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    <oef:RiskReturnHeading contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-214">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; SAI Small-Mid Cap Momentum Index Fund 
      
    
   </oef:RiskReturnHeading>
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     Investment Objective 
       
    
   </oef:ObjectiveHeading>
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     Fidelity&#xae; SAI Small-Mid Cap Momentum Index Fund seeks to provide investment results that correspond to the total return of small- to mid-capitalization stocks with high momentum characteristics. 
       
    
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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. 
    
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     Shareholder fees 
       
    
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      decimals="0"
      id="ixv-51444"
      unitRef="usd">0</oef:ShareholderFeeOther>
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     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
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      contextRef="Pid_S000050321_Cid_C000158877"
      decimals="6"
      id="ixv-51445"
      unitRef="pure">0.0011</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000050321_Cid_C000158877"
      decimals="6"
      id="ixv-51446"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000050321_Cid_C000158877"
      decimals="6"
      id="ixv-51447"
      unitRef="pure">0.0001</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000050321_Cid_C000158877"
      decimals="6"
      id="ixv-51448"
      unitRef="pure">0.0012</oef:ExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000050321_Cid_C000158877"
      decimals="6"
      id="footnoteS000050321SV3-PROAOE_AC000158877_FW"
      unitRef="pure">-0.0007</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000050321_Cid_C000158877"
      decimals="6"
      id="ixv-51450"
      unitRef="pure">0.0005</oef:NetExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-341">2027-11-30</oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination>
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     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_S000050321_Cid_C000158877"
      decimals="0"
      id="ixv-51451"
      unitRef="usd">5</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000050321_Cid_C000158877"
      decimals="0"
      id="ixv-51452"
      unitRef="usd">29</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000050321_Cid_C000158877"
      decimals="0"
      id="ixv-51453"
      unitRef="usd">58</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000050321_Cid_C000158877"
      decimals="0"
      id="ixv-51454"
      unitRef="usd">144</oef:ExpenseExampleYear10>
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     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
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     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 
      
       
       
     
       
       180 
       
       
     % of the average value of its portfolio. 
       
    
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      decimals="4"
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      unitRef="pure">1.80</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-420">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
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      Normally investing at least 80% of assets in securities included in the Fidelity U.S. Small-Mid Cap Momentum Focus IndexSM. 
      
     The Fidelity U.S. Small-Mid Cap Momentum Focus Index SM is designed to reflect a well-diversified portfolio that invests in companies based on price and earnings momentum metrics. It is a subset of the Fidelity U.S. Extended Investable Market Index SM , a float-adjusted market capitalization-weighted index designed to reflect the performance of U.S. mid- and small-cap stocks. The Fidelity U.S. Extended Investable Market Index SM is a subset of the Fidelity U.S. Total Investable Market Index SM , excluding the 500 largest companies. For purposes of this fund, small- and mid-capitalization stocks are considered to be stocks whose market capitalization is similar to the market capitalization of companies in the Russell Extended Market Index, which consists of securities included in the Russell 3000 &#xae; Index, excluding the top 500 largest stocks.  
     The Fidelity U.S. Small-Mid Cap Momentum Focus Index SM &#160;was created by Fidelity Product Services LLC (FPS) using a rules-based proprietary index methodology that includes all U.S. stocks meeting certain market capitalization, liquidity and investability requirements. 
     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. 
      
      Primarily using replication; however, the fund may or may not hold all of the securities in the index. 
      Lending securities to earn income for the fund. 
      
    
   </oef:StrategyNarrativeTextBlock>
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      Stock Market Volatility. 
      
     Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000050321_contentCd_SV3-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-481">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000050321_contentCd_SV3-PRO_RiskMember_CorrelationToIndexMember"
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      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_S000050321_contentCd_SV3-PRO_RiskMember_PassiveManagementRiskMember"
      id="ixv-504">
     
       
      
      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_S000050321_contentCd_SV3-PRO_RiskMember_RulesBasedStrategyRiskMember"
      id="ixv-515">
     
       
      
      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; 
    
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    <oef:RiskTextBlock
      contextRef="Pid_S000050321_contentCd_SV3-PRO_RiskMember_SmallAndMidCapInvestingMember"
      id="ixv-525">
     
       
      
      Small- and Mid-Cap Investing. 
      
     The value of securities of small to medium size, less well-known issuers can perform differently from the market as a whole and other types of stocks and can be more volatile than that of larger issuers. 
    
   </oef:RiskTextBlock>
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      Momentum Securities Risk. 
      
     Although the fund's underlying index uses a rules-based proprietary index methodology that is designed to identify stocks that exhibit positive momentum signals, there is no guarantee that this methodology will be successful. Stocks that previously exhibited high momentum characteristics may not experience positive momentum or may experience more volatility than the market as a whole. 
    
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      Securities Lending Risk. 
      
     Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000050321_contentCd_SV3-PRO_RiskMember_HighPortfolioTurnoverMember"
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      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_S000050321_contentCd_SV3-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-561">
     
       
     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_S000050321_contentCd_SV3-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-569">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-576">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-581">
     
       
     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. 
        
      
     Prior to December 22, 2025, the fund compared its performance to a different benchmark. The fund's historical performance may not represent its current investment policies. 
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-586"> 
        
      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_S000050321_contentCd_SV3-PRO" id="ixv-593"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-601"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-606">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_2016"
      decimals="INF"
      id="ixv-51456"
      unitRef="pure">0.1462</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_2017"
      decimals="INF"
      id="ixv-51457"
      unitRef="pure">0.1840</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_2018"
      decimals="INF"
      id="ixv-51458"
      unitRef="pure">-0.0925</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_2019"
      decimals="INF"
      id="ixv-51459"
      unitRef="pure">0.2953</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_2020"
      decimals="INF"
      id="ixv-51460"
      unitRef="pure">0.1977</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_2021"
      decimals="INF"
      id="ixv-51461"
      unitRef="pure">0.2092</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_2022"
      decimals="INF"
      id="ixv-51462"
      unitRef="pure">-0.1673</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_2023"
      decimals="INF"
      id="ixv-51463"
      unitRef="pure">0.1775</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_2024"
      decimals="INF"
      id="ixv-51464"
      unitRef="pure">0.1232</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_2025"
      decimals="INF"
      id="ixv-51465"
      unitRef="pure">0.1133</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-717">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000050321_contentCd_SV3-PRO"
      decimals="4"
      id="ixv-51466"
      unitRef="pure">0.2727</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-727">2020-06-30</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-732">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000050321_contentCd_SV3-PRO"
      decimals="4"
      id="ixv-51467"
      unitRef="pure">-0.2906</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-743">2020-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-748">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000050321_contentCd_SV3-PRO"
      decimals="4"
      id="ixv-51468"
      unitRef="pure">0.3772</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-758">2026-06-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-764">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-769">
     
       
      
        
      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_S000050321_contentCd_SV3-PRO" id="ixv-772"> 
        
      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_S000050321_contentCd_SV3-PRO" id="ixv-779"> 
        
      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_S000050321_contentCd_SV3-PRO" id="ixv-784"> 
        
      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_S000050321_Cid_C000158877_ReturnBeforeTaxes_01"
      id="ixv-830">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-51469"
      unitRef="pure">0.1133</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-51470"
      unitRef="pure">0.0819</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_ReturnBeforeTaxes_10"
      decimals="4"
      id="ixv-51471"
      unitRef="pure">0.1097</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000050321_Cid_C000158877_AfterTaxesOnDistributions_01"
      id="ixv-845">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-51472"
      unitRef="pure">0.0141</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-51473"
      unitRef="pure">0.0161</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_AfterTaxesOnDistributions_10"
      decimals="4"
      id="ixv-51474"
      unitRef="pure">0.0688</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000050321_Cid_C000158877_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-860">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-51475"
      unitRef="pure">0.1354</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-51476"
      unitRef="pure">0.0555</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Cid_C000158877_AfterTaxesOnDistributionsAndSales_10"
      decimals="4"
      id="ixv-51477"
      unitRef="pure">0.0830</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000050321_Indexid_IXRAQ_contentCd_SV3-PRO_01"
      id="ixv-876">
         Fidelity SAI Small-Mid Cap Linked Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_IXRAQ_contentCd_SV3-PRO_01"
      decimals="4"
      id="ixv-51478"
      unitRef="pure">0.1129</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_IXRAQ_contentCd_SV3-PRO_05"
      decimals="4"
      id="ixv-51479"
      unitRef="pure">0.0818</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_IXRAQ_contentCd_SV3-PRO_10"
      decimals="4"
      id="ixv-51480"
      unitRef="pure">0.1101</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000050321_Indexid_IXR15_contentCd_SV3-PRO_01"
      id="ixv-901">
         Fidelity U.S. Small-Mid Cap Momentum Focus Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_IXR15_contentCd_SV3-PRO_01"
      id="footnoteSV3-PROS000050321AAR_A_BM_1_01"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_IXR15_contentCd_SV3-PRO_05"
      id="footnoteSV3-PROS000050321AAR_A_BM_1_05"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_IXR15_contentCd_SV3-PRO_10"
      id="footnoteSV3-PROS000050321AAR_A_BM_1_10"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000050321_Indexid_IX280_contentCd_SV3-PRO_01"
      id="ixv-930">
         Russell SMID 500&#x2122; Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_IX280_contentCd_SV3-PRO_01"
      decimals="4"
      id="ixv-51484"
      unitRef="pure">0.1133</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_IX280_contentCd_SV3-PRO_05"
      decimals="4"
      id="ixv-51485"
      unitRef="pure">0.0819</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_IX280_contentCd_SV3-PRO_10"
      decimals="4"
      id="ixv-51486"
      unitRef="pure">0.1101</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000050321_Indexid_RS003_contentCd_SV3-PRO_01"
      id="ixv-955">
         Russell 3000&#xae; Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_RS003_contentCd_SV3-PRO_01"
      decimals="4"
      id="ixv-51487"
      unitRef="pure">0.1715</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_RS003_contentCd_SV3-PRO_05"
      decimals="4"
      id="ixv-51488"
      unitRef="pure">0.1315</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000050321_Indexid_RS003_contentCd_SV3-PRO_10"
      decimals="4"
      id="ixv-51489"
      unitRef="pure">0.1429</oef:AvgAnnlRtrPct>
    <oef:PerformanceTableMarketIndexChanged contextRef="Pid_S000050321_contentCd_SV3-PRO" id="ixv-997">
     
