<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.26.3</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>162</ContextCount>
  <ElementCount>303</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>38</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>75000 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DocumentCoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>75010 - Statement - Condensed Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_StatementCondensedConsolidatedBalanceSheets</Role>
      <ShortName>Condensed Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>75020 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_StatementCondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Condensed Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>75030 - Statement - Condensed Consolidated Statements of Comprehensive Operations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/StatementCondensedConsolidatedStatementsOfComprehensiveOperations</Role>
      <ShortName>Condensed Consolidated Statements of Comprehensive Operations</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>75040 - Statement - Condensed Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_StatementCondensedConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Condensed Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>75050 - Statement - Condensed Consolidated Statements of Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_StatementCondensedConsolidatedStatementsOfStockholdersEquity</Role>
      <ShortName>Condensed Consolidated Statements of Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>995410 - Disclosure - Pay vs Performance Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/PvpDisclosure</Role>
      <ShortName>Pay vs Performance Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.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>8</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>995455 - Disclosure - Organization and Basis of Presentation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureOrganizationAndBasisOfPresentation</Role>
      <ShortName>Organization and Basis of Presentation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>995465 - Disclosure - Recent Accounting Pronouncements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureRecentAccountingPronouncements</Role>
      <ShortName>Recent Accounting Pronouncements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>995475 - Disclosure - Revenue Recognition</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureRevenueRecognition</Role>
      <ShortName>Revenue Recognition</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>995485 - Disclosure - Inventories</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureInventories</Role>
      <ShortName>Inventories</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>995495 - Disclosure - Goodwill and Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureGoodwillAndIntangibleAssets</Role>
      <ShortName>Goodwill and Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>995505 - Disclosure - Third-Party Production Payments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureThirdpartyProductionPayments</Role>
      <ShortName>Third-Party Production Payments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>995515 - Disclosure - Note Receivable</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNoteReceivable</Role>
      <ShortName>Note Receivable</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>995525 - Disclosure - Net Income (Loss) per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNetIncomeLossPerShare</Role>
      <ShortName>Net Income (Loss) per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>995535 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureCommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>995545 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>995555 - Disclosure - Line of Credit</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureLineOfCredit</Role>
      <ShortName>Line of Credit</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>995565 - Disclosure - Fair Value Measures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureFairValueMeasures</Role>
      <ShortName>Fair Value Measures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995575 - Disclosure - Common Stock and Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureCommonStockAndStockBasedCompensation</Role>
      <ShortName>Common Stock and Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995595 - Disclosure - Segment Reporting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureSegmentReporting</Role>
      <ShortName>Segment Reporting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>995615 - Disclosure - Related Party Transactions</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureRelatedPartyTransactions</Role>
      <ShortName>Related Party Transactions</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>995625 - Disclosure - Revenue Recognition (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureRevenueRecognitionTables</Role>
      <ShortName>Revenue Recognition (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureRevenueRecognition</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>995635 - Disclosure - Inventories (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureInventoriesTables</Role>
      <ShortName>Inventories (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureInventories</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>995645 - Disclosure - Goodwill and Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureGoodwillAndIntangibleAssetsTables</Role>
