XML 112 R8.htm IDEA: XBRL DOCUMENT v3.22.1
Label Element Value
Risk Return Abstract rr_RiskReturnAbstract  
Registrant Name dei_EntityRegistrantName Vanguard Variable Insurance Funds
Prospectus Date rr_ProspectusDate May 02, 2022
Equity Index Portfolio  
Risk Return Abstract rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading <span style="color:#000000;font-family:Arial;font-size:13pt;font-weight:bold;">Portfolio 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 Portfolio seeks to track the performance of a benchmark index that measures the investment return of large-capitalization stocks.
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 Portfolio. The expenses shown in the table and in the example that follows do not reflect additional fees and expenses associated with the annuity or life insurance program through which you invest. If those additional fees and expenses were included, overall expenses would be higher.
Operating Expenses Caption [Text] rr_OperatingExpensesCaption <span style="color:#000000;font-family:Arial;font-size:8.5pt;font-weight:bold;">Annual Portfolio 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 Portfolio 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. These costs, which are not reflected in annual portfolio operating expenses or in the previous expense example, reduce the Portfolio's performance. During the most recent fiscal year, the Portfolio's turnover rate was 4% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 4.00%
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 Portfolio 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 Portfolio's shares. This example assumes that the Portfolio provides a return of 5% each year and that total annual portfolio 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 Portfolio employs an indexing investment approach designed to track the performance of the Standard & Poor's 500 Index, a widely recognized benchmark of U.S. stock market performance that is dominated by the stocks of large U.S. companies. The Portfolio attempts to replicate the target index by investing all, or substantially all, of its assets in the stocks that make up the Index, holding each stock in approximately the same proportion as its weighting in the Index.
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 An investment in the Portfolio could lose money over short or long periods of time. You should expect the Portfolio's share price and total return to fluctuate within a wide range. The Portfolio is subject to the following risks, which could affect the Portfolio's performance:• Stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Portfolio’s target index tracks a subset of the U.S. stock market, which could cause the Portfolio to perform differently from the overall stock market. In addition, the Portfolio’s target index may, at times, become focused in stocks of a particular market sector, which would subject the Portfolio to proportionately higher exposure to the risks of that sector.• Investment style risk, which is the chance that returns from large-capitalization stocks will trail returns from the overall stock market. Large-cap stocks tend to go through cycles of doing better—or worse—than other segments of the stock market or the stock market in general. These periods have, in the past, lasted for as long as several years.An investment in the Portfolio 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 <span style="color:#000000;font-family:Arial;font-size:9.5pt;">An investment in the Portfolio could lose money over short or long periods of time.</span>
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution <span style="color:#000000;font-family:Arial;font-size:9.5pt;font-weight:bold;">An investment in the Portfolio is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.</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 Portfolio. The bar chart shows how the performance of the Portfolio has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Portfolio compare with those of its target index and another comparative index, which have investment characteristics similar to those of the Portfolio. The Portfolio’s returns are net of its expenses, but do not reflect additional fees and expenses that are deducted by the annuity or life insurance program through which you invest. If such fees and expenses were included in the calculation of the Portfolio’s returns, the returns would be lower. Keep in mind that the Portfolio's past performance does not indicate how the Portfolio will perform in the future.Updated performance information is available on our website for Financial Advisors at advisors.vanguard.com or by calling Vanguard toll-free at 800-522-5555.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns <span style="color:#000000;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 Portfolio. The bar chart shows how the performance of the Portfolio has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Portfolio compare with those of its target index and another comparative index, which have investment characteristics similar to those of the Portfolio.</span>
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone <span style="color:#000000;font-family:Arial;font-size:9.5pt;">800-522-5555</span>
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress <span style="color:#000000;font-family:Arial;font-size:9.5pt;font-style:italic;">advisors.vanguard.com</span>
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture <span style="color:#000000;font-family:Arial;font-size:9.5pt;"> Keep in mind that the Portfolio's past </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;">performance does not indicate how the Portfolio 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 — Equity Index Portfolio</span>
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads <span style="color:#000000;font-family:Arial;font-size:9.5pt;"> The Portfolio’s returns </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;">are net of its expenses, but do not reflect additional fees and expenses that are deducted by the annuity or life insurance program through which you invest. If such fees and expenses were included in the calculation of the Portfolio’s </span><span style="color:#000000;font-family:Arial;font-size:9.5pt;">returns, the returns would be lower.</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>
Equity Index Portfolio | Equity Index Portfolio  
Risk Return Abstract rr_RiskReturnAbstract  
Management Fees rr_ManagementFeesOverAssets 0.13%
12b-1 Distribution Fee rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01%
Total Annual Portfolio Operating Expenses rr_ExpensesOverAssets 0.14%
1 Year rr_ExpenseExampleYear01 $ 14
3 Years rr_ExpenseExampleYear03 45
5 Years rr_ExpenseExampleYear05 79
10 Years rr_ExpenseExampleYear10 $ 179
2012 rr_AnnualReturn2012 15.86%
2013 rr_AnnualReturn2013 32.18%
2014 rr_AnnualReturn2014 13.51%
2015 rr_AnnualReturn2015 1.27%
2016 rr_AnnualReturn2016 11.81%
2017 rr_AnnualReturn2017 21.66%
2018 rr_AnnualReturn2018 (4.51%)
2019 rr_AnnualReturn2019 31.30%
2020 rr_AnnualReturn2020 18.20%
2021 rr_AnnualReturn2021 28.55%
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 20.53%
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 (19.66%)
1 Year rr_AverageAnnualReturnYear01 28.55%
5 Years rr_AverageAnnualReturnYear05 18.31%
10 Years rr_AverageAnnualReturnYear10 16.39%
Equity Index Portfolio | 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 25.66%
5 Years rr_AverageAnnualReturnYear05 17.92%
10 Years rr_AverageAnnualReturnYear10 16.24%
Equity Index Portfolio | Standard & Poor's 500 Index (reflects no deduction for fees, expenses, or taxes)  
Risk Return Abstract rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 28.71%
5 Years rr_AverageAnnualReturnYear05 18.47%
10 Years rr_AverageAnnualReturnYear10 16.55%