2.2.0.25truefalse010000 - Document - Risk/Return Summary {Unlabeled}falsefalsetrue1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Retail {dei_LegalEntityAxis} : Vanguard Convertible Securities Fund 12/1/2009 - 11/30/2010 v_Retail_S000002837http://www.sec.gov/CIK0000791107duration2009-12-01T00:00:002010-11-30T00:00:00falsefalsevanguard_RetailMemberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_RetailMemberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsevanguard_S000002837Memberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberpureStandardhttp://www.xbrl.org/2003/instancepurexbrli01false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://xbrl.sec.gov/rr/role/riskreturn1falsefalsefalse00Retail | Vanguard Convertible Securities FundRetail | Vanguard Convertible Securities Fundfalsefalsefalsefalsefalse1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Retail {dei_LegalEntityAxis} : Vanguard Convertible Securities Fund 12/1/2009 - 11/30/2010 v_Retail_S000002837http://www.sec.gov/CIK0000791107duration2009-12-01T00:00:002010-11-30T00:00:00falsefalsevanguard_RetailMemberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_RetailMemberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsevanguard_S000002837Memberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberpureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalseRetail | Vanguard Convertible Securities Fund3false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Risk/ReturnfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicatedReference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 falsefalseRisk/Return4false0rr_ObjectiveHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Investment ObjectivefalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseInvestment objective:5false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund seeks to provide current income and long-term capital appreciation.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseInvestment objective6false0rr_ExpenseHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Fees and ExpensesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Fee Table Includes the following information, in plain English under rule 421(d) under the Securities Act, after Item 2 Fees and expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Shareholder Fees (fees paid directly from your investment) Example This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a "New Fund" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. The following Instructions apply to New Funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpenses Heading7false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown.The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. Modify the narrative explanation to state that Fund shares are sold on a national securities exchange at the end of the time periods indicated, and that brokerage commissions for buying and selling Fund shares through a broker are not reflected.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseFees and Expenses of the Fund8false0rr_ShareholderFeesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Shareholder Fees (Fees paid directly from your investment)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringShareholder Fees (fees paid directly from your investment).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subsection table falsefalseShareholder Fees Caption9false0rr_ShareholderFeesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://vanguard/role/S000002837ShareholderFeesRetail column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> falsefalse<div style="display:none">~ http://vanguard/role/S000002837ShareholderFeesRetail column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> falsehttp://vanguard/role/S000002837ShareholderFeesRetailfalsefalse1621630 - Schedule - Shareholder Fees (Vanguard Convertible Securities Fund Retail)truefalsefalse1falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00truefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberfalsefalseParticipantdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_ParticipantMemberdei_DocumentInformationDocumentAxisexplicitMemberShare ClassesParticipantStandard0falseUSDfalsefalse$2falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00truefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberfalsefalseRetaildei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_RetailMemberdei_DocumentInformationDocumentAxisexplicitMemberShare ClassesRetailStandard0falseUSDfalsefalse$3falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00falsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMembertruefalseAll Prospectusesdei_DocumentInformationDocumentAxisdei_DocumentDomaindei_DocumentInformationDocumentAxisexplicitMemberVanguard Convertible Securities Fund - Investor SharesAll ProspectusesusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member3false0rr_MaximumCumulativeSalesChargeOverOfferingPricerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruetrue00falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalse3truetruetrue00falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureMaximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price). If a sales charge (load) is imposed on shares purchased with reinvested capital gains distributions or returns of capital, include the bracketed words in the third caption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection table falsefalseSales charge (load) imposed on purchasesfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_MaximumCumulativeSalesChargeOverOfferingPricetruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truetruetrue00falsefalsefalsetruefalseOthernanafalsefalseSales charge (load) imposed on purchases2falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member4false0rr_MaximumCumulativeSalesChargeOverOtherrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruetrue00falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalse3truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureMaximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price). If a sales charge (load) is imposed on shares purchased with reinvested capital gains distributions or returns of capital, include the bracketed words in the third caption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection table falsefalsePurchase FeefalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_MaximumCumulativeSalesChargeOverOthertruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalsePurchase Fee3falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member5false0rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOtherrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruetrue00falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalse3truetruetrue00falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureMaximum Sales Charge (Load) Imposed on Reinvested Dividends[and other Distributions] (as a percentage of ____)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 3 -Subsection table falsefalseSales charge (load) imposed on reinvested dividendsfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOthertruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truetruetrue00falsefalsefalsetruefalseOthernanafalsefalseSales charge (load) imposed on reinvested dividends4falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member6false0rr_RedemptionFeeOverRedemptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1falsetruetrue00falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalse3truetruetrue0.01000.0100falsefalsefalsetruefalseOtherrr:NonPositivePure4Typepure"Redemption Fee" (as a percentage of amount redeemed, if applicable) If the Fund is an Exchange-Traded Fund and issues or redeems shares in creation units of not less than 25,000 shares each, exclude any fees charged for the purchase and redemption of the Fund's creation units. "Redemption Fee" includes a fee charged for any redemption of the Fund's shares, but does not include a deferred sales charge (load) imposed upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph b -Subsection instructions falsefalseRedemption FeefalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_RedemptionFeeOverRedemptiontruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truetruetrue0.01000.0100falsefalsefalsetruefalseOthernanafalsefalseRedemption Fee5falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member7false0vanguard_RedemptionFeeParentheticalvanguardfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00(on shares held less than one year)falsefalsefalsetruefalse2falsefalsefalse00(on shares held less than one year)falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalseOtherxbrli:stringItemTypestringNo definition available.No authoritative reference available.falsefalseRedemption Fee ParentheticalfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0vanguard_RedemptionFeeParentheticaltruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00(on