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     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Low Duration Bond ETF 
    
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     Investment Objective 
       
    
   </oef:ObjectiveHeading>
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     Fidelity&#xae; Low Duration Bond ETF seeks to obtain a high level of current income consistent with preservation of capital. 
       
    
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     Fee Table 
       
    
   </oef:ExpenseHeading>
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     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. 
    
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     Shareholder fees 
       
    
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      contextRef="Pid_S000084018_contentCd_LOD-PRO"
      decimals="0"
      id="ixv-62426"
      unitRef="usd">0</oef:ShareholderFeeOther>
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     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000084018_Cid_C000248144"
      decimals="6"
      id="ixv-62427"
      unitRef="pure">0.0020</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000084018_Cid_C000248144"
      decimals="6"
      id="ixv-62428"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000084018_Cid_C000248144"
      decimals="6"
      id="ixv-62429"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000084018_Cid_C000248144"
      decimals="6"
      id="ixv-62430"
      unitRef="pure">0.0020</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock contextRef="Pid_S000084018_contentCd_LOD-PRO" id="ixv-311">
     
       
     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: 
    
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      contextRef="Pid_S000084018_Cid_C000248144"
      decimals="0"
      id="ixv-62431"
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    <oef:ExpenseExampleYear03
      contextRef="Pid_S000084018_Cid_C000248144"
      decimals="0"
      id="ixv-62432"
      unitRef="usd">64</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000084018_Cid_C000248144"
      decimals="0"
      id="ixv-62433"
      unitRef="usd">113</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000084018_Cid_C000248144"
      decimals="0"
      id="ixv-62434"
      unitRef="usd">255</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading contextRef="Pid_S000084018_contentCd_LOD-PRO" id="ixv-368">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock contextRef="Pid_S000084018_contentCd_LOD-PRO" id="ixv-373">
     
       
     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 
       
     
       
       60 
       
       
     % of the average value of its portfolio. 
       
    
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    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000084018_contentCd_LOD-PRO"
      decimals="4"
      id="ixv-62435"
      unitRef="pure">0.60</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000084018_contentCd_LOD-PRO" id="ixv-382">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock contextRef="Pid_S000084018_contentCd_LOD-PRO" id="ixv-387">
     
       
      
       
        Normally investing at least 80% of assets in investment-grade debt securities (those of medium and high quality) of all types and repurchase agreements for those securities. 
      
     Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).&#160; 
     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. 
     A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 
     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 maintaining a duration of 1 year or less. 
      Managing the fund to have similar overall interest rate risk to the Bloomberg US Treasury Bill: 6-9 Months Index. 
      Normally maintaining a dollar-weighted average maturity of two years or less. 
      Allocating assets across different market sectors and maturities. 
      Investing more than 25% of total assets in the financial services industries. 
      Investing in domestic and foreign issuers. 
      Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000084018_contentCd_LOD-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-422">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000084018_contentCd_LOD-PRO_RiskMember_ForeignExposureMember"
      id="ixv-431">
     
       
      
      Foreign Exposure. 
      
     Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000084018_contentCd_LOD-PRO_RiskMember_FinancialServicesConcentrationMember"
      id="ixv-440">
     
       
      
      Financial Services Concentration. 
      
     Changes in government regulation and interest rates and economic downturns can have a significant negative effect on issuers in the financial services sector, including the price of their securities or their ability to meet their payment obligations. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000084018_contentCd_LOD-PRO_RiskMember_PrepaymentMember"
      id="ixv-449">
     
       
      
      Prepayment. 
      
     The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000084018_contentCd_LOD-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-458">
     
       
      
      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_S000084018_contentCd_LOD-PRO_RiskMember_FluctuationOfNetAssetValueAndSharePriceMember"
      id="ixv-469">
     
       
      
      Fluctuation of Net Asset Value and Share Price. 
      
     The net asset value per share (NAV) of the fund will generally fluctuate with changes in the market value of the fund's holdings. The fund's shares can be bought and sold in the secondary market at market prices. Disruptions to creations and redemptions, the existence of extreme market volatility or potential lack of an active trading market for the fund's shares may result in the fund's shares trading significantly above (at a premium) or below (at a discount) to NAV. 
     Given the nature of the relevant markets for certain of the fund's securities, shares may trade at a larger premium or discount to the NAV than shares of other ETFs. 
     In addition, in stressed market conditions or periods of market disruption or volatility,&#160;the market for shares may become less liquid in response to deteriorating liquidity in the markets for the fund's underlying portfolio holdings. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000084018_contentCd_LOD-PRO_RiskMember_TradingIssuesMember"
      id="ixv-484">
     
       
      
      Trading Issues. 
      
     There can be no assurance that an active trading market will be maintained. Market makers and Authorized Participants are not obligated to make a market in the fund's shares or to submit purchase and redemption orders for creation units. Decisions by market makers or Authorized Participants to reduce their role with respect to market making or creation and redemption activities during times of market stress, or a decline in the number of Authorized Participants due to decisions to exit the business, bankruptcy, or other factors, could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying value of the fund's portfolio securities and the market price of fund shares. In addition, trading may be halted, for example, due to market conditions. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000084018_contentCd_LOD-PRO_RiskMember_LeverageRiskMember"
      id="ixv-493">
     
       
      
      Leverage Risk. 
      
     Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000084018_contentCd_LOD-PRO_RiskMember_CashTransactionsRiskMember"
      id="ixv-502">
     
       
      
      Cash Transactions Risk. 
      
     Unlike certain ETFs, the fund may effect some or all creations and redemptions using cash, rather than in-kind securities. As a result, an investment in the fund may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000084018_contentCd_LOD-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-512">
     
       
     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_S000084018_contentCd_LOD-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-520">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
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     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000084018_contentCd_LOD-PRO" id="ixv-534">
     
       
      
       The following information is intended to help you understand the risks of investing in the fund. 
      
        
      The information illustrates the performance of the fund's shares over the past 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_S000084018_contentCd_LOD-PRO" id="ixv-540"> 
        
      The information illustrates the performance of the fund's shares over the past 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_S000084018_contentCd_LOD-PRO" id="ixv-545"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000084018_contentCd_LOD-PRO" id="ixv-551"> 
        
       
        
      www.fidelity.com  
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     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000084018_Cid_C000248144_2025"
      decimals="INF"
      id="ixv-62436"
      unitRef="pure">0.0479</oef:AnnlRtrPct>
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          &#160;&#160;&#160;Highest Quarter Return
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    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000084018_contentCd_LOD-PRO"
      decimals="4"
      id="ixv-62437"
      unitRef="pure">0.0124</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate contextRef="Pid_S000084018_contentCd_LOD-PRO" id="ixv-649">2025-09-30</oef:BarChartHighestQuarterlyReturnDate>
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          &#160;&#160;&#160;Lowest Quarter Return
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      contextRef="Pid_S000084018_contentCd_LOD-PRO"
      decimals="4"
      id="ixv-62438"
      unitRef="pure">0.0108</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate contextRef="Pid_S000084018_contentCd_LOD-PRO" id="ixv-664">2025-12-31</oef:BarChartLowestQuarterlyReturnDate>
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          &#160;&#160;&#160;Year-to-Date Return
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      contextRef="Pid_S000084018_contentCd_LOD-PRO"
      decimals="4"
      id="ixv-62439"
      unitRef="pure">0.0248</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate contextRef="Pid_S000084018_contentCd_LOD-PRO" id="ixv-679">2026-09-30</oef:BarChartYearToDateReturnDate>
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     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
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      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_S000084018_contentCd_LOD-PRO" id="ixv-692"> 
        
      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_S000084018_contentCd_LOD-PRO" id="ixv-699"> 
        
      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_S000084018_contentCd_LOD-PRO" id="ixv-704"> 
        
      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>
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      id="ixv-743">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000084018_Cid_C000248144_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-62440"
      unitRef="pure">0.0479</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000084018_Cid_C000248144_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteLOD-PROS000084018AAR_A_RBT_loc"
      unitRef="pure">0.0516</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
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         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000084018_Cid_C000248144_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-62442"
      unitRef="pure">0.0281</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000084018_Cid_C000248144_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteLOD-PROS000084018AAR_A_ATD_loc"
      unitRef="pure">0.0319</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000084018_Cid_C000248144_AfterTaxesOnDistributionsAndSales_01"
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         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000084018_Cid_C000248144_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-62444"
      unitRef="pure">0.0283</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000084018_Cid_C000248144_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteLOD-PROS000084018AAR_A_ATDS_loc"
      unitRef="pure">0.0311</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
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         Bloomberg US Treasury Bill: 6-9 Months Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
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      decimals="4"
      id="ixv-62446"
      unitRef="pure">0.0415</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
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      id="ixv-62447"
      unitRef="pure">0.0459</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
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         Bloomberg U.S. Aggregate Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000084018_Indexid_LB001_contentCd_LOD-PRO_01"
      decimals="4"
      id="ixv-62448"
      unitRef="pure">0.0730</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000084018_Indexid_LB001_contentCd_LOD-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-62449"
      unitRef="pure">0.0579</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000084018_Cid_C000248144" id="ixv-834">2024-02-22</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2092">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Tactical Bond ETF 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2101">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2106">
     
       
     Fidelity&#xae; Tactical Bond ETF seeks a high level of current income. Growth of capital may also be considered. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2111">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2117">
     
       
     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_S000079047_contentCd_TBE-PRO" id="ixv-2129">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000079047_contentCd_TBE-PRO"
      decimals="0"
      id="ixv-62450"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2144">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000079047_Cid_C000239880"
      decimals="6"
      id="ixv-62451"
      unitRef="pure">0.0055</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000079047_Cid_C000239880"
      decimals="6"
      id="ixv-62452"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000079047_Cid_C000239880"
      decimals="6"
      id="ixv-62453"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000079047_Cid_C000239880"
      decimals="6"
      id="ixv-62454"
      unitRef="pure">0.0055</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2191">
     
       
     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_S000079047_Cid_C000239880"
      decimals="0"
      id="ixv-62455"
      unitRef="usd">56</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000079047_Cid_C000239880"
      decimals="0"
      id="ixv-62456"
      unitRef="usd">176</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000079047_Cid_C000239880"
      decimals="0"
      id="ixv-62457"
      unitRef="usd">307</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000079047_Cid_C000239880"
      decimals="0"
      id="ixv-62458"
      unitRef="usd">689</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2248">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2253">
     
       
     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 
       
     
       
       48 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000079047_contentCd_TBE-PRO"
      decimals="4"
      id="ixv-62459"
      unitRef="pure">0.48</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2262">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2267">
     
       
      
       
        Normally investing at least 80% of assets in debt securities of all types and repurchase agreements for those securities. 
      
     Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).&#160; 
     A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 
     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. 
      
      Allocating assets across the full spectrum of the debt market, including investment-grade (those of medium and high quality), high yield and emerging markets debt securities across different maturities. In addition to the debt securities listed above, investments also will normally include lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds), investment-grade securitized debt securities (those of medium and high quality), floating rate loans and other floating rate securities, inflation-protected debt securities, preferred securities, contingent convertible securities, and securities of foreign issuers, including securities of issuers located in emerging markets. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. 
      
      
      Investing in both U.S. dollar-denominated and non-U.S. dollar-denominated securities, and generally hedging the fund's foreign currency exposures utilizing forward foreign currency exchange contracts. 
      Investing in collateralized loan obligations (CLO). 
      Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_ImpairmentOfCollateralMember"
      id="ixv-2295">
     
       
      
      Impairment of Collateral. 
      
