| Label | Element | Value |
|---|---|---|
| Risk Return Abstract | rr_RiskReturnAbstract | |
| Registrant Name | dei_EntityRegistrantName | VANGUARD STAR FUNDS |
| Prospectus Date | rr_ProspectusDate | Feb. 27, 2024 |
| Retail | Vanguard STAR Fund | ||
| Risk Return Abstract | rr_RiskReturnAbstract | |
| Risk/Return [Heading] | rr_RiskReturnHeading | <span style="color:#000000;font-family:Arial;font-size:13pt;font-weight:bold;">Fund Summary</span> |
| Objective [Heading] | rr_ObjectiveHeading | <span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Investment Objective</span> |
| Objective, Primary [Text Block] | rr_ObjectivePrimaryTextBlock | The Fund seeks to provide long-term capital appreciation and income. |
| Expense [Heading] | rr_ExpenseHeading | <span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Fees and Expenses</span> |
| Expense Narrative [Text Block] | rr_ExpenseNarrativeTextBlock | The following tables describe the fees and expenses you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and example below. |
| Shareholder Fees Caption [Text] | rr_ShareholderFeesCaption | <span style="color:#000000;font-family:Arial;font-size:8.5pt;font-weight:bold;">Shareholder Fees</span> <br/><span style="color:#000000;font-family:Arial;font-size:8.5pt;margin-left:0%;">(Fees paid directly from your investment)</span> |
| Operating Expenses Caption [Text] | rr_OperatingExpensesCaption | <span style="color:#000000;font-family:Arial;font-size:8.5pt;font-weight:bold;">Annual Fund Operating Expenses</span> <br/><span style="color:#000000;font-family:Arial;font-size:8.5pt;margin-left:0%;">(Expenses that you pay each year as a percentage of the value of your investment)</span> |
| Portfolio Turnover [Heading] | rr_PortfolioTurnoverHeading | <span style="color:#000000;font-family:Arial;font-size:9.5pt;">Portfolio Turnover</span> |
| Portfolio Turnover [Text Block] | rr_PortfolioTurnoverTextBlock | The Fund may pay transaction costs, such as purchase fees, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 6% of the average value of its portfolio. |
| Portfolio Turnover, Rate | rr_PortfolioTurnoverRate | 6.00% |
| Expense Example [Heading] | rr_ExpenseExampleHeading | <span style="color:#000000;font-family:Arial;font-size:9.5pt;">Example</span> |
| Expense Example Narrative [Text Block] | rr_ExpenseExampleNarrativeTextBlock | The following example is intended to help you compare the cost of investing in the Fund (based on the fees and expenses of the acquired funds) 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 of the Fund and its underlying funds 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 | As a fund of funds, Vanguard STAR Fund invests in a diversified portfolio of other Vanguard mutual funds rather than in individual securities. The Fund follows a balanced investment approach by investing 60% to 70% of its assets in common stocks through seven underlying stock funds; 20% to 30% of its assets in bonds through two underlying bond funds; and 10% to 20% of its assets in short-term investments through an underlying short-term bond fund. Through the underlying funds, Vanguard STAR Fund owns a diversified mix of stocks and bonds. The Fund’s stock holdings emphasize large-capitalization stocks of domestic companies and, to a lesser extent, a diversified group of stocks in companies located outside the United States. The Fund’s bond holdings focus predominantly on short- and long-term investment-grade corporate bonds and GNMA mortgage-backed securities. |
| Risk [Heading] | rr_RiskHeading | <span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Risks</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 composite stock/bond benchmarks, which have investment characteristics similar to those of the Fund. The STAR Composite Index is a custom blended index developed by Vanguard weighted 43.75% MSCI U.S. Broad Market Index, 25% Bloomberg U.S. Aggregate Bond Index, 12.5% Bloomberg U.S. 1-5 Year Credit Bond Index, and 18.75% MSCI ACWI ex USA Index. MSCI international benchmark returns are adjusted for withholding taxes. The STAR Composite Average is based on data provided by Lipper, a Thomson Reuters Company, and is weighted 43.75% general equity funds average, 25% fixed income funds average, 12.5% 1-5 year investment-grade funds average, and 18.75% international funds average. Returns for the STAR Composite Average are derived from data provided by Lipper, a Thomson Reuters Company. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447. |
