v3.22.4
Label Element Value
Virtus International Small-Cap Fund  
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading Virtus International Small-Cap Fund
Objective [Heading] rr_ObjectiveHeading Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks maximum long-term capital appreciation.

Expense [Heading] rr_ExpenseHeading Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The tables below illustrate the fees and expenses that 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 examples below. You may qualify for sales charge discounts in Class A Shares if you and your family invest, or agree to invest in the future, at least $50,000 in Virtus Funds. More information on these and other discounts is available: (i) from your financial professional or other financial intermediary; (ii) under “Sales Charges” on page 74 of the fund’s prospectus; (iii) with respect to purchase of shares through specific intermediaries, in Appendix A to the fund’s prospectus, entitled “Intermediary Sales Charge Discounts and Waivers;” and (iv) under “Alternative Purchase Arrangements” on page 113 of the fund’s SAI.

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 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 and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual

fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 131% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 131.00%
Expense Breakpoint Discounts [Text] rr_ExpenseBreakpointDiscounts You may qualify for sales charge discounts in Class A Shares if you and your family invest, or agree to invest in the future, at least $50,000 in Virtus Funds.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Expense Example [Heading] rr_ExpenseExampleHeading Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all of your shares at the end of those periods or continued to hold them. The example also assumes that your investment has a 5% return each year, that the fund’s operating expenses remain the same and that the expense reimbursement agreement remains in place for the contractual period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption 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 seeks to achieve its objective by normally investing at least 80% of its net assets (plus borrowings made for investment purposes) in companies with smaller market capitalizations. The fund currently defines companies with smaller market capitalizations as those with market capitalizations comparable to companies included in the MSCI ACWI ex US Small Cap Index. Under normal market and other conditions, the fund expects to maintain a weighted-average market capitalization between 50% and 200% of the weighted-average market capitalization of the securities in the MSCI ACWI ex US Small-Cap Index, which as of September 30, 2022 would permit the fund to maintain a weighted-average market capitalization ranging from $700 million to $2.9 billion. The fund normally invests principally in securities of issuers located outside the United States and allocates its investments among at least eight different countries. The fund may invest up to 30% of its assets in emerging market securities (but no more than 10% in any one emerging market country).

Members of the portfolio management team believe that behavioral biases of investors contribute to market inefficiencies. Their quantitative investment process begins with a proprietary investment-return forecasting model which combines behavioral factors (which seek to capitalize on human behavioral biases (i.e., systematic tendencies) from financial analysts, company management and investors), with intrinsic and valuation factors (which are expected to provide tangible measures of a company’s true worth). The portfolio managers integrate this multi-factor approach with a proprietary risk model to form the basis of portfolio construction, with constraints at the individual security, country and industry levels to manage exposures relative to the benchmark. Additionally, all investment recommendations are thoroughly vetted on an individual company level to confirm the investment rationale and suitability before a purchase or sale.

In addition to common stocks and other equity securities (such as preferred stocks, convertible securities and warrants), the fund may invest in securities issued in initial public offerings (IPOs), real estate investment trusts (“REITs”) and may utilize foreign currency exchange contracts, options, stock index futures contracts and other derivative instruments. The fund typically does not engage in active hedging of currency but retains flexibility to do so depending on market performance. Although the fund did not invest significantly in derivative instruments as of the most recent fiscal year end, it may do so at any time.

Risk [Heading] rr_RiskHeading Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

The fund may not achieve its objective(s), and it is not intended to be a complete investment program. The value of the fund’s investments that supports your share value may decrease. If between the time you purchase shares and the time you sell shares the value of the fund’s investments decreases, you will lose money. Investment values can decrease for a number of reasons. Conditions affecting the overall economy, specific industries or companies in which the fund invests can be worse than expected, and investments may fail to perform as the subadviser expects. As a result, the value of your shares may decrease. Purchase and redemption activities by fund shareholders may impact the management of the fund and its ability to achieve its investment objective(s). The principal risks of investing in the fund are identified below (in alphabetical order after the first six risks).

> Market Volatility Risk. The value of the securities in the fund may go up or down in response to the prospects of individual companies and/or general economic conditions. Price changes may be short- or long-term. Local, regional or global events such as war or military conflict (e.g. Russia’s invasion of Ukraine), acts of terrorism, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the fund and its investments, including hampering the ability of the fund’s portfolio manager(s) to invest the fund’s assets as intended.

> Issuer Risk. The fund will be affected by factors specific to the issuers of securities and other instruments in which the fund invests, including actual or perceived changes in the financial condition or business prospects of such issuers.

> Equity Securities Risk. The value of the stocks held by the fund may be negatively affected by the financial market, industries in which the fund invests, or issuer-specific events. Focus on a particular style or in small or medium-sized companies may enhance that risk.

> Foreign Investing Risk. Investing in foreign securities subjects the fund to additional risks such as increased volatility; currency fluctuations; less liquidity; less publicly available information about the foreign investment; and political, regulatory, economic, and market risk.

> Emerging Markets Risk. Foreign investing risk may be particularly high to the extent that the fund invests in emerging market securities. Emerging markets securities may be more volatile, or more greatly affected by negative conditions, than those of their counterparts in more established foreign markets.

> Small and Medium Market Capitalization Risk. The fund’s investments in small and medium market capitalization companies may increase the volatility and risk of loss to the fund, as compared with investments in larger, more established companies.

> Allocation Risk. If the fund’s exposure to equities and fixed income securities, or to other asset classes, deviates from the intended allocation, or if the fund’s allocation is not optimal for market conditions at a given time, the fund’s performance may suffer.

> Counterparty Risk. A counterparty to a derivatives contract, repurchase agreement, a loan of portfolio securities or an unsettled transaction may be unable or unwilling to make timely settlement payments or otherwise honor its obligations to the fund.

> Credit Risk. If the issuer of a debt instrument fails to pay interest or principal in a timely manner, or negative perceptions exist in the market of the issuer’s ability to make such payments, the price of the security may decline.

> Currency Rate Risk. Fluctuations in the exchange rates between the U.S. dollar and foreign currencies may negatively affect the value of the fund’s shares.

> Derivatives Risk. Derivatives may include, among other things, futures, options, forwards and swap agreements and may be used in order to hedge portfolio risks, create leverage or attempt to increase returns. Investments in derivatives may result in increased volatility and the fund may incur a loss greater than its principal investment.

> Focused Investment Risk. To the extent the fund focuses its investments on a limited number of issuers, sectors, industries or geographic regions, it may be subject to increased risk and volatility.

> IPO Risk. Securities purchased in initial public offerings have no trading history, limited issuer information and increased volatility.

> Leverage Risk. When a fund leverages its portfolio by borrowing or certain types of transactions or instruments, including derivatives, fund may be less liquid, may liquidate positions at an unfavorable time, and the volatility of the fund’s value may increase.

> Liquidity Risk. Certain securities may be substantially less liquid than many other securities, such as U.S. Government securities or common stocks. To the extent the fund invests in less liquid securities or the level of liquidity in a particular market is constrained, the lack of an active market for investments may cause delay in disposition or force a sale below fair value.

> Redemption Risk. One or more large shareholders or groups of shareholders may redeem their holdings in the fund, resulting in an adverse impact on remaining shareholders in the fund by causing the fund to take actions it would not otherwise have taken.

> Real Estate Investment Risk. The fund may be negatively affected by changes in real estate values or economic conditions, credit risk and interest rate fluctuations, changes in the value of the underlying real estate and defaults by lessees and/or borrowers.

Please see “More Information About Risks Related to Principal Investment Strategies” in the fund’s prospectus for a more detailed description of the fund’s risks.

Risk Lose Money [Text] rr_RiskLoseMoney If between the time you purchase shares and the time you sell shares the value of the fund’s investments decreases, you will lose money.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance Information
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The bar chart and table below provide some indication of the potential risks of investing in the fund. The fund’s past performance, before and after taxes, is not necessarily an indication of how the fund will perform in the future.

The bar chart shows changes in the fund’s performance from year to year over a 10-year period. The table shows how the fund’s average annual returns compare to those of two broad-based securities market indexes. Updated performance information is available at virtus.com or by calling 800-243-1574.

Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart and table below provide some indication of the potential risks of investing in the fund.
Performance Additional Market Index [Text] rr_PerformanceAdditionalMarketIndex the MSCI All Country World ex USA Small Cap Index (net) replacing MSCI World Ex USA Small Cap Index (net) and MSCI EAFE Small Cap Index (net). This change is being made to more closely match the fund’s primary benchmark to its principal investment strategy. The MSCI All Country World ex USA Small Cap Index (net) is a free float-adjusted market capitalization-weighted index that measures mid- and small-cap performance across 22 of 23 Developed Market countries (excluding the U.S.) and 24 Emerging Markets countries. The index is calculated on a total return basis with net dividends reinvested. The index is unmanaged and not available for direct investment.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone 800-243-1574
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress virtus.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund’s past performance, before and after taxes, is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Calendar year total returns for Institutional Class Shares 
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads Returns do not reflect sales charges applicable to other share classes and would be lower if they did.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock
      

