Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	VANGUARD VARIABLE INSURANCE FUNDS
Prospectus Date	rr_ProspectusDate	Apr. 28, 2017
Balanced Portfolio
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Balanced Portfolio
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Portfolio seeks to provide long-term capital appreciation and reasonable 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 shares of the Portfolio. The expenses shown in the table and in the example that follow 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	Annual Portfolio 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 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 33% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	33.00%
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 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 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 Portfolio invests 60% to 70% of its assets in dividend-paying and, to a lesser extent, non-dividend-paying common stocks of established large companies. In choosing these companies, the advisor seeks those that appear to be undervalued but have prospects for improvement. These stocks are commonly referred to as value stocks. The remaining 30% to 40% of Portfolio assets are invested mainly in fixed income securities that the advisor believes will generate a reasonable level of current income. These securities include investment-grade corporate bonds, with some exposure to U.S. Treasury and government agency bonds, and mortgage-backed securities.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The Portfolio is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money. However, because stock and bond prices can move in different directions or to different degrees, the Portfolio’s bond holdings may counteract some of the volatility experienced by the Portfolio’s stock holdings. • With approximately 60% to 70% of its assets allocated to stocks, the Portfolio is proportionately subject to the following stock risks: stock market risk, which is the chance that stock prices overall will decline; and investment style risk, which is the chance that returns from large-capitalization value 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. • With approximately 30% to 40% of its assets allocated to bonds, the Portfolio is proportionately subject to the following bond risks: 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 Portfolio’s income will decline because of falling 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; liquidity risk, which is the chance that Portfolio may not be able to sell a security in a timely manner at a desired price; and 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 Portfolio 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 Portfolio’s income. Such redemptions and subsequent reinvestments would also increase the Portfolio’s turnover rate. For mortgage-backed securities, this risk is known as prepayment risk. • The Portfolio is also subject to manager risk, which is the chance that poor security selection will cause the Portfolio to underperform relevant benchmarks or other funds with a similar investment objective. In addition, significant investment in the financial sector subjects the Portfolio to proportionately higher exposure to the risks of this sector. 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	The Portfolio is subject to the risks associated with the stock and bond markets, any of which could cause an investor to lose money.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	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.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Annual Total Returns
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 a relevant market index and a composite stock/bond 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	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 a relevant market index and a composite stock/bond index, which have investment characteristics similar to those of the Portfolio.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-522-5555
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	advisors.vanguard.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	Keep in mind that the Portfolio’s past performance does not indicate how the Portfolio will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns — Balanced Portfolio
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	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.
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	During the periods shown in the bar chart, the highest return for a calendar quarter was 13.60% (quarter ended June 30, 2009), and the lowest return for a quarter was –10.86% (quarter ended December 31, 2008).
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns for Periods Ended December 31, 2016
Balanced Portfolio | Balanced Portfolio
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.21%
12b-1 Distribution Fee	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.02%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	0.23%
1 Year	rr_ExpenseExampleYear01	$ 24
3 Years	rr_ExpenseExampleYear03	74
5 Years	rr_ExpenseExampleYear05	130
10 Years	rr_ExpenseExampleYear10	293
1 Year	rr_ExpenseExampleNoRedemptionYear01	24
3 Years	rr_ExpenseExampleNoRedemptionYear03	74
5 Years	rr_ExpenseExampleNoRedemptionYear05	130
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 293
2007	rr_AnnualReturn2007	8.36%
2008	rr_AnnualReturn2008	(22.57%)
2009	rr_AnnualReturn2009	22.90%
2010	rr_AnnualReturn2010	11.02%
2011	rr_AnnualReturn2011	3.70%
2012	rr_AnnualReturn2012	12.56%
2013	rr_AnnualReturn2013	19.88%
2014	rr_AnnualReturn2014	9.84%
2015	rr_AnnualReturn2015	0.09%
2016	rr_AnnualReturn2016	11.01%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	13.60%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(10.86%)
1 Year	rr_AverageAnnualReturnYear01	11.01%
5 Years	rr_AverageAnnualReturnYear05	10.49%
10 Years	rr_AverageAnnualReturnYear10	6.93%
Balanced Portfolio | Standard & Poor's 500 Index
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	11.96%	[1]
5 Years	rr_AverageAnnualReturnYear05	14.66%	[1]
10 Years	rr_AverageAnnualReturnYear10	6.95%	[1]
Balanced Portfolio | Composite Stock/Bond Index
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	9.22%	[1]
5 Years	rr_AverageAnnualReturnYear05	10.77%	[1]
10 Years	rr_AverageAnnualReturnYear10	6.47%	[1]

[1] Comparative Indexes (reflect no deduction for fees or expenses)