shares held less than one year)(on shares held less than one year)falsefalsefalsetruefalse2falsefalsefalse00(on shares held less than one year)(on shares held less than one year)falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseRedemption Fee Parenthetical6falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member8false0rr_MaximumAccountFeerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsetrue00falsefalsefalsetruefalse2falsefalsetrue00falsefalsefalsetruefalse3truefalsetrue2020falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryInclude the caption "Maximum Account Fees" only if the Fund charges these fees. A Fund may omit other captions if the Fund does not charge the fees or expenses covered by the captions. Disclose account fees that may be charged to a typical investor in the Fund; fees that apply to only a limited number of shareholders based on their particular circumstances need not be disclosed. Include a caption describing the maximum account fee (e.g., "Maximum Account Maintenance Fee" or "Maximum Cash Management Fee"). State the maximum annual account fee as either a fixed dollar amount or a percentage of assets. Include in a parenthetical to the caption the basis on which any percentage is calculated. If an account fee is charged only to accounts that do not meet a certain threshold (e.g., accounts under $5)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph c -Subsection instructions falsefalseAccount Service Fee (for fund account balances below $10,000)falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_MaximumAccountFeetruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truefalsetrue2020falsefalsefalsetruefalseOthernanafalsefalseAccount Service Fee (for fund account balances below $10,000)36Shareholder Fees (Vanguard Convertible Securities Fund Retail) Vanguard Convertible Securities FundUnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*RowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837MemberfalsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ShareholderFeesData.No authoritative reference available.falsefalseShareholder Fees (Fees paid directly from your investment) [Table]10false0rr_OperatingExpensesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalseOperating Expenses Caption11false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://vanguard/role/S000002837OperatingExpensesRetail column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> falsefalse<div style="display:none">~ http://vanguard/role/S000002837OperatingExpensesRetail column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> falsehttp://vanguard/role/S000002837OperatingExpensesRetailfalsefalse1621627 - Schedule - Annual Fund Operating Expenses (Vanguard Convertible Securities Fund Retail)truefalsefalse1falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00falsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberVanguard Convertible Securities Fund - Investor SharesusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member3false0rr_ManagementFeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00650.0065falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureManagement Fees include investment advisory fees (including any fees based on the Fund's performance), any other management fees payable to the investment adviser or its affiliates, and administrative fees payable to the investment adviser or its affiliates that are not included as "Other Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph a -Subsection instructions falsefalseManagement ExpensesfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_ManagementFeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00650.0065falsefalsefalsetruefalseOthernanafalsefalseManagement Expenses2falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member4false0rr_DistributionAndService12b1FeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue00falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureDistribution [and/or Service] (12b-1) Fees" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalse12b-1 Distribution FeefalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue00falsefalsefalsetruefalseOthernanafalsefalse12b-1 Distribution Fee3falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member5false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00030.0003falsefalsefalsetruefalseOtherrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions falsefalseOther ExpensesfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00030.0003falsefalsefalsetruefalseOthernanafalsefalseOther Expenses4falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member6false0rr_NetExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00680.0068falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseTotal Annual Fund Operating ExpensesfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_NetExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00680.0068falsefalsefalsetruefalseOthernanafalsefalseTotal Annual Fund Operating Expenses14Annual Fund Operating Expenses (Vanguard Convertible Securities Fund Retail) Vanguard Convertible Securities FundUnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837MemberfalsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Expenses that you pay each year as a percentage of the value of your investment]12false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Example</p>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseEXAMPLE13false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>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 invest $10,000 in the Fund's shares. This example assumes that the Fund provides a return of 5% a year and that operating expenses remain as stated in the preceding table. The results apply 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:</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection example falsefalseExpense Example, Narrative [Text Block]14false0rr_ExpenseExampleNoRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://vanguard/role/S000002837ExpenseExampleNoRedemptionRetail column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> falsefalse<div style="display:none">~ http://vanguard/role/S000002837ExpenseExampleNoRedemptionRetail column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> truehttp://vanguard/role/S000002837ExpenseExampleNoRedemptionRetailfalsefalse1621614 - Schedule - Expense Example, No Redemption {Transposed} (Vanguard Convertible Securities Fund Retail)truefalsefalse1falseColumnprimaryElement*Columndei_LegalEntityAxisAxisvanguard_S000002837Member3false0rr_ExpenseExampleNoRedemptionYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue6969falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph 1 -Subsection example falsefalse1 YEARfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities FundfalseUSDfalsefalse$2falseColumnprimaryElement*Columndei_LegalEntityAxisAxisvanguard_S000002837Member4false0rr_ExpenseExampleNoRedemptionYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue218218falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph 1 -Subsection example falsefalse3 YEARfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities FundfalseUSDfalsefalse$3falseColumnprimaryElement*Columndei_LegalEntityAxisAxisvanguard_S000002837Member5false0rr_ExpenseExampleNoRedemptionYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue379379falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subparagraph f -Subsection instructions falsefalse5 YEARfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities FundfalseUSDfalsefalse$4falseColumnprimaryElement*Columndei_LegalEntityAxisAxisvanguard_S000002837Member6false0rr_ExpenseExampleNoRedemptionYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue847847falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subparagraph f -Subsection instructions falsefalse10 YEARfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities FundfalseUSDfalsefalse$1falseRowperiodPeriod*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00falsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberVanguard Convertible Securities Fund - Investor SharesusdStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue6969falsefalsefalsetruefalse2truefalsetrue218218falsefalsefalsetruefalse3truefalsetrue379379falsefalsefalsetruefalse4truefalsetrue847847falsefalsefalsetruefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares41Expense Example, No Redemption (Vanguard Convertible Securities Fund Retail) Vanguard Convertible Securities Fund (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*Columndei_LegalEntityAxisAxisvanguard_S000002837MemberRowperiodPeriod*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExampleNoRedemption.No authoritative reference available.falsefalseExpense Example, No Redemption15false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Portfolio Turnover</p>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover Heading16false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund pays transaction costs, such as commissions, when it buys and sells securities (or 'turns over' its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual 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 103%. </p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover17false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Primary Investment StrategiesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy:18false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund invests at least 80% of its assets in U.S. and foreign convertible securities, which are hybrid securities that combine the investment characteristics of bonds and common stocks. Convertible securities include corporate bonds and preferred stocks that are convertible into common stock, as well as debt securities with warrants or common stock attached. Many convertible securities have credit ratings that are below investment grade.