rr_RiskReturnAbstract

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Vanguard Extended Market Index FundSupplement to the Prospectus and Summary Prospectus Dated April 26, 2024As approved by the Fund’s Board of Trustees, Vanguard Extended Market Index Fund (the Fund) has reduced its expense ratio. Effective February 3, 2025, the Annual Fund Operating Expenses table and the hypothetical expenses example for the Fund are hereby deleted and replaced with the following:Prospectus and Summary Prospectus Text Changes for Vanguard Extended Market Index FundAnnual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)Management Fees0.0412b-1 Distribution FeeNoneOther Expenses0.01Total Annual Fund Operating Expenses0.051The expense information shown in the table has been restated to reflect current fees.ExampleThe following example is intended to help you compare the cost of investing in the Fund’s Admiral Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:1 Year3 Years5 Years10 Years$5$16$28$64© 2025 The Vanguard Group, Inc. All rights reserved.Vanguard Marketing Corporation, Distributor.PS 598A 022025Vanguard Extended Market ETFSupplement to the Prospectus and Summary Prospectus Dated April 26, 2024As approved by the Fund’s Board of Trustees, Vanguard Extended Market ETF (the Fund) has reduced its expense ratio. Effective February 3, 2025, the Annual Fund Operating Expenses table and the hypothetical expenses example for the Fund are hereby deleted and replaced with the following:Prospectus and Summary Prospectus Text Changes for Vanguard Extended Market ETFAnnual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)Management Fees0.0412b-1 Distribution FeeNoneOther Expenses0.01Total Annual Fund Operating Expenses0.051The expense information shown in the table has been restated to reflect current fees.ExampleThe following example is intended to help you compare the cost of investing in the Fund’s ETF Shares with the cost of investing in other funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to sell your shares at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:1 Year3 Years5 Years10 Years$5$16$28$64This example does not include the brokerage commissions that you may pay to buy and sell ETF Shares of the Fund.© 2025 The Vanguard Group, Inc. All rights reserved.Vanguard Marketing Corporation, Distributor.PS 965A 022025

Risk Return Abstract

rr_RiskReturnAbstract

Supplement to Prospectus [Text Block]

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Vanguard Extended Market Index FundSupplement to the Prospectus and Summary Prospectus Dated April 26, 2024As approved by the Fund’s Board of Trustees, Vanguard Extended Market Index Fund (the Fund) has reduced its expense ratio. Effective February 3, 2025, the Annual Fund Operating Expenses table and the hypothetical expenses example for the Fund are hereby deleted and replaced with the following:Prospectus and Summary Prospectus Text Changes for Vanguard Extended Market Index FundAnnual Fund Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)Management Fees0.0412b-1 Distribution FeeNoneOther Expenses0.01Total Annual Fund Operating Expenses0.051The expense information shown in the table has been restated to reflect current fees.ExampleThe following example is intended to help you compare the cost of investing in the Fund’s Admiral Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:1 Year3 Years5 Years10 Years$5$16$28$64© 2025 The Vanguard Group, Inc. All rights reserved.Vanguard Marketing Corporation, Distributor.PS 598A 022025

Expense Example [Heading]

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Example

Management Fees

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0.04%

Other Expenses

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0.01%

1 Year

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$ 5

5 Years

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28

Prospectus Date

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Apr. 26, 2024

Operating Expenses Caption [Text]

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Prospectus and Summary Prospectus Text Changes for Vanguard Extended Market ETFAnnual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment)

Expense Example Narrative [Text Block]

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The following example is intended to help you compare the cost of investing in the Fund’s ETF Shares with the cost of investing in other funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to sell your shares at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be: