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        <period>
            <instant>2024-10-31</instant>
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            <startDate>2024-04-30</startDate>
            <endDate>2024-10-31</endDate>
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    <unit id="usd">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="pure">
        <measure>pure</measure>
    </unit>
    <unit id="holding">
        <measure>shares</measure>
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    <dei:DocumentType contextRef="Trust" id="ixv-142628">N-CSRS</dei:DocumentType>
    <dei:AmendmentFlag contextRef="Trust" id="ixv-142629">false</dei:AmendmentFlag>
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    <dei:EntityInvCompanyType contextRef="Trust" id="ixv-142631">N-1A</dei:EntityInvCompanyType>
    <dei:EntityRegistrantName contextRef="Trust" id="ixv-142632">Fidelity Salem Street Trust</dei:EntityRegistrantName>
    <dei:DocumentPeriodEndDate contextRef="Trust" id="ixv-100">2024-10-31</dei:DocumentPeriodEndDate>
    <oef:FundName contextRef="C000177585_ClassMember" id="ixv-112">Fidelity Flex&#xae; Mid Cap Index Fund</oef:FundName>
    <oef:ClassName contextRef="C000177585_ClassMember" id="ixv-115">Fidelity Flex&#xae; Mid Cap Index Fund</oef:ClassName>
    <dei:TradingSymbol contextRef="C000177585_ClassMember" id="ixv-119">FLAPX</dei:TradingSymbol>
    <oef:AnnlOrSemiAnnlStatementTextBlock contextRef="C000177585_ClassMember" id="ixv-138">This semi-annual shareholder report contains information about Fidelity Flex&#xae; Mid Cap Index Fund for the period May 1, 2024 to October 31, 2024.</oef:AnnlOrSemiAnnlStatementTextBlock>
    <oef:ShareholderReportAnnualOrSemiAnnual contextRef="C000177585_ClassMember" id="ixv-140">semi-annual shareholder report</oef:ShareholderReportAnnualOrSemiAnnual>
    <oef:AddlInfoTextBlock contextRef="C000177585_ClassMember" id="ixv-145">You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.</oef:AddlInfoTextBlock>
    <oef:AddlInfoWebsite contextRef="C000177585_ClassMember" id="ixv-147">fundresearch.fidelity.com/prospectus/sec</oef:AddlInfoWebsite>
    <oef:AddlInfoPhoneNumber contextRef="C000177585_ClassMember" id="ixv-150">1-800-544-3455</oef:AddlInfoPhoneNumber>
    <oef:AddlInfoEmail contextRef="C000177585_ClassMember" id="ixv-153">fidfunddocuments@fidelity.com</oef:AddlInfoEmail>
    <oef:ExpensesTextBlock contextRef="C000177585_ClassMember" id="ixv-160">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;What were your Fund costs for the last six months?&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(based on hypothetical $10,000 investment)&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="0" style="border-collapse:collapse;border-style:none;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:45%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs of a $10,000 investment&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs paid as a percentage of a $10,000 investment &lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:45%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fidelity Flex&#xae; Mid Cap Index Fund&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$ &lt;/span&gt;0&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;A&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;0.00&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;B&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;A &lt;/span&gt;&lt;span style="font-family:'Fidelity Sans Cd';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Amount represents less than $.50&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;B &lt;/span&gt;&lt;span style="font-family:'Fidelity Sans Cd';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Amount represents less than 0.005%&lt;/span&gt;&lt;/div&gt;
&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:ExpensesTextBlock>
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      unitRef="usd">0</oef:ExpensesPaidAmt>
    <oef:ExpenseRatioPct
      contextRef="C000177585_ClassMember"
      decimals="INF"
      id="ixv-144506"
      unitRef="pure">0.0000</oef:ExpenseRatioPct>
    <oef:AddlFundStatisticsTextBlock contextRef="C000177585_ClassMember" id="ixv-210">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;Key Fund Statistics&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(as of October 31, 2024)&lt;/span&gt;&lt;/div&gt;
&lt;div&gt;&lt;span style="font-size:11px;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="1" style="border-collapse:separate;border-style:none;margin:auto;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:63%; " valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:12px;color:#000000;font-style:normal;font-weight:bold;"&gt;KEY FACTS&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fund Size&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$&lt;/span&gt;458,809,372&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Number of Holdings&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;816&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Portfolio Turnover&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;29&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:AddlFundStatisticsTextBlock>
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      id="ixv-144507"
      unitRef="usd">458809372</us-gaap:AssetsNet>
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      id="ixv-144508"
      unitRef="holding">816</oef:HoldingsCount>
    <us-gaap:InvestmentCompanyPortfolioTurnover
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      decimals="INF"
      id="ixv-144509"
      unitRef="pure">0.29</us-gaap:InvestmentCompanyPortfolioTurnover>
    <oef:HoldingsTableTextBlock contextRef="C000177585_ClassMember" id="ixv-270">
&#160;
MARKET SECTORS
(% of Fund's net assets)

&#160;

&#160;


Industrials

17.5

&#160;


Financials

16.2

&#160;


Information Technology

12.5

&#160;


Consumer Discretionary

10.6

&#160;


Health Care

9.7

&#160;


Real Estate

7.9

&#160;


Materials

5.9

&#160;


Utilities

5.7

&#160;


Energy

5.2

&#160;


Consumer Staples

4.9

&#160;


Communication Services

3.6

&#160;


&#160;




Common Stocks

99.7


Preferred Stocks

0.0


Short-Term Investments and Net Other Assets (Liabilities)

0.3




ASSET ALLOCATION (% of Fund's net assets)









United States

98.7


Brazil

0.5


Korea (South)

0.3


Canada

0.1


Bermuda

0.1


United Kingdom

0.1


Belgium

0.1


Puerto Rico

0.1


Japan

0.0




GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)


&#160;


&#160;







</oef:HoldingsTableTextBlock>
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      id="ixv-144510"
      unitRef="pure">0.175</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_MS_FinancialsSectorMember"
      decimals="INF"
      id="ixv-144511"
      unitRef="pure">0.162</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_MS_InformationTechnologySectorMember"
      decimals="INF"
      id="ixv-144512"
      unitRef="pure">0.125</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_MS_ConsumerDiscretionarySectorMember"
      decimals="INF"
      id="ixv-144513"
      unitRef="pure">0.106</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_MS_HealthcareSectorMember"
      decimals="INF"
      id="ixv-144514"
      unitRef="pure">0.097</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_MS_RealEstateSectorMember"
      decimals="INF"
      id="ixv-144515"
      unitRef="pure">0.079</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_MS_MaterialsSectorMember"
      decimals="INF"
      id="ixv-144516"
      unitRef="pure">0.059</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_MS_UtilitiesSectorMember"
      decimals="INF"
      id="ixv-144517"
      unitRef="pure">0.057</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_MS_EnergySectorMember"
      decimals="INF"
      id="ixv-144518"
      unitRef="pure">0.052</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_MS_ConsumerStaplesSectorMember"
      decimals="INF"
      id="ixv-144519"
      unitRef="pure">0.049</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_MS_CommunicationsSectorMember"
      decimals="INF"
      id="ixv-144520"
      unitRef="pure">0.036</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_AA_CommonStocks_Member"
      decimals="INF"
      id="ixv-144521"
      unitRef="pure">0.997</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_AA_PreferredStocks_Member"
      decimals="INF"
      id="ixv-144522"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_AA_ShortTermInvestmentsandNetOtherAssetsLiabilities_Member"
      decimals="INF"
      id="ixv-144523"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_GD_US_Member"
      decimals="INF"
      id="ixv-144524"
      unitRef="pure">0.987</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_GD_BR_Member"
      decimals="INF"
      id="ixv-144525"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_GD_KR_Member"
      decimals="INF"
      id="ixv-144526"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_GD_CA_Member"
      decimals="INF"
      id="ixv-144527"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_GD_BM_Member"
      decimals="INF"
      id="ixv-144528"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_GD_GB_Member"
      decimals="INF"
      id="ixv-144529"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_GD_BE_Member"
      decimals="INF"
      id="ixv-144530"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_GD_PR_Member"
      decimals="INF"
      id="ixv-144531"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_GD_JP_Member"
      decimals="INF"
      id="ixv-144532"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:LargestHoldingsTableTextBlock contextRef="C000177585_ClassMember" id="ixv-506">TOP HOLDINGS
(% of Fund's net assets)

