<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2025"
  xmlns:fmr="http://www.fidelity.com/20260401"
  xmlns:iso4217="http://www.xbrl.org/2003/iso4217"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:oef="http://xbrl.sec.gov/oef/2025"
  xmlns:xbrldi="http://xbrl.org/2006/xbrldi"
  xmlns:xhtml="http://www.w3.org/1999/xhtml"
  xmlns:xlink="http://www.w3.org/1999/xlink">
    <link:schemaRef xlink:href="fmr-20260401.xsd" xlink:type="simple"/>
    <context id="Trust">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_contentCd_SFB-PRO">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_contentCd_SFB-PRO_RiskMember_MunicipalMarketVolatilityMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:MunicipalMarketVolatilityMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_contentCd_SFB-PRO_RiskMember_InterestRateChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:InterestRateChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_contentCd_SFB-PRO_RiskMember_IssuerSpecificChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:IssuerSpecificChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_contentCd_SFB-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskNotInsuredDepositoryInstitutionMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_contentCd_SFB-PRO_RiskMember_RiskLoseMoneyMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskLoseMoneyMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_2016">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-01-01</startDate>
            <endDate>2016-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_2017">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2017-01-01</startDate>
            <endDate>2017-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_2018">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2018-01-01</startDate>
            <endDate>2018-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_2019">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2019-01-01</startDate>
            <endDate>2019-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_2020">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2020-01-01</startDate>
            <endDate>2020-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_2021">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-01-01</startDate>
            <endDate>2021-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_2022">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-01-01</startDate>
            <endDate>2022-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_2023">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-01-01</startDate>
            <endDate>2023-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_2024">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2024-01-01</startDate>
            <endDate>2024-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_2025">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-01-01</startDate>
            <endDate>2025-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_ReturnBeforeTaxes_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_ReturnBeforeTaxes_10">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributions_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributions_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributions_10">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributionsAndSales_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributionsAndSales_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributionsAndSales_10">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000048850Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Indexid_LB123_contentCd_SFB-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB123Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Indexid_LB123_contentCd_SFB-PRO_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB123Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Indexid_LB123_contentCd_SFB-PRO_10">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB123Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Indexid_LB015_contentCd_SFB-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Indexid_LB015_contentCd_SFB-PRO_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000017680_Indexid_LB015_contentCd_SFB-PRO_10">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelityTax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000017680Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_contentCd_XS6-PRO">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_contentCd_XS6-PRO_RiskMember_StockMarketVolatilityMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:StockMarketVolatilityMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_contentCd_XS6-PRO_RiskMember_IssuerSpecificChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:IssuerSpecificChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_contentCd_XS6-PRO_RiskMember_CorrelationToIndexMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:CorrelationToIndexMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_contentCd_XS6-PRO_RiskMember_PassiveManagementRiskMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:PassiveManagementRiskMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_contentCd_XS6-PRO_RiskMember_ValueInvestingMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:ValueInvestingMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_contentCd_XS6-PRO_RiskMember_SecuritiesLendingRiskMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:SecuritiesLendingRiskMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_contentCd_XS6-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskNotInsuredDepositoryInstitutionMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_contentCd_XS6-PRO_RiskMember_RiskLoseMoneyMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskLoseMoneyMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_2016">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-01-01</startDate>
            <endDate>2016-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_2017">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2017-01-01</startDate>
            <endDate>2017-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_2018">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2018-01-01</startDate>
            <endDate>2018-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_2019">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2019-01-01</startDate>
            <endDate>2019-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_2020">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2020-01-01</startDate>
            <endDate>2020-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_2021">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-01-01</startDate>
            <endDate>2021-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_2022">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-01-01</startDate>
            <endDate>2022-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_2023">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-01-01</startDate>
            <endDate>2023-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_2024">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2024-01-01</startDate>
            <endDate>2024-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_2025">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-01-01</startDate>
            <endDate>2025-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_ReturnBeforeTaxes_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_ReturnBeforeTaxes_10">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributions_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributions_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributions_10">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributionsAndSales_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributionsAndSales_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributionsAndSales_10">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000131781Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Indexid_RS005_contentCd_XS6-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexRS005Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Indexid_RS005_contentCd_XS6-PRO_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexRS005Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Indexid_RS005_contentCd_XS6-PRO_10">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexRS005Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Indexid_RS001_contentCd_XS6-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexRS001Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Indexid_RS001_contentCd_XS6-PRO_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexRS001Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000042625_Indexid_RS001_contentCd_XS6-PRO_10">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySeriesLargeCapValueIndexFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000042625Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexRS001Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2016-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_contentCd_STF-PRO">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_contentCd_STF-PRO_RiskMember_MunicipalMarketVolatilityMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:MunicipalMarketVolatilityMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_contentCd_STF-PRO_RiskMember_InterestRateChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:InterestRateChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_contentCd_STF-PRO_RiskMember_IssuerSpecificChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:IssuerSpecificChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_contentCd_STF-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskNotInsuredDepositoryInstitutionMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_contentCd_STF-PRO_RiskMember_RiskLoseMoneyMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskLoseMoneyMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_2019">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2019-01-01</startDate>
            <endDate>2019-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_2020">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2020-01-01</startDate>
            <endDate>2020-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_2021">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-01-01</startDate>
            <endDate>2021-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_2022">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-01-01</startDate>
            <endDate>2022-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_2023">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-01-01</startDate>
            <endDate>2023-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_2024">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2024-01-01</startDate>
            <endDate>2024-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_2025">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-01-01</startDate>
            <endDate>2025-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_ReturnBeforeTaxes_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_ReturnBeforeTaxes_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2018-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributions_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributions_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2018-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributionsAndSales_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributionsAndSales_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000200825Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2018-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Indexid_LB123_contentCd_STF-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB123Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Indexid_LB123_contentCd_STF-PRO_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB123Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Indexid_LB123_contentCd_STF-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB123Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2018-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Indexid_LB015_contentCd_STF-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Indexid_LB015_contentCd_STF-PRO_05">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2021-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000062003_Indexid_LB015_contentCd_STF-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAITax-FreeBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000062003Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2018-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_SNT-PRO">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235223">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235223Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_SNT-PRO_RiskMember_MunicipalMarketVolatilityMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:MunicipalMarketVolatilityMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_SNT-PRO_RiskMember_SustainabilityRiskMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:SustainabilityRiskMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_SNT-PRO_RiskMember_InterestRateChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:InterestRateChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_SNT-PRO_RiskMember_IssuerSpecificChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:IssuerSpecificChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_SNT-PRO_RiskMember_ManagementRiskMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:ManagementRiskMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_SNT-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskNotInsuredDepositoryInstitutionMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_SNT-PRO_RiskMember_RiskLoseMoneyMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskLoseMoneyMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235223_2023">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235223Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-01-01</startDate>
            <endDate>2023-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235223_2024">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235223Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2024-01-01</startDate>
            <endDate>2024-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235223_2025">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235223Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-01-01</startDate>
            <endDate>2025-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235223_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235223Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235223_ReturnBeforeTaxes_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235223Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235223_AfterTaxesOnDistributions_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235223Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235223_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235223Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235223_AfterTaxesOnDistributionsAndSales_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235223Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235223_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235223Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Indexid_IXWQ5_contentCd_SNT-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexIXWQ5Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Indexid_IXWQ5_contentCd_SNT-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexIXWQ5Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Indexid_LB015_contentCd_SNT-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Indexid_LB015_contentCd_SNT-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-RetailPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_ASNT-PRO">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235228">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235228Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235224">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235224Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235225">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235225Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235226">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235226Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235227">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235227Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_MunicipalMarketVolatilityMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:MunicipalMarketVolatilityMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_SustainabilityRiskMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:SustainabilityRiskMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_InterestRateChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:InterestRateChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_IssuerSpecificChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:IssuerSpecificChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_ManagementRiskMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:ManagementRiskMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskNotInsuredDepositoryInstitutionMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_RiskLoseMoneyMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskLoseMoneyMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235228_2023">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235228Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-01-01</startDate>
            <endDate>2023-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235228_2024">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235228Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2024-01-01</startDate>
            <endDate>2024-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235228_2025">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235228Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-01-01</startDate>
            <endDate>2025-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235228_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235228Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235228_ReturnBeforeTaxes_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235228Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235228_AfterTaxesOnDistributions_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235228Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235228_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235228Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235228_AfterTaxesOnDistributionsAndSales_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235228Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235228_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235228Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235224_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235224Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235224_ReturnBeforeTaxes_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235224Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235225_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235225Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235225_ReturnBeforeTaxes_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235225Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235226_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235226Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235226_ReturnBeforeTaxes_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235226Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235227_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235227Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Cid_C000235227_ReturnBeforeTaxes_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235227Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Indexid_IXWQ5_contentCd_ASNT-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexIXWQ5Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Indexid_IXWQ5_contentCd_ASNT-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexIXWQ5Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Indexid_LB015_contentCd_ASNT-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075893_Indexid_LB015_contentCd_ASNT-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySustainableIntermediateMunicipalIncomeFund-AMCIZPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075893Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_contentCd_MNI-PRO">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Cid_C000235213">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235213Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_contentCd_MNI-PRO_RiskMember_MunicipalMarketVolatilityMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:MunicipalMarketVolatilityMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_contentCd_MNI-PRO_RiskMember_SustainabilityRiskMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:SustainabilityRiskMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_contentCd_MNI-PRO_RiskMember_InterestRateChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:InterestRateChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_contentCd_MNI-PRO_RiskMember_IssuerSpecificChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:IssuerSpecificChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_contentCd_MNI-PRO_RiskMember_ManagementRiskMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:ManagementRiskMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_contentCd_MNI-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskNotInsuredDepositoryInstitutionMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_contentCd_MNI-PRO_RiskMember_RiskLoseMoneyMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskLoseMoneyMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Cid_C000235213_2023">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235213Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-01-01</startDate>
            <endDate>2023-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Cid_C000235213_2024">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235213Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2024-01-01</startDate>
            <endDate>2024-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Cid_C000235213_2025">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235213Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-01-01</startDate>
            <endDate>2025-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Cid_C000235213_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235213Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Cid_C000235213_ReturnBeforeTaxes_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235213Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Cid_C000235213_AfterTaxesOnDistributions_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235213Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Cid_C000235213_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235213Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Cid_C000235213_AfterTaxesOnDistributionsAndSales_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235213Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Cid_C000235213_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235213Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Indexid_IXV4E_contentCd_MNI-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexIXV4EMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Indexid_IXV4E_contentCd_MNI-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexIXV4EMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Indexid_LB319_contentCd_MNI-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB319Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Indexid_LB319_contentCd_MNI-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB319Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Indexid_LB015_contentCd_MNI-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075888_Indexid_LB015_contentCd_MNI-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075888Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_contentCd_MNI-PRO">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Cid_C000235216">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235216Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_contentCd_MNI-PRO_RiskMember_MunicipalMarketVolatilityMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:MunicipalMarketVolatilityMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_contentCd_MNI-PRO_RiskMember_SustainabilityRiskMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:SustainabilityRiskMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_contentCd_MNI-PRO_RiskMember_InterestRateChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:InterestRateChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_contentCd_MNI-PRO_RiskMember_IssuerSpecificChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:IssuerSpecificChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_contentCd_MNI-PRO_RiskMember_ManagementRiskMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:ManagementRiskMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_contentCd_MNI-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskNotInsuredDepositoryInstitutionMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_contentCd_MNI-PRO_RiskMember_RiskLoseMoneyMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskLoseMoneyMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Cid_C000235216_2023">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235216Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-01-01</startDate>
            <endDate>2023-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Cid_C000235216_2024">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235216Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2024-01-01</startDate>
            <endDate>2024-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Cid_C000235216_2025">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235216Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-01-01</startDate>
            <endDate>2025-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Cid_C000235216_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235216Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Cid_C000235216_ReturnBeforeTaxes_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235216Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Cid_C000235216_AfterTaxesOnDistributions_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235216Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Cid_C000235216_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235216Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Cid_C000235216_AfterTaxesOnDistributionsAndSales_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235216Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Cid_C000235216_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000235216Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Indexid_LB083_contentCd_MNI-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB083Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Indexid_LB083_contentCd_MNI-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB083Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Indexid_LB015_contentCd_MNI-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000075891_Indexid_LB015_contentCd_MNI-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAISustainableMunicipalIncomeSustainableConservativeIncomeMunicipalBondFunds-ComboPROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000075891Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2022-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_contentCd_CIM-PRO">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Cid_C000245667">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000245667Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_contentCd_CIM-PRO_RiskMember_MunicipalMarketVolatilityMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:MunicipalMarketVolatilityMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_contentCd_CIM-PRO_RiskMember_InterestRateChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:InterestRateChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_contentCd_CIM-PRO_RiskMember_IssuerSpecificChangesMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">fmr:IssuerSpecificChangesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_contentCd_CIM-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskNotInsuredDepositoryInstitutionMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_contentCd_CIM-PRO_RiskMember_RiskLoseMoneyMember">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:RiskAxis">oef:RiskLoseMoneyMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2026-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Cid_C000245667_2024">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000245667Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2024-01-01</startDate>
            <endDate>2024-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Cid_C000245667_2025">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000245667Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-01-01</startDate>
            <endDate>2025-12-31</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Cid_C000245667_ReturnBeforeTaxes_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000245667Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Cid_C000245667_ReturnBeforeTaxes_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000245667Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Cid_C000245667_AfterTaxesOnDistributions_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000245667Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Cid_C000245667_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000245667Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Cid_C000245667_AfterTaxesOnDistributionsAndSales_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000245667Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Cid_C000245667_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:ClassAxis">fmr:C000245667Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">oef:AfterTaxesOnDistributionsAndSalesMember</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Indexid_F1872_contentCd_CIM-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexF1872Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Indexid_F1872_contentCd_CIM-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexF1872Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Indexid_LB319_contentCd_CIM-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB319Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Indexid_LB319_contentCd_CIM-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB319Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Indexid_LB015_contentCd_CIM-PRO_01">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2025-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <context id="Pid_S000082358_Indexid_LB015_contentCd_CIM-PRO_AverageAnnualReturnSinceInception">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0000035315</identifier>
            <segment>
                <xbrldi:explicitMember dimension="dei:DocumentInformationDocumentAxis">fmr:FidelitySAIConservativeIncomeMunicipalBondFund-PROMember</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="dei:LegalEntityAxis">fmr:S000082358Member</xbrldi:explicitMember>
                <xbrldi:explicitMember dimension="oef:PerformanceMeasureAxis">fmr:IndexLB015Member</xbrldi:explicitMember>
            </segment>
        </entity>
        <period>
            <startDate>2023-04-01</startDate>
            <endDate>2026-04-01</endDate>
        </period>
    </context>
    <unit id="usd">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="pure">
        <measure>pure</measure>
    </unit>
    <dei:DocumentType contextRef="Trust" id="ixv-54376">485BPOS</dei:DocumentType>
    <dei:DocumentPeriodEndDate contextRef="Trust" id="ixv-54377">2026-04-01</dei:DocumentPeriodEndDate>
    <dei:AmendmentFlag contextRef="Trust" id="ixv-54378">false</dei:AmendmentFlag>
    <dei:EntityCentralIndexKey contextRef="Trust" id="ixv-54379">0000035315</dei:EntityCentralIndexKey>
    <dei:EntityInvCompanyType contextRef="Trust" id="ixv-54380">N-1A</dei:EntityInvCompanyType>
    <dei:EntityRegistrantName contextRef="Trust" id="ixv-54381">Fidelity Salem Street Trust</dei:EntityRegistrantName>
    <oef:RiskReturnHeading contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-211">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Tax-Free Bond Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-220">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-225">
     