     A floating rate loan may not be fully collateralized which may cause the floating rate loan to decline significantly in value. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_FloatingRateLoanLiquidityMember"
      id="ixv-2304">
     
       
      
      Floating Rate Loan Liquidity. 
      
     Floating rate loans generally are subject to restrictions on resale. Floating rate loans sometimes trade infrequently in the secondary market. As a result, valuing a floating rate loan can be more difficult, and buying and selling a floating rate loan at an acceptable price can be more difficult or delayed, including extended trade settlement periods. Difficulty in selling a floating rate loan can result in a loss. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-2313">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_ForeignAndEmergingMarketsRiskMember"
      id="ixv-2322">
     
       
      
      Foreign and Emerging Markets Risk. 
      
     Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. 
     The extent of economic development; political stability; market depth, infrastructure, and capitalization; and regulatory oversight can be less than in more developed markets. Emerging markets typically have less established legal, accounting and financial reporting systems than those in more developed markets, which may reduce the scope or quality of financial information available to investors. 
     Emerging markets can be subject to greater social, economic, regulatory, and political uncertainties and can be extremely volatile. 
     Foreign exchange rates also can be extremely volatile. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_ForeignCurrencyTransactionsMember"
      id="ixv-2337">
     
       
      
      Foreign Currency Transactions. 
      
     Although a forward foreign currency exchange contract is used to reduce or hedge a fund's exposure to changes in the value of the currency, suitable hedging transactions may not be available in all circumstances, may not be successful, and may eliminate any chance for the fund to benefit from favorable fluctuations in relevant foreign currencies. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_PrepaymentMember"
      id="ixv-2346">
     
       
      
      Prepayment. 
      
     The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-2355">
     
       
      
      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. 
     Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) and certain types of other securities involve greater risk of default or price changes due to changes in the credit quality of the issuer. The value of lower-quality debt securities and certain types of other securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments and can be difficult to resell. 
     CLO tranches can experience substantial losses due to actual and anticipated defaults, as well as aversion to CLO securities as a class. 
     Investments in covenant-lite loans carry more risk than traditional loans as they allow issuers to engage in activities that would otherwise be difficult or impossible under a traditional loan agreement. In the event of default, covenant-lite obligations have lower recovery values as the lender may not have the opportunity to negotiate with the borrower prior to default. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_FluctuationOfNetAssetValueAndSharePriceMember"
      id="ixv-2372">
     
       
      
      Fluctuation of Net Asset Value and Share Price. 
      
     The net asset value per share (NAV) of the fund will generally fluctuate with changes in the market value of the fund's holdings. The fund's shares can be bought and sold in the secondary market at market prices. Disruptions to creations and redemptions, the existence of extreme market volatility or potential lack of an active trading market for the fund's shares may result in the fund's shares trading significantly above (at a premium) or below (at a discount) to NAV. 
     Given the nature of the relevant markets for certain of the fund's securities, shares may trade at a larger premium or discount to the NAV than shares of other ETFs. 
     In addition, in stressed market conditions or periods of market disruption or volatility,&#160;the market for shares may become less liquid in response to deteriorating liquidity in the markets for the fund's underlying portfolio holdings. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_ContingentConvertibleSecuritiesRiskMember"
      id="ixv-2387">
     
       
      
      Contingent Convertible Securities Risk. 
      
     Contingent convertible securities have unique equity conversion or principal write-down features that involve additional risks, which may include cancellation of interest payments by the issuer or a regulatory authority; subordination to other creditors due to either a liquidation or other bankruptcy-related event or a conversion of the security from debt to equity; and a write-down of the security's principal amount. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_TradingIssuesMember"
      id="ixv-2396">
     
       
      
      Trading Issues. 
      
     There can be no assurance that an active trading market will be maintained. Market makers and Authorized Participants are not obligated to make a market in the fund's shares or to submit purchase and redemption orders for creation units. Decisions by market makers or Authorized Participants to reduce their role with respect to market making or creation and redemption activities during times of market stress, or a decline in the number of Authorized Participants due to decisions to exit the business, bankruptcy, or other factors, could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying value of the fund's portfolio securities and the market price of fund shares. In addition, trading may be halted, for example, due to market conditions. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_LeverageRiskMember"
      id="ixv-2405">
     
       
      
      Leverage Risk. 
      
     Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_CashTransactionsRiskMember"
      id="ixv-2414">
     
       
      
      Cash Transactions Risk. 
      
     Unlike certain ETFs, the fund may effect some or all creations and redemptions using cash, rather than in-kind securities. As a result, an investment in the fund may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_InflationProtectedDebtExposureMember"
      id="ixv-2423">
     
       
      
      Inflation-Protected Debt Exposure. 
      
     Increases in real interest rates can cause the price of inflation-protected debt securities to decrease. Interest payments on inflation-protected debt securities can be unpredictable. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000079047_contentCd_TBE-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-2433">
     
       
     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_S000079047_contentCd_TBE-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-2441">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2450">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2455">
     
       
      
       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 over various periods of time. 
        
      
       
     The index description appears 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_S000079047_contentCd_TBE-PRO" id="ixv-2461"> 
        
      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 over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2472"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2478"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2483">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000079047_Cid_C000239880_2024"
      decimals="INF"
      id="ixv-62460"
      unitRef="pure">0.0167</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000079047_Cid_C000239880_2025"
      decimals="INF"
      id="ixv-62461"
      unitRef="pure">0.0837</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2568">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000079047_contentCd_TBE-PRO"
      decimals="4"
      id="ixv-62462"
      unitRef="pure">0.0529</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2578">2024-09-30</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2583">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000079047_contentCd_TBE-PRO"
      decimals="4"
      id="ixv-62463"
      unitRef="pure">-0.0326</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2594">2024-12-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2599">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000079047_contentCd_TBE-PRO"
      decimals="4"
      id="ixv-62464"
      unitRef="pure">-0.0210</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2610">2026-09-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2615">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock contextRef="Pid_S000079047_contentCd_TBE-PRO" id="ixv-2620">
     
       
      
        
      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_S000079047_contentCd_TBE-PRO" id="ixv-2623"> 
        
      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_S000079047_contentCd_TBE-PRO" id="ixv-2630"> 
        
      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_S000079047_contentCd_TBE-PRO" id="ixv-2635"> 
        
      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_S000079047_Cid_C000239880_ReturnBeforeTaxes_01"
      id="ixv-2673">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000079047_Cid_C000239880_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-62465"
      unitRef="pure">0.0837</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000079047_Cid_C000239880_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteTBE-PROS000079047AAR_A_RBT_loc"
      unitRef="pure">0.0469</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000079047_Cid_C000239880_AfterTaxesOnDistributions_01"
      id="ixv-2686">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000079047_Cid_C000239880_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-62467"
      unitRef="pure">0.0616</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000079047_Cid_C000239880_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteTBE-PROS000079047AAR_A_ATD_loc"
      unitRef="pure">0.0260</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000079047_Cid_C000239880_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-2699">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000079047_Cid_C000239880_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-62469"
      unitRef="pure">0.0492</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000079047_Cid_C000239880_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteTBE-PROS000079047AAR_A_ATDS_loc"
      unitRef="pure">0.0267</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000079047_Indexid_LB001_contentCd_TBE-PRO_01"
      id="ixv-2713">
         Bloomberg U.S. Aggregate Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000079047_Indexid_LB001_contentCd_TBE-PRO_01"
      decimals="4"
      id="ixv-62471"
      unitRef="pure">0.0730</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000079047_Indexid_LB001_contentCd_TBE-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-62472"
      unitRef="pure">0.0368</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000079047_Cid_C000239880" id="ixv-2745">2023-01-24</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4112">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Systematic Municipal Bond Index ETF 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4121">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4126">
     
       
     Fidelity&#xae; Systematic Municipal Bond Index ETF seeks to provide a high current yield exempt from federal income tax. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4131">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4137">
     
       
     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_S000089371_contentCd_SMBI-PRO"
      id="ixv-4149">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      decimals="0"
      id="ixv-62473"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4164">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000089371_Cid_C000255893"
      decimals="6"
      id="ixv-62474"
      unitRef="pure">0.0005</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000089371_Cid_C000255893"
      decimals="6"
      id="ixv-62475"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000089371_Cid_C000255893"
      decimals="6"
      id="ixv-62476"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000089371_Cid_C000255893"
      decimals="6"
      id="ixv-62477"
      unitRef="pure">0.0005</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4211">
     
       
      
       
     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_S000089371_Cid_C000255893"
      decimals="0"
      id="ixv-62478"
      unitRef="usd">5</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000089371_Cid_C000255893"
      decimals="0"
      id="ixv-62479"
      unitRef="usd">16</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000089371_Cid_C000255893"
      decimals="0"
      id="ixv-62480"
      unitRef="usd">28</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000089371_Cid_C000255893"
      decimals="0"
      id="ixv-62481"
      unitRef="usd">64</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4269">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4274">
     
       
     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 
       
     
       
       15 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      decimals="4"
      id="ixv-62482"
      unitRef="pure">0.15</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4283">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4288">
     
       
      
       
        Normally investing at least 80% of assets in municipal securities whose interest is exempt from federal income tax (but may be subject to the federal alternative minimum tax). 
      Normally investing at least 80% of assets in securities included in the Fidelity Systematic U.S. Municipal Bond IndexSM, which aims to increase exposure to municipal bonds with higher risk-adjusted performance and liquidity characteristics relative to traditional market-capitalization weighted U.S. investment grade municipal bond indices. 
      The Fidelity Systematic U.S. Municipal Bond Index SM is constructed using Fidelity's rules-based proprietary index methodology. The universe of securities includes U.S. dollar-denominated investment-grade tax-exempt debt publicly issued in the domestic market by U.S. states and territories, and their political subdivisions, that meet specific criteria such as issue size, deal size and maturity. Mandatory put or mandatory tender securities, as well as original issue zero-coupon bonds, are included in the universe. Floating rate bonds, derivatives, secondarily insured securities, Rule 144A securities, securities in legal default, securities issued under the municipal liquidity facility, or a municipal commercial paper program, and limited offering securities are excluded from the universe. Index constituents are not market capitalization weighted; instead each constituent's weight is determined by its characteristics such as credit quality, issue size, and maturity - aiming for higher risk-adjusted performance at the index level. Additionally, exposure is balanced across maturity buckets to ensure the index's overall duration is similar to traditional indices. 
      Using statistical sampling techniques based on duration, maturity, interest rate sensitivity, security structure, and credit quality to attempt to replicate the returns of the Fidelity Systematic U.S. Municipal Bond IndexSM using a smaller number of securities. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO_RiskMember_MunicipalMarketVolatilityMember"
      id="ixv-4310">
     
       
      
      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_S000089371_contentCd_SMBI-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-4319">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO_RiskMember_PrepaymentMember"
      id="ixv-4328">
     
       
      
      Prepayment. 
      
     The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-4337">
     
       
      
      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_S000089371_contentCd_SMBI-PRO_RiskMember_FluctuationOfNetAssetValueAndSharePriceMember"
      id="ixv-4348">
     
       
      
      Fluctuation of Net Asset Value and Share Price. 
      
