Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	VANGUARD SPECIALIZED FUNDS
Prospectus Date	rr_ProspectusDate	May 25, 2017
Investor Shares For Annuity | Vanguard Dividend Growth Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summary
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide, primarily, a growing stream of income over time and,
Objective, Secondary [Text Block]	rr_ObjectiveSecondaryTextBlock	secondarily, long-term capital appreciation and current income.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder Fees (Fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
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 27% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	27.00%
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	The following example is intended to help you compare the cost of investing in the Fund 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 Fund provides 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 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:
Expense Example Closing [Text Block]	rr_ExpenseExampleClosingTextBlock	This example does not include fees associated with the income annuity program through which you invest. Detailed information about the annuity program fees is presented in the "Fee Table" section of the accompanying prospectus of the insurance company for the annuity program through which Fund shares are offered.
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests primarily in stocks that tend to offer current dividends. The Fund focuses on high-quality companies that have prospects for long-term total returns as a result of their ability to grow earnings and their willingness to increase dividends over time. These stocks typically—but not always—will be large-cap, will be undervalued relative to the market, and will show potential for increasing dividends. The Fund seeks to be diversified across industry sectors.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	An investment in the Fund could lose money over short or even long periods. You should expect the Fund’s share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund’s performance: • 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. • Manager risk, which is the chance that poor security selection will cause the Fund to underperform relevant benchmarks or other funds with a similar investment objective. • Investment style risk, which is the chance that returns from dividend-paying large-capitalization stocks will trail returns from the overall stock market. Large-cap stocks tend to go through cycles of doing better—or worse—than other segments of the stock market or the stock market in general. These periods have, in the past, lasted for as long as several years. • Asset concentration risk, which is the chance that, because the Fund tends to invest a high percentage of assets in its ten largest holdings, the Fund’s performance may be hurt disproportionately by the poor performance of relatively few stocks. 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.
Risk Lose Money [Text]	rr_RiskLoseMoney	An investment in the Fund could lose money over short or even long periods.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	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.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Annual Total Returns
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 has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of a relevant market index and other comparative indexes, which have investment characteristics similar to those of the Fund. The bar chart and table do not reflect additional fees and expenses that are deducted by the income annuity program through which you invest. If such fees and expenses were included in the calculation of the Fund’s returns, the returns would be lower. Keep in mind that the Fund’s past performance 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	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 has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of a relevant market index and other comparative indexes, which have investment characteristics similar to those of the Fund.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-662-7447
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	vanguard.com/performance
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	Keep in mind that the Fund’s past performance does not indicate how the Fund will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns — Vanguard Dividend Growth Fund Investor Shares
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	The bar chart and table do not reflect additional fees and expenses that are deducted by the income annuity program through which you invest. If such fees and expenses were included in the calculation of the Fund’s returns, the returns would be lower.
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	During the periods shown in the bar chart, the highest return for a calendar quarter was 11.91% (quarter ended December 31, 2011), and the lowest return for a quarter was –17.10% (quarter ended December 31, 2008).
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns for Periods Ended December 31, 2016
Investor Shares For Annuity | Vanguard Dividend Growth Fund | Investor Shares
Risk/Return:	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	0.28%
12b-1 Distribution Fee	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.02%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.30%
1 Year	rr_ExpenseExampleYear01	$ 31
3 Years	rr_ExpenseExampleYear03	97
5 Years	rr_ExpenseExampleYear05	169
10 Years	rr_ExpenseExampleYear10	381
1 Year	rr_ExpenseExampleNoRedemptionYear01	31
3 Years	rr_ExpenseExampleNoRedemptionYear03	97
5 Years	rr_ExpenseExampleNoRedemptionYear05	169
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 381
2007	rr_AnnualReturn2007	7.00%	[1]
2008	rr_AnnualReturn2008	(25.57%)	[1]
2009	rr_AnnualReturn2009	21.74%	[1]
2010	rr_AnnualReturn2010	11.42%	[1]
2011	rr_AnnualReturn2011	9.43%	[1]
2012	rr_AnnualReturn2012	10.39%	[1]
2013	rr_AnnualReturn2013	31.53%	[1]
2014	rr_AnnualReturn2014	11.85%	[1]
2015	rr_AnnualReturn2015	2.62%	[1]
2016	rr_AnnualReturn2016	7.53%	[1]
Year to Date Return, Label	rr_YearToDateReturnLabel	year-to-date return
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Mar. 31, 2017
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	5.87%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Dec. 31, 2011
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	11.91%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(17.10%)
1 Year	rr_AverageAnnualReturnYear01	7.53%
5 Years	rr_AverageAnnualReturnYear05	12.37%
10 Years	rr_AverageAnnualReturnYear10	7.79%
Investor Shares For Annuity | Vanguard Dividend Growth Fund | Russell 1000 Index
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	12.05%	[2]
5 Years	rr_AverageAnnualReturnYear05	14.69%	[2]
10 Years	rr_AverageAnnualReturnYear10	7.08%	[2]
Investor Shares For Annuity | Vanguard Dividend Growth Fund | Dividend Growth Spliced Index
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	11.93%	[2]
5 Years	rr_AverageAnnualReturnYear05	11.76%	[2]
10 Years	rr_AverageAnnualReturnYear10	5.94%	[2]
Investor Shares For Annuity | Vanguard Dividend Growth Fund | NASDAQ US Dividend Achievers Select Index
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	11.93%	[2]
5 Years	rr_AverageAnnualReturnYear05	11.76%	[2]
10 Years	rr_AverageAnnualReturnYear10	7.08%	[2]

[1] The year-to-date return as of the most recent calendar quarter, which ended on March 31, 2017, was 5.87%.

[2] Comparative Indexes (reflect no deduction for fees or expenses)