       
     Fidelity&#xae; Tax-Free Bond Fund seeks to provide a high current yield exempt from federal income tax. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-230">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-236">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-247">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000017680_contentCd_SFB-PRO"
      decimals="0"
      id="ixv-56653"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-262">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000017680_Cid_C000048850"
      decimals="6"
      id="ixv-56654"
      unitRef="pure">0.0042</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000017680_Cid_C000048850"
      decimals="6"
      id="ixv-56655"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000017680_Cid_C000048850"
      decimals="6"
      id="ixv-56656"
      unitRef="pure">0.0001</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000017680_Cid_C000048850"
      decimals="6"
      id="ixv-56657"
      unitRef="pure">0.0043</oef:ExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000017680_Cid_C000048850"
      decimals="6"
      id="footnoteS000017680SFB-PROAOE_AC000048850_FW"
      unitRef="pure">-0.0018</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000017680_Cid_C000048850"
      decimals="6"
      id="ixv-56659"
      unitRef="pure">0.0025</oef:NetExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-337">2027-05-31</oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination>
    <oef:ExpenseExampleNarrativeTextBlock contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-346">
     
       
     This  
     example 
       
     helps compare the cost of investing in the fund with the cost of investing in other funds. 
       
     Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 
    
   </oef:ExpenseExampleNarrativeTextBlock>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000017680_Cid_C000048850"
      decimals="0"
      id="ixv-56660"
      unitRef="usd">26</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000017680_Cid_C000048850"
      decimals="0"
      id="ixv-56661"
      unitRef="usd">113</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000017680_Cid_C000048850"
      decimals="0"
      id="ixv-56662"
      unitRef="usd">217</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000017680_Cid_C000048850"
      decimals="0"
      id="ixv-56663"
      unitRef="usd">519</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-403">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-408">
     
       
     The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 
       
     
       
       20 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000017680_contentCd_SFB-PRO"
      decimals="4"
      id="ixv-56664"
      unitRef="pure">0.20</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-417">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-422">
     
       
      
       Normally investing at least 80% of assets in municipal securities whose interest is exempt from federal income tax. The municipal securities in which the fund invests are normally investment-grade (those of medium and high quality). 
     Municipal debt securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal debt securities in which the fund invests include securities issued by U.S. territories and possessions, general obligation bonds of municipalities, local or state governments, project or revenue-specific bonds, or pre-refunded or escrowed bonds, municipal money market securities, and synthetic securities. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. 
     Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. 
      
       
        Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. 
      Normally not investing in municipal securities whose interest is subject to federal income tax or in municipal securities whose interest is subject to the federal alternative minimum tax. 
      Managing the fund to have similar overall interest rate risk to the index. 
      Allocating assets across different market sectors and maturities. 
      Potentially investing more than 25% of total assets in municipal securities that finance similar types of projects. 
      Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000017680_contentCd_SFB-PRO_RiskMember_MunicipalMarketVolatilityMember"
      id="ixv-449">
     
       
      
      Municipal Market Volatility. 
      
     The municipal market is volatile and can be significantly affected by adverse tax, legislative, or political changes and the financial condition of the issuers of municipal securities. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000017680_contentCd_SFB-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-458">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000017680_contentCd_SFB-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-467">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000017680_contentCd_SFB-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-479">
     
       
     An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency 
       
     . 
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000017680_contentCd_SFB-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-487">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-496">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-501">
     
       
      
       The following information is intended to help you understand the risks of investing in the fund. 
      
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
      
       
     The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. 
       
      
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
      
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-507"> 
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-514"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-520"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-525">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_2016"
      decimals="INF"
      id="ixv-56665"
      unitRef="pure">0.0037</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_2017"
      decimals="INF"
      id="ixv-56666"
      unitRef="pure">0.0643</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_2018"
      decimals="INF"
      id="ixv-56667"
      unitRef="pure">0.0086</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_2019"
      decimals="INF"
      id="ixv-56668"
      unitRef="pure">0.0857</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_2020"
      decimals="INF"
      id="ixv-56669"
      unitRef="pure">0.0501</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_2021"
      decimals="INF"
      id="ixv-56670"
      unitRef="pure">0.0262</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_2022"
      decimals="INF"
      id="ixv-56671"
      unitRef="pure">-0.1012</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_2023"
      decimals="INF"
      id="ixv-56672"
      unitRef="pure">0.0750</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_2024"
      decimals="INF"
      id="ixv-56673"
      unitRef="pure">0.0177</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_2025"
      decimals="INF"
      id="ixv-56674"
      unitRef="pure">0.0449</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-635">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000017680_contentCd_SFB-PRO"
      decimals="4"
      id="ixv-56675"
      unitRef="pure">0.0820</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-645">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-650">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000017680_contentCd_SFB-PRO"
      decimals="4"
      id="ixv-56676"
      unitRef="pure">-0.0657</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-661">2022-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:PerformanceTableHeading contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-666">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-671">
     
       
      
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
      
       
     Actual after-tax returns may differ depending on your individual circumstances. 
       
      
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
      
       
    
   </oef:PerformanceTableNarrativeTextBlock>
    <oef:PerformanceTableUsesHighestFederalRate contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-674"> 
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
     </oef:PerformanceTableUsesHighestFederalRate>
    <oef:PerformanceTableExplanationAfterTaxHigher contextRef="Pid_S000017680_contentCd_SFB-PRO" id="ixv-681"> 
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
     </oef:PerformanceTableExplanationAfterTaxHigher>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000017680_Cid_C000048850_ReturnBeforeTaxes_01"
      id="ixv-726">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56677"
      unitRef="pure">0.0449</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-56678"
      unitRef="pure">0.0107</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_ReturnBeforeTaxes_10"
      decimals="4"
      id="ixv-56679"
      unitRef="pure">0.0262</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributions_01"
      id="ixv-741">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-56680"
      unitRef="pure">0.0449</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-56681"
      unitRef="pure">0.0105</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributions_10"
      decimals="4"
      id="ixv-56682"
      unitRef="pure">0.0257</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-756">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-56683"
      unitRef="pure">0.0398</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-56684"
      unitRef="pure">0.0146</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Cid_C000048850_AfterTaxesOnDistributionsAndSales_10"
      decimals="4"
      id="ixv-56685"
      unitRef="pure">0.0269</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000017680_Indexid_LB123_contentCd_SFB-PRO_01"
      id="ixv-772">
         Bloomberg 3+ Year Non-AMT Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Indexid_LB123_contentCd_SFB-PRO_01"
      decimals="4"
      id="ixv-56686"
      unitRef="pure">0.0427</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Indexid_LB123_contentCd_SFB-PRO_05"
      decimals="4"
      id="ixv-56687"
      unitRef="pure">0.0066</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Indexid_LB123_contentCd_SFB-PRO_10"
      decimals="4"
      id="ixv-56688"
      unitRef="pure">0.0243</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000017680_Indexid_LB015_contentCd_SFB-PRO_01"
      id="ixv-797">
         Bloomberg Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Indexid_LB015_contentCd_SFB-PRO_01"
      decimals="4"
      id="ixv-56689"
      unitRef="pure">0.0425</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Indexid_LB015_contentCd_SFB-PRO_05"
      decimals="4"
      id="ixv-56690"
      unitRef="pure">0.0080</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000017680_Indexid_LB015_contentCd_SFB-PRO_10"
      decimals="4"
      id="ixv-56691"
      unitRef="pure">0.0234</oef:AvgAnnlRtrPct>
    <oef:RiskReturnHeading contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-2849">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Series Large Cap Value Index Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-2858">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-2863">
     
       
     Fidelity&#xae; Series Large Cap Value Index Fund seeks to provide investment results that correspond to the total return of stocks of large capitalization United States companies. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-2868">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-2874">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-2884">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000042625_contentCd_XS6-PRO"
      decimals="0"
      id="ixv-56692"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-2899">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000042625_Cid_C000131781"
      decimals="6"
      id="ixv-56693"
      unitRef="pure">0.0000</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000042625_Cid_C000131781"
      decimals="6"
      id="ixv-56694"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000042625_Cid_C000131781"
      decimals="6"
      id="ixv-56695"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000042625_Cid_C000131781"
      decimals="6"
      id="ixv-56696"
      unitRef="pure">0.0000</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-2946">
     
       
     This  
     example 
       
     helps compare the cost of investing in the fund with the cost of investing in other funds. 
       
     Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 
    
   </oef:ExpenseExampleNarrativeTextBlock>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000042625_Cid_C000131781"
      decimals="0"
      id="ixv-56697"
      unitRef="usd">0</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000042625_Cid_C000131781"
      decimals="0"
      id="ixv-56698"
      unitRef="usd">0</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000042625_Cid_C000131781"
      decimals="0"
      id="ixv-56699"
      unitRef="usd">0</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000042625_Cid_C000131781"
      decimals="0"
      id="ixv-56700"
      unitRef="usd">0</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3003">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3008">
     
       
     The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 
       
     
       
       17 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000042625_contentCd_XS6-PRO"
      decimals="4"
      id="ixv-56701"
      unitRef="pure">0.17</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3017">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3022">
     
       
      
       
        Normally investing at least 80% of assets in securities of companies in the Russell 1000&#xae; Value Index. 
      
     The Russell 1000 &#xae; Value Index is a market capitalization-weighted index designed to measure the performance of the large-cap value segment of the U.S. equity market. It includes those Russell 1000 &#xae; Index companies with lower price-to-book ratios and lower expected growth rates. The stocks of these companies are often called "value" stocks. 
     Effective  
       March 24, 2025,  
       the Russell 1000 &#xae; Value Index applies a capping methodology. Index constituents are capped quarterly so that no more than 22.5% of the index weight may be allocated to a single constituent, and the sum of the weights of all constituents representing more than 4.5% of the index should not exceed 45% of the total index weight. For periods prior to March 24, 2025, the index was uncapped. 
      
      Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. 
      Lending securities to earn income for the fund. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042625_contentCd_XS6-PRO_RiskMember_StockMarketVolatilityMember"
      id="ixv-3060">
     
       
      
      Stock Market Volatility. 
      
     Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042625_contentCd_XS6-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-3069">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042625_contentCd_XS6-PRO_RiskMember_CorrelationToIndexMember"
      id="ixv-3080">
     
       
      
      Correlation to Index. 
      
     The performance of the fund and its underlying index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from the index. Errors in the construction or calculation of the index may occur from time to time and may not be identified and corrected for some period of time, which may have an adverse impact on the fund and its shareholders. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042625_contentCd_XS6-PRO_RiskMember_PassiveManagementRiskMember"
      id="ixv-3089">
     
       
      
      Passive Management Risk. 
      
     The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund's index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund's performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042625_contentCd_XS6-PRO_RiskMember_ValueInvestingMember"
      id="ixv-3098">
     
       
      
      "Value" Investing. 
      
