| Label | Element | Value | ||
|---|---|---|---|---|
| Risk Return Abstract | rr_RiskReturnAbstract | |||
| Registrant Name | dei_EntityRegistrantName | VANGUARD ADMIRAL FUNDS | ||
| Prospectus Date | rr_ProspectusDate | Dec. 21, 2022 | ||
| Retail | Vanguard Treasury Money Market Fund | ||||
| Risk Return Abstract | rr_RiskReturnAbstract | |||
| Risk/Return [Heading] | rr_RiskReturnHeading | <span style="color:#000000;font-family:Arial;font-size:13pt;font-weight:bold;">Vanguard Treasury Money Market Fund</span> | ||
| Objective [Heading] | rr_ObjectiveHeading | <span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Investment Objective</span> | ||
| Objective, Primary [Text Block] | rr_ObjectivePrimaryTextBlock | The Fund seeks to provide current income while maintaining liquidity and a stable share price of $1. | ||
| Expense [Heading] | rr_ExpenseHeading | <span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Fees and Expenses</span> | ||
| Expense Narrative [Text Block] | rr_ExpenseNarrativeTextBlock | The following table describes the fees and expenses you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and example below. | ||
| Shareholder Fees Caption [Text] | rr_ShareholderFeesCaption | <span style="color:#000000;font-family:Arial;font-size:8.5pt;font-weight:bold;">Shareholder Fees</span> <br/><span style="color:#000000;font-family:Arial;font-size:8.5pt;margin-left:0%;">(Fees paid directly from your investment)</span> | ||
| Operating Expenses Caption [Text] | rr_OperatingExpensesCaption | <span style="color:#000000;font-family:Arial;font-size:8.5pt;font-weight:bold;">Annual Fund Operating Expenses</span> <br/><span style="color:#000000;font-family:Arial;font-size:8.5pt;margin-left:0%;">(Expenses that you pay each year as a percentage of the value of your investment)</span> | ||
| Expense Example [Heading] | rr_ExpenseExampleHeading | <span style="color:#000000;font-family:Arial;font-size:9.5pt;">Example</span> | ||
| Expense Example Narrative [Text Block] | rr_ExpenseExampleNarrativeTextBlock | The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund's shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be: | ||
| Strategy [Heading] | rr_StrategyHeading | <span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Investment Strategies</span> | ||
| Strategy Narrative [Text Block] | rr_StrategyNarrativeTextBlock | The Fund invests solely in high-quality, short-term money market instruments whose interest and principal payments are backed by the full faith and credit of the U.S. government. Under normal circumstances, at least 80% of the Fund’s assets will be invested in U.S. Treasury securities and in repurchase agreements fully collateralized by U.S. Treasury securities; the remainder of the assets will also be invested in U.S. Treasury securities and in repurchase agreements fully collateralized by U.S. Treasury securities. The only repurchase agreements that the Fund will invest in are those with the Federal Reserve Bank of New York that are fully collateralized by U.S. Treasury securities. The Fund maintains a dollar-weighted average maturity of 60 days or less and a dollar-weighted average life of 120 days or less.Government money market funds are required to invest at least 99.5% of their total assets in cash, U.S. government securities, and/or repurchase agreements that are collateralized solely by U.S. government securities or cash (collectively, government securities). The Fund generally invests 100% of its assets in U.S. Treasury securities and in repurchase agreements fully collateralized by U.S. Treasury securities and therefore satisfies the 99.5% requirement for designation as a government money market fund. | ||
| Risk [Heading] | rr_RiskHeading | <span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Risks</span> | ||
