<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2026"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="sam-20261022.xsd" xlink:type="simple"/>
    <context id="C_69b21e7b-060b-4f82-9e86-61ee0a60419e">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000949870</identifier>
        </entity>
        <period>
            <startDate>2026-10-22</startDate>
            <endDate>2026-10-22</endDate>
        </period>
    </context>
    <dei:AmendmentFlag
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_d67363a8-b9e0-4751-ac3e-a83523dc56cb">false</dei:AmendmentFlag>
    <dei:EntityCentralIndexKey
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_3345c666-f307-4b37-a46a-7255e143c9bb">0000949870</dei:EntityCentralIndexKey>
    <dei:DocumentType
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_38b3cafc-4443-4134-8c88-78d0471bbcea">8-K</dei:DocumentType>
    <dei:DocumentPeriodEndDate
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_20c39aec-fd32-419a-91c0-f3634471491d">2026-10-22</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_3a70757a-8c95-4714-8987-e382e84ca938">The Boston Beer Company, Inc.</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_5673498e-80db-46ce-9eb8-bccbaf35c5f6">MA</dei:EntityIncorporationStateCountryCode>
    <dei:EntityFileNumber
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_35e19e11-39bd-4d1b-a1db-e08acb12aeac">001-14092</dei:EntityFileNumber>
    <dei:EntityTaxIdentificationNumber
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_e19bb340-2b21-42a8-a7b0-0cdec0fc1776">04-3284048</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_3c8ff64e-3f18-4883-b1f3-94404e60852f">One Design Center Place</dei:EntityAddressAddressLine1>
    <dei:EntityAddressAddressLine2
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_b3a7ea24-3308-43e0-bcf6-fd7113884e9c">Suite 850</dei:EntityAddressAddressLine2>
    <dei:EntityAddressCityOrTown
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_021e7086-bfc8-44f7-bc03-e54d3f29975a">Boston</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_f72546c7-4333-4b0c-8a30-6abe6c8900f5">MA</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_bbe5fdb0-3393-4244-803e-6a1d1a639971">02210</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_59cc3317-b7d5-4b25-9d45-40a8e079bb33">(617)</dei:CityAreaCode>
    <dei:LocalPhoneNumber
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_35f95a28-13cc-4020-b97a-611b300ada58">368-5000</dei:LocalPhoneNumber>
    <dei:WrittenCommunications
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_5ea1984c-c742-421e-ba17-694e83b69f81">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_1b147d38-64fa-443b-98a4-72857da531fe">false</dei:SolicitingMaterial>
    <dei:PreCommencementTenderOffer
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_0f986c5d-4bcc-492e-9e5c-1cb52ceff9e1">false</dei:PreCommencementTenderOffer>
    <dei:PreCommencementIssuerTenderOffer
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_c35021c7-7216-4004-bde4-7d90e12962e9">false</dei:PreCommencementIssuerTenderOffer>
    <dei:Security12bTitle
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_e0126e82-c8db-4ba5-a731-ced44fe1058d">Class A Common Stock</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_adefb7fe-6d11-4b29-b828-c63e20e94929">SAM</dei:TradingSymbol>
    <dei:SecurityExchangeName
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_953a4566-1787-4a48-ac9f-7a06a490b6bf">NYSE</dei:SecurityExchangeName>
    <dei:EntityEmergingGrowthCompany
      contextRef="C_69b21e7b-060b-4f82-9e86-61ee0a60419e"
      id="F_68f1ac61-c2ad-4063-b14d-a4aaaa0da809">false</dei:EntityEmergingGrowthCompany>
</xbrl>