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategyNarrative19false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Primary RisksfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk:20false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>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, like the fluctuations of global stock markets. The Fund's performance could be hurt by:</p><p>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. In addition, investments in foreign stocks can be riskier than U.S. stock investments. The prices of foreign stocks and the prices of U.S. stocks have, at times, moved in opposite directions. </p><p>Interest rate risk, which is the chance that prices of convertible securities will decline along with overall bond prices because of rising interest rates. Convertible securities are particularly sensitive to interest rate changes when their predetermined conversion price is much higher than the price of the issuing company's common stock.</p><p>Credit risk, which is the chance that the issuer of a convertible security will fail to pay interest or dividends and principal in a timely manner, or that negative perceptions of the issuer's ability to make such payments will cause the price of that security to decline. Companies that issue convertible securities are often small to medium size, and they often have low credit ratings. In addition, the credit rating of a company's convertible securities is generally lower than that of its non-convertible debt securities. Convertibles are normally considered 'junior' securities-that is, the company usually must pay interest on its non-convertible debt before it can make payments on its convertible securities. If an issuer stops making interest or principal payments, these securities may become worthless and the Fund could lose its entire investment. Reflecting the universe of convertible securities, most of the Fund's rated holdings are below investment-grade. Therefore, credit risk is greater for the Fund than for funds that invest in higher-grade securities.</p><p>Manager risk, which is the chance that poor security selection or focus on securities in a particular sector, category, or group of companies will cause the Fund to underperform relevant benchmarks or other funds with a similar investment objective. </p><p>Liquidity risk, which is the chance that the Fund will experience market difficulty in buying or selling securities quickly enough to prevent or minimize a loss. Liquidity risk arises when there is an insufficient market for a particular security or class of securities.</p><p>Country/regional risk, which is the chance that world events-such as political upheaval, financial troubles, or natural disasters-will adversely affect the value of securities issued by companies in foreign countries or regions. Because the Fund may invest a large portion of its assets in securities of companies located in any one country or region, the Fund's performance may be hurt disproportionately by the poor performance of its investments in that area. </p><p>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.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative21false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Total ReturnsfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table22false0rr_BarChartNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>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 compare with those of a relevant market index and other comparative benchmarks, which have investment characteristics similar to those of the Fund. As of January 1, 2011, the Fund's performance benchmark was changed to a composite benchmark consisting of 70% Bank of America Merrill Lynch All US Convertibles Index and 30% Bank of America Merrill Lynch Global 300 Convertibles ex-US Index (hedged), because the Fund's board of trustees believes that the new composite benchmark is more consistent with the Fund's investment strategy. As of January 1, 2011, the Spliced Convertibles Composite Index consists of the returns of the CS First Boston Convertible Securities Index through November 30, 2004; the Bank of America Merrill Lynch All US Convertibles Index (formerly the Bank of America Merrill Lynch All Convertibles-All Qualities Index) through December 31, 2010; and a composite index consisting of 70% Bank of America Merrill Lynch All US Convertibles Index and 30% Bank of America Merrill Lynch Global 300 Convertibles ex-US Index (hedged) thereafter. Returns for the Convertible Securities Funds Average are derived from data provided by Lipper Inc. 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.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringProvide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph i -Subsection b falsefalseBar Chart Narrative23false0rr_BarChartHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Total Returns - Vanguard Convertible Securities Fund Investor SharesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart24false0rr_BarChartTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://xbrl.sec.gov/rr/role/BarChartData column rr_ProspectusShareClassAxis compact vanguard_C000007767Member ~ </div> falsefalseBarChart1.jpg<div style="display:none">~ http://xbrl.sec.gov/rr/role/BarChartData column rr_ProspectusShareClassAxis compact vanguard_C000007767Member ~ </div> falsehttp://xbrl.sec.gov/rr/role/BarChartDatafalsefalse020050 - Schedule - Annual Total Returnstruefalsefalse1falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxisvanguard_C000007767MemberColumndei_LegalEntityAxisAxis*ColumnunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00falsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund - Investor SharesVanguard Convertible Securities FundusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*3false0rr_AnnualReturnInceptionDaterrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse001986-06-17falsefalsetruetruefalseOtherxbrli:dateItemTypedateIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets). When a Multiple Class Fund offering one or more Classes offers a new Class in a prospectus that does not offer the shares of any other Class, include the bar chart with annual total returns for any other existing Class for the first year that the Class is offered. Explain in a footnote that the returns are for a Class that is not offered in the prospectus that would have substantially similar annual returns because the shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Include return information for the other Class reflected in the bar chart in the performance table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseAnnual Return Inception Date0rr_AnnualReturnInceptionDatetruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse001986-06-171986-06-17falsefalsetruetruefalseOthernanafalsefalseAnnual Return Inception