       
     Effective December 22, 2025, the fund began comparing its performance to the Fidelity U.S. Small-Mid Cap Momentum Focus Index 
       
     SM 
       
     rather than the Russell SMID 500 
       
     TM 
       
     Index because the Fidelity U.S. Small-Mid Cap Momentum Focus Index 
       
     SM 
       
     conforms more closely to the fund's investment policies. 
       
     &#160; 
       
    
   </oef:PerformanceTableMarketIndexChanged>
    <oef:RiskReturnHeading contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2567">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; SAI Real Estate Index Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2576">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2581">
     
       
     Fidelity&#xae; SAI Real Estate Index Fund seeks to provide investment results that correspond to the total return of equity real estate investment trusts (REITs) and other real estate-related investments. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2586">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2592">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2602">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000051993_contentCd_SV8-PRO"
      decimals="0"
      id="ixv-51490"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2617">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000051993_Cid_C000163539"
      decimals="6"
      id="ixv-51491"
      unitRef="pure">0.0007</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000051993_Cid_C000163539"
      decimals="6"
      id="ixv-51492"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000051993_Cid_C000163539"
      decimals="6"
      id="ixv-51493"
      unitRef="pure">0.0006</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000051993_Cid_C000163539"
      decimals="6"
      id="ixv-51494"
      unitRef="pure">0.0013</oef:ExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000051993_Cid_C000163539"
      decimals="6"
      id="footnoteS000051993SV8-PROAOE_AC000163539_FW"
      unitRef="pure">-0.0006</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000051993_Cid_C000163539"
      decimals="6"
      id="ixv-51496"
      unitRef="pure">0.0007</oef:NetExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2691">2027-11-30</oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination>
    <oef:ExpenseExampleNarrativeTextBlock contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2700">
     
       
     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_S000051993_Cid_C000163539"
      decimals="0"
      id="ixv-51497"
      unitRef="usd">7</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000051993_Cid_C000163539"
      decimals="0"
      id="ixv-51498"
      unitRef="usd">34</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000051993_Cid_C000163539"
      decimals="0"
      id="ixv-51499"
      unitRef="usd">65</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000051993_Cid_C000163539"
      decimals="0"
      id="ixv-51500"
      unitRef="usd">158</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2757">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2762">
     
       
     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_S000051993_contentCd_SV8-PRO"
      decimals="4"
      id="ixv-51501"
      unitRef="pure">0.15</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2771">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2776">
     
       
      
       
        Normally investing at least 80% of assets in securities included in the MSCI US IMI Real Estate 25/25 Index. 
      
     The MSCI US IMI Real Estate 25/25 Index is a modified market capitalization-weighted index of stocks designed to measure the performance of real estate companies in the MSCI US Investable Market 2500 Index. 
      
       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. 
      
      Primarily using replication; however, the fund may or may not hold all of the securities in the index. 
      Lending securities to earn income for the fund. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051993_contentCd_SV8-PRO_RiskMember_StockMarketVolatilityMember"
      id="ixv-2796">
     
       
      
      Stock Market Volatility. 
      
     Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051993_contentCd_SV8-PRO_RiskMember_RealEstateIndustryConcentrationMember"
      id="ixv-2805">
     
       
      
      Real Estate Industry Concentration. 
      
     Changes in real estate values or economic downturns can have a significant negative effect on issuers in the real estate industry. The value of securities of issuers in the real estate industry can be affected by changes in real estate values and rental income, property taxes, interest rates, tax and regulatory requirements, and the management skill and creditworthiness of the issuer. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051993_contentCd_SV8-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-2814">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051993_contentCd_SV8-PRO_RiskMember_CorrelationToIndexMember"
      id="ixv-2825">
     
       
      
      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_S000051993_contentCd_SV8-PRO_RiskMember_PassiveManagementRiskMember"
      id="ixv-2837">
     
       
      
      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_S000051993_contentCd_SV8-PRO_RiskMember_SecuritiesLendingRiskMember"
      id="ixv-2848">
     
       
      
      Securities Lending Risk. 
      
     Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051993_contentCd_SV8-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-2857">
     
       
     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_S000051993_contentCd_SV8-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-2865">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2872">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2877">
     
       
     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. 
        
      
     Prior to December 1, 2020, the fund compared its performance to a different benchmark. The fund's historical performance may not represent its current investment policies. 
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2882"> 
        
      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_S000051993_contentCd_SV8-PRO" id="ixv-2891"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2899"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-2904">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_2017"
      decimals="INF"
      id="ixv-51502"
      unitRef="pure">0.0373</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_2018"
      decimals="INF"
      id="ixv-51503"
      unitRef="pure">-0.0418</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_2019"
      decimals="INF"
      id="ixv-51504"
      unitRef="pure">0.2306</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_2020"
      decimals="INF"
      id="ixv-51505"
      unitRef="pure">-0.1110</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_2021"
      decimals="INF"
      id="ixv-51506"
      unitRef="pure">0.4062</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_2022"
      decimals="INF"
      id="ixv-51507"
      unitRef="pure">-0.2614</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_2023"
      decimals="INF"
      id="ixv-51508"
      unitRef="pure">0.1187</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_2024"
      decimals="INF"
      id="ixv-51509"
      unitRef="pure">0.0483</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_2025"
      decimals="INF"
      id="ixv-51510"
      unitRef="pure">0.0308</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-3013">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000051993_contentCd_SV8-PRO"
      decimals="4"
      id="ixv-51511"
      unitRef="pure">0.1811</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-3023">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-3028">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000051993_contentCd_SV8-PRO"
      decimals="4"
      id="ixv-51512"
      unitRef="pure">-0.2846</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-3039">2020-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-3044">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000051993_contentCd_SV8-PRO"
      decimals="4"
      id="ixv-51513"
      unitRef="pure">0.1092</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-3054">2026-06-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-3059">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock contextRef="Pid_S000051993_contentCd_SV8-PRO" id="ixv-3064">
     
       
      
        
      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_S000051993_contentCd_SV8-PRO" id="ixv-3067"> 
        
      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_S000051993_contentCd_SV8-PRO" id="ixv-3074"> 
        
      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_S000051993_contentCd_SV8-PRO" id="ixv-3079"> 
        
      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_S000051993_Cid_C000163539_ReturnBeforeTaxes_01"
      id="ixv-3125">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-51514"
      unitRef="pure">0.0308</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-51515"
      unitRef="pure">0.0466</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSV8-PROS000051993AAR_A_RBT_loc"
      unitRef="pure">0.0439</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051993_Cid_C000163539_AfterTaxesOnDistributions_01"
      id="ixv-3141">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-51517"
      unitRef="pure">0.0208</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-51518"
      unitRef="pure">-0.0024</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSV8-PROS000051993AAR_A_ATD_loc"
      unitRef="pure">0.0132</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051993_Cid_C000163539_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-3158">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-51520"
      unitRef="pure">0.0209</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-51521"
      unitRef="pure">0.0281</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Cid_C000163539_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSV8-PROS000051993AAR_A_ATDS_loc"
      unitRef="pure">0.0280</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051993_Indexid_IXWLE_contentCd_SV8-PRO_01"
      id="ixv-3175">
         Fidelity Real Estate Linked Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Indexid_IXWLE_contentCd_SV8-PRO_01"
      decimals="4"
      id="ixv-51523"
      unitRef="pure">0.0301</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Indexid_IXWLE_contentCd_SV8-PRO_05"
      decimals="4"
      id="ixv-51524"
      unitRef="pure">0.0472</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Indexid_IXWLE_contentCd_SV8-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-51525"
      unitRef="pure">0.0442</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051993_Indexid_IXWEX_contentCd_SV8-PRO_01"
      id="ixv-3200">
         MSCI US IMI Real Estate 25/25 Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Indexid_IXWEX_contentCd_SV8-PRO_01"
      decimals="4"
      id="ixv-51526"
      unitRef="pure">0.0301</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Indexid_IXWEX_contentCd_SV8-PRO_05"
      decimals="4"
      id="ixv-51527"
      unitRef="pure">0.0472</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Indexid_IXWEX_contentCd_SV8-PRO_AverageAnnualReturnSinceInception"
      id="footnoteSV8-PROS000051993AAR_B_BM_1_loc"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051993_Indexid_SP001_contentCd_SV8-PRO_01"
      id="ixv-3227">
         S&amp;P 500&#xae; Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Indexid_SP001_contentCd_SV8-PRO_01"
      decimals="4"
      id="ixv-51529"
      unitRef="pure">0.1788</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Indexid_SP001_contentCd_SV8-PRO_05"
      decimals="4"
      id="ixv-51530"
      unitRef="pure">0.1442</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051993_Indexid_SP001_contentCd_SV8-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-51531"
      unitRef="pure">0.1577</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000051993_Cid_C000163539" id="ixv-3268">2016-02-02</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4823">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; Real Estate Index Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4832">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4837">
     
