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Label Element Value
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading Lazard US Realty Equity Portfolio
Objective [Heading] rr_ObjectiveHeading Investment Objectives
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The Portfolio’s primary investment objective is long-term capital appreciation,
Objective, Secondary [Text Block] rr_ObjectiveSecondaryTextBlock

with current income, including interest and dividends from portfolio securities, as a secondary objective.

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

This table describes the fees and expenses that you may pay if you buy and hold shares of the Portfolio.

Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
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)
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination 2025-05-01
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 and may result in higher taxes when Portfolio shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’s portfolio turnover rate was 43% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 43.00%rr_PortfolioTurnoverRate
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 Portfolio with the cost of investing in other mutual funds.


The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then hold or redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same, giving effect to the fee waiver and expense reimbursement arrangement described above. 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

Under normal circumstances, the Portfolio invests at least 80% of its assets in equity securities (including common, convertible and preferred stocks) of US Realty Companies (defined below), as well as certain synthetic instruments related to US Realty Companies. Such synthetic instruments are investments that have economic characteristics similar to the Portfolio’s direct investments in US Realty Companies and may include warrants, rights, options and shares of ETFs.


The Investment Manager conducts proprietary quantitative, qualitative and on-site real estate analysis to select the Portfolio’s investments, which may include, as appropriate, research at the macroeconomic, sector, company and property level. The Investment Manager’s individual company research may consider a number of quantitative measures, including earnings growth potential, price to earnings or free cash flow multiples, price to NAV ratios, dividend yield and potential for growth, return on equity and return on assets, as well as qualitative factors such as overall business and growth strategy and quality of management.


“Realty Companies” are real estate-related companies of any size including, but not limited to, REITs, real estate operating or service companies and companies in the homebuilding, lodging and hotel industries, as well as companies engaged in the natural resources and utility industries, and other companies whose investments, balance sheets or income statements are real estate-intensive (i.e. the company’s actual or anticipated revenues, profits, assets, services or products are related to real estate including, but not limited to, the ownership, renting, leasing, construction, management, development or financing of commercial, industrial or residential real estate).


The Portfolio may invest in issuers of any market capitalization and securities of any maturity, and the Portfolio’s investments also may include securities purchased in IPOs.


The Portfolio also may invest up to 20% of its assets in equity and fixed-income securities and instruments of companies or entities (which need not be US Realty Companies), including, but not limited to, securities of non-US companies and other investment companies.


The Portfolio’s investments in preferred stock and convertible and fixed income securities may include securities which, at the time of purchase, are rated below “investment grade” by an NRSRO, or the unrated equivalent as determined by the Investment Manager (“junk bonds”).


In addition to purchasing options, the Portfolio may, but is not required to, write put and covered call options on securities and indexes, for hedging purposes or to seek to increase returns.


The Portfolio is classified as “non-diversified” under the 1940 Act, which means that it may invest a relatively high percentage of its assets in a limited number of issuers, when compared to a diversified fund.

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

The value of your investment in the Portfolio will fluctuate, which means you could lose money.


Market Risk. Market risks, including political, regulatory, market and economic developments, and developments that impact specific economic sectors, industries or segments of the market, can affect the value of the Portfolio’s investments. In addition, turbulence in financial markets and reduced liquidity in equity, credit and/or fixed income markets may negatively affect many issuers, which could adversely affect the Portfolio.


Issuer Risk. The value of a security may decline for a number of reasons which directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods or services, as well as the historical and prospective earnings of the issuer and the value of its assets or factors unrelated to the issuer’s value, such as investor perception.


Other Equity Securities Risk. Preferred stock is subject to credit and interest rate risk (described below) and the risk that the dividend on the stock may be changed or omitted by the issuer and, unlike common stock, participation in the growth of an issuer may be limited. The market value of a convertible security tends to perform like that of a regular debt security so that, if market interest rates rise, the value of the convertible security falls. Investments in rights and warrants involve certain risks, including the possible lack of a liquid market for resale, price fluctuations and the failure of the price of the underlying security to reach a level at which the right or warrant can be prudently exercised, in which case the warrant may expire without being exercised and result in a loss of the Portfolio’s entire investment.


Realty Companies Risk. Since the Portfolio focuses its investments in Realty Companies, the Portfolio could lose money due to the performance of real estate-related securities even if securities markets generally are experiencing positive results. The performance of investments made by the Portfolio may be determined to a great extent by the current status of the real estate industry in general, or by other factors (such as interest rates and the availability of loan capital) that may affect the real estate industry, even if other industries would not be so affected. Consequently, the investment strategies of the Portfolio could lead to securities investment results that may be significantly different from investments in securities of other industries or sectors or in a more broad-based portfolio generally.