Date2falseRowprimaryElement*4false0rr_AnnualReturn2001rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0309-0.0309falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20010rr_AnnualReturn2001truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0309-0.0309falsefalsefalsetruefalseOthernanafalsefalse20013falseRowprimaryElement*5false0rr_AnnualReturn2002rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0935-0.0935falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20020rr_AnnualReturn2002truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0935-0.0935falsefalsefalsetruefalseOthernanafalsefalse20024falseRowprimaryElement*6false0rr_AnnualReturn2003rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.31580.3158falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20030rr_AnnualReturn2003truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.31580.3158falsefalsefalsetruefalseOthernanafalsefalse20035falseRowprimaryElement*7false0rr_AnnualReturn2004rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.07200.0720falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20040rr_AnnualReturn2004truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.07200.0720falsefalsefalsetruefalseOthernanafalsefalse20046falseRowprimaryElement*8false0rr_AnnualReturn2005rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.06600.0660falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20050rr_AnnualReturn2005truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.06600.0660falsefalsefalsetruefalseOthernanafalsefalse20057falseRowprimaryElement*9false0rr_AnnualReturn2006rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.12940.1294falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20060rr_AnnualReturn2006truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.12940.1294falsefalsefalsetruefalseOthernanafalsefalse20068falseRowprimaryElement*10false0rr_AnnualReturn2007rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.10610.1061falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20070rr_AnnualReturn2007truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.10610.1061falsefalsefalsetruefalseOthernanafalsefalse20079falseRowprimaryElement*11false0rr_AnnualReturn2008rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.2979-0.2979falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20080rr_AnnualReturn2008truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.2979-0.2979falsefalsefalsetruefalseOthernanafalsefalse200810falseRowprimaryElement*12false0rr_AnnualReturn2009rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.40810.4081falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20090rr_AnnualReturn2009truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.40810.4081falsefalsefalsetruefalseOthernanafalsefalse200911falseRowprimaryElement*13false0rr_AnnualReturn2010rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.19240.1924falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20100rr_AnnualReturn2010truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.19240.1924falsefalsefalsetruefalseOthernanafalsefalse2010111Annual Total Returns UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxisvanguard_C000007767MemberColumndei_LegalEntityAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to BarChartData.No authoritative reference available.falsefalseBar Chart:25false0rr_BarChartClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>During the periods shown in the bar chart, the highest return for a calendar quarter was 14.66% (quarter ended September 30, 2009 ), and the lowest return for a quarter was -15.90% (quarter ended December 31, 2008 ).</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseBar Chart Closing26false0rr_PerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Average Annual Total Returns for Periods Ended December 31, 2010falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit c -Subsection b falsefalseBar Chart and Performance Table:27false0rr_PerformanceTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://vanguard/role/S000002837PerformanceTableDataRetail column primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member row rr_ProspectusShareClassAxis compact * row rr_PerformanceMeasureAxis compact * ~ </div> falsefalse<div style="display:none">~ http://vanguard/role/S000002837PerformanceTableDataRetail column primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member row rr_ProspectusShareClassAxis compact * row rr_PerformanceMeasureAxis compact * ~ </div> falsehttp://vanguard/role/S000002837PerformanceTableDataRetailfalsefalse1621652 - Schedule - Average Annual Total Returns (Vanguard Convertible Securities Fund Retail)truefalsefalse1falseColumnperiodPeriod*ColumnprimaryElement*ColumnunitUnit*3false0rr_AverageAnnualReturnYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.15580.1558falsefalsefalsetruefalse2truetruetrue0.13150.1315falsefalsefalsetruefalse3truetruetrue0.16770.1677falsefalsefalsetruefalse4truetruetrue0.16850.1685falsefalsefalsetruefalse5truetruetrue0.16770.1677falsefalsefalsetruefalse6truetruetrue0.19240.1924falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseOne Yearduration2009-12-01T00:00:002010-11-30T00:00:00falseUSDfalsefalse$2falseColumnperiodPeriod*ColumnprimaryElement*ColumnunitUnit*4false0rr_AverageAnnualReturnYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.05690.0569falsefalsefalsetruefalse2truetruetrue0.05670.0567falsefalsefalsetruefalse3truetruetrue0.05710.0571falsefalsefalsetruefalse4truetruetrue0.05550.0555falsefalsefalsetruefalse5truetruetrue0.05710.0571falsefalsefalsetruefalse6truetruetrue0.08050.0805falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseFive Yearsduration2009-12-01T00:00:002010-11-30T00:00:00falseUSDfalsefalse$3falseColumnperiodPeriod*ColumnprimaryElement*ColumnunitUnit*5false0rr_AverageAnnualReturnYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.04900.0490falsefalsefalsetruefalse2truetruetrue0.04840.0484falsefalsefalsetruefalse3truetruetrue0.04970.0497falsefalsefalsetruefalse4truetruetrue0.04380.0438falsefalsefalsetruefalse5truetruetrue0.04730.0473falsefalsefalsetruefalse6truetruetrue0.06880.0688falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseTen Yearsduration2009-12-01T00:00:002010-11-30T00:00:00falseUSDfalsefalse$4falseColumnperiodPeriod*ColumnprimaryElement*ColumnunitUnit*7false0vanguard_ComparativeBenchmarkvanguardfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5falsefalsefalse00falsefalsefalsetruefalse6falsefalsefalse00Comparative BenchmarksfalsefalsefalsetruefalseOtherxbrli:stringItemTypestringNo definition available.No authoritative reference available.falsefalseComparative Benchmarkduration2009-12-01T00:00:002010-11-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberfalsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMembertruefalseReturn Before Taxesrr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberVanguard Convertible Securities FundVanguard Convertible Securities Fund - Investor SharesReturn Before Taxes0truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.19240.1924falsefalsefalsetruefalse2truetruetrue0.08050.0805falsefalsefalsetruefalse3truetruetrue0.06880.0688falsefalsefalsetruefalse4falsefalsefalse00Comparative BenchmarksComparative BenchmarksfalsefalsefalsetruefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares2falseRowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberfalsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseReturn After Taxes on Distributionsrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldirr_AfterTaxesOnDistributionsMemberrr_PerformanceMeasureAxisexplicitMemberVanguard Convertible Securities FundVanguard Convertible Securities Fund - Investor SharesReturn After Taxes on Distributions0truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.15580.1558falsefalsefalsetruefalse2truetruetrue0.05690.0569falsefalsefalsetruefalse3truetruetrue0.04900.0490falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares Return After Taxes on Distributions3falseRowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberfalsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseReturn After Taxes on Distributions and Sale of Fund Sharesrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldirr_AfterTaxesOnDistributionsAndSalesMemberrr_PerformanceMeasureAxisexplicitMemberVanguard Convertible Securities FundVanguard Convertible Securities Fund - Investor SharesReturn After Taxes on Distributions and Sale of Fund Shares0truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.13150.1315falsefalsefalsetruefalse2truetruetrue0.05670.0567falsefalsefalsetruefalse3truetruetrue0.04840.0484falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares Return After Taxes on Distributions and Sale of Fund Shares4falseRowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberfalsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseBank of America Merrill Lynch All US Convertibles Indexrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_BankofAmericaMerrillLynchAllUSConvertiblesMemberrr_PerformanceMeasureAxisexplicitMemberVanguard Convertible Securities FundVanguard Convertible Securities Fund - Investor SharesBank of America Merrill Lynch All US Convertibles Index0truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.16770.1677falsefalsefalsetruefalse2truetruetrue0.05710.0571falsefalsefalsetruefalse3truetruetrue0.04970.0497falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares Bank of America Merrill Lynch All US Convertibles Index5falseRowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberfalsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseConvertible Securities Funds Averagerr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_ConvertibleSecuritiesFundsAverageMemberrr_PerformanceMeasureAxisexplicitMemberVanguard Convertible Securities FundVanguard Convertible Securities Fund - Investor SharesConvertible Securities Funds