm-debt-details-textual</Role>
      <ShortName>Note 9 - Third-party Long-term Debt (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-9-thirdparty-longterm-debt-tables</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>995500 - Disclosure - Note 9 - Third-party Long-term Debt - Loan Agreements Summary (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-9-thirdparty-longterm-debt-loan-agreements-summary-details</Role>
      <ShortName>Note 9 - Third-party Long-term Debt - Loan Agreements Summary (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>995501 - Disclosure - Note 9 - Third-party Long-term Debt - Outstanding Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-9-thirdparty-longterm-debt-outstanding-debt-details</Role>
      <ShortName>Note 9 - Third-party Long-term Debt - Outstanding Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>995502 - Disclosure - Note 9 - Third-party Long-term Debt - Unamortized Debt Issuance Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-9-thirdparty-longterm-debt-unamortized-debt-issuance-costs-details</Role>
      <ShortName>Note 9 - Third-party Long-term Debt - Unamortized Debt Issuance Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>995503 - Disclosure - Note 9 - Third-party Long-term Debt - Accrued Interest (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-9-thirdparty-longterm-debt-accrued-interest-details</Role>
      <ShortName>Note 9 - Third-party Long-term Debt - Accrued Interest (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>995504 - Disclosure - Note 10 - AROs (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-10-aros-details-textual</Role>
      <ShortName>Note 10 - AROs (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-10-aros-tables</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>995505 - Disclosure - Note 10 - AROs - ARO Liability (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-10-aros-aro-liability-details</Role>
      <ShortName>Note 10 - AROs - ARO Liability (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>995506 - Disclosure - Note 11 - Lease Obligations (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-11-lease-obligations-details-textual</Role>
      <ShortName>Note 11 - Lease Obligations (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-11-lease-obligations-tables</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>995507 - Disclosure - Note 11 - Lease Obligations - Lease-related Assets and Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-11-lease-obligations-leaserelated-assets-and-liabilities-details</Role>
      <ShortName>Note 11 - Lease Obligations - Lease-related Assets and Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>995508 - Disclosure - Note 11 - Lease Obligations - Weighted Average Remaining Lease Term and Discount Rate (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-11-lease-obligations-weighted-average-remaining-lease-term-and-discount-rate-details</Role>
      <ShortName>Note 11 - Lease Obligations - Weighted Average Remaining Lease Term and Discount Rate (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>995509 - Disclosure - Note 11 - Lease Obligations - Lease Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-11-lease-obligations-lease-costs-details</Role>
      <ShortName>Note 11 - Lease Obligations - Lease Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>65</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>995510 - Disclosure - Note 11 - Lease Obligations - Supplemental Cash Flow Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-11-lease-obligations-supplemental-cash-flow-information-details</Role>
      <ShortName>Note 11 - Lease Obligations - Supplemental Cash Flow Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>995511 - Disclosure - Note 11 - Lease Obligations - Future Minimum Annual Lease Commitments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-11-lease-obligations-future-minimum-annual-lease-commitments-details</Role>
      <ShortName>Note 11 - Lease Obligations - Future Minimum Annual Lease Commitments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>995512 - Disclosure - Note 12 - Income Taxes (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-12-income-taxes-details-textual</Role>
      <ShortName>Note 12 - Income Taxes (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-12-income-taxes-tables</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>995513 - Disclosure - Note 12 - Income Taxes - Provision for Income Tax Benefit (Expense) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-12-income-taxes-provision-for-income-tax-benefit-expense-details</Role>
      <ShortName>Note 12 - Income Taxes - Provision for Income Tax Benefit (Expense) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>69</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>995514 - Disclosure - Note 12 - Income Taxes - Deferred Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-12-income-taxes-deferred-income-taxes-details</Role>
      <ShortName>Note 12 - Income Taxes - Deferred Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>70</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>995515 - Disclosure - Note 12 - Income Taxes - NOL Carryforwards (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-12-income-taxes-nol-carryforwards-details</Role>
      <ShortName>Note 12 - Income Taxes - NOL Carryforwards (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>71</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R72.htm</HtmlFileName>
      <LongName>995516 - Disclosure - Note 13 - Earnings and Dividends Per Share (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-13-earnings-and-dividends-per-share-details-textual</Role>
      <ShortName>Note 13 - Earnings and Dividends Per Share (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-13-earnings-and-dividends-per-share-tables</ParentRole>
      <Position>72</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>995517 - Disclosure - Note 13 - Earnings and Dividends Per Share - Reconciliation Between Basic and Diluted Income Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-13-earnings-and-dividends-per-share-reconciliation-between-basic-and-diluted-income-per-share-details</Role>
      <ShortName>Note 13 - Earnings and Dividends Per Share - Reconciliation Between Basic and Diluted Income Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>73</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>995518 - Disclosure - Note 14 - Commitments and Contingencies (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-14-commitments-and-contingencies-details-textual</Role>
      <ShortName>Note 14 - Commitments and Contingencies (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-14-commitments-and-contingencies</ParentRole>
      <Position>74</Position>
    </Report>
    <Report instance="bdco20250630_10q.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R75.htm</HtmlFileName>
      <LongName>995519 - Disclosure - Note 15 - Subsequent Events (Details Textual)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.blue-dolphin-energy.com/20250630/role/statement-note-15-subsequent-events-details-textual</Role>
      <ShortName>Note 15 - Subsequent Events (Details Textual)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.blue-dolphin-energy.com/20250630/role/statement-note-15-subsequent-events</ParentRole>
      <Position>75</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>bdco-20250630.xsd</File>
    <File>bdco-20250630_cal.xml</File>
    <File>bdco-20250630_def.xml</File>
    <File>bdco-20250630_lab.xml</File>
    <File>bdco-20250630_pre.xml</File>
    <File doctype="10-Q" isDefinitelyFs="true" isUsgaap="true" original="bdco20250630_10q.htm">bdco20250630_10q.htm</File>
  </InputFiles>
  <SupplementalFiles>
    <File>image02.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy items="961">http://fasb.org/us-gaap/2025</BaseTaxonomy>
    <BaseTaxonomy items="27">http://xbrl.sec.gov/dei/2025</BaseTaxonomy>
    <BaseTaxonomy items="5">http://xbrl.sec.gov/ecd/2025</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