      <ShortName>Goodwill and Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureGoodwillAndIntangibleAssets</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>995655 - Disclosure - Net Income (Loss) per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNetIncomeLossPerShareTables</Role>
      <ShortName>Net Income (Loss) per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNetIncomeLossPerShare</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>995665 - Disclosure - Commitments and Contingencies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureCommitmentsAndContingenciesTables</Role>
      <ShortName>Commitments and Contingencies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureCommitmentsAndContingencies</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>995675 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureIncomeTaxes</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>995685 - Disclosure - Common Stock and Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureCommonStockAndStockBasedCompensationTables</Role>
      <ShortName>Common Stock and Stock-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureCommonStockAndStockBasedCompensation</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>995695 - Disclosure - Segment Reporting (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureSegmentReportingTables</Role>
      <ShortName>Segment Reporting (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureSegmentReporting</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>995705 - Disclosure - Recent Accounting Pronouncements - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureRecentAccountingPronouncementsAdditionalInformationDetail</Role>
      <ShortName>Recent Accounting Pronouncements - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>995715 - Disclosure - Revenue Recognition - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureRevenueRecognitionAdditionalInformationDetail</Role>
      <ShortName>Revenue Recognition - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>995725 - Disclosure - Revenue Recognition - Schedule of Breakdown of Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureRevenueRecognitionScheduleOfBreakdownOfRevenueDetails</Role>
      <ShortName>Revenue Recognition - Schedule of Breakdown of Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>995735 - Disclosure - Revenue Recognition - Schedule of Revenue Recorded as Reductions to Net Revenue or as Advertising, Promotional and Selling Expenses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureRevenueRecognitionScheduleOfRevenueRecordedAsReductionsToNetRevenueOrAsAdvertisingPromotionalAndSellingExpensesDetails</Role>
      <ShortName>Revenue Recognition - Schedule of Revenue Recorded as Reductions to Net Revenue or as Advertising, Promotional and Selling Expenses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>995745 - Disclosure - Inventories - Components of Inventories (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureInventoriesComponentsOfInventoriesDetail</Role>
      <ShortName>Inventories - Components of Inventories (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>995755 - Disclosure - Inventories - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureInventoriesAdditionalInformationDetail</Role>
      <ShortName>Inventories - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>995765 - Disclosure - Goodwill and Intangible Assets - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureGoodwillAndIntangibleAssetsAdditionalInformationDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>995775 - Disclosure - Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureGoodwillAndIntangibleAssetsScheduleOfIntangibleAssetsDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>995785 - Disclosure - Goodwill and Intangible Assets - Schedule of Future Amortization Expense (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureGoodwillAndIntangibleAssetsScheduleOfFutureAmortizationExpenseDetail</Role>
      <ShortName>Goodwill and Intangible Assets - Schedule of Future Amortization Expense (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>995795 - Disclosure - Third-Party Production Payments - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureThirdpartyProductionPaymentsAdditionalInformationDetail</Role>
      <ShortName>Third-Party Production Payments - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>995805 - Disclosure - Note Receivable - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNoteReceivableAdditionalInformationDetail</Role>
      <ShortName>Note Receivable - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>995815 - Disclosure - Net Income (Loss) per Share - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNetIncomeLossPerShareAdditionalInformationDetail</Role>
      <ShortName>Net Income (Loss) per Share - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNetIncomeLossPerShareTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>995825 - Disclosure - Net Income (Loss) per Share - Computation of Net (Loss) Income Per Share, Basic (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNetIncomeLossPerShareComputationOfNetLossIncomePerShareBasicDetail</Role>
      <ShortName>Net Income (Loss) per Share - Computation of Net (Loss) Income Per Share, Basic (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNetIncomeLossPerShareTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>995835 - Disclosure - Net Income (Loss) per Share - Computation of Diluted Net (Loss) Income Per Share (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNetIncomeLossPerShareComputationOfDilutedNetLossIncomePerShareDetail</Role>