| Performance Information Illustrates Variability of Returns [Text] | rr_PerformanceInformationIllustratesVariabilityOfReturns | <span style="font-family:Arial;font-size:9.5pt;">The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund 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 composite stock/bond benchmarks, which have investment characteristics similar to those of the Fund. The STAR Composite Index is a custom blended index developed by Vanguard weighted 43.75% MSCI U.S. Broad Market Index, 25% Bloomberg U.S. Aggregate Bond Index, 12.5% Bloomberg U.S. 1-5 Year Credit Bond Index, and 18.75% MSCI ACWI ex USA Index. MSCI international benchmark returns are adjusted for withholding taxes. The STAR Composite Average is based on data provided by Lipper, a Thomson Reuters Company, and is weighted 43.75% general equity funds average, 25% fixed income funds average, 12.5% 1-5 year investment-grade funds average, and 18.75% international funds average. Returns for the STAR Composite Average are derived from data provided by Lipper, a Thomson Reuters Company. </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</span><span style="font-family:Arial;font-size:9.5pt;">’s past performance (before and after taxes) does not indicate how the Fund will perform in the future.</span> |
| Bar Chart [Heading] | rr_BarChartHeading | <span style="font-family:Arial;font-size:8pt;font-weight:bold;">Annual Total Returns — Vanguard STAR Fund Investor Shares</span> |
| Bar Chart Closing [Text Block] | rr_BarChartClosingTextBlock | During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were: |
| Performance Table Heading | rr_PerformanceTableHeading | <span style="font-family:Arial;font-size:8.5pt;font-weight:bold;">Average Annual Total Returns for Periods Ended December 31, 2023</span> |
| Performance Table Uses Highest Federal Rate | rr_PerformanceTableUsesHighestFederalRate | <span style="color:#000000;font-family:Arial;font-size:9.5pt;">When after-tax returns are calculated, it is </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;">assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. </span> |
| Performance Table Not Relevant to Tax Deferred | rr_PerformanceTableNotRelevantToTaxDeferred | <span style="color:#000000;font-family:Arial;font-size:9.5pt;">Please note that after-tax returns are not relevant for a shareholder </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;">who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. </span> |
| Performance Table Explanation after Tax Higher | rr_PerformanceTableExplanationAfterTaxHigher | <span style="color:#000000;font-family:Arial;font-size:9.5pt;">Also, figures captioned </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;font-style:italic;">Return After Taxes on Distributions and Sale of Fund Shares</span><span style="color:#000000;font-family:Arial;font-size:9.5pt;"> may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.</span> |
| Performance Table Closing [Text Block] | rr_PerformanceTableClosingTextBlock | Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder. |
| Retail | Vanguard STAR Fund | Risk Lose Money [Member] | ||
| Risk Return Abstract | rr_RiskReturnAbstract | |
| Risk [Text Block] | rr_RiskTextBlock | The Fund is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money, and the level of risk may vary based on market conditions. However, because stock and bond prices can move in different directions or to different degrees, the Fund’s bond and short-term investment holdings may counteract some of the volatility experienced by the Fund’s stock holdings. The Fund’s balanced portfolio, in the long run, should result in less investment risk—but a lower investment return—than that of a fund investing exclusively in common stocks. • With 60% to 70% of its assets allocated to stocks, the Fund is proportionately subject to 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. Investments in foreign stocks can be riskier than U.S. stock investments. Foreign stocks may be more volatile and less liquid than U.S. stocks. The prices of foreign stocks and the prices of U.S. stocks may move in opposite directions. The Fund is also subject to the following risks associated with investments in foreign stocks: 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; and 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. • With its remaining assets allocated to bonds and short-term investments, the Fund is proportionately subject to bond risks, including: interest rate