&#160;

&#160;


Palantir Technologies Inc Class A

0.8


&#160;


Digital Realty Trust Inc

0.6


&#160;


Williams Cos Inc/The

0.5


&#160;


Arthur J Gallagher &amp; Co

0.5


&#160;


AFLAC Inc

0.5


&#160;


Hilton Worldwide Holdings Inc

0.5


&#160;


ONEOK Inc

0.5


&#160;


Bank of New York Mellon Corp/The

0.5


&#160;


Simon Property Group Inc

0.5


&#160;


United Rentals Inc

0.5


&#160;


&#160;

5.4

&#160;



</oef:LargestHoldingsTableTextBlock>
    <oef:PctOfNav
      contextRef="C000177585_TH_0_Member"
      decimals="INF"
      id="ixv-144533"
      unitRef="pure">0.008</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_TH_1_Member"
      decimals="INF"
      id="ixv-144534"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_TH_2_Member"
      decimals="INF"
      id="ixv-144535"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177585_TH_3_Member"
      decimals="INF"
      id="ixv-144536"
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      id="ixv-144537"
      unitRef="pure">0.005</oef:PctOfNav>
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      id="ixv-144538"
      unitRef="pure">0.005</oef:PctOfNav>
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      id="ixv-144539"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
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      decimals="INF"
      id="ixv-144540"
      unitRef="pure">0.005</oef:PctOfNav>
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      id="ixv-144541"
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    <dei:DocumentPeriodEndDate contextRef="Trust" id="ixv-677">2024-10-31</dei:DocumentPeriodEndDate>
    <oef:FundName contextRef="C000203457_ClassMember" id="ixv-689">Fidelity&#xae; Series Large Cap Growth Index Fund</oef:FundName>
    <oef:ClassName contextRef="C000203457_ClassMember" id="ixv-692">Fidelity&#xae; Series Large Cap Growth Index Fund</oef:ClassName>
    <dei:TradingSymbol contextRef="C000203457_ClassMember" id="ixv-696">FHOFX</dei:TradingSymbol>
    <oef:AnnlOrSemiAnnlStatementTextBlock contextRef="C000203457_ClassMember" id="ixv-715">This semi-annual shareholder report contains information about Fidelity&#xae; Series Large Cap Growth Index Fund for the period May 1, 2024 to October 31, 2024.</oef:AnnlOrSemiAnnlStatementTextBlock>
    <oef:ShareholderReportAnnualOrSemiAnnual contextRef="C000203457_ClassMember" id="ixv-717">semi-annual shareholder report</oef:ShareholderReportAnnualOrSemiAnnual>
    <oef:AddlInfoTextBlock contextRef="C000203457_ClassMember" id="ixv-722">You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544.</oef:AddlInfoTextBlock>
    <oef:AddlInfoWebsite contextRef="C000203457_ClassMember" id="ixv-724">fundresearch.fidelity.com/prospectus/sec</oef:AddlInfoWebsite>
    <oef:AddlInfoPhoneNumber contextRef="C000203457_ClassMember" id="ixv-727">1-800-544-8544</oef:AddlInfoPhoneNumber>
    <oef:ExpensesTextBlock contextRef="C000203457_ClassMember" id="ixv-734">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;What were your Fund costs for the last six months?&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(based on hypothetical $10,000 investment)&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="0" style="border-collapse:collapse;border-style:none;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:45%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs of a $10,000 investment&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs paid as a percentage of a $10,000 investment &lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:45%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fidelity&#xae; Series Large Cap Growth Index Fund&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$ &lt;/span&gt;0&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;A&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;0.00&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;B&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;A &lt;/span&gt;&lt;span style="font-family:'Fidelity Sans Cd';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Amount represents less than $.50&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;B &lt;/span&gt;&lt;span style="font-family:'Fidelity Sans Cd';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Amount represents less than 0.005%&lt;/span&gt;&lt;/div&gt;
&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:ExpensesTextBlock>
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    <oef:ExpenseRatioPct
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    <oef:AddlFundStatisticsTextBlock contextRef="C000203457_ClassMember" id="ixv-784">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;Key Fund Statistics&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(as of October 31, 2024)&lt;/span&gt;&lt;/div&gt;
&lt;div&gt;&lt;span style="font-size:11px;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="1" style="border-collapse:separate;border-style:none;margin:auto;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:63%; " valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:12px;color:#000000;font-style:normal;font-weight:bold;"&gt;KEY FACTS&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fund Size&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$&lt;/span&gt;1,488,228,107&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Number of Holdings&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;399&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Portfolio Turnover&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;43&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:AddlFundStatisticsTextBlock>
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      unitRef="holding">399</oef:HoldingsCount>
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      unitRef="pure">0.43</us-gaap:InvestmentCompanyPortfolioTurnover>
    <oef:HoldingsTableTextBlock contextRef="C000203457_ClassMember" id="ixv-844">
&#160;
MARKET SECTORS
(% of Fund's net assets)

&#160;

&#160;


Information Technology

48.7

&#160;


Consumer Discretionary

14.1

&#160;


Communication Services

13.1

&#160;


Health Care

7.5

&#160;


Financials

6.6

&#160;


Industrials

4.6

&#160;


Consumer Staples

3.5

&#160;


Materials

0.6

&#160;


Real Estate

0.6

&#160;


Energy

0.4

&#160;


Utilities

0.2

&#160;


&#160;




Common Stocks

99.9


Short-Term Investments and Net Other Assets (Liabilities)

0.1




ASSET ALLOCATION (% of Fund's net assets)









United States

99.7


Brazil

0.2


Korea (South)

0.1


Mexico

0.0


Puerto Rico

0.0




GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)




&#160;







</oef:HoldingsTableTextBlock>
    <oef:PctOfNav
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      decimals="INF"
      id="ixv-144548"
      unitRef="pure">0.487</oef:PctOfNav>
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      decimals="INF"
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      unitRef="pure">0.141</oef:PctOfNav>
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      decimals="INF"
      id="ixv-144550"
      unitRef="pure">0.131</oef:PctOfNav>
    <oef:PctOfNav
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      decimals="INF"
      id="ixv-144551"
      unitRef="pure">0.075</oef:PctOfNav>
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      decimals="INF"
      id="ixv-144552"
      unitRef="pure">0.066</oef:PctOfNav>
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      decimals="INF"
      id="ixv-144553"
      unitRef="pure">0.046</oef:PctOfNav>
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      decimals="INF"
      id="ixv-144554"
      unitRef="pure">0.035</oef:PctOfNav>
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      decimals="INF"
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      decimals="INF"
      id="ixv-144557"
      unitRef="pure">0.004</oef:PctOfNav>
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      decimals="INF"
      id="ixv-144558"
      unitRef="pure">0.002</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_AA_CommonStocks_Member"
      decimals="INF"
      id="ixv-144559"
      unitRef="pure">0.999</oef:PctOfNav>
    <oef:PctOfNav
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      decimals="INF"
      id="ixv-144560"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_GD_US_Member"
      decimals="INF"
      id="ixv-144561"
      unitRef="pure">0.997</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_GD_BR_Member"
      decimals="INF"
      id="ixv-144562"
      unitRef="pure">0.002</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_GD_KR_Member"
      decimals="INF"
      id="ixv-144563"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_GD_MX_Member"
      decimals="INF"
      id="ixv-144564"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:PctOfNav
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    <oef:LargestHoldingsTableTextBlock contextRef="C000203457_ClassMember" id="ixv-1047">TOP HOLDINGS
(% of Fund's net assets)

&#160;

&#160;


Apple Inc

12.0


&#160;


NVIDIA Corp

11.3


&#160;


Microsoft Corp

11.1


&#160;


Amazon.com Inc

6.4


&#160;


Meta Platforms Inc Class A

4.5


&#160;


Alphabet Inc Class A

3.7


&#160;


Alphabet Inc Class C

3.1


&#160;


Broadcom Inc

2.8


&#160;