     "Value" stocks can perform differently from the market as a whole and other types of stocks and can continue to be undervalued by the market for long periods of time. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042625_contentCd_XS6-PRO_RiskMember_SecuritiesLendingRiskMember"
      id="ixv-3107">
     
       
      
      Securities Lending Risk. 
      
     Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042625_contentCd_XS6-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-3116">
     
       
     An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency 
       
     . 
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042625_contentCd_XS6-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-3124">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3131">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3136">
     
       
     The following information is intended to help you understand the risks of investing in the fund. 
      
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
      
       
     The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear 
       
     in the "Additional Index Information" section of the prospectus. 
       
      
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
      
     The performance shown does not reflect the impact of any fees paid at the fee-based account or plan level, if applicable. 
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3141"> 
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3150"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3158"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3163">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_2016"
      decimals="INF"
      id="ixv-56702"
      unitRef="pure">0.1719</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_2017"
      decimals="INF"
      id="ixv-56703"
      unitRef="pure">0.1368</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_2018"
      decimals="INF"
      id="ixv-56704"
      unitRef="pure">-0.0823</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_2019"
      decimals="INF"
      id="ixv-56705"
      unitRef="pure">0.2660</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_2020"
      decimals="INF"
      id="ixv-56706"
      unitRef="pure">0.0286</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_2021"
      decimals="INF"
      id="ixv-56707"
      unitRef="pure">0.2519</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_2022"
      decimals="INF"
      id="ixv-56708"
      unitRef="pure">-0.0753</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_2023"
      decimals="INF"
      id="ixv-56709"
      unitRef="pure">0.1159</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_2024"
      decimals="INF"
      id="ixv-56710"
      unitRef="pure">0.1435</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_2025"
      decimals="INF"
      id="ixv-56711"
      unitRef="pure">0.1589</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3274">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000042625_contentCd_XS6-PRO"
      decimals="4"
      id="ixv-56712"
      unitRef="pure">0.1624</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3284">2020-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3289">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000042625_contentCd_XS6-PRO"
      decimals="4"
      id="ixv-56713"
      unitRef="pure">-0.2669</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3300">2020-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:PerformanceTableHeading contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3305">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3310">
     
       
      
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
      
       
     Actual after-tax returns may differ depending on your individual circumstances. 
       
      
        
      The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). 
        
      
       
      
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
      
       
    
   </oef:PerformanceTableNarrativeTextBlock>
    <oef:PerformanceTableUsesHighestFederalRate contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3313"> 
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
     </oef:PerformanceTableUsesHighestFederalRate>
    <oef:PerformanceTableNotRelevantToTaxDeferred contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3320"> 
        
      The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). 
        
     </oef:PerformanceTableNotRelevantToTaxDeferred>
    <oef:PerformanceTableExplanationAfterTaxHigher contextRef="Pid_S000042625_contentCd_XS6-PRO" id="ixv-3325"> 
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
     </oef:PerformanceTableExplanationAfterTaxHigher>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042625_Cid_C000131781_ReturnBeforeTaxes_01"
      id="ixv-3370">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56714"
      unitRef="pure">0.1589</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-56715"
      unitRef="pure">0.1135</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_ReturnBeforeTaxes_10"
      decimals="4"
      id="ixv-56716"
      unitRef="pure">0.1055</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributions_01"
      id="ixv-3385">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-56717"
      unitRef="pure">0.1484</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-56718"
      unitRef="pure">0.1007</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributions_10"
      decimals="4"
      id="ixv-56719"
      unitRef="pure">0.0933</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-3400">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-56720"
      unitRef="pure">0.1003</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-56721"
      unitRef="pure">0.0869</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Cid_C000131781_AfterTaxesOnDistributionsAndSales_10"
      decimals="4"
      id="ixv-56722"
      unitRef="pure">0.0829</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042625_Indexid_RS005_contentCd_XS6-PRO_01"
      id="ixv-3416">
         Russell 1000&#xae; Value Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Indexid_RS005_contentCd_XS6-PRO_01"
      decimals="4"
      id="ixv-56723"
      unitRef="pure">0.1591</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Indexid_RS005_contentCd_XS6-PRO_05"
      decimals="4"
      id="ixv-56724"
      unitRef="pure">0.1133</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Indexid_RS005_contentCd_XS6-PRO_10"
      decimals="4"
      id="ixv-56725"
      unitRef="pure">0.1053</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042625_Indexid_RS001_contentCd_XS6-PRO_01"
      id="ixv-3441">
         Russell 1000&#xae; Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Indexid_RS001_contentCd_XS6-PRO_01"
      decimals="4"
      id="ixv-56726"
      unitRef="pure">0.1737</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Indexid_RS001_contentCd_XS6-PRO_05"
      decimals="4"
      id="ixv-56727"
      unitRef="pure">0.1359</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042625_Indexid_RS001_contentCd_XS6-PRO_10"
      decimals="4"
      id="ixv-56728"
      unitRef="pure">0.1459</oef:AvgAnnlRtrPct>
    <oef:RiskReturnHeading contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5047">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; SAI Tax-Free Bond Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5056">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5061">
     
       
     Fidelity&#xae; SAI Tax-Free Bond Fund seeks to provide a high current yield exempt from federal income tax. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5066">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5072">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5082">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000062003_contentCd_STF-PRO"
      decimals="0"
      id="ixv-56729"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5097">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000062003_Cid_C000200825"
      decimals="6"
      id="ixv-56730"
      unitRef="pure">0.0033</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000062003_Cid_C000200825"
      decimals="6"
      id="ixv-56731"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000062003_Cid_C000200825"
      decimals="6"
      id="ixv-56732"
      unitRef="pure">0.0002</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000062003_Cid_C000200825"
      decimals="6"
      id="ixv-56733"
      unitRef="pure">0.0035</oef:ExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000062003_Cid_C000200825"
      decimals="6"
      id="footnoteS000062003STF-PROAOE_AC000200825_FW"
      unitRef="pure">-0.0010</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000062003_Cid_C000200825"
      decimals="6"
      id="ixv-56735"
      unitRef="pure">0.0025</oef:NetExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5172">2027-05-31</oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination>
    <oef:ExpenseExampleNarrativeTextBlock contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5181">
     
       
     This  
     example 
       
     helps compare the cost of investing in the fund with the cost of investing in other funds. 
       
     Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 
    
   </oef:ExpenseExampleNarrativeTextBlock>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000062003_Cid_C000200825"
      decimals="0"
      id="ixv-56736"
      unitRef="usd">26</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000062003_Cid_C000200825"
      decimals="0"
      id="ixv-56737"
      unitRef="usd">99</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000062003_Cid_C000200825"
      decimals="0"
      id="ixv-56738"
      unitRef="usd">183</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000062003_Cid_C000200825"
      decimals="0"
      id="ixv-56739"
      unitRef="usd">430</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5238">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5243">
     
       
     The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 
       
     
       
       12 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000062003_contentCd_STF-PRO"
      decimals="4"
      id="ixv-56740"
      unitRef="pure">0.12</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5252">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5257">
     
       
      
       Normally investing at least 80% of assets in municipal securities whose interest is exempt from federal income tax. The municipal securities in which the fund invests are normally investment-grade (those of medium and high quality). 
     Municipal debt securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal debt securities in which the fund invests include securities issued by U.S. territories and possessions, general obligation bonds of municipalities, local or state governments, project or revenue-specific bonds, or pre-refunded or escrowed bonds, municipal money market securities, and synthetic securities. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. 
     Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. 
      
       
        Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. 
      Normally not investing in municipal securities whose interest is subject to federal income tax or in municipal securities whose interest is subject to the federal alternative minimum tax. 
      Managing the fund to have similar overall interest rate risk to the supplemental index (see "Additional Index Information" section of the prospectus). 
      Allocating assets across different market sectors and maturities. 
      Potentially investing more than 25% of total assets in municipal securities that finance similar types of projects. 
      Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062003_contentCd_STF-PRO_RiskMember_MunicipalMarketVolatilityMember"
      id="ixv-5284">
     
       
      
      Municipal Market Volatility. 
      
     The municipal market is volatile and can be significantly affected by adverse tax, legislative, or political changes and the financial condition of the issuers of municipal securities. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062003_contentCd_STF-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-5293">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062003_contentCd_STF-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-5302">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062003_contentCd_STF-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-5314">
     
       
     An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency 
       
     . 
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062003_contentCd_STF-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-5322">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5331">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5336">
     
       
      
       The following information is intended to help you understand the risks of investing in the fund. 
      
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
      
       
     The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. 
       
      
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
      
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5342"> 
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5349"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5355"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5360">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_2019"
      decimals="INF"
      id="ixv-56741"
      unitRef="pure">0.0825</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_2020"
      decimals="INF"
      id="ixv-56742"
      unitRef="pure">0.0390</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_2021"
      decimals="INF"
      id="ixv-56743"
      unitRef="pure">0.0228</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_2022"
      decimals="INF"
      id="ixv-56744"
      unitRef="pure">-0.0932</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_2023"
      decimals="INF"
      id="ixv-56745"
      unitRef="pure">0.0765</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_2024"
      decimals="INF"
      id="ixv-56746"
      unitRef="pure">0.0177</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_2025"
      decimals="INF"
      id="ixv-56747"
      unitRef="pure">0.0415</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5461">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000062003_contentCd_STF-PRO"
      decimals="4"
      id="ixv-56748"
      unitRef="pure">0.0835</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5471">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5476">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000062003_contentCd_STF-PRO"
      decimals="4"
      id="ixv-56749"
      unitRef="pure">-0.0661</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5487">2022-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:PerformanceTableHeading contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5492">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5497">
     
       
      
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
      
       
     Actual after-tax returns may differ depending on your individual circumstances. 
       
      
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
      
       
    
   </oef:PerformanceTableNarrativeTextBlock>
    <oef:PerformanceTableUsesHighestFederalRate contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5500"> 
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
     </oef:PerformanceTableUsesHighestFederalRate>
    <oef:PerformanceTableExplanationAfterTaxHigher contextRef="Pid_S000062003_contentCd_STF-PRO" id="ixv-5507"> 
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
     </oef:PerformanceTableExplanationAfterTaxHigher>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000062003_Cid_C000200825_ReturnBeforeTaxes_01"
      id="ixv-5553">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56750"
      unitRef="pure">0.0415</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-56751"
      unitRef="pure">0.0114</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSTF-PROS000062003AAR_A_RBT_loc"
      unitRef="pure">0.0270</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributions_01"
      id="ixv-5569">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-56753"
      unitRef="pure">0.0414</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-56754"
      unitRef="pure">0.0114</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSTF-PROS000062003AAR_A_ATD_loc"
      unitRef="pure">0.0269</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-5585">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-56756"
      unitRef="pure">0.0380</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-56757"
      unitRef="pure">0.0146</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Cid_C000200825_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSTF-PROS000062003AAR_A_ATDS_loc"
      unitRef="pure">0.0266</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000062003_Indexid_LB123_contentCd_STF-PRO_01"
      id="ixv-5602">
         Bloomberg 3+ Year Non-AMT Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Indexid_LB123_contentCd_STF-PRO_01"
      decimals="4"
      id="ixv-56759"
      unitRef="pure">0.0427</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Indexid_LB123_contentCd_STF-PRO_05"
      decimals="4"
      id="ixv-56760"
      unitRef="pure">0.0066</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Indexid_LB123_contentCd_STF-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56761"
      unitRef="pure">0.0258</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000062003_Indexid_LB015_contentCd_STF-PRO_01"
      id="ixv-5627">
         Bloomberg Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Indexid_LB015_contentCd_STF-PRO_01"
      decimals="4"
      id="ixv-56762"
      unitRef="pure">0.0425</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Indexid_LB015_contentCd_STF-PRO_05"
      decimals="4"
      id="ixv-56763"
      unitRef="pure">0.0080</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062003_Indexid_LB015_contentCd_STF-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56764"
      unitRef="pure">0.0251</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000062003_Cid_C000200825" id="ixv-5668">2018-10-02</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7211">
     
       
     Fund Summary 
       
     Fund /Class: 
     Fidelity&#xae; Sustainable Intermediate Municipal Income Fund 
     /Fidelity&#xae; Sustainable Intermediate Municipal Income Fund  
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7224">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7229">
     
       
     Fidelity&#xae; Sustainable Intermediate Municipal Income Fund seeks as high a level of current income, exempt from federal income tax, as is consistent with the preservation of capital. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7234">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7240">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7251">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000075893_contentCd_SNT-PRO"
      decimals="0"
      id="ixv-56765"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7266">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235223"
      decimals="6"
      id="ixv-56766"
      unitRef="pure">0.0043</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235223"
      decimals="6"
      id="ixv-56767"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235223"
      decimals="6"
      id="ixv-56768"
      unitRef="pure">0.0078</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235223"
      decimals="6"
      id="ixv-56769"
      unitRef="pure">0.0121</oef:ExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000075893_Cid_C000235223"
      decimals="6"
      id="footnoteS000075893SNT-PROAOE_AC000235223_FW"
      unitRef="pure">-0.0084</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235223"
      decimals="6"
      id="ixv-56771"
      unitRef="pure">0.0037</oef:NetExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7341">2027-05-31</oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination>
    <oef:ExpenseExampleNarrativeTextBlock contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7350">
     
       
     This  
     example 
       
     helps compare the cost of investing in the fund with the cost of investing in other funds. 
       
     Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 
    
   </oef:ExpenseExampleNarrativeTextBlock>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000075893_Cid_C000235223"
      decimals="0"
      id="ixv-56772"
      unitRef="usd">38</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000075893_Cid_C000235223"
      decimals="0"
      id="ixv-56773"
      unitRef="usd">271</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000075893_Cid_C000235223"
      decimals="0"
      id="ixv-56774"
      unitRef="usd">555</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000075893_Cid_C000235223"
      decimals="0"
      id="ixv-56775"
      unitRef="usd">1365</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7407">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7412">
     
       
     The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 
       
     
       
       16 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000075893_contentCd_SNT-PRO"
      decimals="4"
      id="ixv-56776"
      unitRef="pure">0.16</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7421">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7426">
     
       
      
       
        Normally investing at least 80% of assets in municipal securities (i) whose interest is exempt from federal income tax and (ii) that Fidelity Management &amp; Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics. The municipal securities in which the fund invests are normally investment-grade (those of medium and high quality). 
      
     Municipal debt securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal debt securities in which the fund invests include securities issued by U.S. territories and possessions, general obligation bonds of municipalities, local or state governments, project or revenue-specific bonds, or pre-refunded or escrowed bonds, municipal money market securities, and synthetic securities. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. 
     Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. 
      
       
        Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. 
      Evaluating each security in which the fund invests using both a traditional municipal bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or obligor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) information on a security's use of proceeds; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. 
      Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team.  
      The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, and vulnerability to the physical impacts of climate change. An assessment of an issuer's social profile includes, but is not limited to, its approach to quality health care access, housing affordability, human capital management, community reinvestment, and safety. An assessment of an issuer's governance profile includes, but is not limited to, its principles of management, oversight and transparency, governance efficiency and structure, and consideration of anticompetitive practices. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, effectiveness at service delivery, and long-term sustainability, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. 
      Assessing a security's use of proceeds by considering factors that provide ESG characteristics, such as energy efficiency, environmentally sustainable management, and providing access to quality health care, essential services and affordable housing. The Adviser will generally consider bonds that finance education, health care, affordable housing, clean energy, municipal water and sewer, public transportation, and designated green bonds, among others, as having positive ESG characteristics. 
      Managing the fund to have similar overall interest rate risk to the supplemental index (see "Additional Index Information" section of the prospectus). 
      In addition to focusing on municipal securities with positive ESG characteristics, the Adviser analyzes the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Normally maintaining a dollar-weighted average maturity between three and 10 years. 
      Allocating assets across different market sectors and maturities. 
      Potentially investing more than 25% of total assets in municipal securities that finance similar types of projects. 
      Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_SNT-PRO_RiskMember_MunicipalMarketVolatilityMember"
      id="ixv-7464">
     
       
      
      Municipal Market Volatility. 
      
     The municipal market is volatile and can be significantly affected by adverse tax, legislative, or political changes and the financial condition of the issuers of municipal securities. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_SNT-PRO_RiskMember_SustainabilityRiskMember"
      id="ixv-7473">
     
       
      
      Sustainability Risk. 
      
     Application of Fidelity Management &amp; Research Company LLC's (FMR) (the Adviser) ESG ratings process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG ratings process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_SNT-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-7482">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_SNT-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-7491">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_SNT-PRO_RiskMember_ManagementRiskMember"
      id="ixv-7502">
     
       
      
      Management Risk. 
      
     The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies . 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_SNT-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-7514">
     
       
     An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency 
       
     . 
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_SNT-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-7522">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7531">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7536">
     
       
      
       The following information is intended to help you understand the risks of investing in the fund. 
      
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
      
       
     The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. 
       
      
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
      
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7542"> 
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7549"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7555"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7560">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235223_2023"
      decimals="INF"
      id="ixv-56777"
      unitRef="pure">0.0625</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235223_2024"
      decimals="INF"
      id="ixv-56778"
      unitRef="pure">0.0137</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235223_2025"
      decimals="INF"
      id="ixv-56779"
      unitRef="pure">0.0531</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7648">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000075893_contentCd_SNT-PRO"
      decimals="4"
      id="ixv-56780"
      unitRef="pure">0.0715</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7658">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7663">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000075893_contentCd_SNT-PRO"
      decimals="4"
      id="ixv-56781"
      unitRef="pure">-0.0279</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7674">2023-09-30</oef:BarChartLowestQuarterlyReturnDate>
    <oef:PerformanceTableHeading contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7679">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7684">
     
       
      
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
      
       
     Actual after-tax returns may differ depending on your individual circumstances.  
      
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
      
       
    
   </oef:PerformanceTableNarrativeTextBlock>
    <oef:PerformanceTableUsesHighestFederalRate contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7687"> 
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
     </oef:PerformanceTableUsesHighestFederalRate>
    <oef:PerformanceTableExplanationAfterTaxHigher contextRef="Pid_S000075893_contentCd_SNT-PRO" id="ixv-7693"> 
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
     </oef:PerformanceTableExplanationAfterTaxHigher>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Cid_C000235223_ReturnBeforeTaxes_01"
      id="ixv-7732">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235223_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56782"
      unitRef="pure">0.0531</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235223_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSNT-PROS000075893AAR_A_RBT_loc"
      unitRef="pure">0.0371</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Cid_C000235223_AfterTaxesOnDistributions_01"
      id="ixv-7745">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235223_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-56784"
      unitRef="pure">0.0530</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235223_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSNT-PROS000075893AAR_A_ATD_loc"
      unitRef="pure">0.0371</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Cid_C000235223_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-7758">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235223_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-56786"
      unitRef="pure">0.0443</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235223_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSNT-PROS000075893AAR_A_ATDS_loc"
      unitRef="pure">0.0353</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Indexid_IXWQ5_contentCd_SNT-PRO_01"
      id="ixv-7772">
         Bloomberg 3-15 Year Blend (2-17) Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Indexid_IXWQ5_contentCd_SNT-PRO_01"
      decimals="4"
      id="ixv-56788"
      unitRef="pure">0.0530</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Indexid_IXWQ5_contentCd_SNT-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56789"
      unitRef="pure">0.0315</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Indexid_LB015_contentCd_SNT-PRO_01"
      id="ixv-7791">
         Bloomberg Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Indexid_LB015_contentCd_SNT-PRO_01"
      decimals="4"
      id="ixv-56790"
      unitRef="pure">0.0425</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Indexid_LB015_contentCd_SNT-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56791"
      unitRef="pure">0.0279</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000075893_Cid_C000235223" id="ixv-7823">2022-04-13</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-9834">
     
       
     Fund Summary 
       
     Fund /Class: 
     Fidelity&#xae; Sustainable Intermediate Municipal Income Fund 
     /Fidelity Advisor&#xae; Sustainable Intermediate Municipal Income Fund A, M, C, I, Z &#160; 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-9849">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-9854">
     
       
     Fidelity&#xae; Sustainable Intermediate Municipal Income Fund seeks as high a level of current income, exempt from federal income tax, as is consistent with the preservation of capital. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-9859">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-9865">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. 
      
        
      You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 
        
       
         
       50,000 
         
       
        
      in the fund or certain other Fidelity 
        
      &#xae; 
        
      funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 39 
        
      of the prospectus 
        
      
       
     and in 
       
     the sales charge 
       
     waiver appendix to 
       
     the prospectus. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ExpenseBreakpointDiscounts
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-9871"> 
        
      You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 
        
       
         
       50,000 
         
       
        
      in the fund or certain other Fidelity 
        
      &#xae; 
        
      funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 39 
        
      of the prospectus 
        
     </oef:ExpenseBreakpointDiscounts>
    <oef:ExpenseBreakpointMinimumInvestmentRequiredAmount
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      decimals="0"
      id="ixv-56792"
      unitRef="usd">50000</oef:ExpenseBreakpointMinimumInvestmentRequiredAmount>
    <oef:ShareholderFeesCaption
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-9894">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:MaximumCumulativeSalesChargeOverOfferingPrice
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="4"
      id="ixv-56793"
      unitRef="pure">0.0400</oef:MaximumCumulativeSalesChargeOverOfferingPrice>
    <oef:MaximumCumulativeSalesChargeOverOfferingPrice
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="4"
      id="ixv-56794"
      unitRef="pure">0.0400</oef:MaximumCumulativeSalesChargeOverOfferingPrice>
    <oef:MaximumCumulativeSalesChargeOverOfferingPrice
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="4"
      id="ixv-56795"
      unitRef="pure">0</oef:MaximumCumulativeSalesChargeOverOfferingPrice>
    <oef:MaximumCumulativeSalesChargeOverOfferingPrice
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="4"
      id="ixv-56796"
      unitRef="pure">0</oef:MaximumCumulativeSalesChargeOverOfferingPrice>
    <oef:MaximumCumulativeSalesChargeOverOfferingPrice
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="4"
      id="ixv-56797"
      unitRef="pure">0</oef:MaximumCumulativeSalesChargeOverOfferingPrice>
    <oef:MaximumDeferredSalesChargeOverOther
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="4"
      id="footnoteASNT-PROS000075893SHF_AC000235228"
      unitRef="pure">0</oef:MaximumDeferredSalesChargeOverOther>
    <oef:MaximumDeferredSalesChargeOverOther
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="4"
      id="footnoteASNT-PROS000075893SHF_AC000235224"
      unitRef="pure">0</oef:MaximumDeferredSalesChargeOverOther>
    <oef:MaximumDeferredSalesChargeOverOther
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="4"
      id="footnoteASNT-PROS000075893SHF_BC000235225"
      unitRef="pure">0.0100</oef:MaximumDeferredSalesChargeOverOther>
    <oef:MaximumDeferredSalesChargeOverOther
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="4"
      id="ixv-56801"
      unitRef="pure">0</oef:MaximumDeferredSalesChargeOverOther>
    <oef:MaximumDeferredSalesChargeOverOther
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="4"
      id="ixv-56802"
      unitRef="pure">0</oef:MaximumDeferredSalesChargeOverOther>
    <oef:ExpensesDeferredChargesTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10000"> 
        
      Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 0.75% and 0.25%, respectively. 
        
     </oef:ExpensesDeferredChargesTextBlock>
    <oef:ExpensesDeferredChargesTextBlock contextRef="Pid_S000075893_Cid_C000235225" id="ixv-10010"> 
        
      On Class C shares redeemed less than one year after purchase. 
        
     </oef:ExpensesDeferredChargesTextBlock>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10015">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="6"
      id="ixv-56803"
      unitRef="pure">0.0048</oef:ManagementFeesOverAssets>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="6"
      id="ixv-56804"
      unitRef="pure">0.0051</oef:ManagementFeesOverAssets>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="6"
      id="ixv-56805"
      unitRef="pure">0.0052</oef:ManagementFeesOverAssets>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="6"
      id="ixv-56806"
      unitRef="pure">0.0052</oef:ManagementFeesOverAssets>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="6"
      id="ixv-56807"
      unitRef="pure">0.0039</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="6"
      id="ixv-56808"
      unitRef="pure">0.0025</oef:DistributionAndService12b1FeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="6"
      id="ixv-56809"
      unitRef="pure">0.0025</oef:DistributionAndService12b1FeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="6"
      id="ixv-56810"
      unitRef="pure">0.0100</oef:DistributionAndService12b1FeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="6"
      id="ixv-56811"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="6"
      id="ixv-56812"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="6"
      id="ixv-56813"
      unitRef="pure">0.0083</oef:OtherExpensesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="6"
      id="ixv-56814"
      unitRef="pure">0.0087</oef:OtherExpensesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="6"
      id="ixv-56815"
      unitRef="pure">0.0082</oef:OtherExpensesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="6"
      id="ixv-56816"
      unitRef="pure">0.0080</oef:OtherExpensesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="6"
      id="ixv-56817"
      unitRef="pure">0.0070</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="6"
      id="ixv-56818"
      unitRef="pure">0.0156</oef:ExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="6"
      id="ixv-56819"
      unitRef="pure">0.0163</oef:ExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="6"
      id="ixv-56820"
      unitRef="pure">0.0234</oef:ExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="6"
      id="ixv-56821"
      unitRef="pure">0.0132</oef:ExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="6"
      id="ixv-56822"
      unitRef="pure">0.0109</oef:ExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="6"
      id="footnoteS000075893ASNT-PROAOE_AC000235228_FW"
      unitRef="pure">-0.0094</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="6"
      id="footnoteS000075893ASNT-PROAOE_AC000235224_FW"
      unitRef="pure">-0.0101</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="6"
      id="footnoteS000075893ASNT-PROAOE_AC000235225_FW"
      unitRef="pure">-0.0097</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="6"
      id="footnoteS000075893ASNT-PROAOE_AC000235226_FW"
      unitRef="pure">-0.0095</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="6"
      id="footnoteS000075893ASNT-PROAOE_AC000235227_FW"
      unitRef="pure">-0.0078</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="6"
      id="ixv-56828"
      unitRef="pure">0.0062</oef:NetExpensesOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="6"
      id="ixv-56829"
      unitRef="pure">0.0062</oef:NetExpensesOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="6"
      id="ixv-56830"
      unitRef="pure">0.0137</oef:NetExpensesOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="6"
      id="ixv-56831"
      unitRef="pure">0.0037</oef:NetExpensesOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="6"
      id="ixv-56832"
      unitRef="pure">0.0031</oef:NetExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10254">2027-05-31</oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10263">
     
       
     This  
     example 
       
     helps compare the cost of investing in the fund with the cost of investing in other funds. 
       
     Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares: 
    
   </oef:ExpenseExampleNarrativeTextBlock>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="0"
      id="ixv-56833"
      unitRef="usd">461</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleNoRedemptionYear01
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="0"
      id="ixv-56834"
      unitRef="usd">461</oef:ExpenseExampleNoRedemptionYear01>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="0"
      id="ixv-56835"
      unitRef="usd">461</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleNoRedemptionYear01
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="0"
      id="ixv-56836"
      unitRef="usd">461</oef:ExpenseExampleNoRedemptionYear01>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="0"
      id="ixv-56837"
      unitRef="usd">239</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleNoRedemptionYear01
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="0"
      id="ixv-56838"
      unitRef="usd">139</oef:ExpenseExampleNoRedemptionYear01>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="0"
      id="ixv-56839"
      unitRef="usd">38</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleNoRedemptionYear01
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="0"
      id="ixv-56840"
      unitRef="usd">38</oef:ExpenseExampleNoRedemptionYear01>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="0"
      id="ixv-56841"
      unitRef="usd">32</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleNoRedemptionYear01
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="0"
      id="ixv-56842"
      unitRef="usd">32</oef:ExpenseExampleNoRedemptionYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="0"
      id="ixv-56843"
      unitRef="usd">753</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleNoRedemptionYear03
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="0"
      id="ixv-56844"
      unitRef="usd">753</oef:ExpenseExampleNoRedemptionYear03>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="0"
      id="ixv-56845"
      unitRef="usd">765</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleNoRedemptionYear03
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="0"
      id="ixv-56846"
      unitRef="usd">765</oef:ExpenseExampleNoRedemptionYear03>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="0"
      id="ixv-56847"
      unitRef="usd">605</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleNoRedemptionYear03
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="0"
      id="ixv-56848"
      unitRef="usd">605</oef:ExpenseExampleNoRedemptionYear03>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="0"
      id="ixv-56849"
      unitRef="usd">291</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleNoRedemptionYear03
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="0"
      id="ixv-56850"
      unitRef="usd">291</oef:ExpenseExampleNoRedemptionYear03>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="0"
      id="ixv-56851"
      unitRef="usd">242</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleNoRedemptionYear03
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="0"
      id="ixv-56852"
      unitRef="usd">242</oef:ExpenseExampleNoRedemptionYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="0"
      id="ixv-56853"
      unitRef="usd">1100</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleNoRedemptionYear05
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="0"
      id="ixv-56854"
      unitRef="usd">1100</oef:ExpenseExampleNoRedemptionYear05>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="0"
      id="ixv-56855"
      unitRef="usd">1127</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleNoRedemptionYear05
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="0"
      id="ixv-56856"
      unitRef="usd">1127</oef:ExpenseExampleNoRedemptionYear05>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="0"
      id="ixv-56857"
      unitRef="usd">1131</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleNoRedemptionYear05
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="0"
      id="ixv-56858"
      unitRef="usd">1131</oef:ExpenseExampleNoRedemptionYear05>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="0"
      id="ixv-56859"
      unitRef="usd">600</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleNoRedemptionYear05
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="0"
      id="ixv-56860"
      unitRef="usd">600</oef:ExpenseExampleNoRedemptionYear05>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="0"
      id="ixv-56861"
      unitRef="usd">498</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleNoRedemptionYear05
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="0"
      id="ixv-56862"
      unitRef="usd">498</oef:ExpenseExampleNoRedemptionYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="0"
      id="ixv-56863"
      unitRef="usd">2078</oef:ExpenseExampleYear10>
    <oef:ExpenseExampleNoRedemptionYear10
      contextRef="Pid_S000075893_Cid_C000235228"
      decimals="0"
      id="ixv-56864"
      unitRef="usd">2078</oef:ExpenseExampleNoRedemptionYear10>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="0"
      id="ixv-56865"
      unitRef="usd">2145</oef:ExpenseExampleYear10>
    <oef:ExpenseExampleNoRedemptionYear10
      contextRef="Pid_S000075893_Cid_C000235224"
      decimals="0"
      id="ixv-56866"
      unitRef="usd">2145</oef:ExpenseExampleNoRedemptionYear10>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="0"
      id="ixv-56867"
      unitRef="usd">2378</oef:ExpenseExampleYear10>
    <oef:ExpenseExampleNoRedemptionYear10
      contextRef="Pid_S000075893_Cid_C000235225"
      decimals="0"
      id="ixv-56868"
      unitRef="usd">2378</oef:ExpenseExampleNoRedemptionYear10>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="0"
      id="ixv-56869"
      unitRef="usd">1477</oef:ExpenseExampleYear10>
    <oef:ExpenseExampleNoRedemptionYear10
      contextRef="Pid_S000075893_Cid_C000235226"
      decimals="0"
      id="ixv-56870"
      unitRef="usd">1477</oef:ExpenseExampleNoRedemptionYear10>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="0"
      id="ixv-56871"
      unitRef="usd">1234</oef:ExpenseExampleYear10>
    <oef:ExpenseExampleNoRedemptionYear10
      contextRef="Pid_S000075893_Cid_C000235227"
      decimals="0"
      id="ixv-56872"
      unitRef="usd">1234</oef:ExpenseExampleNoRedemptionYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10571">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10576">
     
       
     The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 
       
     
       
       16 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      decimals="4"
      id="ixv-56873"
      unitRef="pure">0.16</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10585">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10590">
     
       
      
       
        Normally investing at least 80% of assets in municipal securities (i) whose interest is exempt from federal income tax and (ii) that Fidelity Management &amp; Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics. The municipal securities in which the fund invests are normally investment-grade (those of medium and high quality). 
      
     Municipal debt securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal debt securities in which the fund invests include securities issued by U.S. territories and possessions, general obligation bonds of municipalities, local or state governments, project or revenue-specific bonds, or pre-refunded or escrowed bonds, municipal money market securities, and synthetic securities. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. 
     Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. 
      
       
        Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. 
      Evaluating each security in which the fund invests using both a traditional municipal bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or obligor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) information on a security's use of proceeds; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. 
      Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team.  
      The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, and vulnerability to the physical impacts of climate change. An assessment of an issuer's social profile includes, but is not limited to, its approach to quality health care access, housing affordability, human capital management, community reinvestment, and safety. An assessment of an issuer's governance profile includes, but is not limited to, its principles of management, oversight and transparency, governance efficiency and structure, and consideration of anticompetitive practices. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, effectiveness at service delivery, and long-term sustainability, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. 
      Assessing a security's use of proceeds by considering factors that provide ESG characteristics, such as energy efficiency, environmentally sustainable management, and providing access to quality health care, essential services and affordable housing. The Adviser will generally consider bonds that finance education, health care, affordable housing, clean energy, municipal water and sewer, public transportation, and designated green bonds, among others, as having positive ESG characteristics. 
      Managing the fund to have similar overall interest rate risk to the supplemental index (see "Additional Index Information" section of the prospectus). 
      In addition to focusing on municipal securities with positive ESG characteristics, the Adviser analyzes the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Normally maintaining a dollar-weighted average maturity between three and 10 years. 
      Allocating assets across different market sectors and maturities. 
      Potentially investing more than 25% of total assets in municipal securities that finance similar types of projects. 
      Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_MunicipalMarketVolatilityMember"
      id="ixv-10628">
     
       
      
      Municipal Market Volatility. 
      
     The municipal market is volatile and can be significantly affected by adverse tax, legislative, or political changes and the financial condition of the issuers of municipal securities. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_SustainabilityRiskMember"
      id="ixv-10637">
     
       
      
      Sustainability Risk. 
      
     Application of Fidelity Management &amp; Research Company LLC's (FMR) (the Adviser) ESG ratings process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG ratings process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-10646">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-10655">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_ManagementRiskMember"
      id="ixv-10666">
     
       
      
      Management Risk. 
      
     The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies . 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-10678">
     
       
     An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency 
       
     . 
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-10686">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10695">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10700">
     
       
      
       The following information is intended to help you understand the risks of investing in the fund. 
      
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
      
       
     The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. 
       
      
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
      
     Visit 
       
      
        
      institutional.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10706"> 
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10713"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10719"> 
        
      institutional.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10724">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:BarChartNarrativeTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10728">
     
       
      
        
      The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown. 
        
      
       
    
   </oef:BarChartNarrativeTextBlock>
    <oef:BarChartDoesNotReflectSalesLoads
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10731"> 
        
      The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown. 
        
     </oef:BarChartDoesNotReflectSalesLoads>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235228_2023"
      decimals="INF"
      id="ixv-56874"
      unitRef="pure">0.0599</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235228_2024"
      decimals="INF"
      id="ixv-56875"
      unitRef="pure">0.0102</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235228_2025"
      decimals="INF"
      id="ixv-56876"
      unitRef="pure">0.0515</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10820">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      decimals="4"
      id="ixv-56877"
      unitRef="pure">0.0708</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10830">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10835">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      decimals="4"
      id="ixv-56878"
      unitRef="pure">-0.0285</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10846">2023-09-30</oef:BarChartLowestQuarterlyReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10851">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10856">
     
       
      
        
      Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. 
        
      
       
      
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
      
       
      
        
      After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. 
        
      
       
     Actual after-tax returns may differ depending on your individual circumstances.  
      
        
      The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).  
      
       
      
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
      
       
    
   </oef:PerformanceTableNarrativeTextBlock>
    <oef:PerformanceTableDoesReflectSalesLoads
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10859"> 
        
      Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. 
        
     </oef:PerformanceTableDoesReflectSalesLoads>
    <oef:PerformanceTableUsesHighestFederalRate
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10864"> 
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
     </oef:PerformanceTableUsesHighestFederalRate>
    <oef:PerformanceTableOneClassOfAfterTaxShown
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10869"> 
        
      After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. 
        
     </oef:PerformanceTableOneClassOfAfterTaxShown>
    <oef:PerformanceTableNotRelevantToTaxDeferred
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10875"> 
        
      The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).  
     </oef:PerformanceTableNotRelevantToTaxDeferred>
    <oef:PerformanceTableExplanationAfterTaxHigher
      contextRef="Pid_S000075893_contentCd_ASNT-PRO"
      id="ixv-10879"> 
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
     </oef:PerformanceTableExplanationAfterTaxHigher>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Cid_C000235228_ReturnBeforeTaxes_01"
      id="ixv-10905">
         Return Before Taxes 
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235228_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56879"
      unitRef="pure">0.0094</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235228_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteASNT-PROS000075893AAR_A_RBT_loc"
      unitRef="pure">0.0232</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Cid_C000235228_AfterTaxesOnDistributions_01"
      id="ixv-10920">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235228_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-56881"
      unitRef="pure">0.0094</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235228_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteASNT-PROS000075893AAR_A_ATD_loc"
      unitRef="pure">0.0232</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Cid_C000235228_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-10933">
          Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235228_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-56883"
      unitRef="pure">0.0169</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235228_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteASNT-PROS000075893AAR_A_ATDS_loc"
      unitRef="pure">0.0239</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Cid_C000235224_ReturnBeforeTaxes_01"
      id="ixv-10946">
         Return Before Taxes 
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235224_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56885"
      unitRef="pure">0.0094</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235224_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteASNT-PROS000075893AAR_B_RBT_loc"
      unitRef="pure">0.0232</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Cid_C000235225_ReturnBeforeTaxes_01"
      id="ixv-10959">
         Return Before Taxes 
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235225_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56887"
      unitRef="pure">0.0336</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235225_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteASNT-PROS000075893AAR_C_RBT_loc"
      unitRef="pure">0.0269</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Cid_C000235226_ReturnBeforeTaxes_01"
      id="ixv-10972">
         Return Before Taxes 
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235226_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56889"
      unitRef="pure">0.0531</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235226_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteASNT-PROS000075893AAR_D_RBT_loc"
      unitRef="pure">0.0371</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Cid_C000235227_ReturnBeforeTaxes_01"
      id="ixv-10985">
         Return Before Taxes 
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235227_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56891"
      unitRef="pure">0.0537</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Cid_C000235227_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteASNT-PROS000075893AAR_E_RBT_loc"
      unitRef="pure">0.0377</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Indexid_IXWQ5_contentCd_ASNT-PRO_01"
      id="ixv-10997">
         Bloomberg 3-15 Year Blend (2-17) Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Indexid_IXWQ5_contentCd_ASNT-PRO_01"
      decimals="4"
      id="ixv-56893"
      unitRef="pure">0.0530</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Indexid_IXWQ5_contentCd_ASNT-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56894"
      unitRef="pure">0.0315</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075893_Indexid_LB015_contentCd_ASNT-PRO_01"
      id="ixv-11016">
         Bloomberg Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Indexid_LB015_contentCd_ASNT-PRO_01"
      decimals="4"
      id="ixv-56895"
      unitRef="pure">0.0425</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075893_Indexid_LB015_contentCd_ASNT-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56896"
      unitRef="pure">0.0279</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000075893_Cid_C000235228" id="ixv-11048">2022-04-13</oef:AnnualReturnInceptionDate>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000075893_Cid_C000235224" id="ixv-11061">2022-04-13</oef:AnnualReturnInceptionDate>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000075893_Cid_C000235225" id="ixv-11074">2022-04-13</oef:AnnualReturnInceptionDate>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000075893_Cid_C000235226" id="ixv-11087">2022-04-13</oef:AnnualReturnInceptionDate>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000075893_Cid_C000235227" id="ixv-11100">2022-04-13</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17303">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; SAI Sustainable Conservative Income Municipal Bond Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17312">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17317">
     
       
     Fidelity&#xae; SAI Sustainable Conservative Income Municipal Bond Fund seeks to provide a high level of income, exempt from federal income tax, consistent with preservation of capital. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17322">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17328">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17338">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      decimals="0"
      id="ixv-56897"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17353">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000075888_Cid_C000235213"
      decimals="6"
      id="ixv-56898"
      unitRef="pure">0.0020</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000075888_Cid_C000235213"
      decimals="6"
      id="ixv-56899"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000075888_Cid_C000235213"
      decimals="6"
      id="ixv-56900"
      unitRef="pure">0.0040</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000075888_Cid_C000235213"
      decimals="6"
      id="ixv-56901"
      unitRef="pure">0.0060</oef:ExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000075888_Cid_C000235213"
      decimals="6"
      id="footnoteS000075888MNI-PROAOE_AC000235213_FW"
      unitRef="pure">-0.0040</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000075888_Cid_C000235213"
      decimals="6"
      id="ixv-56903"
      unitRef="pure">0.0020</oef:NetExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17427">2027-05-31</oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17436">
     
       
     This  
     example 
       
     helps compare the cost of investing in the fund with the cost of investing in other funds. 
       
     Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 
    
   </oef:ExpenseExampleNarrativeTextBlock>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000075888_Cid_C000235213"
      decimals="0"
      id="ixv-56904"
      unitRef="usd">20</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000075888_Cid_C000235213"
      decimals="0"
      id="ixv-56905"
      unitRef="usd">138</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000075888_Cid_C000235213"
      decimals="0"
      id="ixv-56906"
      unitRef="usd">281</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000075888_Cid_C000235213"
      decimals="0"
      id="ixv-56907"
      unitRef="usd">698</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17493">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17498">
     
       
     The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 
       
     
       
       70 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      decimals="4"
      id="ixv-56908"
      unitRef="pure">0.70</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17507">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17512">
     
       
      
       
        Normally investing at least 80% of assets in U.S. dollar-denominated municipal money market securities and high quality investment-grade municipal debt securities (i) whose interest is exempt from federal income tax and (ii) that Fidelity Management &amp; Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics. 
      
     Municipal debt securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal debt securities in which the fund invests include securities issued by U.S. territories and possessions, general obligation bonds of municipalities, local or state governments, project or revenue-specific bonds, or pre-refunded or escrowed bonds, municipal money market securities, and synthetic securities. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. 
     Municipal money market securities are high-quality, short-term debt securities that pay a fixed, variable, or floating interest rate, and include variable rate demand notes, commercial paper, and municipal notes. Municipal securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. 
     High quality investment grade securities in which the fund invests include securities or issuers (i) rated at least A- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO) or similarly rated by the Adviser, and (ii) for securities with a credit maturity within one year, rated at least BBB or its equivalent by all NRSROs that rate the security and similarly rated by the Adviser. 
      
       Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. 
      
      Evaluating each security in which the fund invests using both a traditional municipal bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or obligor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) information on a security's use of proceeds; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. 
      Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team.  
      The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, and vulnerability to the physical impacts of climate change. An assessment of an issuer's social profile includes, but is not limited to, its approach to quality health care access, housing affordability, human capital management, community reinvestment, and safety. An assessment of an issuer's governance profile includes, but is not limited to, its principles of management, oversight and transparency, governance efficiency and structure, and consideration of anticompetitive practices. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, effectiveness at service delivery, and long-term sustainability, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. 
      Assessing a security's use of proceeds by considering factors that provide ESG characteristics, such as energy efficiency, environmentally sustainable management, and providing access to quality health care, essential services and affordable housing. The Adviser will generally consider bonds that finance education, health care, affordable housing, clean energy, municipal water and sewer, public transportation, and designated green bonds, among others, as having positive ESG characteristics. 
      Managing the fund to have similar overall interest rate risk to the supplemental index (see "Additional Index Information" section of the prospectus). 
      In addition to focusing on municipal securities with positive ESG characteristics, the Adviser analyzes the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Normally maintaining a dollar-weighted average maturity of one year or less. 
      Normally investing in securities with a maximum maturity of four years. 
      Allocating assets across different market sectors and maturities. 
      Potentially investing more than 25% of total assets in municipal securities that finance similar types of projects. 
      Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO_RiskMember_MunicipalMarketVolatilityMember"
      id="ixv-17554">
     
       
      
      Municipal Market Volatility. 
      
     The municipal market is volatile and can be significantly affected by adverse tax, legislative, or political changes and the financial condition of the issuers of municipal securities. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO_RiskMember_SustainabilityRiskMember"
      id="ixv-17563">
     
       
      
      Sustainability Risk. 
      
     Application of Fidelity Management &amp; Research Company LLC's (FMR) (the Adviser) ESG ratings process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG ratings process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-17572">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt or money market security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-17581">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO_RiskMember_ManagementRiskMember"
      id="ixv-17592">
     
       
      
      Management Risk. 
      
     The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies . 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-17604">
     
       
     An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency 
       
     . 
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-17612">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17621">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17626">
     
       
      
       The following information is intended to help you understand the risks of investing in the fund. 
      
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index, a hypothetical composite of market indexes, and an additional index over various periods of time. 
        
      
       
     The hypothetical composite of market indexes and additional index have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. 
       
      
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
      
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17632"> 
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index, a hypothetical composite of market indexes, and an additional index over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17639"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17645"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17650">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075888_Cid_C000235213_2023"
      decimals="INF"
      id="ixv-56909"
      unitRef="pure">0.0363</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075888_Cid_C000235213_2024"
      decimals="INF"
      id="ixv-56910"
      unitRef="pure">0.0332</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075888_Cid_C000235213_2025"
      decimals="INF"
      id="ixv-56911"
      unitRef="pure">0.0324</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17738">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      decimals="4"
      id="ixv-56912"
      unitRef="pure">0.0160</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17748">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17753">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      decimals="4"
      id="ixv-56913"
      unitRef="pure">0.0053</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17763">2023-09-30</oef:BarChartLowestQuarterlyReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17768">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17773">
     
       
      
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
      
       
     Actual after-tax returns may differ depending on your individual circumstances. 
       
      
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
      
       
    
   </oef:PerformanceTableNarrativeTextBlock>
    <oef:PerformanceTableUsesHighestFederalRate
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17776"> 
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
     </oef:PerformanceTableUsesHighestFederalRate>
    <oef:PerformanceTableExplanationAfterTaxHigher
      contextRef="Pid_S000075888_contentCd_MNI-PRO"
      id="ixv-17783"> 
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
     </oef:PerformanceTableExplanationAfterTaxHigher>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075888_Cid_C000235213_ReturnBeforeTaxes_01"
      id="ixv-17821">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Cid_C000235213_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56914"
      unitRef="pure">0.0324</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Cid_C000235213_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteMNI-PROS000075888AAR_A_RBT_loc"
      unitRef="pure">0.0306</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075888_Cid_C000235213_AfterTaxesOnDistributions_01"
      id="ixv-17834">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Cid_C000235213_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-56916"
      unitRef="pure">0.0323</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Cid_C000235213_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteMNI-PROS000075888AAR_A_ATD_loc"
      unitRef="pure">0.0305</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075888_Cid_C000235213_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-17847">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Cid_C000235213_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-56918"
      unitRef="pure">0.0315</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Cid_C000235213_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteMNI-PROS000075888AAR_A_ATDS_loc"
      unitRef="pure">0.0304</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075888_Indexid_IXV4E_contentCd_MNI-PRO_01"
      id="ixv-17861">
         Fidelity Conservative Income Municipal Bond Composite Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Indexid_IXV4E_contentCd_MNI-PRO_01"
      decimals="4"
      id="ixv-56920"
      unitRef="pure">0.0316</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Indexid_IXV4E_contentCd_MNI-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56921"
      unitRef="pure">0.0292</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075888_Indexid_LB319_contentCd_MNI-PRO_01"
      id="ixv-17880">
         Bloomberg Municipal Bond 1 Year (1-2 Y) Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Indexid_LB319_contentCd_MNI-PRO_01"
      decimals="4"
      id="ixv-56922"
      unitRef="pure">0.0347</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Indexid_LB319_contentCd_MNI-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56923"
      unitRef="pure">0.0280</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075888_Indexid_LB015_contentCd_MNI-PRO_01"
      id="ixv-17899">
         Bloomberg Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Indexid_LB015_contentCd_MNI-PRO_01"
      decimals="4"
      id="ixv-56924"
      unitRef="pure">0.0425</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075888_Indexid_LB015_contentCd_MNI-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56925"
      unitRef="pure">0.0378</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000075888_Cid_C000235213" id="ixv-17931">2022-06-16</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-17979">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; SAI Sustainable Municipal Income Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-17988">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-17993">
     
       
     Fidelity&#xae; SAI Sustainable Municipal Income Fund seeks to provide a high current yield exempt from federal income tax. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-17998">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18004">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18014">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      decimals="0"
      id="ixv-56926"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18029">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000075891_Cid_C000235216"
      decimals="6"
      id="ixv-56927"
      unitRef="pure">0.0033</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000075891_Cid_C000235216"
      decimals="6"
      id="ixv-56928"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000075891_Cid_C000235216"
      decimals="6"
      id="ixv-56929"
      unitRef="pure">0.0020</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000075891_Cid_C000235216"
      decimals="6"
      id="ixv-56930"
      unitRef="pure">0.0053</oef:ExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000075891_Cid_C000235216"
      decimals="6"
      id="footnoteS000075891MNI-PROAOE_AC000235216_FW"
      unitRef="pure">-0.0017</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000075891_Cid_C000235216"
      decimals="6"
      id="ixv-56932"
      unitRef="pure">0.0036</oef:NetExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18104">2027-05-31</oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18113">
     
       
     This  
     example 
       
     helps compare the cost of investing in the fund with the cost of investing in other funds. 
       
     Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 
    
   </oef:ExpenseExampleNarrativeTextBlock>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000075891_Cid_C000235216"
      decimals="0"
      id="ixv-56933"
      unitRef="usd">37</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000075891_Cid_C000235216"
      decimals="0"
      id="ixv-56934"
      unitRef="usd">147</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000075891_Cid_C000235216"
      decimals="0"
      id="ixv-56935"
      unitRef="usd">273</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000075891_Cid_C000235216"
      decimals="0"
      id="ixv-56936"
      unitRef="usd">643</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18170">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18175">
     
       
     The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 
       
     
       
       10 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      decimals="4"
      id="ixv-56937"
      unitRef="pure">0.10</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18184">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18189">
     
       
      
       
        Normally investing at least 80% of assets in municipal securities (i) whose interest is exempt from federal income tax and (ii) that Fidelity Management &amp; Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics. The municipal securities in which the fund invests are normally investment-grade (those of medium and high quality). 
      
     Municipal debt securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal debt securities in which the fund invests include securities issued by U.S. territories and possessions, general obligation bonds of municipalities, local or state governments, project or revenue-specific bonds, or pre-refunded or escrowed bonds, municipal money market securities, and synthetic securities. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. 
     Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. 
      
       
        Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. 
      Evaluating each security in which the fund invests using both a traditional municipal bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or obligor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) information on a security's use of proceeds; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. 
      Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team.  
      The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, and vulnerability to the physical impacts of climate change. An assessment of an issuer's social profile includes, but is not limited to, its approach to quality health care access, housing affordability, human capital management, community reinvestment, and safety. An assessment of an issuer's governance profile includes, but is not limited to, its principles of management, oversight and transparency, governance efficiency and structure, and consideration of anticompetitive practices. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, effectiveness at service delivery, and long-term sustainability, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. 
      Assessing a security's use of proceeds by considering factors that provide ESG characteristics, such as energy efficiency, environmentally sustainable management, and providing access to quality health care, essential services and affordable housing. The Adviser will generally consider bonds that finance education, health care, affordable housing, clean energy, municipal water and sewer, public transportation, and designated green bonds, among others, as having positive ESG characteristics. 
      Managing the fund to have similar overall interest rate risk to the supplemental index (see "Additional Index Information" section of the prospectus). 
      In addition to focusing on municipal securities with positive ESG characteristics, the Adviser analyzes the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Allocating assets across different market sectors and maturities. 
      Potentially investing more than 25% of total assets in municipal securities that finance similar types of projects. 
      Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO_RiskMember_MunicipalMarketVolatilityMember"
      id="ixv-18225">
     
       
      
      Municipal Market Volatility. 
      