The risks related to investments in Realty Companies include, but are not limited to: adverse changes in general economic and local market conditions; adverse developments in employment; changes in supply or demand for similar or competing properties; unfavorable changes in applicable taxes, governmental regulations and interest rates; operating or development expenses; and lack of available financing.


Due to certain special considerations that apply to REITs, investments in REITs may carry additional risks not necessarily present in investments in other securities. REIT securities (including those trading on national exchanges) typically have trading volumes that are less than those of common stocks of non-Realty Companies traded on national exchanges, which may affect a Portfolio’s ability to trade or liquidate those securities. An investment in REITs may be adversely affected if the REIT fails to comply with applicable laws and regulations, including failing to qualify as a REIT under the Code. Failure to qualify with any of these requirements could jeopardize a company’s status as a REIT. The Portfolio generally will have no control over the operations and policies of a REIT, and the Portfolio generally will have no ability to cause a REIT to take the actions necessary to qualify as a REIT.


Small and Mid Cap Companies Risk. Many Realty Companies are small and mid cap companies, which carry additional risks because their earnings tend to be less predictable, their share prices more volatile and their securities less liquid than larger, more established companies. The securities of small and mid cap companies tend to trade less frequently than those of larger companies, which can have an adverse effect on the pricing of these securities and on the ability to sell these securities when the Investment Manager deems it appropriate.


Non-Diversification Risk. The Portfolio’s NAV may be more vulnerable to changes in the market value of a single issuer or group of issuers and may be relatively more susceptible to adverse effects from any single corporate, industry, economic, market, political or regulatory occurrence than if the Portfolio’s investments consisted of securities issued by a larger number of issuers.


Fixed-Income and Debt Securities Risk. The market value of a debt security may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. The debt securities market can be susceptible to increases in volatility and decreases in liquidity. Prices of bonds and other debt securities tend to move inversely with changes in interest rates. Increases in volatility and decreases in liquidity may be caused by a rise in interest rates (or the expectation of a rise in interest rates). Interest rate risk is usually greater for fixed-income securities with longer maturities or durations.


The Portfolio’s investments in lower-rated, higher-yielding securities (“junk bonds”) are subject to greater credit risk than its higher rated investments. Credit risk is the risk that the issuer will not make interest or principal payments, or will not make payments on a timely basis. Non-investment grade securities tend to be more volatile, less liquid and are considered speculative. If there is a decline, or perceived decline, in the credit quality of a debt security (or any guarantor of payment on such security), the security’s value could fall, potentially lowering the Portfolio’s share price. The prices of non-investment grade securities, unlike investment grade debt securities, may fluctuate unpredictably and not necessarily inversely with changes in interest rates. The market for these securities may be less liquid and therefore these securities may be harder to value or sell at an acceptable price, especially during times of market volatility or decline. Liquidity can decline unpredictably in response to overall economic conditions or credit tightening.


Non-US Securities Risk. The Portfolio’s performance will be influenced by political, social and economic factors affecting the non-US countries and companies in which the Portfolio invests. Non-US securities carry special risks, such as less developed or less efficient trading markets, political instability, a lack of company information, differing auditing and legal standards, and, potentially, less liquidity. In addition, investments denominated in currencies other than US dollars may experience a decline in value, in US dollar terms, due solely to fluctuations in currency exchange rates. Emerging market countries can generally have economic structures that are less diverse and mature, and political systems that are less stable, than those of developed countries.


Options Risk. Writing options on securities and indexes, including for hedging purposes, may reduce returns or increase volatility, perhaps substantially, and may cause the Portfolio to experience losses greater than if the Portfolio had not engaged in such transactions. Writing options is subject to many of the risks of, and can be highly sensitive to changes in the value of, the related security or index. As such, a small commitment to written options could potentially have a relatively large impact on the Portfolio’s performance. Purchasing options will reduce returns by the amount of premiums paid for options that are not exercised. Over-the-counter options purchased on securities and indexes are subject to the risk of default by the counterparty and can be illiquid.


Investment Companies and ETF Risk. Any investments in other investment companies and ETFs are subject to the risks of the investments of the investment companies and ETFs, as well as to the general risks of investing in investment companies and ETFs. Portfolio shares will bear not only the Portfolio’s management fees and operating expenses, but also their proportional share of the management fees and operating expenses of any other investment companies and ETFs in which the Portfolio invests.