Average0truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.16850.1685falsefalsefalsetruefalse2truetruetrue0.05550.0555falsefalsefalsetruefalse3truetruetrue0.04380.0438falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares Convertible Securities Funds Average6falseRowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberfalsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseSpliced Convertibles Composite Indexrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_SplicedConvertiblesCompositeIndexMemberrr_PerformanceMeasureAxisexplicitMemberVanguard Convertible Securities FundVanguard Convertible Securities Fund - Investor SharesSpliced Convertibles Composite Index0truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.16770.1677falsefalsefalsetruefalse2truetruetrue0.05710.0571falsefalsefalsetruefalse3truetruetrue0.04730.0473falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares Spliced Convertibles Composite Index46Average Annual Total Returns (Vanguard Convertible Securities Fund Retail) Vanguard Convertible Securities FundUnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*ColumnprimaryElement*ColumnunitUnit*Rowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to PerformanceTableData.No authoritative reference available.falsefalsePerformance28false0rr_PerformanceTableClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>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 will 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.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also shouldshow the returns of an appropriate broadbased securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Subsection b falsefalsePerformance Table Closing29false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://xbrl.sec.gov/rr/role/riskreturn1falsefalsefalse00Participant | Vanguard Convertible Securities FundParticipant | Vanguard Convertible Securities Fundfalsefalsefalsefalsefalse2falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Participant {dei_LegalEntityAxis} : Vanguard Convertible Securities Fund 12/1/2009 - 11/30/2010 v_Participant_S000002837http://www.sec.gov/CIK0000791107duration2009-12-01T00:00:002010-11-30T00:00:00falsefalsevanguard_ParticipantMemberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_ParticipantMemberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsevanguard_S000002837Memberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberpureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalseParticipant | Vanguard Convertible Securities Fund31false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Risk/ReturnfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicatedReference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 falsefalseRisk/Return32false0rr_ObjectiveHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Investment ObjectivefalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseInvestment objective:33false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund seeks to provide current income and long-term capital appreciation.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseInvestment objective34false0rr_ExpenseHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Fees and ExpensesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Fee Table Includes the following information, in plain English under rule 421(d) under the Securities Act, after Item 2 Fees and expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Shareholder Fees (fees paid directly from your investment) Example This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a "New Fund" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. The following Instructions apply to New Funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpenses Heading35false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown.The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. Modify the narrative explanation to state that Fund shares are sold on a national securities exchange at the end of the time periods indicated, and that brokerage commissions for buying and selling Fund shares through a broker are not reflected.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseFees and Expenses of the Fund36false0rr_ShareholderFeesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Shareholder Fees (Fees paid directly from your investment)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringShareholder Fees (fees paid directly from your investment).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subsection table falsefalseShareholder Fees Caption37false0rr_ShareholderFeesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://vanguard/role/S000002837ShareholderFeesParticipant column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> falsefalse<div style="display:none">~ http://vanguard/role/S000002837ShareholderFeesParticipant column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> falsehttp://vanguard/role/S000002837ShareholderFeesParticipantfalsefalse1621660 - Schedule - Shareholder Fees (Vanguard Convertible Securities Fund Participant)truefalsefalse1falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00truefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberfalsefalseParticipantdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_ParticipantMemberdei_DocumentInformationDocumentAxisexplicitMemberShare ClassesParticipantStandard0falseUSDfalsefalse$2falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00truefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberfalsefalseRetaildei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_RetailMemberdei_DocumentInformationDocumentAxisexplicitMemberShare ClassesRetailStandard0falseUSDfalsefalse$3falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00falsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMembertruefalseAll Prospectusesdei_DocumentInformationDocumentAxisdei_DocumentDomaindei_DocumentInformationDocumentAxisexplicitMemberVanguard Convertible Securities Fund - Investor SharesAll ProspectusesusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member3false0rr_MaximumCumulativeSalesChargeOverOfferingPricerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruetrue00falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalse3truetruetrue00falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureMaximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price). If a sales charge (load) is imposed on shares purchased with reinvested capital gains distributions or returns of capital, include the bracketed words in the third caption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection table falsefalseSales charge (load) imposed on purchasesfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_MaximumCumulativeSalesChargeOverOfferingPricetruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truetruetrue00falsefalsefalsetruefalseOthernanafalsefalseSales charge (load) imposed on purchases2falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member4false0rr_MaximumCumulativeSalesChargeOverOtherrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruetrue00falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalse3truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureMaximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price). If a sales charge (load) is imposed on shares purchased with reinvested capital gains distributions or returns of capital, include the bracketed words in the third caption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection table falsefalsePurchase FeefalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_MaximumCumulativeSalesChargeOverOthertruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalsePurchase Fee3falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member5false0rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOtherrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruetrue00falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalse3truetruetrue00falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureMaximum Sales Charge (Load) Imposed on Reinvested Dividends[and other Distributions] (as a percentage of ____)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 3 -Subsection table falsefalseSales charge (load) imposed on reinvested dividendsfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOthertruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truetruetrue00falsefalsefalsetruefalseOthernanafalsefalseSales charge (load) imposed on reinvested dividends4falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member6false0rr_RedemptionFeeOverRedemptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1falsetruetrue00falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalse3truetruetrue0.01000.0100falsefalsefalsetruefalseOtherrr:NonPositivePure4Typepure"Redemption Fee" (as a percentage of amount redeemed, if applicable) If the Fund is an Exchange-Traded Fund and issues or redeems shares in creation units of not less than 25,000 shares each, exclude any fees charged