<?xml version="1.0" encoding="utf-8"?>
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  xmlns:dei="http://xbrl.sec.gov/dei/2025"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:navi="http://navient.com/20261021"
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  xmlns:xbrldi="http://xbrl.org/2006/xbrldi"
  xmlns:xlink="http://www.w3.org/1999/xlink">
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        <entity>
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        <period>
            <startDate>2026-10-21</startDate>
            <endDate>2026-10-21</endDate>
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    <context id="c20261021to20261021_StatementClassOfStockAxis_SixSeniorNotesDueDecember152043Member">
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        </entity>
        <period>
            <startDate>2026-10-21</startDate>
            <endDate>2026-10-21</endDate>
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    </context>
    <context id="c20261021to20261021_StatementClassOfStockAxis_CommonStockMember">
        <entity>
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            <segment>
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        <period>
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            <endDate>2026-10-21</endDate>
        </period>
    </context>
    <dei:AmendmentFlag
      contextRef="c20261021to20261021"
      id="Fact_a2f172a8e9234e919e76b093371c9fcb">false</dei:AmendmentFlag>
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      contextRef="c20261021to20261021"
      id="Fact_b7bb3df9a0794d24a1b86d8323f81ccb">0001593538</dei:EntityCentralIndexKey>
    <dei:DocumentType
      contextRef="c20261021to20261021"
      id="Fact_5316ee95affb4266a864267d13783168">8-K</dei:DocumentType>
    <dei:DocumentPeriodEndDate
      contextRef="c20261021to20261021"
      id="Fact_c1e606a6f6464341ab3a75924de125cb">2026-10-21</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName
      contextRef="c20261021to20261021"
      id="Fact_f92603612b93420abe54ec67c8d7fee4">Navient Corporation</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode
      contextRef="c20261021to20261021"
      id="Fact_98cc00c9d55a4a7a9472540fe57620e0">DE</dei:EntityIncorporationStateCountryCode>
    <dei:EntityFileNumber
      contextRef="c20261021to20261021"
      id="Fact_d0bff3dfe2d9442b9fea76e1d24f1d36">001-36228</dei:EntityFileNumber>
    <dei:EntityTaxIdentificationNumber
      contextRef="c20261021to20261021"
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    <dei:EntityAddressAddressLine1
      contextRef="c20261021to20261021"
      id="Fact_07d6a4363fc74a95bd7bcbcd419eb26a">13865 Sunrise Valley Drive</dei:EntityAddressAddressLine1>
    <dei:EntityAddressCityOrTown
      contextRef="c20261021to20261021"
      id="Fact_a3b0cd9653a34e418f49a19e677ab3de">Herndon</dei:EntityAddressCityOrTown>
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      contextRef="c20261021to20261021"
      id="Fact_b8958e2f1ae047048b5ed3cbdb269333">VA</dei:EntityAddressStateOrProvince>
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      contextRef="c20261021to20261021"
      id="Fact_c3f3fb0ac9bf4975bc6cf4392c163bf7">20171</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode
      contextRef="c20261021to20261021"
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    <dei:LocalPhoneNumber
      contextRef="c20261021to20261021"
      id="Fact_1577b0417fea42a68cc9974b5ef04771">283-8000</dei:LocalPhoneNumber>
    <dei:WrittenCommunications
      contextRef="c20261021to20261021"
      id="Fact_f1c912f9e1cf464e9dbb002ce03bed72">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial
      contextRef="c20261021to20261021"
      id="Fact_fd658964d4654305a22d2cc08dcd5706">false</dei:SolicitingMaterial>
    <dei:PreCommencementTenderOffer
      contextRef="c20261021to20261021"
      id="Fact_52b13f4549e0449cb3a75f0d1fe3ec81">false</dei:PreCommencementTenderOffer>
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      contextRef="c20261021to20261021"
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    <dei:Security12bTitle
      contextRef="c20261021to20261021_StatementClassOfStockAxis_CommonStockMember"
      id="Fact_77fa9590e388473497962cbdb493101e">Common stock, par value $0.01 per share</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="c20261021to20261021_StatementClassOfStockAxis_CommonStockMember"
      id="Fact_33b8962259b3430b8b6fdf7d0c338432">NAVI</dei:TradingSymbol>
    <dei:SecurityExchangeName
      contextRef="c20261021to20261021_StatementClassOfStockAxis_CommonStockMember"
      id="Fact_b7737d456fb1431da444f21730820161">NASDAQ</dei:SecurityExchangeName>
    <dei:Security12bTitle
      contextRef="c20261021to20261021_StatementClassOfStockAxis_SixSeniorNotesDueDecember152043Member"
      id="Fact_209939004b1047af94a6b3c34471f970">6% Senior Notes due December 15, 2043</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="c20261021to20261021_StatementClassOfStockAxis_SixSeniorNotesDueDecember152043Member"
      id="Fact_a0ddeabcc613415a9a4f319df6fdf92a">JSM</dei:TradingSymbol>
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      contextRef="c20261021to20261021_StatementClassOfStockAxis_SixSeniorNotesDueDecember152043Member"
      id="Fact_13b35a3dae664599a110be9af63a9361">NASDAQ</dei:SecurityExchangeName>
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      contextRef="c20261021to20261021"
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