risk, which is the chance that bond prices will decline because of rising interest 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, thus reducing the underlying fund’s return; income risk, which is the chance that an underlying fund’s income will decline because of falling interest rates; liquidity risk, which is the chance that an underlying fund may not be able to sell a security in a timely manner at a desired price; and 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, or the underlying fund’s ability to reinvest repayment proceeds at higher interest rates may be delayed. If an underlying fund holds securities that are callable, the underlying fund’s income may decline because of call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupons or interest rates before their maturity dates. An underlying 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 underlying fund’s income. For mortgage-backed securities, this risk is known as prepayment risk. • The Fund is also subject to asset allocation risk, which is the chance that the selection of underlying funds, and the allocation of a high percentage of assets to a relatively few number of underlying funds, may cause the Fund to be hurt disproportionately by the poor performance of any one underlying fund or to underperform other funds with a similar investment objective. • The Fund is also subject to manager risk, which is the chance that poor security selection will cause one or more of the Fund’s actively managed underlying funds—and, thus, the Fund itself—to underperform relevant benchmarks or other funds with a similar investment objective. |
| Retail | Vanguard STAR Fund | Risk Not Insured Depository Institution [Member] | ||
| Risk Return Abstract | rr_RiskReturnAbstract | |
| Risk [Text Block] | rr_RiskTextBlock | An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail | Vanguard STAR 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 $5,000,000) | rr_MaximumAccountFee | $ 25 |
| Management Fees | rr_ManagementFeesOverAssets | none |
| 12b-1 Distribution Fee | rr_DistributionAndService12b1FeesOverAssets | none |
| Other Expenses | rr_OtherExpensesOverAssets | none |
| Acquired Fund Fees and Expenses | rr_AcquiredFundFeesAndExpensesOverAssets | 0.31% |
| Total Annual Fund Operating Expenses | rr_ExpensesOverAssets | 0.31% |
| 1 Year | rr_ExpenseExampleYear01 | $ 32 |
| 3 Years | rr_ExpenseExampleYear03 | 100 |
| 5 Years | rr_ExpenseExampleYear05 | 174 |
| 10 Years | rr_ExpenseExampleYear10 | $ 393 |
| 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, 2020 |
| Highest Quarterly Return | rr_BarChartHighestQuarterlyReturn | 16.69% |
| 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, 2020 |
| Lowest Quarterly Return | rr_BarChartLowestQuarterlyReturn | (13.02%) |
| 1 Year | rr_AverageAnnualReturnYear01 | 17.11% |
| 5 Years | rr_AverageAnnualReturnYear05 | 9.34% |
| 10 Years | rr_AverageAnnualReturnYear10 | 7.17% |
| Retail | Vanguard STAR Fund | Return After Taxes on Distributions | Investor Shares | ||
| Risk Return Abstract | rr_RiskReturnAbstract | |
| 1 Year | rr_AverageAnnualReturnYear01 | 15.34% |
| 5 Years | rr_AverageAnnualReturnYear05 | 7.45% |
| 10 Years | rr_AverageAnnualReturnYear10 | 5.47% |
| Retail | Vanguard STAR Fund | Return After Taxes on Distributions and Sale of Fund Shares | Investor Shares | ||
| Risk Return Abstract | rr_RiskReturnAbstract | |
| 1 Year | rr_AverageAnnualReturnYear01 | 10.80% |
| 5 Years | rr_AverageAnnualReturnYear05 | 7.02% |
| 10 Years | rr_AverageAnnualReturnYear10 | 5.28% |
| Retail | Vanguard STAR Fund | Dow Jones U.S. Total Stock Market Float Adjusted Index (reflects no deduction for fees, expenses, or taxes) | ||
| Risk Return Abstract | rr_RiskReturnAbstract | |
| 1 Year | rr_AverageAnnualReturnYear01 | 26.06% |
| 5 Years | rr_AverageAnnualReturnYear05 | 15.05% |
| 10 Years | rr_AverageAnnualReturnYear10 | 11.40% |
| Retail | Vanguard STAR Fund | STAR Composite Index (reflects no deduction for fees, expenses, or taxes) | ||
| Risk Return Abstract | rr_RiskReturnAbstract | |
| 1 Year | rr_AverageAnnualReturnYear01 | 16.49% |
| 5 Years | rr_AverageAnnualReturnYear05 | 9.07% |
| 10 Years | rr_AverageAnnualReturnYear10 | 6.87% |
| Retail | Vanguard STAR Fund | STAR Composite Average (reflects no deduction for taxes) | ||
| Risk Return Abstract | rr_RiskReturnAbstract | |
| 1 Year | rr_AverageAnnualReturnYear01 | 7.35% |
| 5 Years | rr_AverageAnnualReturnYear05 | 4.70% |
| 10 Years | rr_AverageAnnualReturnYear10 | 3.94% |