Best Quarter:

2020, Q2:

22.14%

Worst Quarter:

2020, Q1:

-24.76%

Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns
Performance Table Does Reflect Sales Loads rr_PerformanceTableDoesReflectSalesLoads Returns reflect deduction of maximum sales charges and full redemption at end of periods shown.
Performance Table Market Index Changed rr_PerformanceTableMarketIndexChanged Effective January 1, 2023 the benchmark to which performance of the fund is compared is the MSCI All Country World ex USA Small Cap Index (net) replacing MSCI World Ex USA Small Cap Index (net) and MSCI EAFE Small Cap Index (net). This change is being made to more closely match the fund’s primary benchmark to its principal investment strategy.
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. After-tax returns are shown only for Institutional Class Shares; after-tax returns for other classes will vary. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold fund shares in tax-deferred accounts or to shares held by non-taxable entities. In certain cases, the Return After Taxes on Distributions and Sale of Fund Shares for a period may be higher than other return figures for the same period. This will occur when a capital loss is realized upon the sale of fund shares and provides an assumed tax benefit that increases the return.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold fund shares in tax-deferred accounts or to shares held by non-taxable entities.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are shown only for Institutional Class Shares; after-tax returns for other classes will vary.
Performance Table Explanation after Tax Higher rr_PerformanceTableExplanationAfterTaxHigher In certain cases, the Return After Taxes on Distributions and Sale of Fund Shares for a period may be higher than other return figures for the same period. This will occur when a capital loss is realized upon the sale of fund shares and provides an assumed tax benefit that increases the return.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock

Returns reflect deduction of maximum sales charges and full redemption at end of periods shown.

Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

Effective January 1, 2023 the benchmark to which performance of the fund is compared is the MSCI All Country World ex USA Small Cap Index (net) replacing MSCI World Ex USA Small Cap Index (net) and MSCI EAFE Small Cap Index (net). This change is being made to more closely match the fund’s primary benchmark to its principal investment strategy. The MSCI All Country World ex USA Small Cap Index (net) is a free float-adjusted market capitalization-weighted index that measures mid- and small-cap performance across 22 of 23 Developed Market countries (excluding the U.S.) and 24 Emerging Markets countries. The index is calculated on a total return basis with net dividends reinvested. The index is unmanaged and not available for direct investment.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. After-tax returns are shown only for Institutional Class Shares; after-tax returns for other classes will vary. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold fund shares in tax-deferred accounts or to shares held by non-taxable entities. In certain cases, the Return After Taxes on Distributions and Sale of Fund Shares for a period may be higher than other return figures for the same period. This will occur when a capital loss is realized upon the sale of fund shares and provides an assumed tax benefit that increases the return.

