Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	VANGUARD SPECIALIZED FUNDS
Prospectus Date	rr_ProspectusDate	May 24, 2024
Institutional | Vanguard Real Estate Index Fund
Risk Return Abstract	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<span style="color:#000000;font-family:Arial;font-size:13pt;font-weight:bold;">Fund Summary</span>
Objective [Heading]	rr_ObjectiveHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Investment Objective</span>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide a high level of income and moderate long-term capital appreciation by tracking the performance of a benchmark index that measures the performance of publicly traded equity REITs and other real estate-related investments.
Expense [Heading]	rr_ExpenseHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Fees and Expenses</span>
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following tables describe the fees and expenses you may pay if you buy, hold, and sell Institutional Shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and example below.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	<span style="color:#000000;font-family:Arial;font-size:8.5pt;font-weight:bold;">Shareholder Fees</span> <br/><span style="color:#000000;font-family:Arial;font-size:8.5pt;margin-left:0%;">(Fees paid directly from your investment)</span>
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<span style="color:#000000;font-family:Arial;font-size:8.5pt;font-weight:bold;">Annual Fund Operating Expenses</span> <br/><span style="color:#000000;font-family:Arial;font-size:8.5pt;margin-left:0%;">(Expenses that you pay each year as a percentage of the value of your investment)</span>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<span style="color:#000000;font-family:Arial;font-size:9.5pt;">Portfolio Turnover</span>
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 9% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	9.00%
Expense Example [Heading]	rr_ExpenseExampleHeading	<span style="color:#000000;font-family:Arial;font-size:9.5pt;">Example</span>
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	The following example is intended to help you compare the cost of investing in the Fund’s Institutional 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:
Strategy [Heading]	rr_StrategyHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Investment Strategies</span>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund employs an indexing investment approach designed to track the performance of the MSCI US Investable Market Real Estate 25/50 Index (the Index), an index that is made up of stocks of large, mid-size, and small U.S. companies within the real estate sector, as classified under the Global Industry Classification Standard (GICS). The GICS real estate sector is composed of equity real estate investment trusts (known as REITs), which include specialized REITs, and real estate management and development companies.The Fund seeks to track the Index by investing all, or substantially all, of its assets directly or indirectly through a wholly owned subsidiary (the underlying fund) and holding each stock in approximately the same proportion as its weighting in the Index. The underlying fund is a registered investment company. The Fund may invest a portion of its assets in the underlying fund.
Risk [Heading]	rr_RiskHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Risks</span>
Risk [Text Block]	rr_RiskTextBlock	• Industry concentration risk, which is the chance that the stocks of REITs and other real estate-related investments will decline because of adverse developments affecting the real estate industry and real property values. Because the Fund concentrates its assets in these stocks, industry concentration risk is high.• Interest rate risk, which is the chance that REIT stock prices overall will decline and that the cost of borrowing for REITs will increase because of rising interest rates. Interest rate risk is high for the Fund.• Stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund’s target index may, at times, become focused in stocks of a limited number of companies, which could cause the Fund to underperform the overall stock market.• Asset concentration risk, which is the chance that, because the Fund’s target index (and therefore the Fund) tends to be heavily weighted in its ten largest holdings, the Fund’s performance may be hurt disproportionately by the poor performance of relatively few stocks.• Investment style risk, which is the chance that returns from the stocks of REITs and other real estate-related investments—which typically are small- or mid-capitalization stocks—will trail returns from the overall stock market. Historically, these stocks have performed quite differently from the overall market.• Index replicating risk, which is the chance that the Fund may be prevented from holding one or more securities in the same proportion as in its target index.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Annual Total Returns</span>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund’s Institutional Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Institutional Shares compare with those of the Fund’s target index and other comparative indexes, which have investment characteristics similar to those of the Fund. Effective July 24, 2018, the Fund began tracking the MSCI US Investable Market Real Estate 25/50 Index as its target index. The inception date for the MSCI US Investable Market Real Estate 25/50 Index was September 1, 2016. Index returns are not provided prior to that date. The Real Estate Spliced Index reflects the performance of the MSCI US REIT Index through February 1, 2018; the MSCI US Investable Market Real Estate 25/50 Transition Index through July 24, 2018; and the MSCI US Investable Market Real Estate 25/50 Index thereafter. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	<span style="font-family:Arial;font-size:9.5pt;">The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund’s Institutional Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Institutional Shares compare with those of the Fund’s target index and other comparative indexes, which have investment characteristics similar to those of the Fund.</span>
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	<span style="font-family:Arial;font-size:9.5pt;">800-662-7447</span>
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	<span style="font-family:Arial;font-size:9.5pt;font-style:italic;">vanguard.com/performance</span>
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	<span style="font-family:Arial;font-size:9.5pt;">Keep in mind that the Fund’s past performance (before and </span><span style="font-family:Arial;font-size:9.5pt;">after taxes) does not indicate how the Fund will perform in the future.</span>
Bar Chart [Heading]	rr_BarChartHeading	<span style="font-family:Arial;font-size:8pt;font-weight:bold;">Annual Total Returns — Vanguard Real Estate Index Fund Institutional Shares</span><span style="font-family:Arial;font-size:5pt;font-weight:bold;position:relative;top:-3.25pt;">1</span>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:
Performance Table Heading	rr_PerformanceTableHeading	<span style="font-family:Arial;font-size:8.5pt;font-weight:bold;">Average Annual Total Returns for Periods Ended December 31, 2023</span>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	<span style="color:#000000;font-family:Arial;font-size:9.5pt;">When after-tax returns are calculated, it is </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;">assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. </span>
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	<span style="color:#000000;font-family:Arial;font-size:9.5pt;">Please note that after-tax returns are not relevant for a shareholder </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;">who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. </span>
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	<span style="color:#000000;font-family:Arial;font-size:9.5pt;">Also, figures captioned </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;font-style:italic;">Return After Taxes on Distributions and Sale of Fund Shares</span><span style="color:#000000;font-family:Arial;font-size:9.5pt;"> may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.</span>
Performance Table Closing [Text Block]	rr_PerformanceTableClosingTextBlock	Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.
