Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	VANGUARD MALVERN FUNDS
Prospectus Date	rr_ProspectusDate	Mar. 10, 2016
Investor Shares for Participants | Vanguard Core Bond Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summary
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide total return while generating a moderate level of current income.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses you may pay if you buy and hold Investor Shares of the Fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder Fees (Fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund has no operating history and therefore has no portfolio turnover information.
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	The following example is intended to help you compare the cost of investing in the Fund’s Investor Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you invested $10,000 in the Fund’s shares. This example assumes that the Shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests in fixed income securities of various maturities, yields, and qualities. Under normal circumstances, the Fund will invest at least 80% of its assets in bonds, which include fixed income securities such as corporate bonds, U.S. Treasury obligations and other U.S. government and agency securities, and asset-backed, mortgage-backed and mortgage-related securities. All bonds purchased by the Fund will have a maturity of 90 days or more at the time of their issuance. In addition, the Fund invests predominantly in U.S. dollar-denominated bonds, although these bonds may be issued by a foreign corporation or a U.S. affiliate of a foreign corporation or a foreign government or its agencies and instrumentalities. The Fund may also invest up to 10% of its assets in non-U.S. dollar-denominated bonds. The Fund’s dollar average weighted maturity will normally range between 4 and 12 years, and may either be longer or shorter under certain market conditions. Since the Fund will have holdings in asset-backed, mortgage-backed and similar securities, the Fund’s average weighted maturity may be approximate to the dollar average weighted maturity of the cash flows in the securities held by the Fund, given certain prepayment assumptions. This is also known as weighted average life. The Fund can purchase bonds of any quality. High-quality fixed income securities are those rated the equivalent of A3 or better by Moody‘s Investors Service, Inc., or another independent rating agency or, if unrated, are determined to be of comparable quality by the Fund’s advisor; medium-quality fixed income securities are those rated the equivalent of Baa1, Baa2, or Baa3 by Moody‘s or another independent rating agency or, if unrated, are determined to be of comparable quality by the Fund’s advisor; and lower-range credit-quality ratings—commonly known as “junk bonds”—are those rated the equivalent of Ba1 or lower by Moody’s, or another independent rating agency, or if unrated, are determined to be of comparable quality by the Fund’s advisor. No more than 5% of the Fund’s assets may be invested in non-investment-grade fixed income securities, or junk bonds.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	An investment in the Fund could lose money over short or even long periods. You should expect the Fund’s share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund’s performance, and the level of risk may vary based on market conditions: • Interest rate risk, which is the chance that bond prices will decline because of rising interest rates. • Income risk, which is the chance that the Fund’s income will decline because of falling interest rates. Income risk is generally high for short-term bond funds and moderate for intermediate-term bond funds, so investors should expect the Fund’s monthly income to fluctuate accordingly. • Call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund’s income. Such redemptions and subsequent reinvestments would also increase the Fund‘s portfolio turnover rate. • Prepayment risk, which is the chance that during periods of falling interest rates, homeowners will refinance their mortgages before their maturity dates, resulting in prepayment of mortgage-backed securities held by the Fund. The Fund would then lose any price appreciation above the mortgage’s principal and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund’s income. Such prepayments and subsequent reinvestments would also increase the Fund’s portfolio turnover rate. • Extension risk, which is the chance that during periods of rising interest rates, certain debt securities will be paid off substantially more slowly than originally anticipated, and the value of those securities may fall. For mortgage-backed securites, extension risk is the chance that during periods of rising interest rates, homeowners will prepay their mortgages at slower rates. • Credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline. • Liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price. • Currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. • Manager risk, which is the chance that poor security selection will cause the Fund to underperform relevant benchmarks or other funds with a similar investment objective. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Risk Lose Money [Text]	rr_RiskLoseMoney	An investment in the Fund could lose money over short or even long periods.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Annual Total Returns
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The Fund began operations on March 10, 2016, so performance information is not yet available.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	The Fund began operations on March 10, 2016, so performance information is not yet available.
Investor Shares for Participants | Vanguard Core Bond Fund | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
Purchase Fee	rr_MaximumCumulativeSalesChargeOverOther	none
Sales Charge (Load) Imposed on Purchases	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Sales Charge (Load) Imposed on Reinvested Dividends	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Redemption Fee	rr_RedemptionFeeOverRedemption	none
Management Fees	rr_ManagementFeesOverAssets	0.22%
12b-1 Distribution Fee	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.03%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.25%
1 Year	rr_ExpenseExampleYear01	$ 26
3 Years	rr_ExpenseExampleYear03	80
1 Year	rr_ExpenseExampleNoRedemptionYear01	26
3 Years	rr_ExpenseExampleNoRedemptionYear03	$ 80