     The net asset value per share (NAV) of the fund will generally fluctuate with changes in the market value of the fund's holdings. The fund's shares can be bought and sold in the secondary market at market prices. Disruptions to creations and redemptions, the existence of extreme market volatility or potential lack of an active trading market for the fund's shares may result in the fund's shares trading significantly above (at a premium) or below (at a discount) to NAV. 
     Given the nature of the relevant markets for certain of the fund's securities, shares may trade at a larger premium or discount to the NAV than shares of other ETFs. 
     In addition, in stressed market conditions or periods of market disruption or volatility,&#160;the market for shares may become less liquid in response to deteriorating liquidity in the markets for the fund's underlying portfolio holdings. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO_RiskMember_CorrelationToIndexMember"
      id="ixv-4363">
     
       
      
      Correlation to Index. 
      
     The performance of the fund and its  
       benchmark 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_S000089371_contentCd_SMBI-PRO_RiskMember_PassiveManagementRiskMember"
      id="ixv-4375">
     
       
      
      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 benchmark 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_S000089371_contentCd_SMBI-PRO_RiskMember_RulesBasedStrategyRiskMember"
      id="ixv-4386">
     
       
      
      Rules-Based Strategy Risk. 
      
     Although the index uses a rules-based proprietary index methodology, there is no guarantee that this methodology will be successful.&#160; 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO_RiskMember_TradingIssuesMember"
      id="ixv-4396">
     
       
      
      Trading Issues. 
      
     There can be no assurance that an active trading market will be maintained. Market makers and Authorized Participants are not obligated to make a market in the fund's shares or to submit purchase and redemption orders for creation units. Decisions by market makers or Authorized Participants to reduce their role with respect to market making or creation and redemption activities during times of market stress, or a decline in the number of Authorized Participants due to decisions to exit the business, bankruptcy, or other factors, could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying value of the fund's portfolio securities and the market price of fund shares. In addition, trading may be halted, for example, due to market conditions. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO_RiskMember_CashTransactionsRiskMember"
      id="ixv-4405">
     
       
      
      Cash Transactions Risk. 
      
     Unlike certain ETFs, the fund may effect some or all creations and redemptions using cash, rather than in-kind securities. As a result, an investment in the fund may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-4415">
     
       
     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_S000089371_contentCd_SMBI-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-4423">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4432">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4437">
     
       
      
       Effective April 4, 2025, Fidelity&#xae; Municipal Bond Index Fund ("Predecessor Fund") was reorganized into Fidelity&#xae; Systematic Municipal Bond Index ETF ("Reorganization"). The Predecessor Fund is designated as the accounting survivor in the Reorganization. Therefore, Fidelity&#xae; Systematic Municipal Bond Index ETF has assumed the Predecessor Fund's historical performance and the performance information shown below for periods prior to April 4, 2025, reflects that of the Predecessor Fund. The performance&#160;of the Predecessor Fund has not been restated to reflect the annual operating expenses of Fidelity&#xae; Systematic Municipal Bond Index ETF, which are lower than those of the&#160;Predecessor Fund. Past performance may have been different if Fidelity&#xae; Systematic Municipal Bond Index ETF's current fee structure had been in place during the period.  
     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 Predecessor Fund's shares from year to year and compares the performance of the Predecessor Fund's shares to the performance of the Bloomberg Municipal Bond Index.&#160;The Predecessor Fund had a principal investment strategy attempting to replicate the performance of the Bloomberg Municipal Bond Index whereas Fidelity&#xae; Systematic Municipal Bond Index ETF has a principal investment strategy to attempt to replicate the performance of the Fidelity Systematic U.S. Municipal Bond Index SM . As a result, the Predecessor Fund's historical performance may not represent Fidelity&#xae; Systematic Municipal Bond Index ETF's current principal investment strategies. &#160;&#160; 
     Index descriptions appear in the "Additional Index Information" section of the prospectus.&#160;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:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4466"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4471">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_2020"
      decimals="INF"
      id="ixv-62483"
      unitRef="pure">0.0310</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_2021"
      decimals="INF"
      id="ixv-62484"
      unitRef="pure">0.0127</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_2022"
      decimals="INF"
      id="ixv-62485"
      unitRef="pure">-0.0942</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_2023"
      decimals="INF"
      id="ixv-62486"
      unitRef="pure">0.0592</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_2024"
      decimals="INF"
      id="ixv-62487"
      unitRef="pure">0.0130</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_2025"
      decimals="INF"
      id="ixv-62488"
      unitRef="pure">0.0372</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4569">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      decimals="4"
      id="ixv-62489"
      unitRef="pure">0.0770</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4579">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4584">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      decimals="4"
      id="ixv-62490"
      unitRef="pure">-0.0614</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4595">2022-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4600">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      decimals="4"
      id="ixv-62491"
      unitRef="pure">-0.0418</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4611">2026-09-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4616">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000089371_contentCd_SMBI-PRO"
      id="ixv-4621">
     
       
      
        
      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_S000089371_contentCd_SMBI-PRO"
      id="ixv-4624"> 
        
      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_S000089371_contentCd_SMBI-PRO"
      id="ixv-4631"> 
        
      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_S000089371_Cid_C000255893_ReturnBeforeTaxes_01"
      id="ixv-4677">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-62492"
      unitRef="pure">0.0372</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-62493"
      unitRef="pure">0.0041</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSMBI-PROS000089371AAR_A_RBT_loc"
      unitRef="pure">0.0096</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000089371_Cid_C000255893_AfterTaxesOnDistributions_01"
      id="ixv-4693">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-62495"
      unitRef="pure">0.0371</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-62496"
      unitRef="pure">0.0041</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSMBI-PROS000089371AAR_A_ATD_loc"
      unitRef="pure">0.0096</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000089371_Cid_C000255893_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-4709">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-62498"
      unitRef="pure">0.0349</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-62499"
      unitRef="pure">0.0082</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Cid_C000255893_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSMBI-PROS000089371AAR_A_ATDS_loc"
      unitRef="pure">0.0122</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000089371_Indexid_LB015_contentCd_SMBI-PRO_01"
      id="ixv-4726">
         Bloomberg Municipal Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Indexid_LB015_contentCd_SMBI-PRO_01"
      decimals="4"
      id="ixv-62501"
      unitRef="pure">0.0425</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Indexid_LB015_contentCd_SMBI-PRO_05"
      decimals="4"
      id="ixv-62502"
      unitRef="pure">0.0080</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Indexid_LB015_contentCd_SMBI-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-62503"
      unitRef="pure">0.0172</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000089371_Indexid_IXTRM_contentCd_SMBI-PRO_01"
      id="ixv-4751">
         Fidelity Systematic U.S. Municipal Bond Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Indexid_IXTRM_contentCd_SMBI-PRO_01"
      decimals="4"
      id="ixv-62504"
      unitRef="pure">0.0408</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Indexid_IXTRM_contentCd_SMBI-PRO_05"
      id="footnoteSMBI-PROS000089371AAR_B_BM_1_05"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000089371_Indexid_IXTRM_contentCd_SMBI-PRO_AverageAnnualReturnSinceInception"
      id="footnoteSMBI-PROS000089371AAR_B_BM_1_loc"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000089371_Cid_C000255893" id="ixv-4796">2019-07-11</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6433">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Low Duration Bond Factor ETF 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6442">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6447">
     
       
     Fidelity&#xae; Low Duration Bond Factor ETF seeks to provide investment returns that correspond, before fees and expenses, generally to the performance of the Fidelity Low Duration Investment Grade Factor Index&#x2120;. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6452">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6458">
     
       
     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_S000062079_contentCd_LDE-PRO" id="ixv-6470">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000062079_contentCd_LDE-PRO"
      decimals="0"
      id="ixv-62507"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6485">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000062079_Cid_C000201028"
      decimals="6"
      id="ixv-62508"
      unitRef="pure">0.0015</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000062079_Cid_C000201028"
      decimals="6"
      id="ixv-62509"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000062079_Cid_C000201028"
      decimals="6"
      id="ixv-62510"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000062079_Cid_C000201028"
      decimals="6"
      id="ixv-62511"
      unitRef="pure">0.0015</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6532">
     
       
     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_S000062079_Cid_C000201028"
      decimals="0"
      id="ixv-62512"
      unitRef="usd">15</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000062079_Cid_C000201028"
      decimals="0"
      id="ixv-62513"
      unitRef="usd">48</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000062079_Cid_C000201028"
      decimals="0"
      id="ixv-62514"
      unitRef="usd">85</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000062079_Cid_C000201028"
      decimals="0"
      id="ixv-62515"
      unitRef="usd">192</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6589">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6594">
     
       
     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 
       
     
       
       34 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000062079_contentCd_LDE-PRO"
      decimals="4"
      id="ixv-62516"
      unitRef="pure">0.34</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6603">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6608">
     
       
      
       
        Normally investing at least 80% of assets in securities included in the Fidelity Low Duration Investment Grade Factor IndexSM. The index is designed to optimize the balance of interest rate risk and credit risk such that both returns and risk measures may be improved relative to traditional U.S. investment grade floating rate note indices. The index is comprised solely of U.S. investment grade floating rate notes and U.S. Treasury notes. 
      
     The Fidelity Low Duration Investment Grade Factor Index is constructed using Fidelity's rules-based proprietary index methodology. The weight of each component in the blend is set to target a duration, which seeks to optimize the balance of credit risk and interest rate risk. The final weights of securities within the corporate floating rate notes component are determined by their market capitalization, subject to an issuer cap of 3.5%. 
     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 maintaining a duration of 1 year or less. 
      Using statistical sampling techniques based on duration, maturity, interest rate sensitivity, security structure, and credit quality to attempt to replicate the returns of the Fidelity Low Duration Investment Grade Factor Index&#x2120; using a smaller number of securities. 
      Lending securities to earn income for the fund. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-6630">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_FloatingRateNotesMember"
      id="ixv-6639">
     
       
      
      Floating Rate Notes. 
      
     Securities with floating interest rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value if their interest rates do not rise as much, or as quickly, as interest rates in general. Floating rate notes typically carry lower yields than fixed rate notes of the same maturity. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_FinancialServicesConcentrationMember"
      id="ixv-6648">
     
       
      
      Financial Services Concentration. 
      
     Changes in government regulation and interest rates and economic downturns can have a significant negative effect on issuers in the financial services sector, including the price of their securities or their ability to meet their payment obligations. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_PrepaymentMember"
      id="ixv-6657">
     
       
      
      Prepayment. 
      
     The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-6666">
     
       
      
      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_S000062079_contentCd_LDE-PRO_RiskMember_USTreasuryObligationsMember"
      id="ixv-6677">
     
       
      
      U.S. Treasury Obligations. 
      
     U.S. Treasury obligations are high-quality securities issued or guaranteed by the U.S. Treasury providing minimal risk of loss of principal if held to maturity. Fluctuations in interest rates may cause the market value of such securities to vary. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_FluctuationOfNetAssetValueAndSharePriceMember"
      id="ixv-6686">
     
       
      
      Fluctuation of Net Asset Value and Share Price. 
      
     The net asset value per share (NAV) of the fund will generally fluctuate with changes in the market value of the fund's holdings. The fund's shares can be bought and sold in the secondary market at market prices. Disruptions to creations and redemptions, the existence of extreme market volatility or potential lack of an active trading market for the fund's shares may result in the fund's shares trading significantly above (at a premium) or below (at a discount) to NAV. 
     Given the nature of the relevant markets for certain of the fund's securities, shares may trade at a larger premium or discount to the NAV than shares of other ETFs. 
     In addition, in stressed market conditions or periods of market disruption or volatility,&#160;the market for shares may become less liquid in response to deteriorating liquidity in the markets for the fund's underlying portfolio holdings. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_CorrelationToIndexMember"
      id="ixv-6701">
     
       
      
      Correlation to Index. 
      