Virtus International Small-Cap Fund | MSCI ACWI Ex USA Small Cap Index (net)  
Risk/Return: rr_RiskReturnAbstract  
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes (net) (reflects no deduction for fees, expenses or taxes)
Label rr_AverageAnnualReturnLabel MSCI ACWI Ex USA Small Cap Index (net) (reflects no deduction for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 (19.97%)
5 Years rr_AverageAnnualReturnYear05 0.67%
10 Years rr_AverageAnnualReturnYear10 5.24%
Since Inception rr_AverageAnnualReturnSinceInception 6.20%
Inception Date rr_AverageAnnualReturnInceptionDate Feb. 01, 2016
Virtus International Small-Cap Fund | MSCI World Ex USA Small Cap Index (net)  
Risk/Return: rr_RiskReturnAbstract  
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes (net) (reflects no deduction for fees, expenses or taxes)
Label rr_AverageAnnualReturnLabel MSCI World Ex USA Small Cap Index (net) (reflects no deduction for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 (20.59%)
5 Years rr_AverageAnnualReturnYear05 0.45%
10 Years rr_AverageAnnualReturnYear10 5.77%
Since Inception rr_AverageAnnualReturnSinceInception 5.98%
Inception Date rr_AverageAnnualReturnInceptionDate Feb. 01, 2016
Virtus International Small-Cap Fund | MSCI EAFE Small Cap Index (net)  
Risk/Return: rr_RiskReturnAbstract  
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes (net) (reflects no deduction for fees, expenses or taxes)
Label rr_AverageAnnualReturnLabel MSCI EAFE Small Cap Index (net) (reflects no deduction for fees, expenses or taxes)
1 Year rr_AverageAnnualReturnYear01 (21.39%)
5 Years rr_AverageAnnualReturnYear05 (0.05%)
10 Years rr_AverageAnnualReturnYear10 6.21%
Since Inception rr_AverageAnnualReturnSinceInception 5.53%
Inception Date rr_AverageAnnualReturnInceptionDate Feb. 01, 2016
Virtus International Small-Cap Fund | Class A Shares  
Risk/Return: rr_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol AOPAX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.50%
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Management Fees rr_ManagementFeesOverAssets 1.00%
Distribution and Shareholder Servicing (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other Expenses rr_OtherExpensesOverAssets 0.53%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.79% [1]
Less: Fee Waiver and/or Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.53%) [2]
Total Annual Fund Operating Expenses After Expense Reimbursement rr_NetExpensesOverAssets 1.26% [1],[2]
1 Year rr_ExpenseExampleYear01 $ 671
3 Years rr_ExpenseExampleYear03 1,034
5 Years rr_ExpenseExampleYear05 1,420
10 Years rr_ExpenseExampleYear10 2,498
1 Year rr_ExpenseExampleNoRedemptionYear01 671
3 Years rr_ExpenseExampleNoRedemptionYear03 1,034
5 Years rr_ExpenseExampleNoRedemptionYear05 1,420
10 Years rr_ExpenseExampleNoRedemptionYear10 $ 2,498
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (31.11%)
5 Years rr_AverageAnnualReturnYear05 (4.12%)
10 Years rr_AverageAnnualReturnYear10 3.82%
Virtus International Small-Cap Fund | Class C Shares  
Risk/Return: rr_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol AOPCX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00% [3]
Management Fees rr_ManagementFeesOverAssets 1.00%
Distribution and Shareholder Servicing (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Other Expenses rr_OtherExpensesOverAssets 0.48%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 2.49% [1]
Less: Fee Waiver and/or Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.48%) [2]
Total Annual Fund Operating Expenses After Expense Reimbursement rr_NetExpensesOverAssets 2.01% [1],[2]
1 Year rr_ExpenseExampleYear01 $ 304
3 Years rr_ExpenseExampleYear03 730
5 Years rr_ExpenseExampleYear05 1,282
10 Years rr_ExpenseExampleYear10 2,790
1 Year rr_ExpenseExampleNoRedemptionYear01 204
3 Years rr_ExpenseExampleNoRedemptionYear03 730
5 Years rr_ExpenseExampleNoRedemptionYear05 1,282
10 Years rr_ExpenseExampleNoRedemptionYear10 $ 2,790
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (27.66%)
5 Years rr_AverageAnnualReturnYear05 (3.78%)
10 Years rr_AverageAnnualReturnYear10 3.61%
Virtus International Small-Cap Fund | Institutional Class Shares  
Risk/Return: rr_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol ALOIX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Management Fees rr_ManagementFeesOverAssets 1.00%
Distribution and Shareholder Servicing (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.46%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.47% [1]
Less: Fee Waiver and/or Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.42%) [2]
Total Annual Fund Operating Expenses After Expense Reimbursement rr_NetExpensesOverAssets 1.05% [1],[2]
1 Year rr_ExpenseExampleYear01 $ 107
3 Years rr_ExpenseExampleYear03 424
5 Years rr_ExpenseExampleYear05 763
10 Years rr_ExpenseExampleYear10 1,721
1 Year rr_ExpenseExampleNoRedemptionYear01 107
3 Years rr_ExpenseExampleNoRedemptionYear03 424
5 Years rr_ExpenseExampleNoRedemptionYear05 763
10 Years rr_ExpenseExampleNoRedemptionYear10 $ 1,721
Annual Return 2013 rr_AnnualReturn2013 32.95%
Annual Return 2014 rr_AnnualReturn2014 (8.42%)
Annual Return 2015 rr_AnnualReturn2015 15.74%
Annual Return 2016 rr_AnnualReturn2016 (7.51%)
Annual Return 2017 rr_AnnualReturn2017 39.28%
Annual Return 2018 rr_AnnualReturn2018 (22.60%)
Annual Return 2019 rr_AnnualReturn2019 24.57%
Annual Return 2020 rr_AnnualReturn2020 15.90%
Annual Return 2021 rr_AnnualReturn2021 6.14%
Annual Return 2022 rr_AnnualReturn2022 (26.96%)
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn none
Label rr_HighestQuarterlyReturnLabel Best Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2020
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 22.14%
Label rr_LowestQuarterlyReturnLabel Worst Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Mar. 31, 2020
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (24.76%)
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (26.96%)
5 Years rr_AverageAnnualReturnYear05 (2.83%)
10 Years rr_AverageAnnualReturnYear10 4.63%
Virtus International Small-Cap Fund | Institutional Class Shares | After Taxes on Distributions  
Risk/Return: rr_RiskReturnAbstract  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions
1 Year rr_AverageAnnualReturnYear01 (26.98%)
5 Years rr_AverageAnnualReturnYear05 (4.59%)
10 Years rr_AverageAnnualReturnYear10 2.87%
Virtus International Small-Cap Fund | Institutional Class Shares | After Taxes on Distributions and Sales  
Risk/Return: rr_RiskReturnAbstract  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions and Sale of Fund Shares
1 Year rr_AverageAnnualReturnYear01 (15.61%)
5 Years rr_AverageAnnualReturnYear05 (2.07%)
10 Years rr_AverageAnnualReturnYear10 3.51%
Virtus International Small-Cap Fund | Class P Shares  
Risk/Return: rr_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol ALOPX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Management Fees rr_ManagementFeesOverAssets 1.00%
Distribution and Shareholder Servicing (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.36%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.37% [1]
Less: Fee Waiver and/or Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.26%) [2]
Total Annual Fund Operating Expenses After Expense Reimbursement rr_NetExpensesOverAssets 1.11% [1],[2]
1 Year rr_ExpenseExampleYear01 $ 113
3 Years rr_ExpenseExampleYear03 408
5 Years rr_ExpenseExampleYear05 725
10 Years rr_ExpenseExampleYear10 1,624
1 Year rr_ExpenseExampleNoRedemptionYear01 113
3 Years rr_ExpenseExampleNoRedemptionYear03 408
5 Years rr_ExpenseExampleNoRedemptionYear05 725
10 Years rr_ExpenseExampleNoRedemptionYear10 $ 1,624
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (27.01%)
5 Years rr_AverageAnnualReturnYear05 (2.89%)
10 Years rr_AverageAnnualReturnYear10 4.57%
Virtus International Small-Cap Fund | Class R6 Shares  
Risk/Return: rr_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol AIISX
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage of Offering Price) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Management Fees rr_ManagementFeesOverAssets 1.00%
Distribution and Shareholder Servicing (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.36%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.37% [1]
Less: Fee Waiver and/or Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.36%) [2]
Total Annual Fund Operating Expenses After Expense Reimbursement rr_NetExpensesOverAssets 1.01% [1],[2]
1 Year rr_ExpenseExampleYear01 $ 103
3 Years rr_ExpenseExampleYear03 398
5 Years rr_ExpenseExampleYear05 716
10 Years rr_ExpenseExampleYear10 1,615
1 Year rr_ExpenseExampleNoRedemptionYear01 103
3 Years rr_ExpenseExampleNoRedemptionYear03 398
5 Years rr_ExpenseExampleNoRedemptionYear05 716
10 Years rr_ExpenseExampleNoRedemptionYear10 $ 1,615
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 (26.92%)
5 Years rr_AverageAnnualReturnYear05 (2.79%)
Since Inception rr_AverageAnnualReturnSinceInception 2.79%
Inception Date rr_AverageAnnualReturnInceptionDate Feb. 01, 2016
[1]