Tesla Inc

2.6


&#160;


Eli Lilly &amp; Co

2.5


&#160;


&#160;

60.0

&#160;



</oef:LargestHoldingsTableTextBlock>
    <oef:PctOfNav
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      decimals="INF"
      id="ixv-144566"
      unitRef="pure">0.120</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_TH_1_Member"
      decimals="INF"
      id="ixv-144567"
      unitRef="pure">0.113</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_TH_2_Member"
      decimals="INF"
      id="ixv-144568"
      unitRef="pure">0.111</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_TH_3_Member"
      decimals="INF"
      id="ixv-144569"
      unitRef="pure">0.064</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_TH_4_Member"
      decimals="INF"
      id="ixv-144570"
      unitRef="pure">0.045</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_TH_5_Member"
      decimals="INF"
      id="ixv-144571"
      unitRef="pure">0.037</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_TH_6_Member"
      decimals="INF"
      id="ixv-144572"
      unitRef="pure">0.031</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_TH_7_Member"
      decimals="INF"
      id="ixv-144573"
      unitRef="pure">0.028</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_TH_8_Member"
      decimals="INF"
      id="ixv-144574"
      unitRef="pure">0.026</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000203457_TH_9_Member"
      decimals="INF"
      id="ixv-144575"
      unitRef="pure">0.025</oef:PctOfNav>
    <dei:DocumentPeriodEndDate contextRef="Trust" id="ixv-1218">2024-10-31</dei:DocumentPeriodEndDate>
    <oef:FundName contextRef="C000170033_ClassMember" id="ixv-1230">Fidelity&#xae; Large Cap Growth Index Fund</oef:FundName>
    <oef:ClassName contextRef="C000170033_ClassMember" id="ixv-1233">Fidelity&#xae; Large Cap Growth Index Fund</oef:ClassName>
    <dei:TradingSymbol contextRef="C000170033_ClassMember" id="ixv-1237">FSPGX</dei:TradingSymbol>
    <oef:AnnlOrSemiAnnlStatementTextBlock contextRef="C000170033_ClassMember" id="ixv-1256">This semi-annual shareholder report contains information about Fidelity&#xae; Large Cap Growth Index Fund for the period May 1, 2024 to October 31, 2024.</oef:AnnlOrSemiAnnlStatementTextBlock>
    <oef:ShareholderReportAnnualOrSemiAnnual contextRef="C000170033_ClassMember" id="ixv-1258">semi-annual shareholder report</oef:ShareholderReportAnnualOrSemiAnnual>
    <oef:AddlInfoTextBlock contextRef="C000170033_ClassMember" id="ixv-1263">You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.</oef:AddlInfoTextBlock>
    <oef:AddlInfoWebsite contextRef="C000170033_ClassMember" id="ixv-1265">fundresearch.fidelity.com/prospectus/sec</oef:AddlInfoWebsite>
    <oef:AddlInfoPhoneNumber contextRef="C000170033_ClassMember" id="ixv-1268">1-800-544-8544</oef:AddlInfoPhoneNumber>
    <oef:AddlInfoEmail contextRef="C000170033_ClassMember" id="ixv-1271">fidfunddocuments@fidelity.com</oef:AddlInfoEmail>
    <oef:ExpensesTextBlock contextRef="C000170033_ClassMember" id="ixv-1278">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;What were your Fund costs for the last six months?&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(based on hypothetical $10,000 investment)&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="0" style="border-collapse:collapse;border-style:none;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:45%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs of a $10,000 investment&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs paid as a percentage of a $10,000 investment &lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:45%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fidelity&#xae; Large Cap Growth Index Fund&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$ &lt;/span&gt;2&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;0.03&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:ExpensesTextBlock>
    <oef:ExpensesPaidAmt
      contextRef="C000170033_ClassMember"
      decimals="0"
      id="ixv-144576"
      unitRef="usd">2</oef:ExpensesPaidAmt>
    <oef:ExpenseRatioPct
      contextRef="C000170033_ClassMember"
      decimals="INF"
      id="ixv-144577"
      unitRef="pure">0.0003</oef:ExpenseRatioPct>
    <oef:AddlFundStatisticsTextBlock contextRef="C000170033_ClassMember" id="ixv-1318">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;Key Fund Statistics&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(as of October 31, 2024)&lt;/span&gt;&lt;/div&gt;
&lt;div&gt;&lt;span style="font-size:11px;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="1" style="border-collapse:separate;border-style:none;margin:auto;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:63%; " valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:12px;color:#000000;font-style:normal;font-weight:bold;"&gt;KEY FACTS&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fund Size&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$&lt;/span&gt;28,433,616,039&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Number of Holdings&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;399&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Portfolio Turnover&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;13&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:AddlFundStatisticsTextBlock>
    <us-gaap:AssetsNet
      contextRef="C000170033_InstantMember"
      decimals="0"
      id="ixv-144578"
      unitRef="usd">28433616039</us-gaap:AssetsNet>
    <oef:HoldingsCount
      contextRef="C000170033_InstantMember"
      decimals="INF"
      id="ixv-144579"
      unitRef="holding">399</oef:HoldingsCount>
    <us-gaap:InvestmentCompanyPortfolioTurnover
      contextRef="C000170033_ClassMember"
      decimals="INF"
      id="ixv-144580"
      unitRef="pure">0.13</us-gaap:InvestmentCompanyPortfolioTurnover>
    <oef:HoldingsTableTextBlock contextRef="C000170033_ClassMember" id="ixv-1378">
&#160;
MARKET SECTORS
(% of Fund's net assets)

&#160;

&#160;


Information Technology

48.5

&#160;


Consumer Discretionary

14.1

&#160;


Communication Services

13.1

&#160;


Health Care

7.5

&#160;


Financials

6.6

&#160;


Industrials

4.6

&#160;


Consumer Staples

3.5

&#160;


Materials

0.6

&#160;


Real Estate

0.6

&#160;


Energy

0.4

&#160;


Utilities

0.2

&#160;


&#160;




Common Stocks

99.7


Short-Term Investments and Net Other Assets (Liabilities)

0.3




ASSET ALLOCATION (% of Fund's net assets)









United States

99.7


Brazil

0.2


Korea (South)

0.1


Mexico

0.0


Puerto Rico

0.0




GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)




&#160;







</oef:HoldingsTableTextBlock>
    <oef:PctOfNav
      contextRef="C000170033_MS_InformationTechnologySectorMember"
      decimals="INF"
      id="ixv-144581"
      unitRef="pure">0.485</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_MS_ConsumerDiscretionarySectorMember"
      decimals="INF"
      id="ixv-144582"
      unitRef="pure">0.141</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_MS_CommunicationsSectorMember"
      decimals="INF"
      id="ixv-144583"
      unitRef="pure">0.131</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_MS_HealthcareSectorMember"
      decimals="INF"
      id="ixv-144584"
      unitRef="pure">0.075</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_MS_FinancialsSectorMember"
      decimals="INF"
      id="ixv-144585"
      unitRef="pure">0.066</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_MS_IndustrialSectorMember"
      decimals="INF"
      id="ixv-144586"
      unitRef="pure">0.046</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_MS_ConsumerStaplesSectorMember"
      decimals="INF"
      id="ixv-144587"
      unitRef="pure">0.035</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_MS_MaterialsSectorMember"
      decimals="INF"
      id="ixv-144588"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_MS_RealEstateSectorMember"
      decimals="INF"
      id="ixv-144589"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_MS_EnergySectorMember"
      decimals="INF"
      id="ixv-144590"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_MS_UtilitiesSectorMember"
      decimals="INF"
      id="ixv-144591"
      unitRef="pure">0.002</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_AA_CommonStocks_Member"
      decimals="INF"
      id="ixv-144592"
      unitRef="pure">0.997</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_AA_ShortTermInvestmentsandNetOtherAssetsLiabilities_Member"
      decimals="INF"
      id="ixv-144593"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_GD_US_Member"
      decimals="INF"
      id="ixv-144594"
      unitRef="pure">0.997</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_GD_BR_Member"
      decimals="INF"
      id="ixv-144595"
      unitRef="pure">0.002</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_GD_KR_Member"
      decimals="INF"
      id="ixv-144596"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_GD_MX_Member"
      decimals="INF"
      id="ixv-144597"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_GD_PR_Member"
      decimals="INF"
      id="ixv-144598"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:LargestHoldingsTableTextBlock contextRef="C000170033_ClassMember" id="ixv-1581">TOP HOLDINGS
(% of Fund's net assets)

