<?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/2021"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="cvlt-20211026.xsd" xlink:type="simple"/>
    <context id="i9f9e6653b62641c89252714c7b650814_D20211026-20211026">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001169561</identifier>
        </entity>
        <period>
            <startDate>2021-10-26</startDate>
            <endDate>2021-10-26</endDate>
        </period>
    </context>
    <dei:EntityCentralIndexKey
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl80L2ZyYWc6ZGI2ZjQ2N2VhNmMwNGMzOGIxZjg1MzU2YTk5MGIyMTAvdGFibGU6MzhhZmEzMjQ4OGYyNGY0MTk4ZGU0YjA3NDU1NWU5MDcvdGFibGVyYW5nZTozOGFmYTMyNDg4ZjI0ZjQxOThkZTRiMDc0NTU1ZTkwN18yLTEtMS0xLTcxMTg_5c0c03dd-1f95-49b6-9bd5-2d7a3e47db16">0001169561</dei:EntityCentralIndexKey>
    <dei:AmendmentFlag
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl80L2ZyYWc6ZGI2ZjQ2N2VhNmMwNGMzOGIxZjg1MzU2YTk5MGIyMTAvdGFibGU6MzhhZmEzMjQ4OGYyNGY0MTk4ZGU0YjA3NDU1NWU5MDcvdGFibGVyYW5nZTozOGFmYTMyNDg4ZjI0ZjQxOThkZTRiMDc0NTU1ZTkwN18zLTEtMS0xLTcxMTg_3b9ccd57-1e99-4505-ab15-75bb1ae75081">false</dei:AmendmentFlag>
    <dei:DocumentType
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjgw_394ebe75-7746-44c0-9d78-fa7e88737faf">8-K</dei:DocumentType>
    <dei:DocumentPeriodEndDate
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18yMzE_831fbf7f-4921-45c3-adc5-3d261f852029">2021-10-26</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjgx_180a3fd7-785a-4e23-ae89-59edb7f1fb1e">COMMVAULT SYSTEMS, INC.</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGFibGU6YjllYjRiMGUzYjViNGFhMTlhZGRmZWMyYmY3NGFhMWEvdGFibGVyYW5nZTpiOWViNGIwZTNiNWI0YWExOWFkZGZlYzJiZjc0YWExYV8wLTAtMS0xLTcxMTg_c3578ca9-5a90-4dcb-a115-3d32765fedc4">DE</dei:EntityIncorporationStateCountryCode>
    <dei:EntityFileNumber
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGFibGU6YjllYjRiMGUzYjViNGFhMTlhZGRmZWMyYmY3NGFhMWEvdGFibGVyYW5nZTpiOWViNGIwZTNiNWI0YWExOWFkZGZlYzJiZjc0YWExYV8wLTItMS0xLTcxMTg_823eb427-0937-47c5-ae56-5abd0e0639ed">1-33026</dei:EntityFileNumber>
    <dei:EntityTaxIdentificationNumber
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGFibGU6YjllYjRiMGUzYjViNGFhMTlhZGRmZWMyYmY3NGFhMWEvdGFibGVyYW5nZTpiOWViNGIwZTNiNWI0YWExOWFkZGZlYzJiZjc0YWExYV8wLTQtMS0xLTcxMTg_c016763d-d004-48eb-a416-324e1c49010f">22-3447504</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjcy_4df4564b-d775-456f-bafd-e11fd3c2dbc2">1 Commvault Way</dei:EntityAddressAddressLine1>
    <dei:EntityAddressCityOrTown
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjc0_15d1fde4-ba22-4e78-a918-3fddd4663c9c">Tinton Falls</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjcz_f4f58f4c-9971-498b-9e05-1edf4fe21c20">NJ</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjY5_320b17bb-7ccd-4320-918b-cbe4f95b287b">07724</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjc1_c2648232-a531-48fe-b44d-d2e494e969fd">732</dei:CityAreaCode>
    <dei:LocalPhoneNumber
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjcw_7121a138-594a-4763-b021-3d33e37c4826">870-4000</dei:LocalPhoneNumber>
    <dei:WrittenCommunications
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjc2_b8a1c140-42e1-4d9a-bad9-a459422f1a7d">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjc3_c8c76840-2148-40e7-b38c-845b641452f9">false</dei:SolicitingMaterial>
    <dei:PreCommencementTenderOffer
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjc4_9cb5e422-a8af-405a-8783-87a9a174cd14">false</dei:PreCommencementTenderOffer>
    <dei:PreCommencementIssuerTenderOffer
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjc5_0c8cb7a8-2136-4905-af86-9b0e53fc32c1">false</dei:PreCommencementIssuerTenderOffer>
    <dei:Security12bTitle
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGFibGU6MTRhZmVhY2VlZjhjNGM1NWI2Mjg5NTU1MTIyMDI1ZDEvdGFibGVyYW5nZToxNGFmZWFjZWVmOGM0YzU1YjYyODk1NTUxMjIwMjVkMV8xLTAtMS0xLTcxMTg_45c472fc-96f7-4e50-8f2f-4f3de85d2aa6">Common Stock</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGFibGU6MTRhZmVhY2VlZjhjNGM1NWI2Mjg5NTU1MTIyMDI1ZDEvdGFibGVyYW5nZToxNGFmZWFjZWVmOGM0YzU1YjYyODk1NTUxMjIwMjVkMV8xLTEtMS0xLTcxMTg_42d9c98e-b004-4ac7-90a4-ab2aa2e16e0f">CVLT</dei:TradingSymbol>
    <dei:SecurityExchangeName
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGFibGU6MTRhZmVhY2VlZjhjNGM1NWI2Mjg5NTU1MTIyMDI1ZDEvdGFibGVyYW5nZToxNGFmZWFjZWVmOGM0YzU1YjYyODk1NTUxMjIwMjVkMV8xLTItMS0xLTcxMTg_29ffa799-76fa-4747-b81a-fec615ef71af">NASDAQ</dei:SecurityExchangeName>
    <dei:EntityEmergingGrowthCompany
      contextRef="i9f9e6653b62641c89252714c7b650814_D20211026-20211026"
      id="id3VybDovL2RvY3MudjEvZG9jOmZmOGZkY2IwMDM5MzQyOTlhNWVjZDc3ZjhhNDhmNjVmL3NlYzpmZjhmZGNiMDAzOTM0Mjk5YTVlY2Q3N2Y4YTQ4ZjY1Zl8xL2ZyYWc6NzI3MzlmZjZmOWM0NGM5Zjg3YTg4ZWIxZDljYzU1ZTcvdGV4dHJlZ2lvbjo3MjczOWZmNmY5YzQ0YzlmODdhODhlYjFkOWNjNTVlN18xNjcx_b1dd802e-c14f-4965-bf69-39dd3fbfab78">false</dei:EntityEmergingGrowthCompany>
</xbrl>