     The performance of the fund and its  
       benchmark 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_S000062079_contentCd_LDE-PRO_RiskMember_PassiveManagementRiskMember"
      id="ixv-6713">
     
       
      
      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 benchmark 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. 
     The fund will be concentrated to approximately the same extent that the fund's benchmark index concentrates in the securities of issuers in a particular industry. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_FactorBasedStrategyRiskMember"
      id="ixv-6728">
     
       
      
      Factor-Based Strategy Risk. 
      
     Although the fund's underlying index uses a rules-based proprietary index methodology that seeks to optimize the balance of certain risks, there is no guarantee that this methodology will be successful. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_TradingIssuesMember"
      id="ixv-6737">
     
       
      
      Trading Issues. 
      
     There can be no assurance that an active trading market will be maintained. Market makers and Authorized Participants are not obligated to make a market in the fund's shares or to submit purchase and redemption orders for creation units. Decisions by market makers or Authorized Participants to reduce their role with respect to market making or creation and redemption activities during times of market stress, or a decline in the number of Authorized Participants due to decisions to exit the business, bankruptcy, or other factors, could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying value of the fund's portfolio securities and the market price of fund shares. In addition, trading may be halted, for example, due to market conditions. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_CashTransactionsRiskMember"
      id="ixv-6746">
     
       
      
      Cash Transactions Risk. 
      
     Unlike certain ETFs, the fund may effect some or all creations and redemptions using cash, rather than in-kind securities. As a result, an investment in the fund may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000062079_contentCd_LDE-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-6756">
     
       
     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_S000062079_contentCd_LDE-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-6764">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6773">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6778">
     
       
      
       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 additional indexes 
        
      over various periods of time. 
        
      
       
     The additional indexes 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_S000062079_contentCd_LDE-PRO" id="ixv-6784"> 
        
      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 additional indexes 
        
      over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6793"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6799"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6804">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_2019"
      decimals="INF"
      id="ixv-62517"
      unitRef="pure">0.0451</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_2020"
      decimals="INF"
      id="ixv-62518"
      unitRef="pure">0.0198</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_2021"
      decimals="INF"
      id="ixv-62519"
      unitRef="pure">-0.0004</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_2022"
      decimals="INF"
      id="ixv-62520"
      unitRef="pure">-0.0056</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_2023"
      decimals="INF"
      id="ixv-62521"
      unitRef="pure">0.0639</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_2024"
      decimals="INF"
      id="ixv-62522"
      unitRef="pure">0.0573</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_2025"
      decimals="INF"
      id="ixv-62523"
      unitRef="pure">0.0546</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6906">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000062079_contentCd_LDE-PRO"
      decimals="4"
      id="ixv-62524"
      unitRef="pure">0.0356</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6916">2020-06-30</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6921">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000062079_contentCd_LDE-PRO"
      decimals="4"
      id="ixv-62525"
      unitRef="pure">-0.0220</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6932">2020-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6937">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000062079_contentCd_LDE-PRO"
      decimals="4"
      id="ixv-62526"
      unitRef="pure">0.0219</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6947">2026-09-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6952">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock contextRef="Pid_S000062079_contentCd_LDE-PRO" id="ixv-6957">
     
       
      
        
      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_S000062079_contentCd_LDE-PRO" id="ixv-6960"> 
        
      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_S000062079_contentCd_LDE-PRO" id="ixv-6967"> 
        
      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_S000062079_contentCd_LDE-PRO" id="ixv-6972"> 
        
      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_S000062079_Cid_C000201028_ReturnBeforeTaxes_01"
      id="ixv-7018">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-62527"
      unitRef="pure">0.0546</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-62528"
      unitRef="pure">0.0335</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteLDE-PROS000062079AAR_A_RBT_loc"
      unitRef="pure">0.0319</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000062079_Cid_C000201028_AfterTaxesOnDistributions_01"
      id="ixv-7034">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-62530"
      unitRef="pure">0.0347</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-62531"
      unitRef="pure">0.0184</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteLDE-PROS000062079AAR_A_ATD_loc"
      unitRef="pure">0.0190</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000062079_Cid_C000201028_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-7050">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-62533"
      unitRef="pure">0.0320</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-62534"
      unitRef="pure">0.0191</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Cid_C000201028_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteLDE-PROS000062079AAR_A_ATDS_loc"
      unitRef="pure">0.0189</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000062079_Indexid_IXXXY_contentCd_LDE-PRO_01"
      id="ixv-7067">
         Bloomberg US Treasury Bill: 6-9 Months Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Indexid_IXXXY_contentCd_LDE-PRO_01"
      decimals="4"
      id="ixv-62536"
      unitRef="pure">0.0415</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Indexid_IXXXY_contentCd_LDE-PRO_05"
      decimals="4"
      id="ixv-62537"
      unitRef="pure">0.0274</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Indexid_IXXXY_contentCd_LDE-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-62538"
      unitRef="pure">0.0247</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000062079_Indexid_IXQB0_contentCd_LDE-PRO_01"
      id="ixv-7092">
         Fidelity Low Duration Investment Grade Factor Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Indexid_IXQB0_contentCd_LDE-PRO_01"
      decimals="4"
      id="ixv-62539"
      unitRef="pure">0.0562</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Indexid_IXQB0_contentCd_LDE-PRO_05"
      decimals="4"
      id="ixv-62540"
      unitRef="pure">0.0352</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Indexid_IXQB0_contentCd_LDE-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-62541"
      unitRef="pure">0.0339</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000062079_Indexid_LB001_contentCd_LDE-PRO_01"
      id="ixv-7117">
         Bloomberg U.S. Aggregate Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Indexid_LB001_contentCd_LDE-PRO_01"
      decimals="4"
      id="ixv-62542"
      unitRef="pure">0.0730</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Indexid_LB001_contentCd_LDE-PRO_05"
      decimals="4"
      id="ixv-62543"
      unitRef="pure">-0.0036</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000062079_Indexid_LB001_contentCd_LDE-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-62544"
      unitRef="pure">0.0213</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000062079_Cid_C000201028" id="ixv-7159">2018-06-12</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8644">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; AAA CLO ETF 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8653">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8658">
     
       
     Fidelity&#xae; AAA CLO ETF seeks to generate income. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8663">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8669">
     
       
     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_S000099377_contentCd_ACLO-PRO"
      id="ixv-8680">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      decimals="0"
      id="ixv-62545"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8695">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000099377_Cid_C000269153"
      decimals="6"
      id="ixv-62546"
      unitRef="pure">0.0020</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000099377_Cid_C000269153"
      decimals="6"
      id="ixv-62547"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000099377_Cid_C000269153"
      decimals="6"
      id="ixv-62548"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000099377_Cid_C000269153"
      decimals="6"
      id="ixv-62549"
      unitRef="pure">0.0020</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8743">
     
       
      
       
     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_S000099377_Cid_C000269153"
      decimals="0"
      id="ixv-62550"
      unitRef="usd">20</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000099377_Cid_C000269153"
      decimals="0"
      id="ixv-62551"
      unitRef="usd">64</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000099377_Cid_C000269153"
      decimals="0"
      id="ixv-62552"
      unitRef="usd">113</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000099377_Cid_C000269153"
      decimals="0"
      id="ixv-62553"
      unitRef="usd">255</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8802">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8807">
     
       
     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. For the period from February 10, 2026 to August 31, 2026, the fund's portfolio turnover rate was 
       
     
       
       10 
       
       
     % (annualized) of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      decimals="4"
      id="ixv-62554"
      unitRef="pure">0.10</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8816">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-8821">
     
       
      
       
        Normally investing at least 80% of assets in collateralized loan obligations (CLOs) that are rated AAA. 
      
     AAA rated securities in which the fund invests include securities or issuers rated at least AAA 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. 
     CLOs are a type of asset-backed security. A CLO is typically collateralized by a pool of loans, which may include domestic and foreign senior secured loans, senior unsecured loans, and subordinate corporate loans, including loans that may be rated below investment grade or equivalent unrated loans, and including "covenant lite" loans, which have few or no financial maintenance covenants. CLOs may charge management fees and other expenses. Cash flows from the CLO are split into two or more portions, called tranches, which can vary in risk and yield. A CLO's more senior tranches are partially protected from defaults, typically have higher ratings and lower yields than their underlying securities and can be rated investment grade. More junior tranches offer the potential for higher yield but are more exposed to loss and have lower ratings. 
     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 J.P. Morgan CLOIE AAA Index. 
      Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Purchasing CLOs in both the primary market and the secondary market. 
      May also invest in other CLOs with a minimum rating of A-. 
      Investing no more than 10% of assets in fixed-rate CLOs. 
      Investing up to 25% in non-U.S. dollar-denominated CLOs and hedging the fund's foreign currency exposures utilizing forward foreign currency exchange contracts. 
      Investing in U.S. Treasury securities. The Adviser may also invest in cash or other short-term instruments, such as money market instruments or money market funds, while seeking to deploy new capital, or for liquidity management purposes, managing redemptions, or for defensive purposes, including navigating unusual market conditions. 
      Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_CollateralizedLoanObligationsRiskMember"
      id="ixv-8853">
     
       
      
      Collateralized Loan Obligations Risk. 
      
     The risks of investing in a CLO can be generally summarized as a combination of economic risks of the underlying loans and the risks associated with the CLO structure governing the priority of payments. The risks of investing in CLOs depend largely on the type of the collateral securities and the tranche of the CLO. In stressed market conditions, it is possible that even senior CLO debt tranches, such as those in which the fund will invest, could experience losses due to actual defaults, downgrades of the underlying collateral by rating agencies, forced liquidation of the collateral pool due to a failure of coverage tests, increased sensitivity to defaults due to collateral default and the disappearance of protecting tranches, market anticipation of defaults as well as investor aversion to CLO securities as an asset class. While the fund invests principally in CLO tranches that are rated AAA, such ratings do not constitute a guarantee of credit quality and may be downgraded. To the extent that the fund invests in CLO tranches rated below AAA, the risks of investing in CLOs will be greater. To the extent that the fund invests in unrated CLO tranches, the fund's ability to achieve its investment objective will be more dependent on the Adviser's credit analysis than would be the case when the fund invests in rated CLO tranches. The Adviser may not be able to accurately predict how specific CLOs or the portfolio of underlying loans for such CLOs will react to changes or stresses in the market, including changes in interest rates.  
     CLOs, and their underlying loan obligations, are typically not registered for sale to the public and therefore are subject to certain restrictions on transfer and sale, potentially making them less liquid than other types of securities. Because there may be relatively few potential purchasers for such securities, especially under adverse market or economic conditions or in the event of adverse changes in the financial condition of the issuer, the fund may find it more difficult to sell such securities when it may be advisable to do so or it may be able to sell such securities only at prices lower than if such securities were more widely held and traded. At times, it also may be more difficult to determine the fair value of such securities for purposes of computing the fund's net asset value due to the absence of an active trading market. &#160; 
     Additionally, newly issued CLO securities purchased in the primary market typically experience delayed or extended settlement periods, possibly longer than seven days. In the period following a purchase of CLO securities in the primary market and prior to settlement, these CLO securities may be considered less liquid than similar CLOs available in the secondary market. In such circumstances the fund bears a risk of loss if the value of the CLO declines before the settlement date or if the fund is required to sell the CLO security prior to settlement. There is also the risk that the security will not be issued or that the counterparty will not meet its obligation, resulting in a loss of the investment opportunity. The proceeds from the sale of CLO securities may not be readily available to make additional investments or to meet the fund's redemption obligations. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_CloManagerRiskMember"
      id="ixv-8867">
     
       
      
      CLO Manager Risk. 
      