for the purchase and redemption of the Fund's creation units. "Redemption Fee" includes a fee charged for any redemption of the Fund's shares, but does not include a deferred sales charge (load) imposed upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph b -Subsection instructions falsefalseRedemption FeefalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_RedemptionFeeOverRedemptiontruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3truetruetrue0.01000.0100falsefalsefalsetruefalseOthernanafalsefalseRedemption Fee5falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member7false0vanguard_RedemptionFeeParentheticalvanguardfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00(on shares held less than one year)falsefalsefalsetruefalse2falsefalsefalse00(on shares held less than one year)falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalseOtherxbrli:stringItemTypestringNo definition available.No authoritative reference available.falsefalseRedemption Fee ParentheticalfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0vanguard_RedemptionFeeParentheticaltruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00(on shares held less than one year)(on shares held less than one year)falsefalsefalsetruefalse2falsefalsefalse00(on shares held less than one year)(on shares held less than one year)falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseRedemption Fee Parenthetical35Shareholder Fees (Vanguard Convertible Securities Fund Participant) Vanguard Convertible Securities FundUnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*RowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837MemberfalsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ShareholderFeesData.No authoritative reference available.falsefalseShareholder Fees (Fees paid directly from your investment) [Table]38false0rr_OperatingExpensesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalseOperating Expenses Caption39false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://vanguard/role/S000002837OperatingExpensesParticipant column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> falsefalse<div style="display:none">~ http://vanguard/role/S000002837OperatingExpensesParticipant column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> falsehttp://vanguard/role/S000002837OperatingExpensesParticipantfalsefalse1621659 - Schedule - Annual Fund Operating Expenses (Vanguard Convertible Securities Fund Participant)truefalsefalse1falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00falsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberVanguard Convertible Securities Fund - Investor SharesusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member3false0rr_ManagementFeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00650.0065falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureManagement Fees include investment advisory fees (including any fees based on the Fund's performance), any other management fees payable to the investment adviser or its affiliates, and administrative fees payable to the investment adviser or its affiliates that are not included as "Other Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph a -Subsection instructions falsefalseManagement ExpensesfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_ManagementFeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00650.0065falsefalsefalsetruefalseOthernanafalsefalseManagement Expenses2falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member4false0rr_DistributionAndService12b1FeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue00falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureDistribution [and/or Service] (12b-1) Fees" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalse12b-1 Distribution FeefalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue00falsefalsefalsetruefalseOthernanafalsefalse12b-1 Distribution Fee3falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member5false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00030.0003falsefalsefalsetruefalseOtherrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions falsefalseOther ExpensesfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00030.0003falsefalsefalsetruefalseOthernanafalsefalseOther Expenses4falseRowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837Member6false0rr_NetExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00680.0068falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseTotal Annual Fund Operating ExpensesfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund0rr_NetExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00680.0068falsefalsefalsetruefalseOthernanafalsefalseTotal Annual Fund Operating Expenses14Annual Fund Operating Expenses (Vanguard Convertible Securities Fund Participant) Vanguard Convertible Securities FundUnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*Rowdei_LegalEntityAxisAxisvanguard_S000002837MemberfalsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Expenses that you pay each year as a percentage of the value of your investment]40false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Example</p>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseEXAMPLE41false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>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 invest $10,000 in the Fund's shares. This example assumes that the Fund provides a return of 5% a year and that operating expenses remain as stated in the preceding table. The results apply 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:</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection example falsefalseExpense Example, Narrative [Text Block]42false0rr_ExpenseExampleNoRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://vanguard/role/S000002837ExpenseExampleNoRedemptionParticipant column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> falsefalse<div style="display:none">~ http://vanguard/role/S000002837ExpenseExampleNoRedemptionParticipant column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member ~ </div> truehttp://vanguard/role/S000002837ExpenseExampleNoRedemptionParticipantfalsefalse1621649 - Schedule - Expense Example, No Redemption {Transposed} (Vanguard Convertible Securities Fund Participant)truefalsefalse1falseColumnprimaryElement*Columndei_LegalEntityAxisAxisvanguard_S000002837Member3false0rr_ExpenseExampleNoRedemptionYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue6969falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph 1 -Subsection example falsefalse1 YEARfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities FundfalseUSDfalsefalse$2falseColumnprimaryElement*Columndei_LegalEntityAxisAxisvanguard_S000002837Member4false0rr_ExpenseExampleNoRedemptionYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue218218falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph 1 -Subsection example falsefalse3 YEARfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities FundfalseUSDfalsefalse$3falseColumnprimaryElement*Columndei_LegalEntityAxisAxisvanguard_S000002837Member5false0rr_ExpenseExampleNoRedemptionYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue379379falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subparagraph f -Subsection instructions falsefalse5 YEARfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities FundfalseUSDfalsefalse$4falseColumnprimaryElement*Columndei_LegalEntityAxisAxisvanguard_S000002837Member6false0rr_ExpenseExampleNoRedemptionYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue847847falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryYou would pay the following expenses if you did not redeem your shares. Include the second 1-, 3-, 5-, and 10-year periods and related narrative explanation only if a sales charge (load) or other fee is charged upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subparagraph f -Subsection instructions falsefalse10 YEARfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities FundfalseUSDfalsefalse$1falseRowperiodPeriod*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00falsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberVanguard Convertible Securities Fund - Investor SharesusdStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue6969falsefalsefalsetruefalse2truefalsetrue218218falsefalsefalsetruefalse3truefalsetrue379379falsefalsefalsetruefalse4truefalsetrue847847falsefalsefalsetruefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares41Expense Example, No Redemption (Vanguard Convertible Securities Fund Participant) Vanguard Convertible Securities Fund (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*Columndei_LegalEntityAxisAxisvanguard_S000002837MemberRowperiodPeriod*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExampleNoRedemption.No authoritative reference available.falsefalseExpense Example, No Redemption43false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Portfolio Turnover</p>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover Heading44false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund pays transaction costs, such as commissions, when it buys and sells securities (or 'turns over' its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual 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 103%. </p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover45false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Primary Investment StrategiesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy:46false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund invests at least 80% of its assets in U.S. and foreign convertible securities, which are hybrid securities that combine the investment characteristics of bonds and common stocks. Convertible securities include corporate bonds and preferred stocks that are convertible into common stock, as well as debt securities with warrants or common stock attached. Many convertible securities have credit ratings that are below investment grade.