       
     Fidelity&#xae; Real Estate Index Fund seeks to provide investment results that correspond to the total return of equity REITs and other real estate-related investments. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4842">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4848">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4859">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      decimals="0"
      id="ixv-51532"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4874">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000033639_Cid_C000103377"
      decimals="6"
      id="ixv-51533"
      unitRef="pure">0.0007</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000033639_Cid_C000103377"
      decimals="6"
      id="ixv-51534"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000033639_Cid_C000103377"
      decimals="6"
      id="ixv-51535"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000033639_Cid_C000103377"
      decimals="6"
      id="ixv-51536"
      unitRef="pure">0.0007</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4921">
     
       
     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_S000033639_Cid_C000103377"
      decimals="0"
      id="ixv-51537"
      unitRef="usd">7</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000033639_Cid_C000103377"
      decimals="0"
      id="ixv-51538"
      unitRef="usd">23</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000033639_Cid_C000103377"
      decimals="0"
      id="ixv-51539"
      unitRef="usd">40</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000033639_Cid_C000103377"
      decimals="0"
      id="ixv-51540"
      unitRef="usd">90</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4978">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4983">
     
       
     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 
       
     
       
       5 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      decimals="4"
      id="ixv-51541"
      unitRef="pure">0.05</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4992">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-4997">
     
       
      
       
        Normally investing at least 80% of assets in securities included in the MSCI US IMI Real Estate 25/25 Index. 
      
     The MSCI US IMI Real Estate 25/25 Index is a modified market capitalization-weighted index of stocks designed to measure the performance of real estate companies in the MSCI US Investable Market 2500 Index. 
      
       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. 
      
      Primarily using replication; however, the fund may or may not hold all of the securities in the index. 
      Lending securities to earn income for the fund. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO_RiskMember_StockMarketVolatilityMember"
      id="ixv-5017">
     
       
      
      Stock Market Volatility. 
      
     Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO_RiskMember_RealEstateIndustryConcentrationMember"
      id="ixv-5026">
     
       
      
      Real Estate Industry Concentration. 
      
     Changes in real estate values or economic downturns can have a significant negative effect on issuers in the real estate industry. The value of securities of issuers in the real estate industry can be affected by changes in real estate values and rental income, property taxes, interest rates, tax and regulatory requirements, and the management skill and creditworthiness of the issuer. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-5035">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO_RiskMember_CorrelationToIndexMember"
      id="ixv-5046">
     
       
      
      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_S000033639_contentCd_URX-I-PRO_RiskMember_PassiveManagementRiskMember"
      id="ixv-5058">
     
       
      
      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_S000033639_contentCd_URX-I-PRO_RiskMember_SecuritiesLendingRiskMember"
      id="ixv-5069">
     
       
      
      Securities Lending Risk. 
      
     Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-5078">
     
       
     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_S000033639_contentCd_URX-I-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-5086">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5093">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5098">
     
       
     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. 
        
      
     Prior to December 1, 2020, the fund compared its performance to a different benchmark. The fund's historical performance may not represent its current investment policies. 
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5103"> 
        
      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_S000033639_contentCd_URX-I-PRO"
      id="ixv-5112"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5120"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5125">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_2016"
      decimals="INF"
      id="ixv-51542"
      unitRef="pure">0.0660</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_2017"
      decimals="INF"
      id="ixv-51543"
      unitRef="pure">0.0375</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_2018"
      decimals="INF"
      id="ixv-51544"
      unitRef="pure">-0.0421</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_2019"
      decimals="INF"
      id="ixv-51545"
      unitRef="pure">0.2302</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_2020"
      decimals="INF"
      id="ixv-51546"
      unitRef="pure">-0.1133</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_2021"
      decimals="INF"
      id="ixv-51547"
      unitRef="pure">0.4066</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_2022"
      decimals="INF"
      id="ixv-51548"
      unitRef="pure">-0.2612</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_2023"
      decimals="INF"
      id="ixv-51549"
      unitRef="pure">0.1194</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_2024"
      decimals="INF"
      id="ixv-51550"
      unitRef="pure">0.0497</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_2025"
      decimals="INF"
      id="ixv-51551"
      unitRef="pure">0.0303</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5237">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      decimals="4"
      id="ixv-51552"
      unitRef="pure">0.1810</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5247">2023-12-31</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5252">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      decimals="4"
      id="ixv-51553"
      unitRef="pure">-0.2853</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5263">2020-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5268">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      decimals="4"
      id="ixv-51554"
      unitRef="pure">0.1091</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5278">2026-06-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5283">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000033639_contentCd_URX-I-PRO"
      id="ixv-5288">
     
       
      
        
      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_S000033639_contentCd_URX-I-PRO"
      id="ixv-5291"> 
        
      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_S000033639_contentCd_URX-I-PRO"
      id="ixv-5298"> 
        
      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_S000033639_contentCd_URX-I-PRO"
      id="ixv-5303"> 
        
      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_S000033639_Cid_C000103377_ReturnBeforeTaxes_01"
      id="ixv-5348">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-51555"
      unitRef="pure">0.0303</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-51556"
      unitRef="pure">0.0470</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_ReturnBeforeTaxes_10"
      decimals="4"
      id="ixv-51557"
      unitRef="pure">0.0381</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000033639_Cid_C000103377_AfterTaxesOnDistributions_01"
      id="ixv-5363">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-51558"
      unitRef="pure">0.0212</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-51559"
      unitRef="pure">0.0386</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_AfterTaxesOnDistributions_10"
      decimals="4"
      id="ixv-51560"
      unitRef="pure">0.0276</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000033639_Cid_C000103377_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-5378">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-51561"
      unitRef="pure">0.0202</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-51562"
      unitRef="pure">0.0340</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Cid_C000103377_AfterTaxesOnDistributionsAndSales_10"
      decimals="4"
      id="ixv-51563"
      unitRef="pure">0.0261</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000033639_Indexid_IXWLE_contentCd_URX-I-PRO_01"
      id="ixv-5394">
         Fidelity Real Estate Linked Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Indexid_IXWLE_contentCd_URX-I-PRO_01"
      decimals="4"
      id="ixv-51564"
      unitRef="pure">0.0301</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Indexid_IXWLE_contentCd_URX-I-PRO_05"
      decimals="4"
      id="ixv-51565"
      unitRef="pure">0.0472</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Indexid_IXWLE_contentCd_URX-I-PRO_10"
      decimals="4"
      id="ixv-51566"
      unitRef="pure">0.0385</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000033639_Indexid_IXWEX_contentCd_URX-I-PRO_01"
      id="ixv-5419">
         MSCI US IMI Real Estate 25/25 Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Indexid_IXWEX_contentCd_URX-I-PRO_01"
      decimals="4"
      id="ixv-51567"
      unitRef="pure">0.0301</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Indexid_IXWEX_contentCd_URX-I-PRO_05"
      decimals="4"
      id="ixv-51568"
      unitRef="pure">0.0472</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Indexid_IXWEX_contentCd_URX-I-PRO_10"
      id="footnoteURX-I-PROS000033639AAR_A_BM_1_10"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000033639_Indexid_SP001_contentCd_URX-I-PRO_01"
      id="ixv-5445">
         S&amp;P 500&#xae; Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Indexid_SP001_contentCd_URX-I-PRO_01"
      decimals="4"
      id="ixv-51570"
      unitRef="pure">0.1788</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Indexid_SP001_contentCd_URX-I-PRO_05"
      decimals="4"
      id="ixv-51571"
      unitRef="pure">0.1442</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000033639_Indexid_SP001_contentCd_URX-I-PRO_10"
      decimals="4"
      id="ixv-51572"
      unitRef="pure">0.1482</oef:AvgAnnlRtrPct>
    <oef:RiskReturnHeading contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7412">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; SAI U.S. Value Index Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7421">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7426">
     
       
     Fidelity&#xae; SAI U.S. Value Index Fund seeks to provide investment results that correspond to the total return of U.S. stocks with attractive valuations. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7431">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7437">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7447">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000059763_contentCd_USV-PRO"
      decimals="0"
      id="ixv-51573"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7462">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000059763_Cid_C000195574"
      decimals="6"
      id="ixv-51574"
      unitRef="pure">0.0010</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000059763_Cid_C000195574"
      decimals="6"
      id="ixv-51575"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000059763_Cid_C000195574"
      decimals="6"
      id="ixv-51576"
      unitRef="pure">0.0001</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000059763_Cid_C000195574"
      decimals="6"
      id="ixv-51577"
      unitRef="pure">0.0011</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7509">
     
       
     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_S000059763_Cid_C000195574"
      decimals="0"
      id="ixv-51578"
      unitRef="usd">11</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000059763_Cid_C000195574"
      decimals="0"
      id="ixv-51579"
      unitRef="usd">35</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000059763_Cid_C000195574"
      decimals="0"
      id="ixv-51580"
      unitRef="usd">62</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000059763_Cid_C000195574"
      decimals="0"
      id="ixv-51581"
      unitRef="usd">141</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7566">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7571">
     
       
     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. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000059763_contentCd_USV-PRO"
      decimals="4"
      id="ixv-51582"
      unitRef="pure">0.60</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7580">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7585">
     
       
      
       
        Normally investing at least 80% of assets in securities included in the Fidelity U.S. Value Focus Index&#x2120;. 
      