&#160;

&#160;


Apple Inc

12.0


&#160;


NVIDIA Corp

11.3


&#160;


Microsoft Corp

11.1


&#160;


Amazon.com Inc

6.4


&#160;


Meta Platforms Inc Class A

4.5


&#160;


Alphabet Inc Class A

3.7


&#160;


Alphabet Inc Class C

3.0


&#160;


Broadcom Inc

2.8


&#160;


Tesla Inc

2.6


&#160;


Eli Lilly &amp; Co

2.5


&#160;


&#160;

59.9

&#160;



</oef:LargestHoldingsTableTextBlock>
    <oef:PctOfNav
      contextRef="C000170033_TH_0_Member"
      decimals="INF"
      id="ixv-144599"
      unitRef="pure">0.120</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_TH_1_Member"
      decimals="INF"
      id="ixv-144600"
      unitRef="pure">0.113</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_TH_2_Member"
      decimals="INF"
      id="ixv-144601"
      unitRef="pure">0.111</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_TH_3_Member"
      decimals="INF"
      id="ixv-144602"
      unitRef="pure">0.064</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_TH_4_Member"
      decimals="INF"
      id="ixv-144603"
      unitRef="pure">0.045</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_TH_5_Member"
      decimals="INF"
      id="ixv-144604"
      unitRef="pure">0.037</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_TH_6_Member"
      decimals="INF"
      id="ixv-144605"
      unitRef="pure">0.030</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_TH_7_Member"
      decimals="INF"
      id="ixv-144606"
      unitRef="pure">0.028</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_TH_8_Member"
      decimals="INF"
      id="ixv-144607"
      unitRef="pure">0.026</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170033_TH_9_Member"
      decimals="INF"
      id="ixv-144608"
      unitRef="pure">0.025</oef:PctOfNav>
    <dei:DocumentPeriodEndDate contextRef="Trust" id="ixv-1752">2024-10-31</dei:DocumentPeriodEndDate>
    <oef:FundName contextRef="C000177589_ClassMember" id="ixv-1764">Fidelity Flex&#xae; Small Cap Index Fund</oef:FundName>
    <oef:ClassName contextRef="C000177589_ClassMember" id="ixv-1767">Fidelity Flex&#xae; Small Cap Index Fund</oef:ClassName>
    <dei:TradingSymbol contextRef="C000177589_ClassMember" id="ixv-1771">FLXSX</dei:TradingSymbol>
    <oef:AnnlOrSemiAnnlStatementTextBlock contextRef="C000177589_ClassMember" id="ixv-1790">This semi-annual shareholder report contains information about Fidelity Flex&#xae; Small Cap Index Fund for the period May 1, 2024 to October 31, 2024.</oef:AnnlOrSemiAnnlStatementTextBlock>
    <oef:ShareholderReportAnnualOrSemiAnnual contextRef="C000177589_ClassMember" id="ixv-1792">semi-annual shareholder report</oef:ShareholderReportAnnualOrSemiAnnual>
    <oef:AddlInfoTextBlock contextRef="C000177589_ClassMember" id="ixv-1797">You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.</oef:AddlInfoTextBlock>
    <oef:AddlInfoWebsite contextRef="C000177589_ClassMember" id="ixv-1799">fundresearch.fidelity.com/prospectus/sec</oef:AddlInfoWebsite>
    <oef:AddlInfoPhoneNumber contextRef="C000177589_ClassMember" id="ixv-1802">1-800-544-3455</oef:AddlInfoPhoneNumber>
    <oef:AddlInfoEmail contextRef="C000177589_ClassMember" id="ixv-1805">fidfunddocuments@fidelity.com</oef:AddlInfoEmail>
    <oef:ExpensesTextBlock contextRef="C000177589_ClassMember" id="ixv-1812">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;What were your Fund costs for the last six months?&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(based on hypothetical $10,000 investment)&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="0" style="border-collapse:collapse;border-style:none;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:45%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs of a $10,000 investment&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs paid as a percentage of a $10,000 investment &lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:45%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fidelity Flex&#xae; Small Cap Index Fund&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$ &lt;/span&gt;0&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;A&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;0.00&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;B&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;A &lt;/span&gt;&lt;span style="font-family:'Fidelity Sans Cd';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Amount represents less than $.50&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:6px;color:#000000;font-style:normal;vertical-align:4px;font-weight:normal;"&gt;B &lt;/span&gt;&lt;span style="font-family:'Fidelity Sans Cd';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Amount represents less than 0.005%&lt;/span&gt;&lt;/div&gt;
&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:ExpensesTextBlock>
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    <oef:ExpenseRatioPct
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      decimals="INF"
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    <oef:AddlFundStatisticsTextBlock contextRef="C000177589_ClassMember" id="ixv-1862">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;Key Fund Statistics&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(as of October 31, 2024)&lt;/span&gt;&lt;/div&gt;
&lt;div&gt;&lt;span style="font-size:11px;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="1" style="border-collapse:separate;border-style:none;margin:auto;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:63%; " valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:12px;color:#000000;font-style:normal;font-weight:bold;"&gt;KEY FACTS&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fund Size&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$&lt;/span&gt;423,819,778&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Number of Holdings&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;1,982&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Portfolio Turnover&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;15&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:AddlFundStatisticsTextBlock>
    <us-gaap:AssetsNet
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      id="ixv-144611"
      unitRef="usd">423819778</us-gaap:AssetsNet>
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      unitRef="holding">1982</oef:HoldingsCount>
    <us-gaap:InvestmentCompanyPortfolioTurnover
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      decimals="INF"
      id="ixv-144613"
      unitRef="pure">0.15</us-gaap:InvestmentCompanyPortfolioTurnover>
    <oef:HoldingsTableTextBlock contextRef="C000177589_ClassMember" id="ixv-1922">
&#160;
MARKET SECTORS
(% of Fund's net assets)

&#160;

&#160;


Financials

18.6

&#160;


Health Care

17.2

&#160;


Industrials

17.0

&#160;


Information Technology

12.6

&#160;


Consumer Discretionary

9.7

&#160;


Real Estate

6.3

&#160;


Energy

5.1

&#160;


Materials

4.6

&#160;


Utilities

2.9

&#160;


Consumer Staples

2.7

&#160;


Communication Services

2.6

&#160;


&#160;




Common Stocks

99.3


Short-Term Investments and Net Other Assets (Liabilities)

0.7




ASSET ALLOCATION (% of Fund's net assets)









United States

97.1


Canada

0.6


Thailand

0.3


Puerto Rico

0.3


Argentina

0.3


Norway

0.2


Brazil

0.2


Cameroon

0.1


Monaco

0.1


Others

0.8




GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)


&#160;


&#160;