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategyNarrative47false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Primary RisksfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk:48false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>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, like the fluctuations of global stock markets. The Fund's performance could be hurt by:</p><p>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. In addition, investments in foreign stocks can be riskier than U.S. stock investments. The prices of foreign stocks and the prices of U.S. stocks have, at times, moved in opposite directions. </p><p>Interest rate risk, which is the chance that prices of convertible securities will decline along with overall bond prices because of rising interest rates. Convertible securities are particularly sensitive to interest rate changes when their predetermined conversion price is much higher than the price of the issuing company's common stock.</p><p>Credit risk, which is the chance that the issuer of a convertible security will fail to pay interest or dividends and principal in a timely manner, or that negative perceptions of the issuer's ability to make such payments will cause the price of that security to decline. Companies that issue convertible securities are often small to medium size, and they often have low credit ratings. In addition, the credit rating of a company's convertible securities is generally lower than that of its non-convertible debt securities. Convertibles are normally considered 'junior' securities-that is, the company usually must pay interest on its non-convertible debt before it can make payments on its convertible securities. If an issuer stops making interest or principal payments, these securities may become worthless and the Fund could lose its entire investment. Reflecting the universe of convertible securities, most of the Fund's rated holdings are below investment-grade. Therefore, credit risk is greater for the Fund than for funds that invest in higher-grade securities.</p><p>Manager risk, which is the chance that poor security selection or focus on securities in a particular sector, category, or group of companies will cause the Fund to underperform relevant benchmarks or other funds with a similar investment objective. </p><p>Liquidity risk, which is the chance that the Fund will experience market difficulty in buying or selling securities quickly enough to prevent or minimize a loss. Liquidity risk arises when there is an insufficient market for a particular security or class of securities.</p><p>Country/regional risk, which is the chance that world events-such as political upheaval, financial troubles, or natural disasters-will adversely affect the value of securities issued by companies in foreign countries or regions. Because the Fund may invest a large portion of its assets in securities of companies located in any one country or region, the Fund's performance may be hurt disproportionately by the poor performance of its investments in that area. </p><p>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.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative49false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Total ReturnsfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table50false0rr_BarChartNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>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 compare with those of a relevant market index and other comparative benchmarks, which have investment characteristics similar to those of the Fund. As of January 1, 2011, the Fund's performance benchmark was changed to a composite benchmark consisting of 70% Bank of America Merrill Lynch All US Convertibles Index and 30% Bank of America Merrill Lynch Global 300 Convertibles ex-US Index (hedged), because the Fund's board of trustees believes that the new composite benchmark is more consistent with the Fund's investment strategy. As of January 1, 2011, the Spliced Convertibles Composite Index consists of the returns of the CS First Boston Convertible Securities Index through November 30, 2004; the Bank of America Merrill Lynch All US Convertibles Index (formerly the Bank of America Merrill Lynch All Convertibles-All Qualities Index) through December 31, 2010; and a composite index consisting of 70% Bank of America Merrill Lynch All US Convertibles Index and 30% Bank of America Merrill Lynch Global 300 Convertibles ex-US Index (hedged) thereafter. Returns for the Convertible Securities Funds Average are derived from data provided by Lipper Inc. 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.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringProvide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph i -Subsection b falsefalseBar Chart Narrative51false0rr_BarChartHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Total Returns - Vanguard Convertible Securities Fund Investor SharesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart52false0rr_BarChartTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://xbrl.sec.gov/rr/role/BarChartData column rr_ProspectusShareClassAxis compact vanguard_C000007767Member ~ </div> falsefalseBarChart2.jpg<div style="display:none">~ http://xbrl.sec.gov/rr/role/BarChartData column rr_ProspectusShareClassAxis compact vanguard_C000007767Member ~ </div> falsehttp://xbrl.sec.gov/rr/role/BarChartDatafalsefalse020050 - Schedule - Annual Total Returnstruefalsefalse1falseColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxisvanguard_C000007767MemberColumndei_LegalEntityAxisAxis*ColumnunitUnit*duration2009-12-01T00:00:002010-11-30T00:00:00falsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberVanguard Convertible Securities Fund - Investor SharesVanguard Convertible Securities FundusdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*3false0rr_AnnualReturnInceptionDaterrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse001986-06-17falsefalsetruetruefalseOtherxbrli:dateItemTypedateIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets). When a Multiple Class Fund offering one or more Classes offers a new Class in a prospectus that does not offer the shares of any other Class, include the bar chart with annual total returns for any other existing Class for the first year that the Class is offered. Explain in a footnote that the returns are for a Class that is not offered in the prospectus that would have substantially similar annual returns because the shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Include return information for the other Class reflected in the bar chart in the performance table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseAnnual Return Inception Date0rr_AnnualReturnInceptionDatetruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse001986-06-171986-06-17falsefalsetruetruefalseOthernanafalsefalseAnnual Return Inception