     The Fidelity U.S. Value Focus Index SM &#160; is designed to reflect the performance of stocks of large- and mid-capitalization companies that have attractive valuations. 
     The universe of stocks for consideration in the index, which is intended to reflect the broader equity market, consists of the largest 1,000 U.S. stocks based on market capitalization and certain liquidity and investability requirements. 
     The Fidelity U.S. Value Focus Index SM is constructed using Fidelity's rules-based proprietary index methodology. Stocks are ranked and given a composite score based on four measures of value: high free-cash-flow yield; low enterprise value to earnings before interest, taxes, depreciation and amortization; high book value to price; high future earnings to price. 
     The index is rebalanced monthly using an optimization process that seeks to select the highest ranked stocks subject to certain sector, security and turnover constraints. 
      
       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. 
      
       
        Primarily using replication; however, the fund may or may not hold all of the securities in the index. 
      Lending securities to earn income for the fund. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000059763_contentCd_USV-PRO_RiskMember_StockMarketVolatilityMember"
      id="ixv-7623">
     
       
      
      Stock Market Volatility. 
      
     Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000059763_contentCd_USV-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-7632">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000059763_contentCd_USV-PRO_RiskMember_CorrelationToIndexMember"
      id="ixv-7643">
     
       
      
      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_S000059763_contentCd_USV-PRO_RiskMember_PassiveManagementRiskMember"
      id="ixv-7655">
     
       
      
      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 or group of industries. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000059763_contentCd_USV-PRO_RiskMember_ValueInvestingMember"
      id="ixv-7670">
     
       
      
      "Value" Investing. 
      
     Although the fund's underlying index uses a rules-based proprietary index methodology that is designed to identify stocks with attractive valuations, there is no guarantee that this methodology will be successful or that these stocks will continue to be good "values." "Value" stocks can perform differently from the market as a whole and other types of stocks and can continue to be undervalued by the market for long periods of time . 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000059763_contentCd_USV-PRO_RiskMember_SecuritiesLendingRiskMember"
      id="ixv-7681">
     
       
      
      Securities Lending Risk. 
      
     Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000059763_contentCd_USV-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-7691">
     
       
     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_S000059763_contentCd_USV-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-7699">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7706">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7711">
     
       
     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_S000059763_contentCd_USV-PRO" id="ixv-7716"> 
        
      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_S000059763_contentCd_USV-PRO" id="ixv-7723"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7729"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7734">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_2018"
      decimals="INF"
      id="ixv-51583"
      unitRef="pure">-0.1071</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_2019"
      decimals="INF"
      id="ixv-51584"
      unitRef="pure">0.2909</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_2020"
      decimals="INF"
      id="ixv-51585"
      unitRef="pure">-0.0444</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_2021"
      decimals="INF"
      id="ixv-51586"
      unitRef="pure">0.3041</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_2022"
      decimals="INF"
      id="ixv-51587"
      unitRef="pure">-0.0369</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_2023"
      decimals="INF"
      id="ixv-51588"
      unitRef="pure">0.1258</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_2024"
      decimals="INF"
      id="ixv-51589"
      unitRef="pure">0.1603</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_2025"
      decimals="INF"
      id="ixv-51590"
      unitRef="pure">0.2249</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7840">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000059763_contentCd_USV-PRO"
      decimals="4"
      id="ixv-51591"
      unitRef="pure">0.1854</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7850">2020-06-30</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7855">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000059763_contentCd_USV-PRO"
      decimals="4"
      id="ixv-51592"
      unitRef="pure">-0.3176</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7866">2020-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7871">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000059763_contentCd_USV-PRO"
      decimals="4"
      id="ixv-51593"
      unitRef="pure">0.1346</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7881">2026-06-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7886">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock contextRef="Pid_S000059763_contentCd_USV-PRO" id="ixv-7891">
     
       
      
        
      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_S000059763_contentCd_USV-PRO" id="ixv-7894"> 
        
      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_S000059763_contentCd_USV-PRO" id="ixv-7901"> 
        
      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_S000059763_contentCd_USV-PRO" id="ixv-7906"> 
        
      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_S000059763_Cid_C000195574_ReturnBeforeTaxes_01"
      id="ixv-7952">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-51594"
      unitRef="pure">0.2249</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-51595"
      unitRef="pure">0.1498</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteUSV-PROS000059763AAR_A_RBT_loc"
      unitRef="pure">0.1037</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000059763_Cid_C000195574_AfterTaxesOnDistributions_01"
      id="ixv-7968">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-51597"
      unitRef="pure">0.1968</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-51598"
      unitRef="pure">0.1250</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteUSV-PROS000059763AAR_A_ATD_loc"
      unitRef="pure">0.0857</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000059763_Cid_C000195574_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-7984">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-51600"
      unitRef="pure">0.1403</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-51601"
      unitRef="pure">0.1126</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Cid_C000195574_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteUSV-PROS000059763AAR_A_ATDS_loc"
      unitRef="pure">0.0780</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000059763_Indexid_IXYEF_contentCd_USV-PRO_01"
      id="ixv-8001">
         Fidelity U.S. Value Focus Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Indexid_IXYEF_contentCd_USV-PRO_01"
      decimals="4"
      id="ixv-51603"
      unitRef="pure">0.2262</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Indexid_IXYEF_contentCd_USV-PRO_05"
      decimals="4"
      id="ixv-51604"
      unitRef="pure">0.1509</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Indexid_IXYEF_contentCd_USV-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-51605"
      unitRef="pure">0.1045</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000059763_Indexid_SP001_contentCd_USV-PRO_01"
      id="ixv-8026">
         S&amp;P 500&#xae; Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Indexid_SP001_contentCd_USV-PRO_01"
      decimals="4"
      id="ixv-51606"
      unitRef="pure">0.1788</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Indexid_SP001_contentCd_USV-PRO_05"
      decimals="4"
      id="ixv-51607"
      unitRef="pure">0.1442</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000059763_Indexid_SP001_contentCd_USV-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-51608"
      unitRef="pure">0.1423</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000059763_Cid_C000195574" id="ixv-8067">2017-12-19</oef:AnnualReturnInceptionDate>
    <oef:RiskReturnHeading contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9588">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; SAI U.S. Quality Index Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9597">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9602">
     
       
     Fidelity&#xae; SAI U.S. Quality Index Fund seeks to provide investment results that correspond to the total return of stocks of quality growth United States companies. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9607">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9613">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9623">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      decimals="0"
      id="ixv-51609"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9638">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000051137_Cid_C000161034"
      decimals="6"
      id="ixv-51610"
      unitRef="pure">0.0010</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000051137_Cid_C000161034"
      decimals="6"
      id="ixv-51611"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000051137_Cid_C000161034"
      decimals="6"
      id="ixv-51612"
      unitRef="pure">0.0001</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000051137_Cid_C000161034"
      decimals="6"
      id="ixv-51613"
      unitRef="pure">0.0011</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9685">
     
       
     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_S000051137_Cid_C000161034"
      decimals="0"
      id="ixv-51614"
      unitRef="usd">11</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000051137_Cid_C000161034"
      decimals="0"
      id="ixv-51615"
      unitRef="usd">35</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000051137_Cid_C000161034"
      decimals="0"
      id="ixv-51616"
      unitRef="usd">62</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000051137_Cid_C000161034"
      decimals="0"
      id="ixv-51617"
      unitRef="usd">141</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9742">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9747">
     
       
     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 
       
     
       
       37 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      decimals="4"
      id="ixv-51618"
      unitRef="pure">0.37</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9756">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9761">
     
       
      
       
        Normally investing at least 80% of assets in equity securities included in the Fidelity U.S. Quality Focus IndexSM. 
      
     The Fidelity U.S. Quality Focus Index SM seeks to capture the performance of a broad range of U.S. equities that have attractive quality scores. The universe of equities for consideration in the index consists of the largest U.S. equities based on float-adjusted market cap and certain liquidity and investability requirements. 
      
