<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xml:lang="en-US"
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2020-01-31"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="lnth-20211231.xsd" xlink:type="simple"/>
    <context id="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001521036</identifier>
        </entity>
        <period>
            <startDate>2021-05-04</startDate>
            <endDate>2021-05-04</endDate>
        </period>
    </context>
    <dei:AmendmentFlag
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl80L2ZyYWc6Y2M2NzA5YzRhMWVmNDUwOWJiNDgzZjNiZWVkMzFlMGUvdGFibGU6ZGY0NmQ4YWI1YTljNDA2ZGJjMWI5YWJjMmNkODAxMDMvdGFibGVyYW5nZTpkZjQ2ZDhhYjVhOWM0MDZkYmMxYjlhYmMyY2Q4MDEwM18wLTAtMS0xLTIyOTI2_43d44083-c967-44a4-95e1-8f934c3b3c88">false</dei:AmendmentFlag>
    <dei:EntityCentralIndexKey
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl80L2ZyYWc6Y2M2NzA5YzRhMWVmNDUwOWJiNDgzZjNiZWVkMzFlMGUvdGFibGU6ZGY0NmQ4YWI1YTljNDA2ZGJjMWI5YWJjMmNkODAxMDMvdGFibGVyYW5nZTpkZjQ2ZDhhYjVhOWM0MDZkYmMxYjlhYmMyY2Q4MDEwM18xLTAtMS0xLTIyOTI2_eb016493-c47c-43ec-ab54-73b855852d11">0001521036</dei:EntityCentralIndexKey>
    <dei:DocumentType
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGV4dHJlZ2lvbjo3Zjg2NzQ5ZmE5NGQ0N2I4YTc0NzNhOTgzMTA1ZjUzMF8zMDMw_43151060-3e5a-4383-8c48-8c392e3ce1a6">8-K</dei:DocumentType>
    <dei:DocumentPeriodEndDate
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGV4dHJlZ2lvbjo3Zjg2NzQ5ZmE5NGQ0N2I4YTc0NzNhOTgzMTA1ZjUzMF8yMzQ_79aa5c8f-f00b-4c61-a9ae-5b74498f2047">2021-12-31</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGV4dHJlZ2lvbjo3Zjg2NzQ5ZmE5NGQ0N2I4YTc0NzNhOTgzMTA1ZjUzMF8zMDM3_37503728-09c0-4e22-a903-cabd8fd98abe">LANTHEUS HOLDINGS,&#160;INC.</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGFibGU6ZmU5YzRmZjMzY2MzNDAzZmI3OTRkNGY3NWEwYWM2ODgvdGFibGVyYW5nZTpmZTljNGZmMzNjYzM0MDNmYjc5NGQ0Zjc1YTBhYzY4OF8wLTAtMS0xLTIyOTI2_73ca59da-5313-4ba4-acaa-25dfd97dc426">DE</dei:EntityIncorporationStateCountryCode>
    <dei:EntityFileNumber
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGFibGU6ZmU5YzRmZjMzY2MzNDAzZmI3OTRkNGY3NWEwYWM2ODgvdGFibGVyYW5nZTpmZTljNGZmMzNjYzM0MDNmYjc5NGQ0Zjc1YTBhYzY4OF8wLTEtMS0xLTIyOTI2_b67fb16b-0ffe-4ce7-992b-f8cb9c3e134d">001-36569</dei:EntityFileNumber>
    <dei:EntityTaxIdentificationNumber
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGFibGU6ZmU5YzRmZjMzY2MzNDAzZmI3OTRkNGY3NWEwYWM2ODgvdGFibGVyYW5nZTpmZTljNGZmMzNjYzM0MDNmYjc5NGQ0Zjc1YTBhYzY4OF8wLTItMS0xLTIyOTI2_cb5fce74-f9f4-41f6-bf01-10e25950e65a">35-2318913</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGFibGU6NzhhNDc0NzVkNzFkNGY1MTlkM2EwNDY0NTA4MTY1MzAvdGFibGVyYW5nZTo3OGE0NzQ3NWQ3MWQ0ZjUxOWQzYTA0NjQ1MDgxNjUzMF8wLTAtMS0xLTIyOTI2L3RleHRyZWdpb246MjJkN2UxZjI5ZmY5NDA5Mzk5YmUyZjNhYzVlMDU1NDlfNA_40a0e592-62f8-4c54-8bf8-4de3e2b310cb">331 Treble Cove Road</dei:EntityAddressAddressLine1>
    <dei:EntityAddressCityOrTown