Date2falseRowprimaryElement*4false0rr_AnnualReturn2001rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0309-0.0309falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20010rr_AnnualReturn2001truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0309-0.0309falsefalsefalsetruefalseOthernanafalsefalse20013falseRowprimaryElement*5false0rr_AnnualReturn2002rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0935-0.0935falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20020rr_AnnualReturn2002truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0935-0.0935falsefalsefalsetruefalseOthernanafalsefalse20024falseRowprimaryElement*6false0rr_AnnualReturn2003rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.31580.3158falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20030rr_AnnualReturn2003truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.31580.3158falsefalsefalsetruefalseOthernanafalsefalse20035falseRowprimaryElement*7false0rr_AnnualReturn2004rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.07200.0720falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20040rr_AnnualReturn2004truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.07200.0720falsefalsefalsetruefalseOthernanafalsefalse20046falseRowprimaryElement*8false0rr_AnnualReturn2005rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.06600.0660falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20050rr_AnnualReturn2005truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.06600.0660falsefalsefalsetruefalseOthernanafalsefalse20057falseRowprimaryElement*9false0rr_AnnualReturn2006rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.12940.1294falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20060rr_AnnualReturn2006truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.12940.1294falsefalsefalsetruefalseOthernanafalsefalse20068falseRowprimaryElement*10false0rr_AnnualReturn2007rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.10610.1061falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20070rr_AnnualReturn2007truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.10610.1061falsefalsefalsetruefalseOthernanafalsefalse20079falseRowprimaryElement*11false0rr_AnnualReturn2008rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.2979-0.2979falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20080rr_AnnualReturn2008truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.2979-0.2979falsefalsefalsetruefalseOthernanafalsefalse200810falseRowprimaryElement*12false0rr_AnnualReturn2009rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.40810.4081falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20090rr_AnnualReturn2009truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.40810.4081falsefalsefalsetruefalseOthernanafalsefalse200911falseRowprimaryElement*13false0rr_AnnualReturn2010rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.19240.1924falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20100rr_AnnualReturn2010truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.19240.1924falsefalsefalsetruefalseOthernanafalsefalse2010111Annual Total Returns UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columnrr_ProspectusShareClassAxisAxisvanguard_C000007767MemberColumndei_LegalEntityAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to BarChartData.No authoritative reference available.falsefalseBar Chart:53false0rr_BarChartClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>During the periods shown in the bar chart, the highest return for a calendar quarter was 14.66% (quarter ended September 30, 2009 ), and the lowest return for a quarter was -15.90% (quarter ended December 31, 2008 ).</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseBar Chart Closing54false0rr_PerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Average Annual Total Returns for Periods Ended December 31, 2010falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit c -Subsection b falsefalseBar Chart and Performance Table:55false0rr_PerformanceTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://vanguard/role/S000002837PerformanceTableDataParticipant column primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member row rr_ProspectusShareClassAxis compact * row rr_PerformanceMeasureAxis compact * ~ </div> falsefalse<div style="display:none">~ http://vanguard/role/S000002837PerformanceTableDataParticipant column primary compact * row dei_LegalEntityAxis compact vanguard_S000002837Member row rr_ProspectusShareClassAxis compact * row rr_PerformanceMeasureAxis compact * ~ </div> falsehttp://vanguard/role/S000002837PerformanceTableDataParticipantfalsefalse1621643 - Schedule - Average Annual Total Returns (Vanguard Convertible Securities Fund Participant)truefalsefalse1falseColumnperiodPeriod*ColumnprimaryElement*ColumnunitUnit*3false0rr_AverageAnnualReturnYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.16770.1677falsefalsefalsetruefalse2truetruetrue0.16850.1685falsefalsefalsetruefalse3truetruetrue0.16770.1677falsefalsefalsetruefalse4truetruetrue0.19240.1924falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseOne Yearduration2009-12-01T00:00:002010-11-30T00:00:00falseUSDfalsefalse$2falseColumnperiodPeriod*ColumnprimaryElement*ColumnunitUnit*4false0rr_AverageAnnualReturnYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.05710.0571falsefalsefalsetruefalse2truetruetrue0.05550.0555falsefalsefalsetruefalse3truetruetrue0.05710.0571falsefalsefalsetruefalse4truetruetrue0.08050.0805falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseFive Yearsduration2009-12-01T00:00:002010-11-30T00:00:00falseUSDfalsefalse$3falseColumnperiodPeriod*ColumnprimaryElement*ColumnunitUnit*5false0rr_AverageAnnualReturnYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.04970.0497falsefalsefalsetruefalse2truetruetrue0.04380.0438falsefalsefalsetruefalse3truetruetrue0.04730.0473falsefalsefalsetruefalse4truetruetrue0.06880.0688falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseTen Yearsduration2009-12-01T00:00:002010-11-30T00:00:00falseUSDfalsefalse$4falseColumnperiodPeriod*ColumnprimaryElement*ColumnunitUnit*7false0vanguard_ComparativeBenchmarkvanguardfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00Comparative BenchmarksfalsefalsefalsetruefalseOtherxbrli:stringItemTypestringNo definition available.No authoritative reference available.falsefalseComparative Benchmarkduration2009-12-01T00:00:002010-11-30T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberfalsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMembertruefalseReturn Before Taxesrr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMemberVanguard Convertible Securities FundVanguard Convertible Securities Fund - Investor SharesReturn Before Taxes0truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.19240.1924falsefalsefalsetruefalse2truetruetrue0.08050.0805falsefalsefalsetruefalse3truetruetrue0.06880.0688falsefalsefalsetruefalse4falsefalsefalse00Comparative BenchmarksComparative BenchmarksfalsefalsefalsetruefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares2falseRowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberfalsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseBank of America Merrill Lynch All US Convertibles Indexrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_BankofAmericaMerrillLynchAllUSConvertiblesMemberrr_PerformanceMeasureAxisexplicitMemberVanguard Convertible Securities FundVanguard Convertible Securities Fund - Investor SharesBank of America Merrill Lynch All US Convertibles Index0truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.16770.1677falsefalsefalsetruefalse2truetruetrue0.05710.0571falsefalsefalsetruefalse3truetruetrue0.04970.0497falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares Bank of America Merrill Lynch All US Convertibles Index3falseRowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberfalsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseConvertible Securities Funds Averagerr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_ConvertibleSecuritiesFundsAverageMemberrr_PerformanceMeasureAxisexplicitMemberVanguard Convertible Securities FundVanguard Convertible Securities Fund - Investor SharesConvertible Securities Funds Average0truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.16850.1685falsefalsefalsetruefalse2truetruetrue0.05550.0555falsefalsefalsetruefalse3truetruetrue0.04380.0438falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares Convertible Securities Funds Average4falseRowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalseVanguard Convertible Securities Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_S000002837Memberdei_LegalEntityAxisexplicitMemberfalsefalseVanguard Convertible Securities Fund - Investor Sharesrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_C000007767Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseSpliced Convertibles Composite Indexrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldivanguard_SplicedConvertiblesCompositeIndexMemberrr_PerformanceMeasureAxisexplicitMemberVanguard Convertible Securities FundVanguard Convertible Securities Fund - Investor SharesSpliced Convertibles Composite Index0truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.16770.1677falsefalsefalsetruefalse2truetruetrue0.05710.0571falsefalsefalsetruefalse3truetruetrue0.04730.0473falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseVanguard Convertible Securities Fund - Investor Shares Spliced Convertibles Composite Index44Average Annual Total Returns (Vanguard Convertible Securities Fund Participant) Vanguard Convertible Securities FundUnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*ColumnprimaryElement*ColumnunitUnit*Rowdei_LegalEntityAxisAxisvanguard_S000002837MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to PerformanceTableData.No authoritative reference available.falsefalsePerformance153Risk/Return Summary (Vanguard Convertible Securities Fund)UnKnownUnKnownUnKnownUnKnownfalsetrue