      The Fidelity U.S. Quality Focus Index SM is constructed using Fidelity rules-based priority index methodology. Equities are ranked within the investment universe and given a composite quality score. Quality scores for non-financial companies and non-real estate investment trusts are based on ten variables: high free cash flow margin, return on invested capital, gross profit margin, and return on equity; stable earnings growth, return on assets, free cash flow, and accruals; and low financial leverage and accruals. Financials and REITs are ranked using a composite score based on four measures of quality: high return on equity, stable earnings growth and return on equity, and low financial leverage. 
      
     The index is rebalanced quarterly using an optimization process that seeks to select the highest ranked equities subject to certain sector, security and turnover constraints. Typically, there are between 90 and 150 index constituents. 
     Equity securities represent an ownership interest, or the right to acquire an ownership interest, in an issuer. Equity securities include common stocks (including depositary receipts evidencing ownership of common stock), preferred stocks and other preferred securities, convertible securities, rights and warrants, and other securities, such as hybrid securities and trust preferred securities, believed to have equity-like characteristics. 
      
       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. 
      
       
        Primarily using replication; however, the fund may or may not hold all of the securities in the index. 
      Lending securities to earn income for the fund. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051137_contentCd_SV4-PRO_RiskMember_QualityStocksMember"
      id="ixv-9802">
     
       
      
      Quality Stocks. 
      
     Although the fund's underlying index uses a rules-based proprietary index methodology that is designed to identify stocks with a higher quality profile than the broader market, there is no guarantee that this methodology will be successful or that the past performance of these stocks will continue. Companies that issue these stocks may experience lower than expected returns or may experience negative growth, as well as increased leverage, resulting in lower than expected or negative returns. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051137_contentCd_SV4-PRO_RiskMember_StockMarketVolatilityMember"
      id="ixv-9811">
     
       
      
      Stock Market Volatility. 
      
     Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051137_contentCd_SV4-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-9820">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051137_contentCd_SV4-PRO_RiskMember_CorrelationToIndexMember"
      id="ixv-9831">
     
       
      
      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_S000051137_contentCd_SV4-PRO_RiskMember_PassiveManagementRiskMember"
      id="ixv-9843">
     
       
      
      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_S000051137_contentCd_SV4-PRO_RiskMember_GrowthInvestingMember"
      id="ixv-9854">
     
       
      
      "Growth" Investing. 
      
     "Growth" stocks can perform differently from the market as a whole and other types of stocks and can be more volatile than other types of stocks. &#160; &#160; &#160; 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051137_contentCd_SV4-PRO_RiskMember_SecuritiesLendingRiskMember"
      id="ixv-9869">
     
       
      
      Securities Lending Risk. 
      
     Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051137_contentCd_SV4-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-9878">
     
       
     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_S000051137_contentCd_SV4-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-9886">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9893">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9898">
     
       
     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. 
        
      
     Prior to March 18, 2019, the fund operated under certain different investment policies and compared its performance to a different index. The fund's historical performance may not represent its current investment policies. 
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9903"> 
        
      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_S000051137_contentCd_SV4-PRO" id="ixv-9912"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9920"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading contextRef="Pid_S000051137_contentCd_SV4-PRO" id="ixv-9925">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_2016"
      decimals="INF"
      id="ixv-51619"
      unitRef="pure">0.0782</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_2017"
      decimals="INF"
      id="ixv-51620"
      unitRef="pure">0.2575</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_2018"
      decimals="INF"
      id="ixv-51621"
      unitRef="pure">-0.0275</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_2019"
      decimals="INF"
      id="ixv-51622"
      unitRef="pure">0.3407</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_2020"
      decimals="INF"
      id="ixv-51623"
      unitRef="pure">0.2067</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_2021"
      decimals="INF"
      id="ixv-51624"
      unitRef="pure">0.2833</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_2022"
      decimals="INF"
      id="ixv-51625"
      unitRef="pure">-0.1809</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_2023"
      decimals="INF"
      id="ixv-51626"
      unitRef="pure">0.2962</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_2024"
      decimals="INF"
      id="ixv-51627"
      unitRef="pure">0.2425</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_2025"
      decimals="INF"
      id="ixv-51628"
      unitRef="pure">0.1675</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      id="ixv-10036">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      decimals="4"
      id="ixv-51629"
      unitRef="pure">0.2140</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      id="ixv-10046">2020-06-30</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      id="ixv-10051">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      decimals="4"
      id="ixv-51630"
      unitRef="pure">-0.1533</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      id="ixv-10062">2020-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      id="ixv-10067">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      decimals="4"
      id="ixv-51631"
      unitRef="pure">0.0927</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      id="ixv-10077">2026-06-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      id="ixv-10082">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000051137_contentCd_SV4-PRO"
      id="ixv-10087">
     
       
      
        
      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_S000051137_contentCd_SV4-PRO"
      id="ixv-10090"> 
        
      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_S000051137_contentCd_SV4-PRO"
      id="ixv-10097"> 
        
      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_S000051137_contentCd_SV4-PRO"
      id="ixv-10102"> 
        
      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_S000051137_Cid_C000161034_ReturnBeforeTaxes_01"
      id="ixv-10147">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-51632"
      unitRef="pure">0.1675</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-51633"
      unitRef="pure">0.1460</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_ReturnBeforeTaxes_10"
      decimals="4"
      id="ixv-51634"
      unitRef="pure">0.1548</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051137_Cid_C000161034_AfterTaxesOnDistributions_01"
      id="ixv-10162">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-51635"
      unitRef="pure">0.1574</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-51636"
      unitRef="pure">0.1300</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_AfterTaxesOnDistributions_10"
      decimals="4"
      id="ixv-51637"
      unitRef="pure">0.1378</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051137_Cid_C000161034_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-10177">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-51638"
      unitRef="pure">0.1059</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-51639"
      unitRef="pure">0.1137</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Cid_C000161034_AfterTaxesOnDistributionsAndSales_10"
      decimals="4"
      id="ixv-51640"
      unitRef="pure">0.1245</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051137_Indexid_IXYXM_contentCd_SV4-PRO_01"
      id="ixv-10193">
         Fidelity SAI U.S. Quality Index Fund Linked Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Indexid_IXYXM_contentCd_SV4-PRO_01"
      decimals="4"
      id="ixv-51641"
      unitRef="pure">0.1775</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Indexid_IXYXM_contentCd_SV4-PRO_05"
      decimals="4"
      id="ixv-51642"
      unitRef="pure">0.1483</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Indexid_IXYXM_contentCd_SV4-PRO_10"
      decimals="4"
      id="ixv-51643"
      unitRef="pure">0.1566</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051137_Indexid_IXYOZ_contentCd_SV4-PRO_01"
      id="ixv-10218">
         Fidelity U.S. Quality Focus Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Indexid_IXYOZ_contentCd_SV4-PRO_01"
      decimals="4"
      id="ixv-51644"
      unitRef="pure">0.1775</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Indexid_IXYOZ_contentCd_SV4-PRO_05"
      decimals="4"
      id="ixv-51645"
      unitRef="pure">0.1483</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Indexid_IXYOZ_contentCd_SV4-PRO_10"
      id="footnoteSV4-PROS000051137AAR_A_BM_1_10"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051137_Indexid_SP001_contentCd_SV4-PRO_01"
      id="ixv-10244">
         S&amp;P 500&#xae; Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Indexid_SP001_contentCd_SV4-PRO_01"
      decimals="4"
      id="ixv-51647"
      unitRef="pure">0.1788</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Indexid_SP001_contentCd_SV4-PRO_05"
      decimals="4"
      id="ixv-51648"
      unitRef="pure">0.1442</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051137_Indexid_SP001_contentCd_SV4-PRO_10"
      decimals="4"
      id="ixv-51649"
      unitRef="pure">0.1482</oef:AvgAnnlRtrPct>
    <oef:RiskReturnHeading
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11802">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; SAI U.S. Momentum Index Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11811">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11816">
     
       
     Fidelity&#xae; SAI U.S. Momentum Index Fund seeks to provide investment results that correspond to the total return of U.S. stocks with high price momentum. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11821">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11827">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11837">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      decimals="0"
      id="ixv-51650"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11852">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000056275_Cid_C000177148"
      decimals="6"
      id="ixv-51651"
      unitRef="pure">0.0010</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000056275_Cid_C000177148"
      decimals="6"
      id="ixv-51652"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000056275_Cid_C000177148"
      decimals="6"
      id="ixv-51653"
      unitRef="pure">0.0000</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000056275_Cid_C000177148"
      decimals="6"
      id="ixv-51654"
      unitRef="pure">0.0010</oef:ExpensesOverAssets>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11899">
     
       
     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_S000056275_Cid_C000177148"
      decimals="0"
      id="ixv-51655"
      unitRef="usd">10</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000056275_Cid_C000177148"
      decimals="0"
      id="ixv-51656"
      unitRef="usd">32</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000056275_Cid_C000177148"
      decimals="0"
      id="ixv-51657"
      unitRef="usd">56</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000056275_Cid_C000177148"
      decimals="0"
      id="ixv-51658"
      unitRef="usd">128</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11956">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11961">
     
       
     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 
       
     
       
       196 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      decimals="4"
      id="ixv-51659"
      unitRef="pure">1.96</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11970">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-11975">
     
       
      
       
        Normally investing at least 80% of assets in securities included in the Fidelity U.S. Large Cap Momentum Focus Index&#x2120;. 
      