| Risk Narrative [Text Block] | rr_RiskNarrativeTextBlock | The Fund is designed for investors with a low tolerance for risk; however, the Fund is subject to the following risks, which could affect the Fund’s performance:• Income risk, which is the chance that the Fund’s income will decline because of falling interest rates. Because the Fund’s income is based on short-term interest rates—which can fluctuate significantly over short periods—income risk is expected to be high. A low or negative interest rate environment will adversely affect the Fund’s return. Low or negative interest rates, depending on their duration and severity, could prevent the Fund from, among other things, providing a positive yield and/or maintaining a stable share price of $1.• 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.You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund's sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time. | ||
| Risk Lose Money [Text] | rr_RiskLoseMoney | <span style="color:#000000;font-family:Arial;font-size:9.5pt;font-weight:bold;">You could lose money by investing in the Fund.</span> | ||
| Risk Money Market Fund May Not Preserve Dollar [Text] | rr_RiskMoneyMarketFundMayNotPreserveDollar | <span style="color:#000000;font-family:Arial;font-size:9.5pt;font-weight:bold;"> Although the Fund seeks to </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;font-weight:bold;">preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. </span> | ||
| Risk Not Insured [Text] | rr_RiskNotInsured | <span style="color:#000000;font-family:Arial;font-size:9.5pt;font-weight:bold;">An investment in the Fund is not insured or </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;font-weight:bold;">guaranteed by the Federal Deposit Insurance Corporation or any other government agency. </span> | ||
| Risk Money Market Fund Sponsor May Not Provide Support [Text] | rr_RiskMoneyMarketFundSponsorMayNotProvideSupport | <span style="color:#000000;font-family:Arial;font-size:9.5pt;font-weight:bold;">The Fund's sponsor has no legal obligation to provide </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;font-weight:bold;">financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time.</span> | ||
| Bar Chart and Performance Table [Heading] | rr_BarChartAndPerformanceTableHeading | <span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Annual Total Returns</span> | ||
| Performance Narrative [Text Block] | rr_PerformanceNarrativeTextBlock | The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of a relevant market index and a comparative benchmark, which have investment characteristics similar to those of the Fund. Returns for the iMoneyNet Money Fund Report's 100% Treasury Funds Average are derived from data provided by iMoneyNet, 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. | ||
| Performance Information Illustrates Variability of Returns [Text] | rr_PerformanceInformationIllustratesVariabilityOfReturns | <span style="font-family:Arial;font-size:9.5pt;">The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Fund compare with those of a relevant market index and a comparative benchmark, which have investment characteristics similar to those of the Fund.</span> | ||
| Performance Availability Phone [Text] | rr_PerformanceAvailabilityPhone | <span style="font-family:Arial;font-size:9.5pt;">800-662-7447</span> | ||
| Performance Availability Website Address [Text] | rr_PerformanceAvailabilityWebSiteAddress | <span style="font-family:Arial;font-size:9.5pt;font-style:italic;">vanguard.com/performance</span> | ||
| Performance Past Does Not Indicate Future [Text] | rr_PerformancePastDoesNotIndicateFuture | <span style="font-family:Arial;font-size:9.5pt;">Keep in mind that the Fund's past performance does not </span><span style="font-family:Arial;font-size:9.5pt;">indicate how the Fund will perform in the future.</span> | ||