Risk Lose Money [Text] rr_RiskLoseMoney The value of your investment in the Portfolio will fluctuate, which means you could lose money.
Risk Nondiversified Status [Text] rr_RiskNondiversifiedStatus The Portfolio’s NAV may be more vulnerable to changes in the market value of a single issuer or group of issuers and may be relatively more susceptible to adverse effects from any single corporate, industry, economic, market, political or regulatory occurrence than if the Portfolio’s investments consisted of securities issued by a larger number of issuers.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance Bar Chart and Table Year-by-Year Total Returns for Open Shares As of 12/31
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The accompanying bar chart and table provide some indication of the risks of investing in Lazard US Realty Equity Portfolio by showing the Portfolio’s year-by-year performance and its average annual performance compared to that of a broad measure of market performance. The Portfolio commenced operations after all of the assets of an investment company advised by Alesco, Grubb & Ellis AGA U.S. Realty Fund (the “Predecessor Realty Equity Fund”), were transferred to the Portfolio in exchange for Open Shares of the Portfolio in a tax-free reorganization on September 23, 2011. The bar chart shows how the performance of the Portfolio’s Open Shares (or the Predecessor Realty Equity Fund’s Class A shares, prior to September 23, 2011) has varied from year to year. Updated performance information is available at www.LazardNet.com or by calling (800) 823-6300. The Portfolio’s past performance (before and after taxes) is not necessarily an indication of how the Portfolio will perform in the future.

Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The accompanying bar chart and table provide some indication of the risks of investing in Lazard US Realty Equity Portfolio by showing the Portfolio’s year-by-year performance and its average annual performance compared to that of a broad measure of market performance.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone (800) 823-6300
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress www.LazardNet.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The Portfolio’s past performance (before and after taxes) is not necessarily an indication of how the Portfolio will perform in the future.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

 

 

 

 

Best Quarter:
9/30/09  36.29%
 
Worst Quarter:
9/30/11  -17.99%

 

Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 36.29%rr_BarChartHighestQuarterlyReturn
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Sep. 30, 2011
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (17.99%)rr_BarChartLowestQuarterlyReturn
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns (for the periods ended December 31, 2014)
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes (reflects no deduction for fees, expenses or taxes)
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the historical highest individual marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred The after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are shown only for Open Shares. After-tax returns of the Portfolio’s other share classes will vary.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock

After-tax returns are shown only for Open Shares. After-tax returns of the Portfolio’s other share classes will vary. After-tax returns are calculated using the historical highest individual marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown. The after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. Returns shown below for the Portfolio’s R6 Shares (which were not operational as of December 31, 2014) reflect the performance of the Portfolio’s Institutional Shares. R6 Shares would have had substantially similar returns as Institutional Shares because the share classes are invested in the same portfolio of securities, and the returns would differ only to the extent that the classes do not have the same expenses.

FTSE NAREIT All Equity REITs Index (reflects no deduction for fees, expenses or taxes) (Open)
  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 28.03%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 16.91%rr_AverageAnnualReturnYear05
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Life of Portfolio rr_AverageAnnualReturnSinceInception 18.69%rr_AverageAnnualReturnSinceInception
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FTSE NAREIT All Equity REITs Index (reflects no deduction for fees, expenses or taxes) (Institutional)
  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 28.03%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 16.91%rr_AverageAnnualReturnYear05
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Life of Portfolio rr_AverageAnnualReturnSinceInception 19.50%rr_AverageAnnualReturnSinceInception
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Institutional Shares
  
Risk/Return: rr_RiskReturnAbstract  
Redemption Fee (as a percentage of Amount Redeemed) rr_RedemptionFeeOverRedemption (1.00%)rr_RedemptionFeeOverRedemption
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Management Fees rr_ManagementFeesOverAssets 0.80%rr_ManagementFeesOverAssets
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Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.38%rr_OtherExpensesOverAssets
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Total Annual Portfolio Operating Expenses rr_ExpensesOverAssets 1.18%rr_ExpensesOverAssets
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Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.13%)rr_FeeWaiverOrReimbursementOverAssets
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Total Annual Portfolio Operating Expenses After Fee Waiver and Expense Reimbursement rr_NetExpensesOverAssets 1.05%rr_NetExpensesOverAssets
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Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 107rr_ExpenseExampleYear01
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Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 334rr_ExpenseExampleYear03
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Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 579rr_ExpenseExampleYear05
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Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,283rr_ExpenseExampleYear10
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1 Year rr_AverageAnnualReturnYear01 25.70%rr_AverageAnnualReturnYear01
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Life of Portfolio rr_AverageAnnualReturnSinceInception 21.08%rr_AverageAnnualReturnSinceInception
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Inception Date rr_AverageAnnualReturnInceptionDate Sep. 26, 2011
Open Shares
  