</oef:HoldingsTableTextBlock>
    <oef:PctOfNav
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      decimals="INF"
      id="ixv-144614"
      unitRef="pure">0.186</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_MS_HealthcareSectorMember"
      decimals="INF"
      id="ixv-144615"
      unitRef="pure">0.172</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_MS_IndustrialSectorMember"
      decimals="INF"
      id="ixv-144616"
      unitRef="pure">0.170</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_MS_InformationTechnologySectorMember"
      decimals="INF"
      id="ixv-144617"
      unitRef="pure">0.126</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_MS_ConsumerDiscretionarySectorMember"
      decimals="INF"
      id="ixv-144618"
      unitRef="pure">0.097</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_MS_RealEstateSectorMember"
      decimals="INF"
      id="ixv-144619"
      unitRef="pure">0.063</oef:PctOfNav>
    <oef:PctOfNav
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      decimals="INF"
      id="ixv-144620"
      unitRef="pure">0.051</oef:PctOfNav>
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      decimals="INF"
      id="ixv-144621"
      unitRef="pure">0.046</oef:PctOfNav>
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      decimals="INF"
      id="ixv-144622"
      unitRef="pure">0.029</oef:PctOfNav>
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      decimals="INF"
      id="ixv-144623"
      unitRef="pure">0.027</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_MS_CommunicationsSectorMember"
      decimals="INF"
      id="ixv-144624"
      unitRef="pure">0.026</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_AA_CommonStocks_Member"
      decimals="INF"
      id="ixv-144625"
      unitRef="pure">0.993</oef:PctOfNav>
    <oef:PctOfNav
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      decimals="INF"
      id="ixv-144626"
      unitRef="pure">0.007</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_GD_US_Member"
      decimals="INF"
      id="ixv-144627"
      unitRef="pure">0.971</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_GD_CA_Member"
      decimals="INF"
      id="ixv-144628"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_GD_TH_Member"
      decimals="INF"
      id="ixv-144629"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_GD_PR_Member"
      decimals="INF"
      id="ixv-144630"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_GD_AR_Member"
      decimals="INF"
      id="ixv-144631"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_GD_NO_Member"
      decimals="INF"
      id="ixv-144632"
      unitRef="pure">0.002</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_GD_BR_Member"
      decimals="INF"
      id="ixv-144633"
      unitRef="pure">0.002</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_GD_CM_Member"
      decimals="INF"
      id="ixv-144634"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_GD_MC_Member"
      decimals="INF"
      id="ixv-144635"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_GD_Other_Member"
      decimals="INF"
      id="ixv-144636"
      unitRef="pure">0.008</oef:PctOfNav>
    <oef:LargestHoldingsTableTextBlock contextRef="C000177589_ClassMember" id="ixv-2158">TOP HOLDINGS
(% of Fund's net assets)

&#160;

&#160;


FTAI Aviation Ltd

0.6


&#160;


Vaxcyte Inc

0.6


&#160;


Sprouts Farmers Market Inc

0.5


&#160;


Insmed Inc

0.5


&#160;


Mueller Industries Inc

0.4


&#160;


Fluor Corp

0.4


&#160;


Applied Industrial Technologies Inc

0.4


&#160;


Ensign Group Inc/The

0.4


&#160;


REVOLUTION Medicines Inc

0.4


&#160;


Jackson Financial Inc

0.4


&#160;


&#160;

4.6

&#160;



</oef:LargestHoldingsTableTextBlock>
    <oef:PctOfNav
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      decimals="INF"
      id="ixv-144637"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_TH_1_Member"
      decimals="INF"
      id="ixv-144638"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_TH_2_Member"
      decimals="INF"
      id="ixv-144639"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_TH_3_Member"
      decimals="INF"
      id="ixv-144640"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_TH_4_Member"
      decimals="INF"
      id="ixv-144641"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_TH_5_Member"
      decimals="INF"
      id="ixv-144642"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_TH_6_Member"
      decimals="INF"
      id="ixv-144643"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_TH_7_Member"
      decimals="INF"
      id="ixv-144644"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_TH_8_Member"
      decimals="INF"
      id="ixv-144645"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000177589_TH_9_Member"
      decimals="INF"
      id="ixv-144646"
      unitRef="pure">0.004</oef:PctOfNav>
    <dei:DocumentPeriodEndDate contextRef="Trust" id="ixv-2329">2024-10-31</dei:DocumentPeriodEndDate>
    <oef:FundName contextRef="C000170037_ClassMember" id="ixv-2341">Fidelity&#xae; Large Cap Value Index Fund</oef:FundName>
    <oef:ClassName contextRef="C000170037_ClassMember" id="ixv-2344">Fidelity&#xae; Large Cap Value Index Fund</oef:ClassName>
    <dei:TradingSymbol contextRef="C000170037_ClassMember" id="ixv-2348">FLCOX</dei:TradingSymbol>
    <oef:AnnlOrSemiAnnlStatementTextBlock contextRef="C000170037_ClassMember" id="ixv-2367">This semi-annual shareholder report contains information about Fidelity&#xae; Large Cap Value Index Fund for the period May 1, 2024 to October 31, 2024.</oef:AnnlOrSemiAnnlStatementTextBlock>
    <oef:ShareholderReportAnnualOrSemiAnnual contextRef="C000170037_ClassMember" id="ixv-2369">semi-annual shareholder report</oef:ShareholderReportAnnualOrSemiAnnual>
    <oef:AddlInfoTextBlock contextRef="C000170037_ClassMember" id="ixv-2374">You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.</oef:AddlInfoTextBlock>
    <oef:AddlInfoWebsite contextRef="C000170037_ClassMember" id="ixv-2376">fundresearch.fidelity.com/prospectus/sec</oef:AddlInfoWebsite>
    <oef:AddlInfoPhoneNumber contextRef="C000170037_ClassMember" id="ixv-2379">1-800-544-8544</oef:AddlInfoPhoneNumber>
    <oef:AddlInfoEmail contextRef="C000170037_ClassMember" id="ixv-2382">fidfunddocuments@fidelity.com</oef:AddlInfoEmail>
    <oef:ExpensesTextBlock contextRef="C000170037_ClassMember" id="ixv-2389">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;What were your Fund costs for the last six months?&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(based on hypothetical $10,000 investment)&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="0" style="border-collapse:collapse;border-style:none;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:45%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs of a $10,000 investment&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs paid as a percentage of a $10,000 investment &lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:45%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fidelity&#xae; Large Cap Value Index Fund&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$ &lt;/span&gt;2&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;0.03&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:ExpensesTextBlock>
    <oef:ExpensesPaidAmt
      contextRef="C000170037_ClassMember"
      decimals="0"
      id="ixv-144647"
      unitRef="usd">2</oef:ExpensesPaidAmt>
    <oef:ExpenseRatioPct
      contextRef="C000170037_ClassMember"
      decimals="INF"
      id="ixv-144648"
      unitRef="pure">0.0003</oef:ExpenseRatioPct>
    <oef:AddlFundStatisticsTextBlock contextRef="C000170037_ClassMember" id="ixv-2429">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;Key Fund Statistics&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(as of October 31, 2024)&lt;/span&gt;&lt;/div&gt;
&lt;div&gt;&lt;span style="font-size:11px;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="1" style="border-collapse:separate;border-style:none;margin:auto;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:63%; " valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:12px;color:#000000;font-style:normal;font-weight:bold;"&gt;KEY FACTS&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fund Size&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$&lt;/span&gt;9,285,824,297&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Number of Holdings&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;876&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Portfolio Turnover&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;27&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:AddlFundStatisticsTextBlock>
    <us-gaap:AssetsNet
      contextRef="C000170037_InstantMember"
      decimals="0"
      id="ixv-144649"
      unitRef="usd">9285824297</us-gaap:AssetsNet>
    <oef:HoldingsCount
      contextRef="C000170037_InstantMember"
      decimals="INF"
      id="ixv-144650"
      unitRef="holding">876</oef:HoldingsCount>
    <us-gaap:InvestmentCompanyPortfolioTurnover
      contextRef="C000170037_ClassMember"
      decimals="INF"
      id="ixv-144651"
      unitRef="pure">0.27</us-gaap:InvestmentCompanyPortfolioTurnover>
    <oef:HoldingsTableTextBlock contextRef="C000170037_ClassMember" id="ixv-2489">
&#160;
MARKET SECTORS
(% of Fund's net assets)

&#160;

&#160;


Financials

22.0

&#160;


Health Care

14.9

&#160;


Industrials

14.7

&#160;


Information Technology

9.0

&#160;


Consumer Staples

7.8

&#160;


Energy

6.8

&#160;


Consumer Discretionary

6.1

&#160;


Real Estate

4.8

&#160;


Utilities

4.8

&#160;


Materials

4.5

&#160;


Communication Services

4.3

&#160;


&#160;




Common Stocks

99.7


Short-Term Investments and Net Other Assets (Liabilities)

0.3




ASSET ALLOCATION (% of Fund's net assets)









United States

99.8


Canada

0.1


Bermuda

0.1


United Kingdom

0.0


Belgium

0.0


Brazil

0.0


Puerto Rico

0.0


Japan

0.0


Luxembourg

0.0




GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)


&#160;


&#160;