     The municipal market is volatile and can be significantly affected by adverse tax, legislative, or political changes and the financial condition of the issuers of municipal securities. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO_RiskMember_SustainabilityRiskMember"
      id="ixv-18234">
     
       
      
      Sustainability Risk. 
      
     Application of Fidelity Management &amp; Research Company LLC's (FMR) (the Adviser) ESG ratings process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG ratings process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-18243">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-18252">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO_RiskMember_ManagementRiskMember"
      id="ixv-18263">
     
       
      
      Management Risk. 
      
     The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies . 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-18275">
     
       
     An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency 
       
     . 
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-18283">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18292">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18297">
     
       
      
       The following information is intended to help you understand the risks of investing in the fund. 
      
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
      
       
     The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. 
       
      
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
      
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18303"> 
        
      The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18310"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18316"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18321">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075891_Cid_C000235216_2023"
      decimals="INF"
      id="ixv-56938"
      unitRef="pure">0.0804</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075891_Cid_C000235216_2024"
      decimals="INF"
      id="ixv-56939"
      unitRef="pure">0.0102</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000075891_Cid_C000235216_2025"
      decimals="INF"
      id="ixv-56940"
      unitRef="pure">0.0466</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18409">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      decimals="4"
      id="ixv-56941"
      unitRef="pure">0.0937</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18419">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18424">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      decimals="4"
      id="ixv-56942"
      unitRef="pure">-0.0376</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18435">2023-09-30</oef:BarChartLowestQuarterlyReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18440">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18445">
     
       
      
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
      
       
     Actual after-tax returns may differ depending on your individual circumstances. 
       
      
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
      
       
    
   </oef:PerformanceTableNarrativeTextBlock>
    <oef:PerformanceTableUsesHighestFederalRate
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18448"> 
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
     </oef:PerformanceTableUsesHighestFederalRate>
    <oef:PerformanceTableExplanationAfterTaxHigher
      contextRef="Pid_S000075891_contentCd_MNI-PRO"
      id="ixv-18455"> 
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
     </oef:PerformanceTableExplanationAfterTaxHigher>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075891_Cid_C000235216_ReturnBeforeTaxes_01"
      id="ixv-18493">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075891_Cid_C000235216_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56943"
      unitRef="pure">0.0466</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075891_Cid_C000235216_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteMNI-PROS000075891AAR_A_RBT_loc"
      unitRef="pure">0.0374</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075891_Cid_C000235216_AfterTaxesOnDistributions_01"
      id="ixv-18506">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075891_Cid_C000235216_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-56945"
      unitRef="pure">0.0466</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075891_Cid_C000235216_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteMNI-PROS000075891AAR_A_ATD_loc"
      unitRef="pure">0.0373</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075891_Cid_C000235216_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-18519">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075891_Cid_C000235216_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-56947"
      unitRef="pure">0.0411</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075891_Cid_C000235216_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteMNI-PROS000075891AAR_A_ATDS_loc"
      unitRef="pure">0.0359</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075891_Indexid_LB083_contentCd_MNI-PRO_01"
      id="ixv-18533">
         Bloomberg 3+ Year Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075891_Indexid_LB083_contentCd_MNI-PRO_01"
      decimals="4"
      id="ixv-56949"
      unitRef="pure">0.0430</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075891_Indexid_LB083_contentCd_MNI-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56950"
      unitRef="pure">0.0279</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000075891_Indexid_LB015_contentCd_MNI-PRO_01"
      id="ixv-18552">
         Bloomberg Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075891_Indexid_LB015_contentCd_MNI-PRO_01"
      decimals="4"
      id="ixv-56951"
      unitRef="pure">0.0425</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000075891_Indexid_LB015_contentCd_MNI-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56952"
      unitRef="pure">0.0279</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000075891_Cid_C000235216" id="ixv-18584">2022-04-13</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-20941">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; SAI Conservative Income Municipal Bond Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-20950">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-20955">
     
       
     Fidelity&#xae; SAI Conservative Income Municipal Bond Fund seeks to provide a high level of income, exempt from federal income tax, consistent with preservation of capital. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-20960">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-20966">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-20976">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      decimals="0"
      id="ixv-56953"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-20991">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000082358_Cid_C000245667"
      decimals="6"
      id="ixv-56954"
      unitRef="pure">0.0020</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000082358_Cid_C000245667"
      decimals="6"
      id="ixv-56955"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000082358_Cid_C000245667"
      decimals="6"
      id="ixv-56956"
      unitRef="pure">0.0001</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000082358_Cid_C000245667"
      decimals="6"
      id="ixv-56957"
      unitRef="pure">0.0021</oef:ExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000082358_Cid_C000245667"
      decimals="6"
      id="footnoteS000082358CIM-PROAOE_AC000245667_FW"
      unitRef="pure">-0.0001</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000082358_Cid_C000245667"
      decimals="6"
      id="ixv-56959"
      unitRef="pure">0.0020</oef:NetExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21065">2027-05-31</oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21074">
     
       
     This  
     example 
       
     helps compare the cost of investing in the fund with the cost of investing in other funds. 
       
     Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 
    
   </oef:ExpenseExampleNarrativeTextBlock>
    <oef:ExpenseExampleYear01
      contextRef="Pid_S000082358_Cid_C000245667"
      decimals="0"
      id="ixv-56960"
      unitRef="usd">20</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000082358_Cid_C000245667"
      decimals="0"
      id="ixv-56961"
      unitRef="usd">66</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000082358_Cid_C000245667"
      decimals="0"
      id="ixv-56962"
      unitRef="usd">117</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000082358_Cid_C000245667"
      decimals="0"
      id="ixv-56963"
      unitRef="usd">266</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21131">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21136">
     
       
     The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 
       
     
       
       64 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      decimals="4"
      id="ixv-56964"
      unitRef="pure">0.64</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21145">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21150">
     
       
      
       
        Normally investing at least 80% of assets in U.S. dollar-denominated municipal money market securities and high quality investment-grade municipal debt securities whose interest is exempt from federal income tax. 
      
     Municipal debt securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal debt securities in which the fund invests include securities issued by U.S. territories and possessions, general obligation bonds of municipalities, local or state governments, project or revenue-specific bonds, or pre-refunded or escrowed bonds, municipal money market securities, and synthetic securities. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. 
     Municipal money market securities are high-quality, short-term debt securities that pay a fixed, variable, or floating interest rate, and include variable rate demand notes, commercial paper, and municipal notes. Municipal securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. 
     High quality investment grade securities in which the fund invests include securities or issuers (i) rated at least A- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO) or similarly rated by the Adviser, and (ii) for securities with a credit maturity within one year, rated at least BBB or its equivalent by all NRSROs that rate the security and similarly rated by the Adviser. 
      
       Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. 
      
      Managing the fund to have similar overall interest rate risk to the supplemental index (see "Additional Index Information" section of the prospectus). 
      Normally maintaining a dollar-weighted average maturity of one year or less. 
      Normally investing in securities with a maximum maturity of four years. 
      Allocating assets across different market sectors and maturities. 
      Potentially investing more than 25% of total assets in municipal securities that finance similar types of projects. 
      Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO_RiskMember_MunicipalMarketVolatilityMember"
      id="ixv-21182">
     
       
      
      Municipal Market Volatility. 
      
     The municipal market is volatile and can be significantly affected by adverse tax, legislative, or political changes and the financial condition of the issuers of municipal securities. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-21191">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt or money market security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-21200">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-21212">
     
       
     An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency 
       
     . 
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-21220">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21229">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21234">
     
       
      
       The following information is intended to help you understand the risks of investing in the fund. 
      
        
      The information illustrates the  
      changes in the  
      performance of the fund's shares  
       
        
      from year to 
       year and compares the performance of the fund's shares to the performance of a securities market index, a hypothetical composite of market indexes, and an additional index over various periods of time.  
      
       
     The hypothetical composite of market indexes and additional index have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus.  
      
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
      
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21240"> 
        
      The information illustrates the  
      changes in the  
      performance of the fund's shares  
       
        
      from year to 
       year and compares the performance of the fund's shares to the performance of a securities market index, a hypothetical composite of market indexes, and an additional index over various periods of time.  
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21250"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21256"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21261">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000082358_Cid_C000245667_2024"
      decimals="INF"
      id="ixv-56965"
      unitRef="pure">0.0330</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000082358_Cid_C000245667_2025"
      decimals="INF"
      id="ixv-56966"
      unitRef="pure">0.0326</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21346">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      decimals="4"
      id="ixv-56967"
      unitRef="pure">0.0125</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21356">2024-09-30</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21361">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      decimals="4"
      id="ixv-56968"
      unitRef="pure">0.0055</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21371">2024-12-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21376">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21381">
     
       
      
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
      
       
     Actual after-tax returns may differ depending on your individual circumstances. 
       
      
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
      
       
    
   </oef:PerformanceTableNarrativeTextBlock>
    <oef:PerformanceTableUsesHighestFederalRate
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21384"> 
        
      After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. 
        
     </oef:PerformanceTableUsesHighestFederalRate>
    <oef:PerformanceTableExplanationAfterTaxHigher
      contextRef="Pid_S000082358_contentCd_CIM-PRO"
      id="ixv-21391"> 
        
      Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares. 
        