     The CLOs in which the fund invests are managed by investment advisers independent of the Adviser. CLO managers are responsible for selecting, managing and replacing the underlying bank loans or bonds within a CLO. CLO managers may have limited operating histories and may be subject to conflicts of interests, including managing the assets of other clients or other investment vehicles, or receiving fees that incentivize maximizing the yield, and indirectly the risk, of a CLO. Adverse developments with respect to a CLO manager, such as personnel and resource constraints, regulatory issues or other developments that may impact the ability and/or performance of the CLO manager, may adversely impact the performance of the CLO securities in which the fund invests. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_ImpairmentOfCollateralMember"
      id="ixv-8876">
     
       
      
      Impairment of Collateral. 
      
     A floating rate loan may not be fully collateralized which may cause the floating rate loan to decline significantly in value. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_FloatingRateLoanLiquidityMember"
      id="ixv-8885">
     
       
      
      Floating Rate Loan Liquidity. 
      
     Floating rate loans generally are subject to restrictions on resale. Floating rate loans sometimes trade infrequently in the secondary market. As a result, valuing a floating rate loan can be more difficult, and buying and selling a floating rate loan at an acceptable price can be more difficult or delayed, including extended trade settlement periods. Difficulty in selling a floating rate loan can result in a loss. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-8894">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_ForeignExposureMember"
      id="ixv-8903">
     
       
      
      Foreign Exposure. 
      
     Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_ForeignCurrencyTransactionsMember"
      id="ixv-8912">
     
       
      
      Foreign Currency Transactions. 
      
     Although a forward foreign currency exchange contract is used to reduce or hedge a fund's exposure to changes in the value of the currency, suitable hedging transactions may not be available in all circumstances, may not be successful, and may eliminate any chance for the fund to benefit from favorable fluctuations in relevant foreign currencies. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_PrepaymentMember"
      id="ixv-8921">
     
       
      
      Prepayment. 
      
     The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-8930">
     
       
      
      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. 
     Investments in covenant-lite loans carry more risk than traditional loans as they allow issuers to engage in activities that would otherwise be difficult or impossible under a traditional loan agreement. In the event of default, covenant-lite obligations have lower recovery values as the lender may not have the opportunity to negotiate with the borrower prior to default. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_FluctuationOfNetAssetValueAndSharePriceMember"
      id="ixv-8943">
     
       
      
      Fluctuation of Net Asset Value and Share Price. 
      
     The net asset value per share (NAV) of the fund will generally fluctuate with changes in the market value of the fund's holdings. The fund's shares can be bought and sold in the secondary market at market prices. Disruptions to creations and redemptions, the existence of extreme market volatility or potential lack of an active trading market for the fund's shares may result in the fund's shares trading significantly above (at a premium) or below (at a discount) to NAV. 
     Given the nature of the relevant markets for certain of the fund's securities, shares may trade at a larger premium or discount to the NAV than shares of other ETFs. 
     In addition, in stressed market conditions or periods of market disruption or volatility,&#160;the market for shares may become less liquid in response to deteriorating liquidity in the markets for the fund's underlying portfolio holdings. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_TradingIssuesMember"
      id="ixv-8958">
     
       
      
      Trading Issues. 
      
     There can be no assurance that an active trading market will be maintained. Market makers and Authorized Participants are not obligated to make a market in the fund's shares or to submit purchase and redemption orders for creation units. Decisions by market makers or Authorized Participants to reduce their role with respect to market making or creation and redemption activities during times of market stress, or a decline in the number of Authorized Participants due to decisions to exit the business, bankruptcy, or other factors, could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying value of the fund's portfolio securities and the market price of fund shares. In addition, trading may be halted, for example, due to market conditions. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_LeverageRiskMember"
      id="ixv-8967">
     
       
      
      Leverage Risk. 
      
     Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_CashTransactionsRiskMember"
      id="ixv-8976">
     
       
      
      Cash Transactions Risk. 
      
     Unlike certain ETFs, the fund may effect some or all creations and redemptions using cash, rather than in-kind securities. As a result, an investment in the fund may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_RiskNondiversifiedStatusMember"
      id="ixv-8986">
     
       
     In addition, the fund is classified as non-diversified under the Investment Company Act of 1940 (1940 Act), which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund. 
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-8991">
     
       
     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_S000099377_contentCd_ACLO-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-8999">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-9008">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-9013">
     
       
      
       
      
        
      Performance history will be available for the fund after the fund has been in operation for one calendar year. 
        
      
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceOneYearOrLess
      contextRef="Pid_S000099377_contentCd_ACLO-PRO"
      id="ixv-9017"> 
        
      Performance history will be available for the fund after the fund has been in operation for one calendar year. 
        
     </oef:PerformanceOneYearOrLess>
    <oef:RiskReturnHeading
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10158">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Corporate Bond ETF 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10167">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10172">
     
       
     Fidelity&#xae; Corporate Bond ETF seeks a high level of current income. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10177">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10183">
     
       
     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_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10195">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      decimals="0"
      id="ixv-62555"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10210">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000040431_Cid_C000125598"
      decimals="6"
      id="ixv-62556"
      unitRef="pure">0.0036</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000040431_Cid_C000125598"
      decimals="6"
      id="ixv-62557"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000040431_Cid_C000125598"
      decimals="6"
      id="ixv-62558"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000040431_Cid_C000125598"
      decimals="6"
      id="ixv-62559"
      unitRef="pure">0.0036</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10257">
     
       
     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_S000040431_Cid_C000125598"
      decimals="0"
      id="ixv-62560"
      unitRef="usd">37</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000040431_Cid_C000125598"
      decimals="0"
      id="ixv-62561"
      unitRef="usd">116</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000040431_Cid_C000125598"
      decimals="0"
      id="ixv-62562"
      unitRef="usd">202</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000040431_Cid_C000125598"
      decimals="0"
      id="ixv-62563"
      unitRef="usd">456</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10314">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10319">
     
       
     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 
       
     
       
       38 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62564"
      unitRef="pure">0.38</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10328">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10333">
     
       
      
       
        Normally investing at least 80% of assets in corporate bonds and other corporate debt securities and repurchase agreements for those securities. 
      
     Corporate debt securities are bonds and other debt securities issued by corporations and other business structures to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Corporate debt securities include repurchase agreements with corporate counterparties and other securities, such as hybrids and synthetic securities, believed to have corporate debt-like characteristics, (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures). 
     A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 
     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 investing primarily in investment-grade corporate debt securities and repurchase agreements for those securities. 
      Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. Credit Bond Index. 
      Investing in domestic and foreign issuers. 
      Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Investing in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). 
      Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-10361">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO_RiskMember_ForeignExposureMember"
      id="ixv-10370">
     
       
      
      Foreign Exposure. 
      
     Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO_RiskMember_PrepaymentMember"
      id="ixv-10379">
     
       
      
      Prepayment. 
      
     The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-10388">
     
       
      
      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. 
     Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) involve greater risk of default or price changes due to changes in the credit quality of the issuer. The value of lower-quality debt securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO_RiskMember_FluctuationOfNetAssetValueAndSharePriceMember"
      id="ixv-10401">
     
       
      
      Fluctuation of Net Asset Value and Share Price. 
      
     The net asset value per share (NAV) of the fund will generally fluctuate with changes in the market value of the fund's holdings. The fund's shares can be bought and sold in the secondary market at market prices. Disruptions to creations and redemptions, the existence of extreme market volatility or potential lack of an active trading market for the fund's shares may result in the fund's shares trading significantly above (at a premium) or below (at a discount) to NAV. 
     Given the nature of the relevant markets for certain of the fund's securities, shares may trade at a larger premium or discount to the NAV than shares of other ETFs. 
     In addition, in stressed market conditions or periods of market disruption or volatility,&#160;the market for shares may become less liquid in response to deteriorating liquidity in the markets for the fund's underlying portfolio holdings. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO_RiskMember_TradingIssuesMember"
      id="ixv-10416">
     
       
      
      Trading Issues. 
      
     There can be no assurance that an active trading market will be maintained. Market makers and Authorized Participants are not obligated to make a market in the fund's shares or to submit purchase and redemption orders for creation units. Decisions by market makers or Authorized Participants to reduce their role with respect to market making or creation and redemption activities during times of market stress, or a decline in the number of Authorized Participants due to decisions to exit the business, bankruptcy, or other factors, could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying value of the fund's portfolio securities and the market price of fund shares. In addition, trading may be halted, for example, due to market conditions. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO_RiskMember_LeverageRiskMember"
      id="ixv-10425">
     
       
      
      Leverage Risk. 
      
     Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO_RiskMember_CashTransactionsRiskMember"
      id="ixv-10434">
     
       
      
      Cash Transactions Risk. 
      
     Unlike certain ETFs, the fund may effect some or all creations and redemptions using cash, rather than in-kind securities. As a result, an investment in the fund may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-10444">
     
       
     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_S000040431_contentCd_FIXETF-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-10452">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10461">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10466">
     
       
      
       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_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10472"> 
        
      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_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10481"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10487"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10492">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_2016"
      decimals="INF"
      id="ixv-62565"
      unitRef="pure">0.0753</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_2017"
      decimals="INF"
      id="ixv-62566"
      unitRef="pure">0.0599</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_2018"
      decimals="INF"
      id="ixv-62567"
      unitRef="pure">-0.0292</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_2019"
      decimals="INF"
      id="ixv-62568"
      unitRef="pure">0.1496</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_2020"
      decimals="INF"
      id="ixv-62569"
      unitRef="pure">0.1086</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_2021"
      decimals="INF"
      id="ixv-62570"
      unitRef="pure">-0.0100</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_2022"
      decimals="INF"
      id="ixv-62571"
      unitRef="pure">-0.1630</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_2023"
      decimals="INF"
      id="ixv-62572"
      unitRef="pure">0.0902</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_2024"
      decimals="INF"
      id="ixv-62573"
      unitRef="pure">0.0303</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_2025"
      decimals="INF"
      id="ixv-62574"
      unitRef="pure">0.0811</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10604">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62575"
      unitRef="pure">0.1071</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10614">2020-06-30</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10619">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62576"
      unitRef="pure">-0.0783</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10630">2022-06-30</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10635">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62577"
      unitRef="pure">-0.0334</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10646">2026-09-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10651">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10656">
     
       
      
        
      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_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10659"> 
        
      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_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10666"> 
        
      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_S000040431_contentCd_FIXETF-PRO"
      id="ixv-10671"> 
        