     The Fidelity U.S. Large Cap Momentum Focus Index &#x2120; is designed to reflect a well-diversified portfolio that invests in companies based on price and earnings momentum metrics. It is a subset of the Fidelity U.S. 1000 Index &#x2120; , designed to reflect the performance of stocks of large and mid-capitalization U.S. companies. The Fidelity U.S. 1000 Index &#x2120; is a subset of the Fidelity U.S. Total Investable Market Index &#x2120; , including the 1,000 largest U.S. stocks based on float adjusted market cap and excluding small-capitalization stocks. 
     The Fidelity U.S. Large Cap Momentum Focus Index &#x2120; was created by Fidelity Product Services LLC (FPS) using a rules-based proprietary index methodology that includes all U.S. stocks meeting certain market capitalization, liquidity and investability requirements. 
      
       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. 
     Primarily using replication; however, the fund may or may not hold all of the securities in the index. 
      
      Lending securities to earn income for the fund. 
      
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO_RiskMember_StockMarketVolatilityMember"
      id="ixv-12020">
     
       
      
      Stock Market Volatility. 
      
     Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-12029">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO_RiskMember_CorrelationToIndexMember"
      id="ixv-12040">
     
       
      
      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_S000056275_contentCd_SY1-PRO_RiskMember_PassiveManagementRiskMember"
      id="ixv-12052">
     
       
      
      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_S000056275_contentCd_SY1-PRO_RiskMember_RulesBasedStrategyRiskMember"
      id="ixv-12063">
     
       
      
      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_S000056275_contentCd_SY1-PRO_RiskMember_MomentumSecuritiesRiskMember"
      id="ixv-12073">
     
       
      
      Momentum Securities Risk. 
      
     Although the fund's underlying index uses a rules-based proprietary index methodology that is designed to identify stocks that exhibit positive momentum signals, there is no guarantee that this methodology will be successful. Stocks that previously exhibited high momentum characteristics may not experience positive momentum or may experience more volatility than the market as a whole. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO_RiskMember_SecuritiesLendingRiskMember"
      id="ixv-12082">
     
       
      
      Securities Lending Risk. 
      
     Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO_RiskMember_HighPortfolioTurnoverMember"
      id="ixv-12091">
     
       
      
      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_S000056275_contentCd_SY1-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-12101">
     
       
     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_S000056275_contentCd_SY1-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-12109">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12116">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12121">
     
       
     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. 
        
      
     Prior to October 31, 2025, the fund compared its performance to a different benchmark. The fund's historical performance may not represent its current investment policies. 
     Visit 
       
      
        
      www.fidelity.com  
      
       
     for more recent performance information. 
    
   </oef:PerformanceNarrativeTextBlock>
    <oef:PerformanceInformationIllustratesVariabilityOfReturns
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12126"> 
        
      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_S000056275_contentCd_SY1-PRO"
      id="ixv-12133"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12141"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12146">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_2018"
      decimals="INF"
      id="ixv-51660"
      unitRef="pure">-0.0140</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_2019"
      decimals="INF"
      id="ixv-51661"
      unitRef="pure">0.2416</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_2020"
      decimals="INF"
      id="ixv-51662"
      unitRef="pure">0.2998</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_2021"
      decimals="INF"
      id="ixv-51663"
      unitRef="pure">0.2263</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_2022"
      decimals="INF"
      id="ixv-51664"
      unitRef="pure">-0.1578</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_2023"
      decimals="INF"
      id="ixv-51665"
      unitRef="pure">0.1462</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_2024"
      decimals="INF"
      id="ixv-51666"
      unitRef="pure">0.3330</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_2025"
      decimals="INF"
      id="ixv-51667"
      unitRef="pure">0.1697</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12251">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      decimals="4"
      id="ixv-51668"
      unitRef="pure">0.2327</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12261">2020-06-30</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12266">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      decimals="4"
      id="ixv-51669"
      unitRef="pure">-0.1682</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12277">2022-06-30</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12282">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      decimals="4"
      id="ixv-51670"
      unitRef="pure">0.3269</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12292">2026-06-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12297">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12302">
     
       
      
        
      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_S000056275_contentCd_SY1-PRO"
      id="ixv-12305"> 
        
      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_S000056275_contentCd_SY1-PRO"
      id="ixv-12312"> 
        
      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_S000056275_contentCd_SY1-PRO"
      id="ixv-12317"> 
        
      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_S000056275_Cid_C000177148_ReturnBeforeTaxes_01"
      id="ixv-12363">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-51671"
      unitRef="pure">0.1697</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-51672"
      unitRef="pure">0.1304</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSY1-PROS000056275AAR_A_RBT_loc"
      unitRef="pure">0.1550</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000056275_Cid_C000177148_AfterTaxesOnDistributions_01"
      id="ixv-12379">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-51674"
      unitRef="pure">0.1620</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-51675"
      unitRef="pure">0.1040</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSY1-PROS000056275AAR_A_ATD_loc"
      unitRef="pure">0.1345</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000056275_Cid_C000177148_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-12395">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-51677"
      unitRef="pure">0.1057</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-51678"
      unitRef="pure">0.0961</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Cid_C000177148_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSY1-PROS000056275AAR_A_ATDS_loc"
      unitRef="pure">0.1226</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000056275_Indexid_IXRW2_contentCd_SY1-PRO_01"
      id="ixv-12412">
         Fidelity U.S. Momentum Linked Index&#x2120;
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_IXRW2_contentCd_SY1-PRO_01"
      decimals="4"
      id="ixv-51680"
      unitRef="pure">0.1712</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_IXRW2_contentCd_SY1-PRO_05"
      decimals="4"
      id="ixv-51681"
      unitRef="pure">0.1315</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_IXRW2_contentCd_SY1-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-51682"
      unitRef="pure">0.1564</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000056275_Indexid_IXRTW_contentCd_SY1-PRO_01"
      id="ixv-12437">
         Fidelity U.S. Large Cap Momentum Focus Index&#x2120; 
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_IXRTW_contentCd_SY1-PRO_01"
      id="footnoteSY1-PROS000056275AAR_B_BM_1_01"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_IXRTW_contentCd_SY1-PRO_05"
      id="footnoteSY1-PROS000056275AAR_B_BM_1_05"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_IXRTW_contentCd_SY1-PRO_AverageAnnualReturnSinceInception"
      id="footnoteSY1-PROS000056275AAR_B_BM_1_loc"
      unitRef="pure"
      xsi:nil="true"/>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000056275_Indexid_IXZE4_contentCd_SY1-PRO_01"
      id="ixv-12467">
         MSCI USA Custom Momentum Composite Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_IXZE4_contentCd_SY1-PRO_01"
      decimals="4"
      id="ixv-51686"
      unitRef="pure">0.1784</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_IXZE4_contentCd_SY1-PRO_05"
      decimals="4"
      id="ixv-51687"
      unitRef="pure">0.1329</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_IXZE4_contentCd_SY1-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-51688"
      unitRef="pure">0.1572</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000056275_Indexid_MS023_contentCd_SY1-PRO_01"
      id="ixv-12492">
         MSCI USA Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_MS023_contentCd_SY1-PRO_01"
      decimals="4"
      id="ixv-51689"
      unitRef="pure">0.1731</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_MS023_contentCd_SY1-PRO_05"
      decimals="4"
      id="ixv-51690"
      unitRef="pure">0.1338</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000056275_Indexid_MS023_contentCd_SY1-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-51691"
      unitRef="pure">0.1434</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000056275_Cid_C000177148" id="ixv-12533">2017-02-09</oef:AnnualReturnInceptionDate>
    <oef:PerformanceTableMarketIndexChanged
      contextRef="Pid_S000056275_contentCd_SY1-PRO"
      id="ixv-12548">
     
       
     Effective 
      October 31, 2025, the fund  
      
       
     began 
      comparing its performance to the Fidelity U.S. Large Cap Momentum Focus Index 
       
     &#x2120; 
       
     rather than the MSCI USA Custom Momentum Composite Index because the Fidelity U.S. Large Cap Momentum Focus Index 
       
     &#x2120; 
       
     &#160; 
     conforms more closely to the fund's investment policies 
       
     . 
       
    
   </oef:PerformanceTableMarketIndexChanged>
    <oef:RiskReturnHeading
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14156">
     
       
     Fund Summary 
       
     Fund: 
     Fidelity&#xae; SAI U.S. Large Cap Index Fund 
    
   </oef:RiskReturnHeading>
    <oef:ObjectiveHeading
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14165">
     
       
     Investment Objective 
       
    
   </oef:ObjectiveHeading>
    <oef:ObjectivePrimaryTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14170">
     
       
     Fidelity&#xae; SAI U.S. Large Cap Index Fund seeks to provide investment results that correspond to the total return of U.S. equities. 
       
    
   </oef:ObjectivePrimaryTextBlock>
    <oef:ExpenseHeading
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14175">
     
       
     Fee Table 
       
    
   </oef:ExpenseHeading>
    <oef:ExpenseNarrativeTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14181">
     
       
     The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. 
    