</oef:HoldingsTableTextBlock>
    <oef:PctOfNav
      contextRef="C000170037_MS_FinancialsSectorMember"
      decimals="INF"
      id="ixv-144652"
      unitRef="pure">0.220</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_MS_HealthcareSectorMember"
      decimals="INF"
      id="ixv-144653"
      unitRef="pure">0.149</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_MS_IndustrialSectorMember"
      decimals="INF"
      id="ixv-144654"
      unitRef="pure">0.147</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_MS_InformationTechnologySectorMember"
      decimals="INF"
      id="ixv-144655"
      unitRef="pure">0.090</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_MS_ConsumerStaplesSectorMember"
      decimals="INF"
      id="ixv-144656"
      unitRef="pure">0.078</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_MS_EnergySectorMember"
      decimals="INF"
      id="ixv-144657"
      unitRef="pure">0.068</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_MS_ConsumerDiscretionarySectorMember"
      decimals="INF"
      id="ixv-144658"
      unitRef="pure">0.061</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_MS_RealEstateSectorMember"
      decimals="INF"
      id="ixv-144659"
      unitRef="pure">0.048</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_MS_UtilitiesSectorMember"
      decimals="INF"
      id="ixv-144660"
      unitRef="pure">0.048</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_MS_MaterialsSectorMember"
      decimals="INF"
      id="ixv-144661"
      unitRef="pure">0.045</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_MS_CommunicationsSectorMember"
      decimals="INF"
      id="ixv-144662"
      unitRef="pure">0.043</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_AA_CommonStocks_Member"
      decimals="INF"
      id="ixv-144663"
      unitRef="pure">0.997</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_AA_ShortTermInvestmentsandNetOtherAssetsLiabilities_Member"
      decimals="INF"
      id="ixv-144664"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_GD_US_Member"
      decimals="INF"
      id="ixv-144665"
      unitRef="pure">0.998</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_GD_CA_Member"
      decimals="INF"
      id="ixv-144666"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_GD_BM_Member"
      decimals="INF"
      id="ixv-144667"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_GD_GB_Member"
      decimals="INF"
      id="ixv-144668"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_GD_BE_Member"
      decimals="INF"
      id="ixv-144669"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_GD_BR_Member"
      decimals="INF"
      id="ixv-144670"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_GD_PR_Member"
      decimals="INF"
      id="ixv-144671"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_GD_JP_Member"
      decimals="INF"
      id="ixv-144672"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_GD_LU_Member"
      decimals="INF"
      id="ixv-144673"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:LargestHoldingsTableTextBlock contextRef="C000170037_ClassMember" id="ixv-2719">TOP HOLDINGS
(% of Fund's net assets)

&#160;

&#160;


Berkshire Hathaway Inc Class B

3.4


&#160;


JPMorgan Chase &amp; Co

2.6


&#160;


Exxon Mobil Corp

2.2


&#160;


UnitedHealth Group Inc

2.0


&#160;


Johnson &amp; Johnson

1.6


&#160;


Walmart Inc

1.5


&#160;


Procter &amp; Gamble Co/The

1.3


&#160;


Bank of America Corp

1.2


&#160;


Chevron Corp

1.1


&#160;


Wells Fargo &amp; Co

1.0


&#160;


&#160;

17.9

&#160;



</oef:LargestHoldingsTableTextBlock>
    <oef:PctOfNav
      contextRef="C000170037_TH_0_Member"
      decimals="INF"
      id="ixv-144674"
      unitRef="pure">0.034</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_TH_1_Member"
      decimals="INF"
      id="ixv-144675"
      unitRef="pure">0.026</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_TH_2_Member"
      decimals="INF"
      id="ixv-144676"
      unitRef="pure">0.022</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_TH_3_Member"
      decimals="INF"
      id="ixv-144677"
      unitRef="pure">0.020</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_TH_4_Member"
      decimals="INF"
      id="ixv-144678"
      unitRef="pure">0.016</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_TH_5_Member"
      decimals="INF"
      id="ixv-144679"
      unitRef="pure">0.015</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_TH_6_Member"
      decimals="INF"
      id="ixv-144680"
      unitRef="pure">0.013</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_TH_7_Member"
      decimals="INF"
      id="ixv-144681"
      unitRef="pure">0.012</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_TH_8_Member"
      decimals="INF"
      id="ixv-144682"
      unitRef="pure">0.011</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000170037_TH_9_Member"
      decimals="INF"
      id="ixv-144683"
      unitRef="pure">0.010</oef:PctOfNav>
    <dei:DocumentPeriodEndDate contextRef="Trust" id="ixv-2890">2024-10-31</dei:DocumentPeriodEndDate>
    <oef:FundName contextRef="C000103373_ClassMember" id="ixv-2902">Fidelity&#xae; Small Cap Index Fund</oef:FundName>
    <oef:ClassName contextRef="C000103373_ClassMember" id="ixv-2905">Fidelity&#xae; Small Cap Index Fund</oef:ClassName>
    <dei:TradingSymbol contextRef="C000103373_ClassMember" id="ixv-2909">FSSNX</dei:TradingSymbol>
    <oef:AnnlOrSemiAnnlStatementTextBlock contextRef="C000103373_ClassMember" id="ixv-2928">This semi-annual shareholder report contains information about Fidelity&#xae; Small Cap Index Fund for the period May 1, 2024 to October 31, 2024.</oef:AnnlOrSemiAnnlStatementTextBlock>
    <oef:ShareholderReportAnnualOrSemiAnnual contextRef="C000103373_ClassMember" id="ixv-2930">semi-annual shareholder report</oef:ShareholderReportAnnualOrSemiAnnual>
    <oef:AddlInfoTextBlock contextRef="C000103373_ClassMember" id="ixv-2935">You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.</oef:AddlInfoTextBlock>
    <oef:AddlInfoWebsite contextRef="C000103373_ClassMember" id="ixv-2937">fundresearch.fidelity.com/prospectus/sec</oef:AddlInfoWebsite>
    <oef:AddlInfoPhoneNumber contextRef="C000103373_ClassMember" id="ixv-2940">1-800-544-8544</oef:AddlInfoPhoneNumber>
    <oef:AddlInfoEmail contextRef="C000103373_ClassMember" id="ixv-2943">fidfunddocuments@fidelity.com</oef:AddlInfoEmail>
    <oef:ExpensesTextBlock contextRef="C000103373_ClassMember" id="ixv-2950">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;What were your Fund costs for the last six months?&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(based on hypothetical $10,000 investment)&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="0" style="border-collapse:collapse;border-style:none;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:45%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs of a $10,000 investment&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs paid as a percentage of a $10,000 investment &lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:45%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fidelity&#xae; Small Cap Index Fund&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$ &lt;/span&gt;1&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;0.02&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:ExpensesTextBlock>
    <oef:ExpensesPaidAmt
      contextRef="C000103373_ClassMember"
      decimals="0"
      id="ixv-144684"
      unitRef="usd">1</oef:ExpensesPaidAmt>
    <oef:ExpenseRatioPct
      contextRef="C000103373_ClassMember"
      decimals="INF"
      id="ixv-144685"
      unitRef="pure">0.0002</oef:ExpenseRatioPct>
    <oef:AddlFundStatisticsTextBlock contextRef="C000103373_ClassMember" id="ixv-2990">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;Key Fund Statistics&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(as of October 31, 2024)&lt;/span&gt;&lt;/div&gt;
&lt;div&gt;&lt;span style="font-size:11px;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="1" style="border-collapse:separate;border-style:none;margin:auto;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:63%; " valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:12px;color:#000000;font-style:normal;font-weight:bold;"&gt;KEY FACTS&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fund Size&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$&lt;/span&gt;26,857,343,200&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Number of Holdings&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;1,983&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Portfolio Turnover&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;19&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:AddlFundStatisticsTextBlock>
    <us-gaap:AssetsNet
      contextRef="C000103373_InstantMember"
      decimals="0"
      id="ixv-144686"
      unitRef="usd">26857343200</us-gaap:AssetsNet>
    <oef:HoldingsCount
      contextRef="C000103373_InstantMember"
      decimals="INF"
      id="ixv-144687"
      unitRef="holding">1983</oef:HoldingsCount>
    <us-gaap:InvestmentCompanyPortfolioTurnover
      contextRef="C000103373_ClassMember"
      decimals="INF"
      id="ixv-144688"
      unitRef="pure">0.19</us-gaap:InvestmentCompanyPortfolioTurnover>
    <oef:HoldingsTableTextBlock contextRef="C000103373_ClassMember" id="ixv-3050">
&#160;
MARKET SECTORS
(% of Fund's net assets)