      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_S000040431_Cid_C000125598_ReturnBeforeTaxes_01"
      id="ixv-10716">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-62578"
      unitRef="pure">0.0811</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-62579"
      unitRef="pure">0.0013</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_ReturnBeforeTaxes_10"
      decimals="4"
      id="ixv-62580"
      unitRef="pure">0.0356</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000040431_Cid_C000125598_AfterTaxesOnDistributions_01"
      id="ixv-10731">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-62581"
      unitRef="pure">0.0614</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-62582"
      unitRef="pure">-0.0134</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_AfterTaxesOnDistributions_10"
      decimals="4"
      id="ixv-62583"
      unitRef="pure">0.0213</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000040431_Cid_C000125598_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-10747">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-62584"
      unitRef="pure">0.0476</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-62585"
      unitRef="pure">-0.0055</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Cid_C000125598_AfterTaxesOnDistributionsAndSales_10"
      decimals="4"
      id="ixv-62586"
      unitRef="pure">0.0212</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000040431_Indexid_LB004_contentCd_FIXETF-PRO_01"
      id="ixv-10764">
         Bloomberg U.S. Credit Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Indexid_LB004_contentCd_FIXETF-PRO_01"
      decimals="4"
      id="ixv-62587"
      unitRef="pure">0.0783</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Indexid_LB004_contentCd_FIXETF-PRO_05"
      decimals="4"
      id="ixv-62588"
      unitRef="pure">-0.0005</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Indexid_LB004_contentCd_FIXETF-PRO_10"
      decimals="4"
      id="ixv-62589"
      unitRef="pure">0.0315</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000040431_Indexid_LB001_contentCd_FIXETF-PRO_01"
      id="ixv-10790">
         Bloomberg U.S. Aggregate Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Indexid_LB001_contentCd_FIXETF-PRO_01"
      decimals="4"
      id="ixv-62590"
      unitRef="pure">0.0730</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Indexid_LB001_contentCd_FIXETF-PRO_05"
      decimals="4"
      id="ixv-62591"
      unitRef="pure">-0.0036</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000040431_Indexid_LB001_contentCd_FIXETF-PRO_10"
      decimals="4"
      id="ixv-62592"
      unitRef="pure">0.0201</oef:AvgAnnlRtrPct>
    <oef:RiskReturnHeading
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-10854">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Investment Grade Bond ETF 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-10863">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-10868">
     
       
     Fidelity&#xae; Investment Grade Bond ETF seeks a high level of current income. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-10873">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-10879">
     
       
     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_S000071131_contentCd_FIXETF-PRO"
      id="ixv-10891">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      decimals="0"
      id="ixv-62593"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-10906">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000071131_Cid_C000225826"
      decimals="6"
      id="ixv-62594"
      unitRef="pure">0.0036</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000071131_Cid_C000225826"
      decimals="6"
      id="ixv-62595"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000071131_Cid_C000225826"
      decimals="6"
      id="ixv-62596"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000071131_Cid_C000225826"
      decimals="6"
      id="ixv-62597"
      unitRef="pure">0.0036</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-10953">
     
       
     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_S000071131_Cid_C000225826"
      decimals="0"
      id="ixv-62598"
      unitRef="usd">37</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000071131_Cid_C000225826"
      decimals="0"
      id="ixv-62599"
      unitRef="usd">116</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000071131_Cid_C000225826"
      decimals="0"
      id="ixv-62600"
      unitRef="usd">202</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000071131_Cid_C000225826"
      decimals="0"
      id="ixv-62601"
      unitRef="usd">456</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11010">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11015">
     
       
     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 
       
     
       
       211 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62602"
      unitRef="pure">2.11</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11024">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11029">
     
       
      
       
        Normally investing at least 80% of assets in investment-grade debt securities (those of medium and high quality) of all types and repurchase agreements for those securities. 
      
     Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).&#160; 
     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. 
     A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 
     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 Bloomberg U.S. Aggregate Bond Index. 
      Allocating assets across different market sectors and maturities. 
      Investing in domestic and foreign issuers. 
      Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Investing in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). 
      Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-11060">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO_RiskMember_ForeignExposureMember"
      id="ixv-11069">
     
       
      
      Foreign Exposure. 
      
     Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO_RiskMember_PrepaymentMember"
      id="ixv-11078">
     
       
      
      Prepayment. 
      
     The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-11087">
     
       
      
      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. 
     Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) involve greater risk of default or price changes due to changes in the credit quality of the issuer. The value of lower-quality debt securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO_RiskMember_FluctuationOfNetAssetValueAndSharePriceMember"
      id="ixv-11100">
     
       
      
      Fluctuation of Net Asset Value and Share Price. 
      
     The net asset value per share (NAV) of the fund will generally fluctuate with changes in the market value of the fund's holdings. The fund's shares can be bought and sold in the secondary market at market prices. Disruptions to creations and redemptions, the existence of extreme market volatility or potential lack of an active trading market for the fund's shares may result in the fund's shares trading significantly above (at a premium) or below (at a discount) to NAV. 
     Given the nature of the relevant markets for certain of the fund's securities, shares may trade at a larger premium or discount to the NAV than shares of other ETFs. 
     In addition, in stressed market conditions or periods of market disruption or volatility,&#160;the market for shares may become less liquid in response to deteriorating liquidity in the markets for the fund's underlying portfolio holdings. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO_RiskMember_TradingIssuesMember"
      id="ixv-11115">
     
       
      
      Trading Issues. 
      
     There can be no assurance that an active trading market will be maintained. Market makers and Authorized Participants are not obligated to make a market in the fund's shares or to submit purchase and redemption orders for creation units. Decisions by market makers or Authorized Participants to reduce their role with respect to market making or creation and redemption activities during times of market stress, or a decline in the number of Authorized Participants due to decisions to exit the business, bankruptcy, or other factors, could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying value of the fund's portfolio securities and the market price of fund shares. In addition, trading may be halted, for example, due to market conditions. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO_RiskMember_LeverageRiskMember"
      id="ixv-11124">
     
       
      
      Leverage Risk. 
      
     Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO_RiskMember_CashTransactionsRiskMember"
      id="ixv-11133">
     
       
      
      Cash Transactions Risk. 
      
     Unlike certain ETFs, the fund may effect some or all creations and redemptions using cash, rather than in-kind securities. As a result, an investment in the fund may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO_RiskMember_HighPortfolioTurnoverMember"
      id="ixv-11142">
     
       
      
      High Portfolio Turnover. 
      
     High portfolio turnover (more than 100%) may result in increased transaction costs and potentially higher capital gains or losses. The effects of higher than normal portfolio turnover may adversely affect the fund's performance. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-11152">
     
       
     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_S000071131_contentCd_FIXETF-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-11160">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11169">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11174">
     
       
      
       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 over various periods of time. 
        
      
       
     The index description appears 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_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11180"> 
        
      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 over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11188"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11194"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11199">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000071131_Cid_C000225826_2022"
      decimals="INF"
      id="ixv-62603"
      unitRef="pure">-0.1360</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000071131_Cid_C000225826_2023"
      decimals="INF"
      id="ixv-62604"
      unitRef="pure">0.0642</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000071131_Cid_C000225826_2024"
      decimals="INF"
      id="ixv-62605"
      unitRef="pure">0.0140</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000071131_Cid_C000225826_2025"
      decimals="INF"
      id="ixv-62606"
      unitRef="pure">0.0725</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11291">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62607"
      unitRef="pure">0.0697</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11301">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11306">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62608"
      unitRef="pure">-0.0587</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11317">2022-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11322">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62609"
      unitRef="pure">-0.0308</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11333">2026-09-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11338">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11343">
     
       
      
        
      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_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11346"> 
        
      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_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11353"> 
        
      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_S000071131_contentCd_FIXETF-PRO"
      id="ixv-11358"> 
        
      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_S000071131_Cid_C000225826_ReturnBeforeTaxes_01"
      id="ixv-11396">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071131_Cid_C000225826_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-62610"
      unitRef="pure">0.0725</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071131_Cid_C000225826_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteFIXETF-PROS000071131AAR_A_RBT_loc"
      unitRef="pure">0.0029</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000071131_Cid_C000225826_AfterTaxesOnDistributions_01"
      id="ixv-11409">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071131_Cid_C000225826_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-62612"
      unitRef="pure">0.0543</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071131_Cid_C000225826_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteFIXETF-PROS000071131AAR_A_ATD_loc"
      unitRef="pure">-0.0103</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000071131_Cid_C000225826_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-11423">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071131_Cid_C000225826_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-62614"
      unitRef="pure">0.0426</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071131_Cid_C000225826_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteFIXETF-PROS000071131AAR_A_ATDS_loc"
      unitRef="pure">-0.0035</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000071131_Indexid_LB001_contentCd_FIXETF-PRO_01"
      id="ixv-11438">
         Bloomberg U.S. Aggregate Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071131_Indexid_LB001_contentCd_FIXETF-PRO_01"
      decimals="4"
      id="ixv-62616"
      unitRef="pure">0.0730</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071131_Indexid_LB001_contentCd_FIXETF-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-62617"
      unitRef="pure">0.0009</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000071131_Cid_C000225826" id="ixv-11470">2021-03-02</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11510">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Investment Grade Securitized ETF 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11519">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11524">
     
       
     Fidelity&#xae; Investment Grade Securitized ETF seeks a high level of current income. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11529">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11535">
     
       
     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_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11547">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      decimals="0"
      id="ixv-62618"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11562">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000071132_Cid_C000225827"
      decimals="6"
      id="ixv-62619"
      unitRef="pure">0.0036</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000071132_Cid_C000225827"
      decimals="6"
      id="ixv-62620"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000071132_Cid_C000225827"
      decimals="6"
      id="ixv-62621"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000071132_Cid_C000225827"
      decimals="6"
      id="ixv-62622"
      unitRef="pure">0.0036</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11609">
     
       
     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_S000071132_Cid_C000225827"
      decimals="0"
      id="ixv-62623"
      unitRef="usd">37</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000071132_Cid_C000225827"
      decimals="0"
      id="ixv-62624"
      unitRef="usd">116</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000071132_Cid_C000225827"
      decimals="0"
      id="ixv-62625"
      unitRef="usd">202</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000071132_Cid_C000225827"
      decimals="0"
      id="ixv-62626"
      unitRef="usd">456</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11666">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11671">
     
       
     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 
       
     
       
       620 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62627"
      unitRef="pure">6.20</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11680">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11685">
     
       
      
       
        Normally investing at least 80% of assets in investment-grade securitized debt securities (those of medium and high quality) and repurchase agreements for those securities. 
      Securitized debt securities are interests in pools of mortgages, loans, receivables, or other assets, and include such instruments as mortgage-backed securities, commercial mortgage-backed securities, and other asset-backed securities that are issued by the U.S. Government, its agencies or instrumentalities, foreign governments, financial institutions, trusts and corporations. Payment of principal or interest on securitized debt instruments generally depends on the cash flows generated by the underlying assets and may be supported by letters of credit, surety bonds, or other credit enhancements. 
      
     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. 
     A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 
     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. 
      
      Investing in U.S. Government securities issued by entities that are chartered or sponsored by Congress but whose securities are neither issued nor guaranteed by the U.S. Treasury. 
      Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. Securitized Index. 
      Allocating assets across different market sectors and maturities. 
      Investing in domestic and foreign issuers. 
      Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Investing in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). 
      Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-11719">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_ForeignExposureMember"
      id="ixv-11728">
     
       
      
      Foreign Exposure. 
      
     Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_SecuritizedDebtSecuritiesExposureMember"
      id="ixv-11737">
     
       
      
      Securitized Debt Securities Exposure. 
      
     Securitized debt securities are dependent on the cash flows generated by the underlying assets and can be significantly affected by changes in interest rates, the availability of information concerning the underlying assets and their structure, and the creditworthiness of the originators of the loans or other receivables or the entities providing credit support. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_PrepaymentMember"
      id="ixv-11746">
     
       
      
      Prepayment. 
      
     The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-11755">
     
       
      
      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. 
     Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) involve greater risk of default or price changes due to changes in the credit quality of the issuer. The value of lower-quality debt securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_USGovernmentObligationsRiskMember"
      id="ixv-11768">
     
       
      
      U.S. Government Obligations Risk. 
      
     Certain securities in which the fund may invest, including securities issued by certain U.S. Government agencies and U.S. Government sponsored enterprises, are not guaranteed by the U.S. Government or supported by the full faith and credit of the United States. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_FluctuationOfNetAssetValueAndSharePriceMember"
      id="ixv-11777">
     
       
      
      Fluctuation of Net Asset Value and Share Price. 
      
     The net asset value per share (NAV) of the fund will generally fluctuate with changes in the market value of the fund's holdings. The fund's shares can be bought and sold in the secondary market at market prices. Disruptions to creations and redemptions, the existence of extreme market volatility or potential lack of an active trading market for the fund's shares may result in the fund's shares trading significantly above (at a premium) or below (at a discount) to NAV. 
     Given the nature of the relevant markets for certain of the fund's securities, shares may trade at a larger premium or discount to the NAV than shares of other ETFs. 
     In addition, in stressed market conditions or periods of market disruption or volatility,&#160;the market for shares may become less liquid in response to deteriorating liquidity in the markets for the fund's underlying portfolio holdings. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_TradingIssuesMember"
      id="ixv-11792">
     
       
      
      Trading Issues. 
      
     There can be no assurance that an active trading market will be maintained. Market makers and Authorized Participants are not obligated to make a market in the fund's shares or to submit purchase and redemption orders for creation units. Decisions by market makers or Authorized Participants to reduce their role with respect to market making or creation and redemption activities during times of market stress, or a decline in the number of Authorized Participants due to decisions to exit the business, bankruptcy, or other factors, could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying value of the fund's portfolio securities and the market price of fund shares. In addition, trading may be halted, for example, due to market conditions. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_LeverageRiskMember"
      id="ixv-11801">
     
       
      
      Leverage Risk. 
      
     Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_CashTransactionsRiskMember"
      id="ixv-11810">
     
       
      
      Cash Transactions Risk. 
      
     Unlike certain ETFs, the fund may effect some or all creations and redemptions using cash, rather than in-kind securities. As a result, an investment in the fund may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_HighPortfolioTurnoverMember"
      id="ixv-11819">
     
       
      
      High Portfolio Turnover. 
      
     High portfolio turnover (more than 100%) may result in increased transaction costs and potentially higher capital gains or losses. The effects of higher than normal portfolio turnover may adversely affect the fund's performance. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-11829">
     
       
     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_S000071132_contentCd_FIXETF-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-11837">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11846">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11851">
     
       
      
       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_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11857"> 
        
      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_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11867"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11873"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11878">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000071132_Cid_C000225827_2022"
      decimals="INF"
      id="ixv-62628"
      unitRef="pure">-0.1257</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000071132_Cid_C000225827_2023"
      decimals="INF"
      id="ixv-62629"
      unitRef="pure">0.0541</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000071132_Cid_C000225827_2024"
      decimals="INF"
      id="ixv-62630"
      unitRef="pure">0.0204</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000071132_Cid_C000225827_2025"
      decimals="INF"
      id="ixv-62631"
      unitRef="pure">0.0839</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11970">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62632"
      unitRef="pure">0.0749</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11980">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11985">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62633"
      unitRef="pure">-0.0534</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-11996">2022-09-30</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-12001">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62634"
      unitRef="pure">-0.0283</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-12012">2026-09-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-12017">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000071132_contentCd_FIXETF-PRO"
      id="ixv-12022">
     
       
      
        
      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_S000071132_contentCd_FIXETF-PRO"
      id="ixv-12025"> 
        
      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_S000071132_contentCd_FIXETF-PRO"
      id="ixv-12032"> 
        
      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_S000071132_contentCd_FIXETF-PRO"
      id="ixv-12037"> 
        
      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_S000071132_Cid_C000225827_ReturnBeforeTaxes_01"
      id="ixv-12075">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071132_Cid_C000225827_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-62635"
      unitRef="pure">0.0839</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071132_Cid_C000225827_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteFIXETF-PROS000071132AAR_A_RBT_loc"
      unitRef="pure">0.0029</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000071132_Cid_C000225827_AfterTaxesOnDistributions_01"
      id="ixv-12088">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071132_Cid_C000225827_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-62637"
      unitRef="pure">0.0653</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071132_Cid_C000225827_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteFIXETF-PROS000071132AAR_A_ATD_loc"
      unitRef="pure">-0.0078</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000071132_Cid_C000225827_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-12102">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071132_Cid_C000225827_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-62639"
      unitRef="pure">0.0494</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071132_Cid_C000225827_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteFIXETF-PROS000071132AAR_A_ATDS_loc"
      unitRef="pure">-0.0025</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000071132_Indexid_LB371_contentCd_FIXETF-PRO_01"
      id="ixv-12117">
         Bloomberg U.S. Securitized Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071132_Indexid_LB371_contentCd_FIXETF-PRO_01"
      decimals="4"
      id="ixv-62641"
      unitRef="pure">0.0849</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071132_Indexid_LB371_contentCd_FIXETF-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-62642"
      unitRef="pure">0.0032</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000071132_Indexid_LB001_contentCd_FIXETF-PRO_01"
      id="ixv-12136">
         Bloomberg U.S. Aggregate Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071132_Indexid_LB001_contentCd_FIXETF-PRO_01"
      decimals="4"
      id="ixv-62643"
      unitRef="pure">0.0730</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000071132_Indexid_LB001_contentCd_FIXETF-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-62644"
      unitRef="pure">0.0009</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000071132_Cid_C000225827" id="ixv-12168">2021-03-02</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12199">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Limited Term Bond ETF 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12208">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12213">
     
       
     Fidelity&#xae; Limited Term Bond ETF seeks to provide a high rate of income. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12218">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12224">
     
       
     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_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12236">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      decimals="0"
      id="ixv-62645"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12251">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000042569_Cid_C000131661"
      decimals="6"
      id="ixv-62646"
      unitRef="pure">0.0025</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000042569_Cid_C000131661"
      decimals="6"
      id="ixv-62647"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000042569_Cid_C000131661"
      decimals="6"
      id="ixv-62648"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000042569_Cid_C000131661"
      decimals="6"
      id="ixv-62649"
      unitRef="pure">0.0025</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12298">
     
       
     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_S000042569_Cid_C000131661"
      decimals="0"
      id="ixv-62650"
      unitRef="usd">26</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000042569_Cid_C000131661"
      decimals="0"
      id="ixv-62651"
      unitRef="usd">80</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000042569_Cid_C000131661"
      decimals="0"
      id="ixv-62652"
      unitRef="usd">141</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000042569_Cid_C000131661"
      decimals="0"
      id="ixv-62653"
      unitRef="usd">318</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12355">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12360">
     
       
     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 
       
     
       
       77 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62654"
      unitRef="pure">0.77</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12369">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12374">
     
       
      
       
        Normally investing at least 80% of assets in debt securities of all types and repurchase agreements for those securities. 
      
      
      Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).&#160; 
      
     A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 
     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. 
      
      Allocating the fund's assets across investment-grade, high yield, and emerging markets debt securities. Using the Fidelity Limited Term Composite Index&#x2120; as a guide in allocating assets across the investment-grade and high yield asset classes. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. 
      Investing up to  
        30% of assets in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). 
      Normally maintaining a dollar-weighted average maturity between two and five years. 
      
      
      Managing the fund to have similar overall interest rate risk to the index. 
      Investing in domestic and foreign issuers. 
      
      
      Allocating assets across different asset classes, market sectors, and maturities. 
      
      
      Investing in collateralized loan obligations (CLO). 
      
      
      Analyzing the credit quality of the issuer, the issuer's potential for success, the credit, currency, and economic risks of the security and its issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-12419">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO_RiskMember_ForeignExposureMember"
      id="ixv-12428">
     
       
      
      Foreign Exposure. 
      
     Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. 
     Foreign exchange rates also can be extremely volatile. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO_RiskMember_PrepaymentMember"
      id="ixv-12439">
     
       
      
      Prepayment. 
      
     The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-12448">
     
       
      
      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. 
     Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) involve greater risk of default or price changes due to changes in the credit quality of the issuer. The value of lower-quality debt securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments. 
     CLO tranches can experience substantial losses due to actual and anticipated defaults, as well as aversion to CLO securities as a class. 
     Investments in covenant-lite loans carry more risk than traditional loans as they allow issuers to engage in activities that would otherwise be difficult or impossible under a traditional loan agreement. In the event of default, covenant-lite obligations have lower recovery values as the lender may not have the opportunity to negotiate with the borrower prior to default. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO_RiskMember_FluctuationOfNetAssetValueAndSharePriceMember"
      id="ixv-12465">
     
       
      
      Fluctuation of Net Asset Value and Share Price. 
      
     The net asset value per share (NAV) of the fund will generally fluctuate with changes in the market value of the fund's holdings. The fund's shares can be bought and sold in the secondary market at market prices. Disruptions to creations and redemptions, the existence of extreme market volatility or potential lack of an active trading market for the fund's shares may result in the fund's shares trading significantly above (at a premium) or below (at a discount) to NAV. 
     Given the nature of the relevant markets for certain of the fund's securities, shares may trade at a larger premium or discount to the NAV than shares of other ETFs. 
     In addition, in stressed market conditions or periods of market disruption or volatility,&#160;the market for shares may become less liquid in response to deteriorating liquidity in the markets for the fund's underlying portfolio holdings. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO_RiskMember_TradingIssuesMember"
      id="ixv-12480">
     
       
      
      Trading Issues. 
      
     There can be no assurance that an active trading market will be maintained. Market makers and Authorized Participants are not obligated to make a market in the fund's shares or to submit purchase and redemption orders for creation units. Decisions by market makers or Authorized Participants to reduce their role with respect to market making or creation and redemption activities during times of market stress, or a decline in the number of Authorized Participants due to decisions to exit the business, bankruptcy, or other factors, could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying value of the fund's portfolio securities and the market price of fund shares. In addition, trading may be halted, for example, due to market conditions. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO_RiskMember_LeverageRiskMember"
      id="ixv-12489">
     
       
      
      Leverage Risk. 
      
     Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO_RiskMember_CashTransactionsRiskMember"
      id="ixv-12498">
     
       
      
      Cash Transactions Risk. 
      
     Unlike certain ETFs, the fund may effect some or all creations and redemptions using cash, rather than in-kind securities. As a result, an investment in the fund may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-12508">
     
       
     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_S000042569_contentCd_FIXETF-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-12516">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12525">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12530">
     
       
      
       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, an additional index, 
        
      and a hypothetical composite of market indexes over various periods of time. 
        