The Total Annual Fund Operating Expenses do not correlate to the ratio of expenses to average net assets appearing in the Financial Highlights tables, which tables reflect only the operating expenses of the fund and do not include acquired fund fees and expenses.

[2]

The fund’s investment adviser has contractually agreed to limit the fund’s total operating expenses (excluding certain expenses, such as taxes, leverage and borrowing expenses (such as commitment, amendment and renewal expenses on credit or redemption facilities), interest, brokerage commissions, expenses incurred in connection with any merger or reorganization, unusual or infrequently occurring expenses (such as litigation), acquired fund fees and expenses, and dividend expenses, if any) so that such expenses do not exceed 1.25% for Class A Shares, 2.00% for Class C Shares, 1.04% for Institutional Class Shares, 1.10% for Class P Shares and 1.00% for Class R6 Shares through February 1, 2024. Following the contractual period, the adviser may discontinue these expense reimbursement arrangements at any time. Under certain conditions, the adviser may recapture operating expenses reimbursed and/or fees waived under these arrangements for a period of three years following the date such waiver or reimbursement occurred, provided that the recapture does not cause the fund to exceed its expense limit in effect at the time of the waiver or reimbursement, and any in effect at the time of recapture, after repayment is taken into account.

[3]

The deferred sales charge is imposed on Class C Shares redeemed during the first year only.