Risk/Return: rr_RiskReturnAbstract  
Redemption Fee (as a percentage of Amount Redeemed) rr_RedemptionFeeOverRedemption (1.00%)rr_RedemptionFeeOverRedemption
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Management Fees rr_ManagementFeesOverAssets 0.80%rr_ManagementFeesOverAssets
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Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%rr_DistributionAndService12b1FeesOverAssets
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Other Expenses rr_OtherExpensesOverAssets 0.37%rr_OtherExpensesOverAssets
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Total Annual Portfolio Operating Expenses rr_ExpensesOverAssets 1.42%rr_ExpensesOverAssets
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Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.07%)rr_FeeWaiverOrReimbursementOverAssets
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Total Annual Portfolio Operating Expenses After Fee Waiver and Expense Reimbursement rr_NetExpensesOverAssets 1.35%rr_NetExpensesOverAssets
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Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 137rr_ExpenseExampleYear01
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Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 428rr_ExpenseExampleYear03
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Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 739rr_ExpenseExampleYear05
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Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,624rr_ExpenseExampleYear10
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Annual Return 2009 rr_AnnualReturn2009 59.47%rr_AnnualReturn2009
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Annual Return 2010 rr_AnnualReturn2010 35.55%rr_AnnualReturn2010
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Annual Return 2011 rr_AnnualReturn2011 9.91%rr_AnnualReturn2011
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Annual Return 2012 rr_AnnualReturn2012 20.58%rr_AnnualReturn2012
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Annual Return 2013 rr_AnnualReturn2013 1.58%rr_AnnualReturn2013
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Annual Return 2014 rr_AnnualReturn2014 25.33%rr_AnnualReturn2014
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1 Year rr_AverageAnnualReturnYear01 25.33%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 17.99%rr_AverageAnnualReturnYear05
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Life of Portfolio rr_AverageAnnualReturnSinceInception 24.06%rr_AverageAnnualReturnSinceInception
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Inception Date rr_AverageAnnualReturnInceptionDate Dec. 31, 2008
Open Shares | After Taxes on Distributions
  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 24.29%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 14.59%rr_AverageAnnualReturnYear05
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Life of Portfolio rr_AverageAnnualReturnSinceInception 20.45%rr_AverageAnnualReturnSinceInception
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Open Shares | After Taxes on Distributions and Sale of Portfolio Shares
  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 14.41%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 13.22%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_PerformanceMeasureAxis
= rr_AfterTaxesOnDistributionsAndSalesMember
/ rr_ProspectusShareClassAxis
= cik0000874964_C000103954Member
Life of Portfolio rr_AverageAnnualReturnSinceInception 18.49%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_PerformanceMeasureAxis
= rr_AfterTaxesOnDistributionsAndSalesMember
/ rr_ProspectusShareClassAxis
= cik0000874964_C000103954Member
R6 Shares
  
Risk/Return: rr_RiskReturnAbstract  
Redemption Fee (as a percentage of Amount Redeemed) rr_RedemptionFeeOverRedemption (1.00%)rr_RedemptionFeeOverRedemption
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member
Management Fees rr_ManagementFeesOverAssets 0.80%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.38%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member		 [2]
Total Annual Portfolio Operating Expenses rr_ExpensesOverAssets 1.18%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.18%)rr_FeeWaiverOrReimbursementOverAssets
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member		 [1]
Total Annual Portfolio Operating Expenses After Fee Waiver and Expense Reimbursement rr_NetExpensesOverAssets 1.00%rr_NetExpensesOverAssets
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member		 [1]
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates “Other Expenses” are based on estimated amounts for the current fiscal year, using “Other Expenses” for Institutional Shares from the last fiscal year.
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 102rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 318rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 552rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,225rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member
1 Year rr_AverageAnnualReturnYear01 25.70%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member
Life of Portfolio rr_AverageAnnualReturnSinceInception 21.08%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= cik0000874964_S000033724Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134202Member
[1] Reflects a contractual agreement by the Investment Manager to waive its fee and, if necessary, reimburse the Portfolio through May 1, 2025, to the extent Total Annual Portfolio Operating Expenses exceed 1.05%, 1.35% and 1.00% of the average daily net assets of the Portfolio's Institutional Shares, Open Shares and R6 Shares, respectively, exclusive of taxes, brokerage, interest on borrowings, fees and expenses of "Acquired Funds" and extraordinary expenses, and excluding shareholder redemption fees or other transaction fees. This agreement can only be amended by agreement of the Fund, upon approval by the Board, and the Investment Manager to lower the net amount shown and will terminate automatically in the event of termination of the Investment Management Agreement between the Investment Manager and the Fund, on behalf of the Portfolio.
[2] "Other Expenses" are based on estimated amounts for the current fiscal year, using "Other Expenses" for Institutional Shares from the last fiscal year.