      
       
     The additional index and hypothetical composite of market indexes 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_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12536"> 
        
      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, an additional index, 
        
      and a hypothetical composite of market indexes over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12545"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12551"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12556">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_2016"
      decimals="INF"
      id="ixv-62655"
      unitRef="pure">0.0229</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_2017"
      decimals="INF"
      id="ixv-62656"
      unitRef="pure">0.0185</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_2018"
      decimals="INF"
      id="ixv-62657"
      unitRef="pure">0.0088</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_2019"
      decimals="INF"
      id="ixv-62658"
      unitRef="pure">0.0613</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_2020"
      decimals="INF"
      id="ixv-62659"
      unitRef="pure">0.0531</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_2021"
      decimals="INF"
      id="ixv-62660"
      unitRef="pure">-0.0107</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_2022"
      decimals="INF"
      id="ixv-62661"
      unitRef="pure">-0.0592</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_2023"
      decimals="INF"
      id="ixv-62662"
      unitRef="pure">0.0600</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_2024"
      decimals="INF"
      id="ixv-62663"
      unitRef="pure">0.0503</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_2025"
      decimals="INF"
      id="ixv-62664"
      unitRef="pure">0.0671</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12667">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62665"
      unitRef="pure">0.0501</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12677">2020-06-30</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12682">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62666"
      unitRef="pure">-0.0367</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12693">2022-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12698">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62667"
      unitRef="pure">-0.0005</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12709">2026-09-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12714">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12719">
     
       
      
        
      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_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12722"> 
        
      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_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12729"> 
        
      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_S000042569_contentCd_FIXETF-PRO"
      id="ixv-12734"> 
        
      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_S000042569_Cid_C000131661_ReturnBeforeTaxes_01"
      id="ixv-12779">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-62668"
      unitRef="pure">0.0671</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-62669"
      unitRef="pure">0.0203</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_ReturnBeforeTaxes_10"
      decimals="4"
      id="ixv-62670"
      unitRef="pure">0.0265</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042569_Cid_C000131661_AfterTaxesOnDistributions_01"
      id="ixv-12794">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-62671"
      unitRef="pure">0.0484</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-62672"
      unitRef="pure">0.0086</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_AfterTaxesOnDistributions_10"
      decimals="4"
      id="ixv-62673"
      unitRef="pure">0.0163</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042569_Cid_C000131661_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-12809">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-62674"
      unitRef="pure">0.0394</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-62675"
      unitRef="pure">0.0104</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Cid_C000131661_AfterTaxesOnDistributionsAndSales_10"
      decimals="4"
      id="ixv-62676"
      unitRef="pure">0.0158</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042569_Indexid_LB087_contentCd_FIXETF-PRO_01"
      id="ixv-12825">
         Bloomberg U.S. 1-5 Year Government/Credit Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Indexid_LB087_contentCd_FIXETF-PRO_01"
      decimals="4"
      id="ixv-62677"
      unitRef="pure">0.0611</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Indexid_LB087_contentCd_FIXETF-PRO_05"
      decimals="4"
      id="ixv-62678"
      unitRef="pure">0.0156</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Indexid_LB087_contentCd_FIXETF-PRO_10"
      decimals="4"
      id="ixv-62679"
      unitRef="pure">0.0217</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042569_Indexid_F1871_contentCd_FIXETF-PRO_01"
      id="ixv-12850">
         Fidelity Limited Term Composite Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Indexid_F1871_contentCd_FIXETF-PRO_01"
      decimals="4"
      id="ixv-62680"
      unitRef="pure">0.0667</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Indexid_F1871_contentCd_FIXETF-PRO_05"
      decimals="4"
      id="ixv-62681"
      unitRef="pure">0.0203</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Indexid_F1871_contentCd_FIXETF-PRO_10"
      decimals="4"
      id="ixv-62682"
      unitRef="pure">0.0267</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042569_Indexid_LB001_contentCd_FIXETF-PRO_01"
      id="ixv-12875">
         Bloomberg U.S. Aggregate Bond Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Indexid_LB001_contentCd_FIXETF-PRO_01"
      decimals="4"
      id="ixv-62683"
      unitRef="pure">0.0730</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Indexid_LB001_contentCd_FIXETF-PRO_05"
      decimals="4"
      id="ixv-62684"
      unitRef="pure">-0.0036</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042569_Indexid_LB001_contentCd_FIXETF-PRO_10"
      decimals="4"
      id="ixv-62685"
      unitRef="pure">0.0201</oef:AvgAnnlRtrPct>
    <oef:RiskReturnHeading
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-12949">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Total Bond ETF 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-12958">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-12963">
     
       
     Fidelity&#xae; Total Bond ETF seeks a high level of current income. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-12968">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-12974">
     
       
     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_S000042567_contentCd_FIXETF-PRO"
      id="ixv-12986">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      decimals="0"
      id="ixv-62686"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13001">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000042567_Cid_C000131659"
      decimals="6"
      id="ixv-62687"
      unitRef="pure">0.0036</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000042567_Cid_C000131659"
      decimals="6"
      id="ixv-62688"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000042567_Cid_C000131659"
      decimals="6"
      id="ixv-62689"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000042567_Cid_C000131659"
      decimals="6"
      id="ixv-62690"
      unitRef="pure">0.0036</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13048">
     
       
     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_S000042567_Cid_C000131659"
      decimals="0"
      id="ixv-62691"
      unitRef="usd">37</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000042567_Cid_C000131659"
      decimals="0"
      id="ixv-62692"
      unitRef="usd">116</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000042567_Cid_C000131659"
      decimals="0"
      id="ixv-62693"
      unitRef="usd">202</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000042567_Cid_C000131659"
      decimals="0"
      id="ixv-62694"
      unitRef="usd">456</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13105">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13110">
     
       
     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 
       
     
       
       157 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62695"
      unitRef="pure">1.57</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13119">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13124">
     
       
      
       
        Normally investing at least 80% of assets in debt securities of all types and repurchase agreements for those securities. 
      
     Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).&#160; 
     A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 
     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. 
      
      Allocating assets across investment-grade, high yield, and emerging markets debt securities. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. 
      Investing up to 20% of assets in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). 
      Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. Aggregate Bond Index. 
      Investing in domestic and foreign issuers. 
      Allocating assets across different asset classes, market sectors, and maturities. 
      Analyzing the credit quality of the issuer, the issuer's potential for success, the credit, currency, and economic risks of the security and its issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 
      Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO_RiskMember_InterestRateChangesMember"
      id="ixv-13155">
     
       
      
      Interest Rate Changes. 
      
     Interest rate increases can cause the price of a debt security to decrease. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO_RiskMember_ForeignExposureMember"
      id="ixv-13164">
     
       
      
      Foreign Exposure. 
      
     Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. 
     Foreign exchange rates also can be extremely volatile. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO_RiskMember_PrepaymentMember"
      id="ixv-13175">
     
       
      
      Prepayment. 
      
     The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-13184">
     
       
      
      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. 
     Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) and certain types of other securities involve greater risk of default or price changes due to changes in the credit quality of the issuer. 
     The value of lower-quality debt securities and certain types of other securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments and can be difficult to resell. 
     Investments in covenant-lite loans carry more risk than traditional loans as they allow issuers to engage in activities that would otherwise be difficult or impossible under a traditional loan agreement. In the event of default, covenant-lite obligations have lower recovery values as the lender may not have the opportunity to negotiate with the borrower prior to default. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO_RiskMember_FluctuationOfNetAssetValueAndSharePriceMember"
      id="ixv-13201">
     
       
      
      Fluctuation of Net Asset Value and Share Price. 
      
     The net asset value per share (NAV) of the fund will generally fluctuate with changes in the market value of the fund's holdings. The fund's shares can be bought and sold in the secondary market at market prices. Disruptions to creations and redemptions, the existence of extreme market volatility or potential lack of an active trading market for the fund's shares may result in the fund's shares trading significantly above (at a premium) or below (at a discount) to NAV. 
     Given the nature of the relevant markets for certain of the fund's securities, shares may trade at a larger premium or discount to the NAV than shares of other ETFs. 
     In addition, in stressed market conditions or periods of market disruption or volatility,&#160;the market for shares may become less liquid in response to deteriorating liquidity in the markets for the fund's underlying portfolio holdings. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO_RiskMember_TradingIssuesMember"
      id="ixv-13216">
     
       
      
      Trading Issues. 
      
     There can be no assurance that an active trading market will be maintained. Market makers and Authorized Participants are not obligated to make a market in the fund's shares or to submit purchase and redemption orders for creation units. Decisions by market makers or Authorized Participants to reduce their role with respect to market making or creation and redemption activities during times of market stress, or a decline in the number of Authorized Participants due to decisions to exit the business, bankruptcy, or other factors, could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying value of the fund's portfolio securities and the market price of fund shares. In addition, trading may be halted, for example, due to market conditions. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO_RiskMember_LeverageRiskMember"
      id="ixv-13225">
     
       
      
      Leverage Risk. 
      
     Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO_RiskMember_CashTransactionsRiskMember"
      id="ixv-13234">
     
       
      
      Cash Transactions Risk. 
      
     Unlike certain ETFs, the fund may effect some or all creations and redemptions using cash, rather than in-kind securities. As a result, an investment in the fund may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO_RiskMember_HighPortfolioTurnoverMember"
      id="ixv-13243">
     
       
      
      High Portfolio Turnover. 
      
     High portfolio turnover (more than 100%) may result in increased transaction costs and potentially higher capital gains or losses. The effects of higher than normal portfolio turnover may adversely affect the fund's performance. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-13253">
     
       
     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_S000042567_contentCd_FIXETF-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-13261">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13270">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13275">
     
       
      
       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  
       
        
      over various periods of time. 
        
      
       
     The  
      
       
     index  
      
       
     description appears 
      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_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13281"> 
        
      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  
       
        
      over various periods of time. 
        
     </oef:PerformanceInformationIllustratesVariabilityOfReturns>
    <oef:PerformancePastDoesNotIndicateFuture
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13295"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13301"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13306">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_2016"
      decimals="INF"
      id="ixv-62696"
      unitRef="pure">0.0664</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_2017"
      decimals="INF"
      id="ixv-62697"
      unitRef="pure">0.0407</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_2018"
      decimals="INF"
      id="ixv-62698"
      unitRef="pure">-0.0067</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_2019"
      decimals="INF"
      id="ixv-62699"
      unitRef="pure">0.0990</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_2020"
      decimals="INF"
      id="ixv-62700"
      unitRef="pure">0.0951</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_2021"
      decimals="INF"
      id="ixv-62701"
      unitRef="pure">-0.0035</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_2022"
      decimals="INF"
      id="ixv-62702"
      unitRef="pure">-0.1273</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_2023"
      decimals="INF"
      id="ixv-62703"
      unitRef="pure">0.0684</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_2024"
      decimals="INF"
      id="ixv-62704"
      unitRef="pure">0.0236</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_2025"
      decimals="INF"
      id="ixv-62705"
      unitRef="pure">0.0758</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13418">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62706"
      unitRef="pure">0.0685</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13428">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13433">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62707"
      unitRef="pure">-0.0597</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13444">2022-06-30</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13449">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      decimals="4"
      id="ixv-62708"
      unitRef="pure">-0.0271</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13460">2026-09-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13465">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13470">
     
       
      
        
      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_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13473"> 
        
      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_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13480"> 
        
      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_S000042567_contentCd_FIXETF-PRO"
      id="ixv-13485"> 
        
      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_S000042567_Cid_C000131659_ReturnBeforeTaxes_01"
      id="ixv-13530">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-62709"
      unitRef="pure">0.0758</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-62710"
      unitRef="pure">0.0046</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_ReturnBeforeTaxes_10"
      decimals="4"
      id="ixv-62711"
      unitRef="pure">0.0310</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042567_Cid_C000131659_AfterTaxesOnDistributions_01"
      id="ixv-13545">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-62712"
      unitRef="pure">0.0553</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-62713"
      unitRef="pure">-0.0105</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000042567_Cid_C000131659_AfterTaxesOnDistributions_10"
      decimals="4"
      id="ixv-62714"
      unitRef="pure">0.0169</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000042567_Cid_C000131659_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-13561">
         Return After Taxes on Distributions and Sale of Fund Shares
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    <oef:AvgAnnlRtrPct
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