Institutional | Vanguard Real Estate Index Fund | Risk Lose Money [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	An investment in the Fund could lose money over short or long periods of time.
Institutional | Vanguard Real Estate Index Fund | Risk Not Insured Depository Institution [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Institutional | Vanguard Real Estate Index Fund | Nondiversification Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	• Nondiversification risk, which is the chance that the Fund may invest a greater percentage of its assets in a particular issuer or group of issuers or may own larger positions of an issuer’s voting stock than a diversified fund.
Institutional | Vanguard Real Estate Index Fund | Institutional Shares
Risk Return Abstract	rr_RiskReturnAbstract
Purchase Fee	rr_MaximumCumulativeSalesChargeOverOther	none
Sales Charge (Load) Imposed on Purchases	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Sales Charge (Load) Imposed on Reinvested Dividends	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption Fee	rr_RedemptionFeeOverRedemption	none
Management Fees	rr_ManagementFeesOverAssets	0.09%
12b-1 Distribution Fee	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.01%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.01%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.11%	[1]
1 Year	rr_ExpenseExampleYear01	$ 11
3 Years	rr_ExpenseExampleYear03	35
5 Years	rr_ExpenseExampleYear05	62
10 Years	rr_ExpenseExampleYear10	$ 141
Year to Date Return, Label	rr_YearToDateReturnLabel	year-to-date return
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Mar. 31, 2024
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	(1.16%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	<span style="font-family:Arial;font-size:8pt;margin-left:0.0pt;">Highest</span>
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Dec. 31, 2023
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	18.13%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	<span style="font-family:Arial;font-size:8pt;margin-left:0.0pt;">Lowest</span>
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Mar. 31, 2020
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(24.10%)
1 Year	rr_AverageAnnualReturnYear01	11.82%
5 Years	rr_AverageAnnualReturnYear05	7.35%
10 Years	rr_AverageAnnualReturnYear10	7.38%
Institutional | Vanguard Real Estate Index Fund | Return After Taxes on Distributions | Institutional Shares
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	10.63%
5 Years	rr_AverageAnnualReturnYear05	6.34%
10 Years	rr_AverageAnnualReturnYear10	6.20%
Institutional | Vanguard Real Estate Index Fund | Return After Taxes on Distributions and Sale of Fund Shares | Institutional Shares
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	7.16%
5 Years	rr_AverageAnnualReturnYear05	5.34%
10 Years	rr_AverageAnnualReturnYear10	5.37%
Institutional | Vanguard Real Estate Index Fund | Dow Jones U.S. Total Stock Market Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	26.06%
5 Years	rr_AverageAnnualReturnYear05	15.05%
10 Years	rr_AverageAnnualReturnYear10	11.40%
Institutional | Vanguard Real Estate Index Fund | Real Estate Spliced Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	11.96%
5 Years	rr_AverageAnnualReturnYear05	7.44%
10 Years	rr_AverageAnnualReturnYear10	7.47%
Institutional | Vanguard Real Estate Index Fund | MSCI US Investable Market Real Estate 25/50 Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	11.96%
5 Years	rr_AverageAnnualReturnYear05	7.44%
10 Years	rr_AverageAnnualReturnYear10

[1] The Total Annual Fund Operating Expenses do not correlate to the ratio of expenses to average net assets provided in the Fund’s Financial Highlights table, which reflects the operating expenses of the Fund.