&#160;

&#160;


Financials

18.7

&#160;


Health Care

17.4

&#160;


Industrials

17.1

&#160;


Information Technology

12.7

&#160;


Consumer Discretionary

9.7

&#160;


Real Estate

6.3

&#160;


Energy

5.2

&#160;


Materials

4.6

&#160;


Utilities

2.9

&#160;


Consumer Staples

2.7

&#160;


Communication Services

2.6

&#160;


&#160;




Common Stocks

99.9


Short-Term Investments and Net Other Assets (Liabilities)

0.1




ASSET ALLOCATION (% of Fund's net assets)









United States

97.0


Canada

0.6


Thailand

0.4


Puerto Rico

0.3


Argentina

0.3


Norway

0.2


Brazil

0.2


Cameroon

0.1


Monaco

0.1


Others

0.8




GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)


&#160;


&#160;







</oef:HoldingsTableTextBlock>
    <oef:PctOfNav
      contextRef="C000103373_MS_FinancialsSectorMember"
      decimals="INF"
      id="ixv-144689"
      unitRef="pure">0.187</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_MS_HealthcareSectorMember"
      decimals="INF"
      id="ixv-144690"
      unitRef="pure">0.174</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_MS_IndustrialSectorMember"
      decimals="INF"
      id="ixv-144691"
      unitRef="pure">0.171</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_MS_InformationTechnologySectorMember"
      decimals="INF"
      id="ixv-144692"
      unitRef="pure">0.127</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_MS_ConsumerDiscretionarySectorMember"
      decimals="INF"
      id="ixv-144693"
      unitRef="pure">0.097</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_MS_RealEstateSectorMember"
      decimals="INF"
      id="ixv-144694"
      unitRef="pure">0.063</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_MS_EnergySectorMember"
      decimals="INF"
      id="ixv-144695"
      unitRef="pure">0.052</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_MS_MaterialsSectorMember"
      decimals="INF"
      id="ixv-144696"
      unitRef="pure">0.046</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_MS_UtilitiesSectorMember"
      decimals="INF"
      id="ixv-144697"
      unitRef="pure">0.029</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_MS_ConsumerStaplesSectorMember"
      decimals="INF"
      id="ixv-144698"
      unitRef="pure">0.027</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_MS_CommunicationsSectorMember"
      decimals="INF"
      id="ixv-144699"
      unitRef="pure">0.026</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_AA_CommonStocks_Member"
      decimals="INF"
      id="ixv-144700"
      unitRef="pure">0.999</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_AA_ShortTermInvestmentsandNetOtherAssetsLiabilities_Member"
      decimals="INF"
      id="ixv-144701"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_GD_US_Member"
      decimals="INF"
      id="ixv-144702"
      unitRef="pure">0.970</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_GD_CA_Member"
      decimals="INF"
      id="ixv-144703"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_GD_TH_Member"
      decimals="INF"
      id="ixv-144704"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_GD_PR_Member"
      decimals="INF"
      id="ixv-144705"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_GD_AR_Member"
      decimals="INF"
      id="ixv-144706"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_GD_NO_Member"
      decimals="INF"
      id="ixv-144707"
      unitRef="pure">0.002</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_GD_BR_Member"
      decimals="INF"
      id="ixv-144708"
      unitRef="pure">0.002</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_GD_CM_Member"
      decimals="INF"
      id="ixv-144709"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_GD_MC_Member"
      decimals="INF"
      id="ixv-144710"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_GD_Other_Member"
      decimals="INF"
      id="ixv-144711"
      unitRef="pure">0.008</oef:PctOfNav>
    <oef:LargestHoldingsTableTextBlock contextRef="C000103373_ClassMember" id="ixv-3286">TOP HOLDINGS
(% of Fund's net assets)

&#160;

&#160;


FTAI Aviation Ltd

0.6


&#160;


Sprouts Farmers Market Inc

0.6


&#160;


Vaxcyte Inc

0.6


&#160;


Insmed Inc

0.5


&#160;


Mueller Industries Inc

0.4


&#160;


Fluor Corp

0.4


&#160;


Applied Industrial Technologies Inc

0.4


&#160;


Fabrinet

0.4


&#160;


Ensign Group Inc/The

0.4


&#160;


REVOLUTION Medicines Inc

0.4


&#160;


&#160;

4.7

&#160;



</oef:LargestHoldingsTableTextBlock>
    <oef:PctOfNav
      contextRef="C000103373_TH_0_Member"
      decimals="INF"
      id="ixv-144712"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_TH_1_Member"
      decimals="INF"
      id="ixv-144713"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_TH_2_Member"
      decimals="INF"
      id="ixv-144714"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_TH_3_Member"
      decimals="INF"
      id="ixv-144715"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_TH_4_Member"
      decimals="INF"
      id="ixv-144716"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_TH_5_Member"
      decimals="INF"
      id="ixv-144717"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_TH_6_Member"
      decimals="INF"
      id="ixv-144718"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_TH_7_Member"
      decimals="INF"
      id="ixv-144719"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_TH_8_Member"
      decimals="INF"
      id="ixv-144720"
      unitRef="pure">0.004</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103373_TH_9_Member"
      decimals="INF"
      id="ixv-144721"
      unitRef="pure">0.004</oef:PctOfNav>
    <dei:DocumentPeriodEndDate contextRef="Trust" id="ixv-3457">2024-10-31</dei:DocumentPeriodEndDate>
    <oef:FundName contextRef="C000103368_ClassMember" id="ixv-3469">Fidelity&#xae; Mid Cap Index Fund</oef:FundName>
    <oef:ClassName contextRef="C000103368_ClassMember" id="ixv-3472">Fidelity&#xae; Mid Cap Index Fund</oef:ClassName>
    <dei:TradingSymbol contextRef="C000103368_ClassMember" id="ixv-3476">FSMDX</dei:TradingSymbol>
    <oef:AnnlOrSemiAnnlStatementTextBlock contextRef="C000103368_ClassMember" id="ixv-3495">This semi-annual shareholder report contains information about Fidelity&#xae; Mid Cap Index Fund for the period May 1, 2024 to October 31, 2024.</oef:AnnlOrSemiAnnlStatementTextBlock>
    <oef:ShareholderReportAnnualOrSemiAnnual contextRef="C000103368_ClassMember" id="ixv-3497">semi-annual shareholder report</oef:ShareholderReportAnnualOrSemiAnnual>
    <oef:AddlInfoTextBlock contextRef="C000103368_ClassMember" id="ixv-3502">You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.</oef:AddlInfoTextBlock>
    <oef:AddlInfoWebsite contextRef="C000103368_ClassMember" id="ixv-3504">fundresearch.fidelity.com/prospectus/sec</oef:AddlInfoWebsite>
    <oef:AddlInfoPhoneNumber contextRef="C000103368_ClassMember" id="ixv-3507">1-800-544-8544</oef:AddlInfoPhoneNumber>
    <oef:AddlInfoEmail contextRef="C000103368_ClassMember" id="ixv-3510">fidfunddocuments@fidelity.com</oef:AddlInfoEmail>
    <oef:ExpensesTextBlock contextRef="C000103368_ClassMember" id="ixv-3517">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;What were your Fund costs for the last six months?&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(based on hypothetical $10,000 investment)&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="0" style="border-collapse:collapse;border-style:none;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:45%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs of a $10,000 investment&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; background-color:#dfe0e4;border:1px solid #dfe0e4;padding:0px 0px 0px 0px;" valign="bottom"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;Costs paid as a percentage of a $10,000 investment &lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:45%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fidelity&#xae; Mid Cap Index Fund&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:24%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$ &lt;/span&gt;1&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:30%; border-bottom:1px solid #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:center;text-align-last:auto;"&gt;0.02&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:1%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:ExpensesTextBlock>
    <oef:ExpensesPaidAmt
      contextRef="C000103368_ClassMember"
      decimals="0"
      id="ixv-144722"
      unitRef="usd">1</oef:ExpensesPaidAmt>
    <oef:ExpenseRatioPct
      contextRef="C000103368_ClassMember"
      decimals="INF"
      id="ixv-144723"
      unitRef="pure">0.0002</oef:ExpenseRatioPct>
    <oef:AddlFundStatisticsTextBlock contextRef="C000103368_ClassMember" id="ixv-3557">&lt;span style="font-family:'Fidelity Sans';font-size:16px;color:#368627;font-style:normal;font-weight:bold;"&gt;Key Fund Statistics&lt;/span&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;(as of October 31, 2024)&lt;/span&gt;&lt;/div&gt;
&lt;div&gt;&lt;span style="font-size:11px;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;table cellpadding="0" cellspacing="1" style="border-collapse:separate;border-style:none;margin:auto;" width="100%"&gt;&lt;tr&gt;&lt;td style="width:63%; " valign="top"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:12px;color:#000000;font-style:normal;font-weight:bold;"&gt;KEY FACTS&lt;/span&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;"&gt;&#160;&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:12px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Fund Size&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;$&lt;/span&gt;36,339,516,503&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Number of Holdings&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;814&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;&lt;td style="width:63%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;Portfolio Turnover&lt;/span&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:32%; border-bottom:1px dashed #000000;padding:0px 0px 0px 0px;" valign="middle"&gt;&lt;div style="text-align:right;text-align-last:auto;"&gt;28&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;"&gt;%&lt;/span&gt;&lt;/div&gt;
&lt;div style="text-align:right;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;td style="width:5%; " valign="top"&gt;&lt;span style="line-height:11px;"&gt;&#160;&lt;/span&gt;&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;/table&gt;
&lt;/div&gt;
&lt;div style="text-align:left;text-align-last:auto;"&gt;&lt;/div&gt;</oef:AddlFundStatisticsTextBlock>
    <us-gaap:AssetsNet
      contextRef="C000103368_InstantMember"
      decimals="0"
      id="ixv-144724"
      unitRef="usd">36339516503</us-gaap:AssetsNet>
    <oef:HoldingsCount
      contextRef="C000103368_InstantMember"
      decimals="INF"
      id="ixv-144725"
      unitRef="holding">814</oef:HoldingsCount>
    <us-gaap:InvestmentCompanyPortfolioTurnover
      contextRef="C000103368_ClassMember"
      decimals="INF"
      id="ixv-144726"
      unitRef="pure">0.28</us-gaap:InvestmentCompanyPortfolioTurnover>
    <oef:HoldingsTableTextBlock contextRef="C000103368_ClassMember" id="ixv-3617">
&#160;
MARKET SECTORS
(% of Fund's net assets)

&#160;

&#160;


Industrials

17.6

&#160;


Financials

16.2

&#160;


Information Technology

12.5

&#160;


Consumer Discretionary

10.6

&#160;


Health Care

9.7

&#160;


Real Estate

7.9

&#160;


Materials

5.9

&#160;


Utilities

5.7

&#160;


Energy

5.2

&#160;


Consumer Staples

4.9

&#160;


Communication Services

3.5

&#160;


&#160;




Common Stocks

99.7


Short-Term Investments and Net Other Assets (Liabilities)

0.3




ASSET ALLOCATION (% of Fund's net assets)









United States

98.8


Brazil

0.5


Korea (South)

0.3


Canada

0.1


Bermuda

0.1


United Kingdom

0.1


Belgium

0.1


Puerto Rico

0.0


Japan

0.0




GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)


&#160;


&#160;







</oef:HoldingsTableTextBlock>
    <oef:PctOfNav
      contextRef="C000103368_MS_IndustrialSectorMember"
      decimals="INF"
      id="ixv-144727"
      unitRef="pure">0.176</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_MS_FinancialsSectorMember"
      decimals="INF"
      id="ixv-144728"
      unitRef="pure">0.162</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_MS_InformationTechnologySectorMember"
      decimals="INF"
      id="ixv-144729"
      unitRef="pure">0.125</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_MS_ConsumerDiscretionarySectorMember"
      decimals="INF"
      id="ixv-144730"
      unitRef="pure">0.106</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_MS_HealthcareSectorMember"
      decimals="INF"
      id="ixv-144731"
      unitRef="pure">0.097</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_MS_RealEstateSectorMember"
      decimals="INF"
      id="ixv-144732"
      unitRef="pure">0.079</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_MS_MaterialsSectorMember"
      decimals="INF"
      id="ixv-144733"
      unitRef="pure">0.059</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_MS_UtilitiesSectorMember"
      decimals="INF"
      id="ixv-144734"
      unitRef="pure">0.057</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_MS_EnergySectorMember"
      decimals="INF"
      id="ixv-144735"
      unitRef="pure">0.052</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_MS_ConsumerStaplesSectorMember"
      decimals="INF"
      id="ixv-144736"
      unitRef="pure">0.049</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_MS_CommunicationsSectorMember"
      decimals="INF"
      id="ixv-144737"
      unitRef="pure">0.035</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_AA_CommonStocks_Member"
      decimals="INF"
      id="ixv-144738"
      unitRef="pure">0.997</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_AA_ShortTermInvestmentsandNetOtherAssetsLiabilities_Member"
      decimals="INF"
      id="ixv-144739"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_GD_US_Member"
      decimals="INF"
      id="ixv-144740"
      unitRef="pure">0.988</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_GD_BR_Member"
      decimals="INF"
      id="ixv-144741"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_GD_KR_Member"
      decimals="INF"
      id="ixv-144742"
      unitRef="pure">0.003</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_GD_CA_Member"
      decimals="INF"
      id="ixv-144743"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_GD_BM_Member"
      decimals="INF"
      id="ixv-144744"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_GD_GB_Member"
      decimals="INF"
      id="ixv-144745"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_GD_BE_Member"
      decimals="INF"
      id="ixv-144746"
      unitRef="pure">0.001</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_GD_PR_Member"
      decimals="INF"
      id="ixv-144747"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_GD_JP_Member"
      decimals="INF"
      id="ixv-144748"
      unitRef="pure">0.000</oef:PctOfNav>
    <oef:LargestHoldingsTableTextBlock contextRef="C000103368_ClassMember" id="ixv-3847">TOP HOLDINGS
(% of Fund's net assets)

&#160;

&#160;


Palantir Technologies Inc Class A

0.8


&#160;


Digital Realty Trust Inc

0.6


&#160;


Bank of New York Mellon Corp/The

0.6


&#160;


Williams Cos Inc/The

0.5


&#160;


Arthur J Gallagher &amp; Co

0.5


&#160;


AFLAC Inc

0.5


&#160;


Hilton Worldwide Holdings Inc

0.5


&#160;


ONEOK Inc

0.5


&#160;


Simon Property Group Inc

0.5


&#160;


United Rentals Inc

0.5


&#160;


&#160;

5.5

&#160;



</oef:LargestHoldingsTableTextBlock>
    <oef:PctOfNav
      contextRef="C000103368_TH_0_Member"
      decimals="INF"
      id="ixv-144749"
      unitRef="pure">0.008</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_TH_1_Member"
      decimals="INF"
      id="ixv-144750"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_TH_2_Member"
      decimals="INF"
      id="ixv-144751"
      unitRef="pure">0.006</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_TH_3_Member"
      decimals="INF"
      id="ixv-144752"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_TH_4_Member"
      decimals="INF"
      id="ixv-144753"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_TH_5_Member"
      decimals="INF"
      id="ixv-144754"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_TH_6_Member"
      decimals="INF"
      id="ixv-144755"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_TH_7_Member"
      decimals="INF"
      id="ixv-144756"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_TH_8_Member"
      decimals="INF"
      id="ixv-144757"
      unitRef="pure">0.005</oef:PctOfNav>
    <oef:PctOfNav
      contextRef="C000103368_TH_9_Member"
      decimals="INF"
      id="ixv-144758"
      unitRef="pure">0.005</oef:PctOfNav>
</xbrl>