     </oef:PerformanceTableExplanationAfterTaxHigher>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000082358_Cid_C000245667_ReturnBeforeTaxes_01"
      id="ixv-21429">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Cid_C000245667_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-56969"
      unitRef="pure">0.0326</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Cid_C000245667_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteCIM-PROS000082358AAR_A_RBT_loc"
      unitRef="pure">0.0360</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000082358_Cid_C000245667_AfterTaxesOnDistributions_01"
      id="ixv-21442">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Cid_C000245667_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-56971"
      unitRef="pure">0.0326</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Cid_C000245667_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteCIM-PROS000082358AAR_A_ATD_loc"
      unitRef="pure">0.0359</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000082358_Cid_C000245667_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-21455">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Cid_C000245667_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-56973"
      unitRef="pure">0.0317</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Cid_C000245667_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteCIM-PROS000082358AAR_A_ATDS_loc"
      unitRef="pure">0.0353</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000082358_Indexid_F1872_contentCd_CIM-PRO_01"
      id="ixv-21469">
         Fidelity Conservative Income Municipal Bond Composite Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Indexid_F1872_contentCd_CIM-PRO_01"
      decimals="4"
      id="ixv-56975"
      unitRef="pure">0.0316</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Indexid_F1872_contentCd_CIM-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56976"
      unitRef="pure">0.0341</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000082358_Indexid_LB319_contentCd_CIM-PRO_01"
      id="ixv-21488">
         Bloomberg Municipal Bond 1 Year (1-2 Y) Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Indexid_LB319_contentCd_CIM-PRO_01"
      decimals="4"
      id="ixv-56977"
      unitRef="pure">0.0347</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Indexid_LB319_contentCd_CIM-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56978"
      unitRef="pure">0.0363</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000082358_Indexid_LB015_contentCd_CIM-PRO_01"
      id="ixv-21507">
         Bloomberg Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Indexid_LB015_contentCd_CIM-PRO_01"
      decimals="4"
      id="ixv-56979"
      unitRef="pure">0.0425</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000082358_Indexid_LB015_contentCd_CIM-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-56980"
      unitRef="pure">0.0558</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000082358_Cid_C000245667" id="ixv-21539">2023-11-06</oef:AnnualReturnInceptionDate>
    <link:footnoteLink
      xlink:role="http://www.xbrl.org/2003/role/link"
      xlink:type="extended">
        <link:loc
          xlink:href="#footnoteS000017680SFB-PROAOE_AC000048850_FW"
          xlink:label="footnoteS000017680SFB-PROAOE_AC000048850_FW"
          xlink:type="locator"/>
        <link:footnote id="footnoteS000017680SFB-PROAOE_A" xlink:label="footnoteS000017680SFB-PROAOE_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
      </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:4.5pt; vertical-align:3pt; ">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">Fidelity Management &amp; Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.25% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">May 31, </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
       </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; font-style:italic; ">2027</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000017680SFB-PROAOE_AC000048850_FW"
          xlink:to="footnoteS000017680SFB-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteS000062003STF-PROAOE_AC000200825_FW"
          xlink:label="footnoteS000062003STF-PROAOE_AC000200825_FW"
          xlink:type="locator"/>
        <link:footnote id="footnoteS000062003STF-PROAOE_A" xlink:label="footnoteS000062003STF-PROAOE_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
      </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:4.5pt; vertical-align:3pt; ">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">Fidelity Management &amp; Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.25% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">May 31, </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
       </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; font-style:italic; ">2027</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000062003STF-PROAOE_AC000200825_FW"
          xlink:to="footnoteS000062003STF-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteSTF-PROS000062003AAR_A_RBT_loc"
          xlink:label="footnoteSTF-PROS000062003AAR_A_RBT_loc"
          xlink:type="locator"/>
        <link:footnote id="footnoteSTF-PROS000062003AAR_A" xlink:label="footnoteSTF-PROS000062003AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.67pt; vertical-align:super">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">October 2, 2018</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteSTF-PROS000062003AAR_A_RBT_loc"
          xlink:to="footnoteSTF-PROS000062003AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteSTF-PROS000062003AAR_A_ATD_loc"
          xlink:label="footnoteSTF-PROS000062003AAR_A_ATD_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteSTF-PROS000062003AAR_A_ATD_loc"
          xlink:to="footnoteSTF-PROS000062003AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteSTF-PROS000062003AAR_A_ATDS_loc"
          xlink:label="footnoteSTF-PROS000062003AAR_A_ATDS_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteSTF-PROS000062003AAR_A_ATDS_loc"
          xlink:to="footnoteSTF-PROS000062003AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteS000075893SNT-PROAOE_AC000235223_FW"
          xlink:label="footnoteS000075893SNT-PROAOE_AC000235223_FW"
          xlink:type="locator"/>
        <link:footnote id="footnoteS000075893SNT-PROAOE_A" xlink:label="footnoteS000075893SNT-PROAOE_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
      </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:4.5pt; vertical-align:3pt; ">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">Fidelity Management &amp; Research Company LLC (FMR) has contractually agreed to reimburse the class of shares of the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.37% (the Expense Cap). If at any time during the current fiscal year expenses for the class of shares of the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">May 31, </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
       </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; font-style:italic; ">2027</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000075893SNT-PROAOE_AC000235223_FW"
          xlink:to="footnoteS000075893SNT-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteSNT-PROS000075893AAR_A_RBT_loc"
          xlink:label="footnoteSNT-PROS000075893AAR_A_RBT_loc"
          xlink:type="locator"/>
        <link:footnote id="footnoteSNT-PROS000075893AAR_A" xlink:label="footnoteSNT-PROS000075893AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.67pt; vertical-align:super">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">April 13, 2022</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteSNT-PROS000075893AAR_A_RBT_loc"
          xlink:to="footnoteSNT-PROS000075893AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteSNT-PROS000075893AAR_A_ATD_loc"
          xlink:label="footnoteSNT-PROS000075893AAR_A_ATD_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteSNT-PROS000075893AAR_A_ATD_loc"
          xlink:to="footnoteSNT-PROS000075893AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteSNT-PROS000075893AAR_A_ATDS_loc"
          xlink:label="footnoteSNT-PROS000075893AAR_A_ATDS_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteSNT-PROS000075893AAR_A_ATDS_loc"
          xlink:to="footnoteSNT-PROS000075893AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteASNT-PROS000075893SHF_AC000235228"
          xlink:label="footnoteASNT-PROS000075893SHF_AC000235228"
          xlink:type="locator"/>
        <link:footnote id="footnoteASNT-PROS000075893SHF_A" xlink:label="footnoteASNT-PROS000075893SHF_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.67pt; vertical-align:super">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 0.75% and 0.25%, respectively.</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteASNT-PROS000075893SHF_AC000235228"
          xlink:to="footnoteASNT-PROS000075893SHF_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteASNT-PROS000075893SHF_AC000235224"
          xlink:label="footnoteASNT-PROS000075893SHF_AC000235224"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteASNT-PROS000075893SHF_AC000235224"
          xlink:to="footnoteASNT-PROS000075893SHF_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteASNT-PROS000075893SHF_BC000235225"
          xlink:label="footnoteASNT-PROS000075893SHF_BC000235225"
          xlink:type="locator"/>
        <link:footnote id="footnoteASNT-PROS000075893SHF_B" xlink:label="footnoteASNT-PROS000075893SHF_B" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.67pt; vertical-align:super">B</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">On Class C shares redeemed less than one year after purchase.</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteASNT-PROS000075893SHF_BC000235225"
          xlink:to="footnoteASNT-PROS000075893SHF_B"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteS000075893ASNT-PROAOE_AC000235228_FW"
          xlink:label="footnoteS000075893ASNT-PROAOE_AC000235228_FW"
          xlink:type="locator"/>
        <link:footnote id="footnoteS000075893ASNT-PROAOE_A" xlink:label="footnoteS000075893ASNT-PROAOE_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
      </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:4.5pt; vertical-align:3pt; ">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">Fidelity Management &amp; Research Company LLC (FMR) has contractually agreed to reimburse Class A, Class M, Class C, Class I, and Class Z of the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of their respective average net assets, exceed 0.62%, 0.62%, 1.37%, 0.37%, and 0.31% (the Expense Caps). If at any time during the current fiscal year expenses for Class A, Class M, Class C, Class I, or Class Z of the fund fall below the Expense Caps, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Caps. These arrangements will remain in effect through </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">May 31, </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
       </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; ">2027</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">. FMR may not terminate these arrangements before the expiration date without the approval of the Board of Trustees and may extend them in its discretion after that date.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000075893ASNT-PROAOE_AC000235228_FW"
          xlink:to="footnoteS000075893ASNT-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteS000075893ASNT-PROAOE_AC000235224_FW"
          xlink:label="footnoteS000075893ASNT-PROAOE_AC000235224_FW"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000075893ASNT-PROAOE_AC000235224_FW"
          xlink:to="footnoteS000075893ASNT-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteS000075893ASNT-PROAOE_AC000235225_FW"
          xlink:label="footnoteS000075893ASNT-PROAOE_AC000235225_FW"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000075893ASNT-PROAOE_AC000235225_FW"
          xlink:to="footnoteS000075893ASNT-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteS000075893ASNT-PROAOE_AC000235226_FW"
          xlink:label="footnoteS000075893ASNT-PROAOE_AC000235226_FW"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000075893ASNT-PROAOE_AC000235226_FW"
          xlink:to="footnoteS000075893ASNT-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteS000075893ASNT-PROAOE_AC000235227_FW"
          xlink:label="footnoteS000075893ASNT-PROAOE_AC000235227_FW"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000075893ASNT-PROAOE_AC000235227_FW"
          xlink:to="footnoteS000075893ASNT-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteASNT-PROS000075893AAR_A_RBT_loc"
          xlink:label="footnoteASNT-PROS000075893AAR_A_RBT_loc"
          xlink:type="locator"/>
        <link:footnote id="footnoteASNT-PROS000075893AAR_A" xlink:label="footnoteASNT-PROS000075893AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">April 13, 2022</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteASNT-PROS000075893AAR_A_RBT_loc"
          xlink:to="footnoteASNT-PROS000075893AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteASNT-PROS000075893AAR_A_ATD_loc"
          xlink:label="footnoteASNT-PROS000075893AAR_A_ATD_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteASNT-PROS000075893AAR_A_ATD_loc"
          xlink:to="footnoteASNT-PROS000075893AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteASNT-PROS000075893AAR_A_ATDS_loc"
          xlink:label="footnoteASNT-PROS000075893AAR_A_ATDS_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteASNT-PROS000075893AAR_A_ATDS_loc"
          xlink:to="footnoteASNT-PROS000075893AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteASNT-PROS000075893AAR_B_RBT_loc"
          xlink:label="footnoteASNT-PROS000075893AAR_B_RBT_loc"
          xlink:type="locator"/>
        <link:footnote id="footnoteASNT-PROS000075893AAR_B" xlink:label="footnoteASNT-PROS000075893AAR_B" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">B</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">April 13, 2022</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteASNT-PROS000075893AAR_B_RBT_loc"
          xlink:to="footnoteASNT-PROS000075893AAR_B"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteASNT-PROS000075893AAR_C_RBT_loc"
          xlink:label="footnoteASNT-PROS000075893AAR_C_RBT_loc"
          xlink:type="locator"/>
        <link:footnote id="footnoteASNT-PROS000075893AAR_C" xlink:label="footnoteASNT-PROS000075893AAR_C" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">C</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">April 13, 2022</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteASNT-PROS000075893AAR_C_RBT_loc"
          xlink:to="footnoteASNT-PROS000075893AAR_C"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteASNT-PROS000075893AAR_D_RBT_loc"
          xlink:label="footnoteASNT-PROS000075893AAR_D_RBT_loc"
          xlink:type="locator"/>
        <link:footnote id="footnoteASNT-PROS000075893AAR_D" xlink:label="footnoteASNT-PROS000075893AAR_D" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">D</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">April 13, 2022</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteASNT-PROS000075893AAR_D_RBT_loc"
          xlink:to="footnoteASNT-PROS000075893AAR_D"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteASNT-PROS000075893AAR_E_RBT_loc"
          xlink:label="footnoteASNT-PROS000075893AAR_E_RBT_loc"
          xlink:type="locator"/>
        <link:footnote id="footnoteASNT-PROS000075893AAR_E" xlink:label="footnoteASNT-PROS000075893AAR_E" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">E</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">April 13, 2022</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteASNT-PROS000075893AAR_E_RBT_loc"
          xlink:to="footnoteASNT-PROS000075893AAR_E"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteS000075888MNI-PROAOE_AC000235213_FW"
          xlink:label="footnoteS000075888MNI-PROAOE_AC000235213_FW"
          xlink:type="locator"/>
        <link:footnote id="footnoteS000075888MNI-PROAOE_A" xlink:label="footnoteS000075888MNI-PROAOE_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">Fidelity Management &amp; Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.20% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">May 31, </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
       </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; ">2027</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000075888MNI-PROAOE_AC000235213_FW"
          xlink:to="footnoteS000075888MNI-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteMNI-PROS000075888AAR_A_RBT_loc"
          xlink:label="footnoteMNI-PROS000075888AAR_A_RBT_loc"
          xlink:type="locator"/>
        <link:footnote id="footnoteMNI-PROS000075888AAR_A" xlink:label="footnoteMNI-PROS000075888AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.67pt; vertical-align:super">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">June 16, 2022</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteMNI-PROS000075888AAR_A_RBT_loc"
          xlink:to="footnoteMNI-PROS000075888AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteMNI-PROS000075888AAR_A_ATD_loc"
          xlink:label="footnoteMNI-PROS000075888AAR_A_ATD_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteMNI-PROS000075888AAR_A_ATD_loc"
          xlink:to="footnoteMNI-PROS000075888AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteMNI-PROS000075888AAR_A_ATDS_loc"
          xlink:label="footnoteMNI-PROS000075888AAR_A_ATDS_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteMNI-PROS000075888AAR_A_ATDS_loc"
          xlink:to="footnoteMNI-PROS000075888AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteS000075891MNI-PROAOE_AC000235216_FW"
          xlink:label="footnoteS000075891MNI-PROAOE_AC000235216_FW"
          xlink:type="locator"/>
        <link:footnote id="footnoteS000075891MNI-PROAOE_A" xlink:label="footnoteS000075891MNI-PROAOE_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
      </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:4.5pt; vertical-align:3pt; ">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">Fidelity Management &amp; Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.36% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">May 31, </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
       </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; ">2027</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt">. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000075891MNI-PROAOE_AC000235216_FW"
          xlink:to="footnoteS000075891MNI-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteMNI-PROS000075891AAR_A_RBT_loc"
          xlink:label="footnoteMNI-PROS000075891AAR_A_RBT_loc"
          xlink:type="locator"/>
        <link:footnote id="footnoteMNI-PROS000075891AAR_A" xlink:label="footnoteMNI-PROS000075891AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.67pt; vertical-align:super">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">April 13, 2022</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteMNI-PROS000075891AAR_A_RBT_loc"
          xlink:to="footnoteMNI-PROS000075891AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteMNI-PROS000075891AAR_A_ATD_loc"
          xlink:label="footnoteMNI-PROS000075891AAR_A_ATD_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteMNI-PROS000075891AAR_A_ATD_loc"
          xlink:to="footnoteMNI-PROS000075891AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteMNI-PROS000075891AAR_A_ATDS_loc"
          xlink:label="footnoteMNI-PROS000075891AAR_A_ATDS_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteMNI-PROS000075891AAR_A_ATDS_loc"
          xlink:to="footnoteMNI-PROS000075891AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteS000082358CIM-PROAOE_AC000245667_FW"
          xlink:label="footnoteS000082358CIM-PROAOE_AC000245667_FW"
          xlink:type="locator"/>
        <link:footnote id="footnoteS000082358CIM-PROAOE_A" xlink:label="footnoteS000082358CIM-PROAOE_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">Fidelity Management &amp; Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.20% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">May 31, </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
       </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; font-style:italic; ">2027</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000082358CIM-PROAOE_AC000245667_FW"
          xlink:to="footnoteS000082358CIM-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteCIM-PROS000082358AAR_A_RBT_loc"
          xlink:label="footnoteCIM-PROS000082358AAR_A_RBT_loc"
          xlink:type="locator"/>
        <link:footnote id="footnoteCIM-PROS000082358AAR_A" xlink:label="footnoteCIM-PROS000082358AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">November 6, 2023</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteCIM-PROS000082358AAR_A_RBT_loc"
          xlink:to="footnoteCIM-PROS000082358AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteCIM-PROS000082358AAR_A_ATD_loc"
          xlink:label="footnoteCIM-PROS000082358AAR_A_ATD_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteCIM-PROS000082358AAR_A_ATD_loc"
          xlink:to="footnoteCIM-PROS000082358AAR_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteCIM-PROS000082358AAR_A_ATDS_loc"
          xlink:label="footnoteCIM-PROS000082358AAR_A_ATDS_loc"
          xlink:type="locator"/>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteCIM-PROS000082358AAR_A_ATDS_loc"
          xlink:to="footnoteCIM-PROS000082358AAR_A"
          xlink:type="arc"/>
    </link:footnoteLink>
</xbrl>