| Bar Chart [Heading] | rr_BarChartHeading | <span style="font-family:Arial;font-size:8pt;font-weight:bold;">Annual Total Returns — Vanguard Treasury Money Market Fund Investor Shares</span><span style="font-family:Arial;font-size:5pt;font-weight:bold;position:relative;top:-3.25pt;">1</span> | ||
| Bar Chart Closing [Text Block] | rr_BarChartClosingTextBlock | During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were: | ||
| Performance Table Heading | rr_PerformanceTableHeading | <span style="font-family:Arial;font-size:8.5pt;font-weight:bold;">Average Annual Total Returns for Periods Ended December 31, 2021</span> | ||
| Retail | Vanguard Treasury Money Market Fund | Investor Shares | ||||
| Risk Return Abstract | rr_RiskReturnAbstract | |||
| Purchase Fee | rr_MaximumCumulativeSalesChargeOverOther | none | ||
| Sales Charge (Load) Imposed on Purchases | rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice | none | ||
| Sales Charge (Load) Imposed on Reinvested Dividends | rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther | none | ||
| Redemption Fee | rr_RedemptionFeeOverRedemption | none | ||
| Account Service Fee Per Year (for certain fund account balances below $1,000,000) | rr_MaximumAccountFee | $ 20 | ||
| Management Fees | rr_ManagementFeesOverAssets | 0.08% | ||
| 12b-1 Distribution Fee | rr_DistributionAndService12b1FeesOverAssets | none | ||
| Other Expenses | rr_OtherExpensesOverAssets | 0.01% | ||
| Total Annual Fund Operating Expenses | rr_ExpensesOverAssets | 0.09% | [1] | |
| 1 Year | rr_ExpenseExampleYear01 | $ 9 | ||
| 3 Years | rr_ExpenseExampleYear03 | 29 | ||
| 5 Years | rr_ExpenseExampleYear05 | 51 | ||
| 10 Years | rr_ExpenseExampleYear10 | $ 115 | ||
| 2012 | rr_AnnualReturn2012 | 0.02% | ||
| 2013 | rr_AnnualReturn2013 | 0.01% | ||
| 2014 | rr_AnnualReturn2014 | 0.01% | ||
| 2015 | rr_AnnualReturn2015 | 0.02% | ||
| 2016 | rr_AnnualReturn2016 | 0.25% | ||
| 2017 | rr_AnnualReturn2017 | 0.79% | ||
| 2018 | rr_AnnualReturn2018 | 1.80% | ||
| 2019 | rr_AnnualReturn2019 | 2.14% | ||
| 2020 | rr_AnnualReturn2020 | 0.47% | ||
| 2021 | rr_AnnualReturn2021 | 0.01% | ||
| Year to Date Return, Label | rr_YearToDateReturnLabel | year-to-date return | ||
| Bar Chart, Year to Date Return, Date | rr_BarChartYearToDateReturnDate | Sep. 30, 2022 | ||
| Bar Chart, Year to Date Return | rr_BarChartYearToDateReturn | 0.64% | ||
| Highest Quarterly Return, Label | rr_HighestQuarterlyReturnLabel | <span style="color:#000000;font-family:Arial;font-size:8pt;margin-left:0.0pt;">Highest</span> | ||
| Highest Quarterly Return, Date | rr_BarChartHighestQuarterlyReturnDate | Jun. 30, 2019 | ||
| Highest Quarterly Return | rr_BarChartHighestQuarterlyReturn | 0.58% | ||
| Lowest Quarterly Return, Label | rr_LowestQuarterlyReturnLabel | <span style="color:#000000;font-family:Arial;font-size:8pt;margin-left:0.0pt;">Lowest</span> | ||
| Lowest Quarterly Return, Date | rr_BarChartLowestQuarterlyReturnDate | Mar. 31, 2015 | ||
| Lowest Quarterly Return | rr_BarChartLowestQuarterlyReturn | none | ||
| 1 Year | rr_AverageAnnualReturnYear01 | 0.01% | ||
| 5 Years | rr_AverageAnnualReturnYear05 | 1.04% | ||
| 10 Years | rr_AverageAnnualReturnYear10 | 0.55% | ||
| Retail | Vanguard Treasury Money Market Fund | FTSE 3-Month U.S. Treasury Bill Index (reflects no deduction for fees or expenses) | ||||
| Risk Return Abstract | rr_RiskReturnAbstract | |||
| 1 Year | rr_AverageAnnualReturnYear01 | 0.05% | ||
| 5 Years | rr_AverageAnnualReturnYear05 | 1.11% | ||
| 10 Years | rr_AverageAnnualReturnYear10 | 0.59% | ||
| Retail | Vanguard Treasury Money Market Fund | iMoneyNet Money Fund Report's 100 percent Treasury Funds Average | ||||
| Risk Return Abstract | rr_RiskReturnAbstract | |||
| 1 Year | rr_AverageAnnualReturnYear01 | 0.01% | ||
| 5 Years | rr_AverageAnnualReturnYear05 | 0.71% | ||
| 10 Years | rr_AverageAnnualReturnYear10 | 0.36% | ||
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