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGFibGU6NzhhNDc0NzVkNzFkNGY1MTlkM2EwNDY0NTA4MTY1MzAvdGFibGVyYW5nZTo3OGE0NzQ3NWQ3MWQ0ZjUxOWQzYTA0NjQ1MDgxNjUzMF8wLTAtMS0xLTIyOTI2L3RleHRyZWdpb246MjJkN2UxZjI5ZmY5NDA5Mzk5YmUyZjNhYzVlMDU1NDlfOA_054338f3-3dae-4593-a42f-2a0b82c82205">North Billerica</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGFibGU6NzhhNDc0NzVkNzFkNGY1MTlkM2EwNDY0NTA4MTY1MzAvdGFibGVyYW5nZTo3OGE0NzQ3NWQ3MWQ0ZjUxOWQzYTA0NjQ1MDgxNjUzMF8wLTAtMS0xLTIyOTI2L3RleHRyZWdpb246MjJkN2UxZjI5ZmY5NDA5Mzk5YmUyZjNhYzVlMDU1NDlfMTI_e7bc532e-9ca6-4e1f-bd5b-758b123a0ab5">MA</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGFibGU6NzhhNDc0NzVkNzFkNGY1MTlkM2EwNDY0NTA4MTY1MzAvdGFibGVyYW5nZTo3OGE0NzQ3NWQ3MWQ0ZjUxOWQzYTA0NjQ1MDgxNjUzMF8wLTItMS0xLTIyOTI2_941e89aa-937a-470b-84b3-d27bd8b160a2">01862</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGV4dHJlZ2lvbjo3Zjg2NzQ5ZmE5NGQ0N2I4YTc0NzNhOTgzMTA1ZjUzMF8zMDI4_c7eec265-cce7-4826-b6ed-a7d2a459f930">978</dei:CityAreaCode>
    <dei:LocalPhoneNumber
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGV4dHJlZ2lvbjo3Zjg2NzQ5ZmE5NGQ0N2I4YTc0NzNhOTgzMTA1ZjUzMF8zMDMx_88726077-b452-4eff-afe2-d83004b5bf21">671-8001</dei:LocalPhoneNumber>
    <dei:WrittenCommunications
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGV4dHJlZ2lvbjo3Zjg2NzQ5ZmE5NGQ0N2I4YTc0NzNhOTgzMTA1ZjUzMF8zMDI5_48904364-ab73-4098-8072-dff30ffc930f">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGV4dHJlZ2lvbjo3Zjg2NzQ5ZmE5NGQ0N2I4YTc0NzNhOTgzMTA1ZjUzMF8zMDMy_faf5c082-4d6c-4eb5-b14e-b2272f9ad147">false</dei:SolicitingMaterial>
    <dei:PreCommencementTenderOffer
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGV4dHJlZ2lvbjo3Zjg2NzQ5ZmE5NGQ0N2I4YTc0NzNhOTgzMTA1ZjUzMF8zMDM1_e45de25c-9512-4ba4-af92-a5bc6afb0780">false</dei:PreCommencementTenderOffer>
    <dei:PreCommencementIssuerTenderOffer
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGV4dHJlZ2lvbjo3Zjg2NzQ5ZmE5NGQ0N2I4YTc0NzNhOTgzMTA1ZjUzMF8zMDM2_fc9dbde2-01c5-4a39-bd44-30a4b130a8e9">false</dei:PreCommencementIssuerTenderOffer>
    <dei:Security12bTitle
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGFibGU6NmI3YTZlYmJhNzc5NDEyYTk2Mjk5YTNhNzMzMTc2OWUvdGFibGVyYW5nZTo2YjdhNmViYmE3Nzk0MTJhOTYyOTlhM2E3MzMxNzY5ZV8xLTAtMS0xLTIyOTI2_d05d052b-8399-49b7-90b6-2e1c49d39c7b">Common stock, par value $0.01 per share</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGFibGU6NmI3YTZlYmJhNzc5NDEyYTk2Mjk5YTNhNzMzMTc2OWUvdGFibGVyYW5nZTo2YjdhNmViYmE3Nzk0MTJhOTYyOTlhM2E3MzMxNzY5ZV8xLTEtMS0xLTIyOTI2_eebff3fe-5dc0-4117-8f58-2307f9cac28b">LNTH</dei:TradingSymbol>
    <dei:SecurityExchangeName
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGFibGU6NmI3YTZlYmJhNzc5NDEyYTk2Mjk5YTNhNzMzMTc2OWUvdGFibGVyYW5nZTo2YjdhNmViYmE3Nzk0MTJhOTYyOTlhM2E3MzMxNzY5ZV8xLTItMS0xLTIyOTI2_1ff87430-917b-47ab-bafb-d91920a8dbb6">NASDAQ</dei:SecurityExchangeName>
    <dei:EntityEmergingGrowthCompany
      contextRef="i61ea3a59d5f144de8da5a09a48f224dc_D20210504-20210504"
      id="id3VybDovL2RvY3MudjEvZG9jOjMwMzE4MGQxYTFjOTRjN2Q4YzM5YzdiNzhmOGMyNzc2L3NlYzozMDMxODBkMWExYzk0YzdkOGMzOWM3Yjc4ZjhjMjc3Nl8xL2ZyYWc6N2Y4Njc0OWZhOTRkNDdiOGE3NDczYTk4MzEwNWY1MzAvdGV4dHJlZ2lvbjo3Zjg2NzQ5ZmE5NGQ0N2I4YTc0NzNhOTgzMTA1ZjUzMF8zMDQx_82ef3150-9005-4b5f-aecd-d78368477e39">false</dei:EntityEmergingGrowthCompany>
</xbrl>
