<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2021"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="rklb-20220118.xsd" xlink:type="simple"/>
    <context id="duration_2022-01-18_to_2022-01-18">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001819994</identifier>
        </entity>
        <period>
            <startDate>2022-01-18</startDate>
            <endDate>2022-01-18</endDate>
        </period>
    </context>
    <dei:AmendmentFlag contextRef="duration_2022-01-18_to_2022-01-18">true</dei:AmendmentFlag>
    <dei:EntityCentralIndexKey
      contextRef="duration_2022-01-18_to_2022-01-18"
      id="Hidden_dei_EntityCentralIndexKey">0001819994</dei:EntityCentralIndexKey>
    <dei:DocumentType contextRef="duration_2022-01-18_to_2022-01-18">8-K/A</dei:DocumentType>
    <dei:DocumentPeriodEndDate contextRef="duration_2022-01-18_to_2022-01-18">2022-01-18</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName contextRef="duration_2022-01-18_to_2022-01-18">Rocket Lab USA, Inc.</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode contextRef="duration_2022-01-18_to_2022-01-18">DE</dei:EntityIncorporationStateCountryCode>
    <dei:EntityFileNumber contextRef="duration_2022-01-18_to_2022-01-18">001-39560</dei:EntityFileNumber>
    <dei:EntityTaxIdentificationNumber contextRef="duration_2022-01-18_to_2022-01-18">98-1550340</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1 contextRef="duration_2022-01-18_to_2022-01-18">3881 McGowen Street</dei:EntityAddressAddressLine1>
    <dei:EntityAddressCityOrTown contextRef="duration_2022-01-18_to_2022-01-18">Long Beach</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince contextRef="duration_2022-01-18_to_2022-01-18">CA</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode contextRef="duration_2022-01-18_to_2022-01-18">90808</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode contextRef="duration_2022-01-18_to_2022-01-18">(714)</dei:CityAreaCode>
    <dei:LocalPhoneNumber contextRef="duration_2022-01-18_to_2022-01-18">465-5737</dei:LocalPhoneNumber>
    <dei:WrittenCommunications contextRef="duration_2022-01-18_to_2022-01-18">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial contextRef="duration_2022-01-18_to_2022-01-18">false</dei:SolicitingMaterial>
    <dei:PreCommencementTenderOffer contextRef="duration_2022-01-18_to_2022-01-18">false</dei:PreCommencementTenderOffer>
    <dei:PreCommencementIssuerTenderOffer contextRef="duration_2022-01-18_to_2022-01-18">false</dei:PreCommencementIssuerTenderOffer>
    <dei:Security12bTitle contextRef="duration_2022-01-18_to_2022-01-18">Common Stock, $0.0001 par value per share</dei:Security12bTitle>
    <dei:TradingSymbol contextRef="duration_2022-01-18_to_2022-01-18">RKLB</dei:TradingSymbol>
    <dei:SecurityExchangeName contextRef="duration_2022-01-18_to_2022-01-18">NASDAQ</dei:SecurityExchangeName>
    <dei:EntityEmergingGrowthCompany contextRef="duration_2022-01-18_to_2022-01-18">true</dei:EntityEmergingGrowthCompany>
    <dei:EntityExTransitionPeriod contextRef="duration_2022-01-18_to_2022-01-18">false</dei:EntityExTransitionPeriod>
    <dei:AmendmentDescription contextRef="duration_2022-01-18_to_2022-01-18">As reported in a Current Report on Form 8-K filed by Rocket Lab USA, Inc., (the &#x201c;Company&#x201d;) on January&#160;19, 2022, the Company completed the acquisition of SolAero Holdings, Inc. on January&#160;18, 2022. The acquisition of SolAero Holdings, Inc. is an acquired business pursuant to Regulation S-X Section&#160;210.11-01(d). However, the Company reevaluated &#x201c;significance&#x201d; of the acquired business using the Company&#x2019;s financial statements for the year ended December&#160;31, 2021, as included in the Company&#x2019;s Annual Report on Form 10-K filed with the Securities and Exchange Commission on March&#160;24, 2022. As a result of such reevaluation, the Company has determined that audited financial statements and unaudited combined pro forma financial statements are not required under Regulation S-X. This Form 8-K/A is being filed solely to amend the disclosure set forth Item 9.01 of the Form 8-K filed on January&#160;19, 2022 to state that no historical financial statements of SolAero Holdings, Inc. or related combined pro forma financial information are required to be filed.</dei:AmendmentDescription>
</xbrl>