   </oef:ExpenseNarrativeTextBlock>
    <oef:ShareholderFeesCaption
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14191">
     
       
     Shareholder fees 
       
    
   </oef:ShareholderFeesCaption>
    <oef:ShareholderFeeOther
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      decimals="0"
      id="ixv-51692"
      unitRef="usd">0</oef:ShareholderFeeOther>
    <oef:OperatingExpensesCaption
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14206">
     
       
     Annual Operating Expenses 
       
    
   </oef:OperatingExpensesCaption>
    <oef:ManagementFeesOverAssets
      contextRef="Pid_S000051994_Cid_C000163540"
      decimals="6"
      id="ixv-51693"
      unitRef="pure">0.00015</oef:ManagementFeesOverAssets>
    <oef:DistributionAndService12b1FeesOverAssets
      contextRef="Pid_S000051994_Cid_C000163540"
      decimals="6"
      id="ixv-51694"
      unitRef="pure">0</oef:DistributionAndService12b1FeesOverAssets>
    <oef:OtherExpensesOverAssets
      contextRef="Pid_S000051994_Cid_C000163540"
      decimals="6"
      id="ixv-51695"
      unitRef="pure">0.00002</oef:OtherExpensesOverAssets>
    <oef:ExpensesOverAssets
      contextRef="Pid_S000051994_Cid_C000163540"
      decimals="6"
      id="ixv-51696"
      unitRef="pure">0.00017</oef:ExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssets
      contextRef="Pid_S000051994_Cid_C000163540"
      decimals="6"
      id="footnoteS000051994SV9-PROAOE_AC000163540_FW"
      unitRef="pure">-0.00002</oef:FeeWaiverOrReimbursementOverAssets>
    <oef:NetExpensesOverAssets
      contextRef="Pid_S000051994_Cid_C000163540"
      decimals="6"
      id="ixv-51698"
      unitRef="pure">0.00015</oef:NetExpensesOverAssets>
    <oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14280">2027-11-30</oef:FeeWaiverOrReimbursementOverAssetsDateOfTermination>
    <oef:ExpenseExampleNarrativeTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14289">
     
       
     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_S000051994_Cid_C000163540"
      decimals="0"
      id="ixv-51699"
      unitRef="usd">2</oef:ExpenseExampleYear01>
    <oef:ExpenseExampleYear03
      contextRef="Pid_S000051994_Cid_C000163540"
      decimals="0"
      id="ixv-51700"
      unitRef="usd">5</oef:ExpenseExampleYear03>
    <oef:ExpenseExampleYear05
      contextRef="Pid_S000051994_Cid_C000163540"
      decimals="0"
      id="ixv-51701"
      unitRef="usd">9</oef:ExpenseExampleYear05>
    <oef:ExpenseExampleYear10
      contextRef="Pid_S000051994_Cid_C000163540"
      decimals="0"
      id="ixv-51702"
      unitRef="usd">22</oef:ExpenseExampleYear10>
    <oef:PortfolioTurnoverHeading
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14346">
     
       
     Portfolio Turnover 
       
    
   </oef:PortfolioTurnoverHeading>
    <oef:PortfolioTurnoverTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14351">
     
       
     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 
       
     
       
       32 
       
       
     % of the average value of its portfolio. 
       
    
   </oef:PortfolioTurnoverTextBlock>
    <oef:PortfolioTurnoverRate
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      decimals="4"
      id="ixv-51703"
      unitRef="pure">0.32</oef:PortfolioTurnoverRate>
    <oef:StrategyHeading
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14360">
     
       
     Principal Investment Strategies 
       
    
   </oef:StrategyHeading>
    <oef:StrategyNarrativeTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14365">
     
       
      
       
        Normally investing at least 80% of assets in common stocks of large capitalization U.S. companies included in the S&amp;P 500&#xae; Index. 
      
     The S&amp;P 500 &#xae; Index is a  
       market capitalization-weighted index of 500 common stocks that represents the performance of  
       the large-capitalization segment of the U.S. market. 
     Common stocks (including depositary receipts evidencing ownership of common stock) are a type of equity security that represents an ownership interest in an issuer. 
      
       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. 
      
      Primarily using replication; however, the fund may or may not hold all of the securities in the index. 
      Lending securities to earn income for the fund. 
      
     The fund may operate as a non-diversified fund, as defined under the Investment Company Act of 1940 (1940 Act), to the approximate extent the index is non-diversified. The fund may therefore operate as non-diversified solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the index. 
    
   </oef:StrategyNarrativeTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO_RiskMember_StockMarketVolatilityMember"
      id="ixv-14401">
     
       
      
      Stock Market Volatility. 
      
     Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO_RiskMember_IssuerSpecificChangesMember"
      id="ixv-14410">
     
       
      
      Issuer-Specific Changes. 
      
     The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. 
     Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. 
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO_RiskMember_CorrelationToIndexMember"
      id="ixv-14421">
     
       
      
      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_S000051994_contentCd_SV9-PRO_RiskMember_PassiveManagementRiskMember"
      id="ixv-14433">
     
       
      
      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_S000051994_contentCd_SV9-PRO_RiskMember_SecuritiesLendingRiskMember"
      id="ixv-14444">
     
       
      
      Securities Lending Risk. 
      
     Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. 
      
       
    
   </oef:RiskTextBlock>
    <oef:RiskTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO_RiskMember_RiskNondiversifiedStatusMember"
      id="ixv-14454">
     
       
     In addition, the fund may operate as a non-diversified fund under the 1940 Act to the approximate extent the index is non-diversified. A non-diversified fund may invest a greater portion of its 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_S000051994_contentCd_SV9-PRO_RiskMember_RiskNotInsuredDepositoryInstitutionMember"
      id="ixv-14459">
     
       
     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_S000051994_contentCd_SV9-PRO_RiskMember_RiskLoseMoneyMember"
      id="ixv-14467">
     
       
     &#160; 
       
     You could lose money by investing in the fund. 
       
    
   </oef:RiskTextBlock>
    <oef:BarChartAndPerformanceTableHeading
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14474">
     
       
     Performance 
       
    
   </oef:BarChartAndPerformanceTableHeading>
    <oef:PerformanceNarrativeTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14479">
     
       
     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_S000051994_contentCd_SV9-PRO"
      id="ixv-14484"> 
        
      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_S000051994_contentCd_SV9-PRO"
      id="ixv-14491"> 
        
      Past performance (before and after taxes) is not an indication of future performance. 
        
     </oef:PerformancePastDoesNotIndicateFuture>
    <oef:PerformanceAvailabilityWebSiteAddress
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14497"> 
        
      www.fidelity.com  
     </oef:PerformanceAvailabilityWebSiteAddress>
    <oef:BarChartHeading
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14502">
     
       
     Year-by-Year Returns  
    
   </oef:BarChartHeading>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_2017"
      decimals="INF"
      id="ixv-51704"
      unitRef="pure">0.2174</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_2018"
      decimals="INF"
      id="ixv-51705"
      unitRef="pure">-0.0436</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_2019"
      decimals="INF"
      id="ixv-51706"
      unitRef="pure">0.3153</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_2020"
      decimals="INF"
      id="ixv-51707"
      unitRef="pure">0.1825</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_2021"
      decimals="INF"
      id="ixv-51708"
      unitRef="pure">0.2871</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_2022"
      decimals="INF"
      id="ixv-51709"
      unitRef="pure">-0.1813</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_2023"
      decimals="INF"
      id="ixv-51710"
      unitRef="pure">0.2623</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_2024"
      decimals="INF"
      id="ixv-51711"
      unitRef="pure">0.2501</oef:AnnlRtrPct>
    <oef:AnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_2025"
      decimals="INF"
      id="ixv-51712"
      unitRef="pure">0.1783</oef:AnnlRtrPct>
    <oef:HighestQuarterlyReturnLabel
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14610">
          &#160;&#160;&#160;Highest Quarter Return
        </oef:HighestQuarterlyReturnLabel>
    <oef:BarChartHighestQuarterlyReturn
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      decimals="4"
      id="ixv-51713"
      unitRef="pure">0.2061</oef:BarChartHighestQuarterlyReturn>
    <oef:BarChartHighestQuarterlyReturnDate
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14620">2020-06-30</oef:BarChartHighestQuarterlyReturnDate>
    <oef:LowestQuarterlyReturnLabel
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14625">
          &#160;&#160;&#160;Lowest Quarter Return
        </oef:LowestQuarterlyReturnLabel>
    <oef:BarChartLowestQuarterlyReturn
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      decimals="4"
      id="ixv-51714"
      unitRef="pure">-0.1972</oef:BarChartLowestQuarterlyReturn>
    <oef:BarChartLowestQuarterlyReturnDate
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14636">2020-03-31</oef:BarChartLowestQuarterlyReturnDate>
    <oef:YearToDateReturnLabel
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14641">
          &#160;&#160;&#160;Year-to-Date Return
        </oef:YearToDateReturnLabel>
    <oef:BarChartYearToDateReturn
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      decimals="4"
      id="ixv-51715"
      unitRef="pure">0.1021</oef:BarChartYearToDateReturn>
    <oef:BarChartYearToDateReturnDate
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14651">2026-06-30</oef:BarChartYearToDateReturnDate>
    <oef:PerformanceTableHeading
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14656">
     