      <ShortName>Net Income (Loss) per Share - Computation of Diluted Net (Loss) Income Per Share (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureNetIncomeLossPerShareTables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>995845 - Disclosure - Commitments and Contingencies - Summary of Non-cancelable Contractual Obligations (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureCommitmentsAndContingenciesSummaryOfNonCancelableContractualObligationsDetail</Role>
      <ShortName>Commitments and Contingencies - Summary of Non-cancelable Contractual Obligations (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>995855 - Disclosure - Commitments and Contingencies - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetail</Role>
      <ShortName>Commitments and Contingencies - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>995865 - Disclosure - Income Taxes - Summary of Effective Income Tax Rates (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureIncomeTaxesSummaryOfEffectiveIncomeTaxRatesDetail</Role>
      <ShortName>Income Taxes - Summary of Effective Income Tax Rates (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>995875 - Disclosure - Income Taxes - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureIncomeTaxesAdditionalInformationDetail</Role>
      <ShortName>Income Taxes - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>995885 - Disclosure - Line of Credit - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureLineOfCreditAdditionalInformationDetail</Role>
      <ShortName>Line of Credit - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>995895 - Disclosure - Fair Value Measures - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureFairValueMeasuresAdditionalInformationDetail</Role>
      <ShortName>Fair Value Measures - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>995905 - Disclosure - Common Stock and Stock-Based Compensation - Summary of Stock Options under Employee Equity Incentive Plan and Stock Option Plan for Non-Employee Directors (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureCommonStockAndStockBasedCompensationSummaryOfStockOptionsUnderEmployeeEquityIncentivePlanAndStockOptionPlanForNonEmployeeDirectorsDetail</Role>
      <ShortName>Common Stock and Stock-Based Compensation - Summary of Stock Options under Employee Equity Incentive Plan and Stock Option Plan for Non-Employee Directors (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>995915 - Disclosure - Common Stock and Stock-Based Compensation - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureCommonStockAndStockBasedCompensationAdditionalInformationDetail</Role>
      <ShortName>Common Stock and Stock-Based Compensation - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>995925 - Disclosure - Common Stock and Stock-Based Compensation - Summary of Vesting Activities of Shares Issued Under Investment Share Program and Restricted Stock Units (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureCommonStockAndStockbasedCompensationSummaryOfVestingActivitiesOfSharesIssuedUnderInvestmentShareProgramAndRestrictedStockUnitsD</Role>
      <ShortName>Common Stock and Stock-Based Compensation - Summary of Vesting Activities of Shares Issued Under Investment Share Program and Restricted Stock Units (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>995935 - Disclosure - Common Stock and Stock-Based Compensation - Stock-Based Compensation Expense Included in Operating Expenses (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureCommonStockAndStockBasedCompensationStockBasedCompensationExpenseIncludedInOperatingExpensesDetail</Role>
      <ShortName>Common Stock and Stock-Based Compensation - Stock-Based Compensation Expense Included in Operating Expenses (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>995945 - Disclosure - Common Stock and Stock-Based Compensation - Summary Of Weighted Average Assumptions used to Estimate Fair Value of Shares Purchased (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureCommonStockAndStockbasedCompensationSummaryOfWeightedAverageAssumptionsUsedToEstimateFairValueOfSharesPurchasedDetail</Role>
      <ShortName>Common Stock and Stock-Based Compensation - Summary Of Weighted Average Assumptions used to Estimate Fair Value of Shares Purchased (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>995955 - Disclosure - Segment Reporting - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureSegmentReportingAdditionalInformationDetail</Role>
      <ShortName>Segment Reporting - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>995965 - Disclosure - Segment Reporting - Summary of Segment Net Income (Loss) (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/DisclosureSegmentReportingSummaryOfSegmentNetIncomeLossDetail</Role>
      <ShortName>Segment Reporting - Summary of Segment Net Income (Loss) (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="sam-20260926.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>995995 - Disclosure - Related Party Transactions - Additional Information (Detail)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.bostonbeer.com/20260926/taxonomy/role/Role_DisclosureRelatedPartyTransactionsAdditionalInformationDetail</Role>
      <ShortName>Related Party Transactions - Additional Information (Detail)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</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" isDefinitelyFs="true" isUsgaap="true" original="sam-20260926.htm">sam-20260926.htm</File>
    <File>sam-20260926.xsd</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="4">http://fasb.org/srt/2026</BaseTaxonomy>
    <BaseTaxonomy items="698">http://fasb.org/us-gaap/2026</BaseTaxonomy>
    <BaseTaxonomy items="30">http://xbrl.sec.gov/dei/2026</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/ecd/2026</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>false</HasPresentationLinkbase>
  <HasCalculationLinkbase>false</HasCalculationLinkbase>
</FilingSummary>