       
     Average Annual Returns 
       
    
   </oef:PerformanceTableHeading>
    <oef:PerformanceTableNarrativeTextBlock
      contextRef="Pid_S000051994_contentCd_SV9-PRO"
      id="ixv-14661">
     
       
      
        
      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_S000051994_contentCd_SV9-PRO"
      id="ixv-14664"> 
        
      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_S000051994_contentCd_SV9-PRO"
      id="ixv-14671"> 
        
      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_S000051994_contentCd_SV9-PRO"
      id="ixv-14676"> 
        
      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_S000051994_Cid_C000163540_ReturnBeforeTaxes_01"
      id="ixv-14722">
         Return Before Taxes
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_ReturnBeforeTaxes_01"
      decimals="4"
      id="ixv-51716"
      unitRef="pure">0.1783</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_ReturnBeforeTaxes_05"
      decimals="4"
      id="ixv-51717"
      unitRef="pure">0.1440</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_ReturnBeforeTaxes_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSV9-PROS000051994AAR_A_RBT_loc"
      unitRef="pure">0.1574</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051994_Cid_C000163540_AfterTaxesOnDistributions_01"
      id="ixv-14738">
         Return After Taxes on Distributions
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_AfterTaxesOnDistributions_01"
      decimals="4"
      id="ixv-51719"
      unitRef="pure">0.1767</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_AfterTaxesOnDistributions_05"
      decimals="4"
      id="ixv-51720"
      unitRef="pure">0.1248</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_AfterTaxesOnDistributions_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSV9-PROS000051994AAR_A_ATD_loc"
      unitRef="pure">0.1446</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051994_Cid_C000163540_AfterTaxesOnDistributionsAndSales_01"
      id="ixv-14754">
         Return After Taxes on Distributions and Sale of Fund Shares
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_AfterTaxesOnDistributionsAndSales_01"
      decimals="4"
      id="ixv-51722"
      unitRef="pure">0.1066</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_AfterTaxesOnDistributionsAndSales_05"
      decimals="4"
      id="ixv-51723"
      unitRef="pure">0.1097</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Cid_C000163540_AfterTaxesOnDistributionsAndSales_AverageAnnualReturnSinceInception"
      decimals="4"
      id="footnoteSV9-PROS000051994AAR_A_ATDS_loc"
      unitRef="pure">0.1290</oef:AvgAnnlRtrPct>
    <oef:AverageAnnualReturnLabel
      contextRef="Pid_S000051994_Indexid_SP001_contentCd_SV9-PRO_01"
      id="ixv-14771">
         S&amp;P 500&#xae; Index
        </oef:AverageAnnualReturnLabel>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Indexid_SP001_contentCd_SV9-PRO_01"
      decimals="4"
      id="ixv-51725"
      unitRef="pure">0.1788</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Indexid_SP001_contentCd_SV9-PRO_05"
      decimals="4"
      id="ixv-51726"
      unitRef="pure">0.1442</oef:AvgAnnlRtrPct>
    <oef:AvgAnnlRtrPct
      contextRef="Pid_S000051994_Indexid_SP001_contentCd_SV9-PRO_AverageAnnualReturnSinceInception"
      decimals="4"
      id="ixv-51727"
      unitRef="pure">0.1577</oef:AvgAnnlRtrPct>
    <oef:AnnualReturnInceptionDate contextRef="Pid_S000051994_Cid_C000163540" id="ixv-14812">2016-02-02</oef:AnnualReturnInceptionDate>
    <link:footnoteLink
      xlink:role="http://www.xbrl.org/2003/role/link"
      xlink:type="extended">
        <link:loc
          xlink:href="#footnoteS000050321SV3-PROAOE_AC000158877_FW"
          xlink:label="footnoteS000050321SV3-PROAOE_AC000158877_FW"
          xlink:type="locator"/>
        <link:footnote id="footnoteS000050321SV3-PROAOE_A" xlink:label="footnoteS000050321SV3-PROAOE_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:4.5pt; vertical-align:3pt; ">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; font-style:italic; ">Fidelity Management &amp; Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.05% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through </xhtml:span><xhtml:span> </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; font-style:italic; ">November 30, 2027</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; font-style:italic; ">. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteS000050321SV3-PROAOE_AC000158877_FW"
          xlink:to="footnoteS000050321SV3-PROAOE_A"
          xlink:type="arc"/>
        <link:loc
          xlink:href="#footnoteSV3-PROS000050321AAR_A_BM_1_01"
          xlink:label="footnoteSV3-PROS000050321AAR_A_BM_1_01"
          xlink:type="locator"/>
        <link:footnote id="footnoteSV3-PROS000050321AAR_A" xlink:label="footnoteSV3-PROS000050321AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:4.5pt; vertical-align:3pt; ">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span
      class="redlineClass"
      style="font-family:Arial; font-size:8.5pt; font-style:italic; ">The inception date for the index was after the fund commenced operations, and returns for this time period are not yet available.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
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        <link:footnote id="footnoteS000051993SV8-PROAOE_A" xlink:label="footnoteS000051993SV8-PROAOE_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.67pt; vertical-align:super">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">Fidelity Management &amp; Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.07% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">November 30, </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
       </xhtml:span><xhtml:span
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      style="font-family:Arial; font-size:8.5pt; font-style:italic; ">2027</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
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        <link:footnote id="footnoteSV8-PROS000051993AAR_A" xlink:label="footnoteSV8-PROS000051993AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.67pt; vertical-align:super">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">February 2, 2016</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
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        <link:loc
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        <link:footnote id="footnoteSV8-PROS000051993AAR_B" xlink:label="footnoteSV8-PROS000051993AAR_B" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">B</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:10pt">The </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">inception date for the index was after the fund commenced operations, and returns for this time period are not yet available.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
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        <link:loc
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        <link:footnote id="footnoteURX-I-PROS000033639AAR_A" xlink:label="footnoteURX-I-PROS000033639AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:10pt">The </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">inception date for the index was after the fund commenced operations, and returns for this time period are not yet available.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
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        <link:loc
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        <link:loc
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        <link:loc
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        <link:footnote id="footnoteSV4-PROS000051137AAR_A" xlink:label="footnoteSV4-PROS000051137AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
      </xhtml:span><xhtml:span
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        <link:footnoteArc
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          xlink:from="footnoteSV4-PROS000051137AAR_A_BM_1_10"
          xlink:to="footnoteSV4-PROS000051137AAR_A"
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        <link:loc
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        <link:footnote id="footnoteSY1-PROS000056275AAR_A" xlink:label="footnoteSY1-PROS000056275AAR_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.5pt; vertical-align:3pt">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">From </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">February 9, 2017</xhtml:span><xhtml:span> </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
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        <link:loc
          xlink:href="#footnoteSY1-PROS000056275AAR_A_ATD_loc"
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        <link:footnoteArc
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        <link:loc
          xlink:href="#footnoteSY1-PROS000056275AAR_A_ATDS_loc"
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        <link:loc
          xlink:href="#footnoteSY1-PROS000056275AAR_B_BM_1_01"
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        <link:footnote id="footnoteSY1-PROS000056275AAR_B" xlink:label="footnoteSY1-PROS000056275AAR_B" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span
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      style="font-family:Arial; font-size:4.5pt; vertical-align:3pt; ">B</xhtml:span><xhtml:span> </xhtml:span><xhtml:span
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      style="font-family:Arial; font-size:8.5pt; font-style:italic; ">The inception date for the index was after the fund commenced operations, and returns for this time period are not yet available.</xhtml:span><xhtml:span> </xhtml:span></xhtml:div></link:footnote>
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          xlink:from="footnoteSY1-PROS000056275AAR_B_BM_1_01"
          xlink:to="footnoteSY1-PROS000056275AAR_B"
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        <link:loc
          xlink:href="#footnoteSY1-PROS000056275AAR_B_BM_1_05"
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        <link:footnoteArc
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        <link:loc
          xlink:href="#footnoteSY1-PROS000056275AAR_B_BM_1_loc"
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        <link:footnoteArc
          xlink:arcrole="http://www.xbrl.org/2003/arcrole/fact-footnote"
          xlink:from="footnoteSY1-PROS000056275AAR_B_BM_1_loc"
          xlink:to="footnoteSY1-PROS000056275AAR_B"
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        <link:loc
          xlink:href="#footnoteS000051994SV9-PROAOE_AC000163540_FW"
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        <link:footnote id="footnoteS000051994SV9-PROAOE_A" xlink:label="footnoteS000051994SV9-PROAOE_A" xlink:role="http://www.xbrl.org/2003/role/footnote" xlink:type="resource" xml:lang="en-US"><xhtml:div style="padding:2px"><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:4.67pt; vertical-align:super">A</xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">Fidelity Management &amp; Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.015% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through </xhtml:span><xhtml:span> </xhtml:span><xhtml:span style="font-family:Arial; font-size:8.5pt; font-style:italic">November 30, </xhtml:span><xhtml:span class="delClass" style="color:#ff0000; display:none;"> 
       </xhtml:span><xhtml:span
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        <link:loc
          xlink:href="#footnoteSV9-PROS000051994AAR_A_RBT_loc"
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          xlink:href="#footnoteSV9-PROS000051994AAR_A_ATD_loc"
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