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

The Portfolio seeks maximum total return from a combination of capital appreciation and current income.

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 2016-05-01
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 28% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 28.00%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 in year one only. 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 fixed-income securities issued by corporations or other non-governmental issuers similar to corporations, which securities are tied economically to the US. The Portfolio typically invests a substantial portion of its assets, and may invest up to 100% of its assets, in securities rated, at the time of purchase, below investment grade by S&P or Moody’s and as low as C or Ca by S&P or Moody’s, respectively, or the unrated equivalent as determined by the Investment Manager (“junk bonds”); however, the Portfolio focuses such investments in below investment grade securities that may be considered “better quality” (i.e., rated B1 or higher by Moody’s, B+ or higher by S&P or the unrated equivalent as determined by the Investment Manager). The Portfolio may invest in dollar-denominated securities of non-US companies, including, to a limited extent, in emerging market companies.


Although the Portfolio may invest in fixed-income securities without regard to their maturity, the Portfolio’s average weighted maturity is expected to range between two and ten years.


Securities are evaluated based on their fundamental and structural characteristics. Valuation analysis is tailored to the specific asset class, but may include credit research, prepayment or call options, maturity, duration, coupon, currency and country risks. The Portfolio is constructed using a bottom-up discipline in which the Investment Manager follows a systematic process to seek out undervalued opportunities within each sector.


The Portfolio may invest up to 20% of its assets in other securities which need not be fixed-income securities as described above and need not be tied economically to the US.

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.


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.

Risk Lose Money [Text] rr_RiskLoseMoney The value of your investment in the Portfolio will fluctuate, which means you could lose money.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance Bar Chart and Table Year-by-Year Total Returns for Institutional 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 Corporate Income 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 bar chart shows how the performance of the Portfolio’s Institutional Shares has varied from year to year over the past 10 calendar years. 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 Corporate Income 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:
6/30/09  13.08%
 
Worst Quarter:
12/31/08  -15.96%

 

Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 13.08%rr_BarChartHighestQuarterlyReturn
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (15.96%)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 Institutional 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 Institutional 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.

Bank of America Merrill Lynch BB-B US Cash Pay Non-Distressed High Yield Index (reflects no deduction for fees, expenses or taxes) (Institutional)
 
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 3.69%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 8.68%rr_AverageAnnualReturnYear05
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10 Years rr_AverageAnnualReturnYear10 6.54%rr_AverageAnnualReturnYear10
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Life of Portfolio rr_AverageAnnualReturnSinceInception 6.61%rr_AverageAnnualReturnSinceInception
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Bank of America Merrill Lynch BB-B US Cash Pay Non-Distressed High Yield Index (reflects no deduction for fees, expenses or taxes) (Open)
 
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 3.69%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 8.68%rr_AverageAnnualReturnYear05
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10 Years rr_AverageAnnualReturnYear10 6.54%rr_AverageAnnualReturnYear10
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Life of Portfolio rr_AverageAnnualReturnSinceInception 6.59%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 0.55%rr_ManagementFeesOverAssets
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Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.16%rr_OtherExpensesOverAssets
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Total Annual Portfolio Operating Expenses rr_ExpensesOverAssets 0.71%rr_ExpensesOverAssets
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Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.16%)rr_FeeWaiverOrReimbursementOverAssets
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[1]
Total Annual Portfolio Operating Expenses After Fee Waiver and Expense Reimbursement rr_NetExpensesOverAssets 0.55%rr_NetExpensesOverAssets
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[1]
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 56rr_ExpenseExampleYear01
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Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 211rr_ExpenseExampleYear03
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Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 379rr_ExpenseExampleYear05
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Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 867rr_ExpenseExampleYear10
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Annual Return 2005 rr_AnnualReturn2005 4.33%rr_AnnualReturn2005
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Annual Return 2006 rr_AnnualReturn2006 9.71%rr_AnnualReturn2006
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Annual Return 2007 rr_AnnualReturn2007 3.63%rr_AnnualReturn2007
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Annual Return 2008 rr_AnnualReturn2008 (20.24%)rr_AnnualReturn2008
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Annual Return 2009 rr_AnnualReturn2009 34.66%rr_AnnualReturn2009
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Annual Return 2010 rr_AnnualReturn2010 11.78%rr_AnnualReturn2010
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Annual Return 2011 rr_AnnualReturn2011 5.17%rr_AnnualReturn2011
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Annual Return 2012 rr_AnnualReturn2012 12.02%rr_AnnualReturn2012
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Annual Return 2013 rr_AnnualReturn2013 6.17%rr_AnnualReturn2013
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Annual Return 2014 rr_AnnualReturn2014 3.31%rr_AnnualReturn2014
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1 Year rr_AverageAnnualReturnYear01 3.31%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 7.63%rr_AverageAnnualReturnYear05
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10 Years rr_AverageAnnualReturnYear10 6.29%rr_AverageAnnualReturnYear10
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Life of Portfolio rr_AverageAnnualReturnSinceInception 4.32%rr_AverageAnnualReturnSinceInception
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Inception Date rr_AverageAnnualReturnInceptionDate Jan. 02, 1998
Institutional Shares | After Taxes on Distributions
 
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 0.98%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 5.02%rr_AverageAnnualReturnYear05
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10 Years rr_AverageAnnualReturnYear10 3.56%rr_AverageAnnualReturnYear10
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Life of Portfolio rr_AverageAnnualReturnSinceInception 1.11%rr_AverageAnnualReturnSinceInception
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Institutional Shares | After Taxes on Distributions and Sale of Portfolio Shares
 
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 1.87%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 4.85%rr_AverageAnnualReturnYear05
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10 Years rr_AverageAnnualReturnYear10 3.74%rr_AverageAnnualReturnYear10
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Life of Portfolio rr_AverageAnnualReturnSinceInception 1.79%rr_AverageAnnualReturnSinceInception
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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 0.55%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 0.75%rr_OtherExpensesOverAssets
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Total Annual Portfolio Operating Expenses rr_ExpensesOverAssets 1.55%rr_ExpensesOverAssets
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Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.70%)rr_FeeWaiverOrReimbursementOverAssets
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Total Annual Portfolio Operating Expenses After Fee Waiver and Expense Reimbursement rr_NetExpensesOverAssets 0.85%rr_NetExpensesOverAssets
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[1]
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 87rr_ExpenseExampleYear01
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Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 421rr_ExpenseExampleYear03
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Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 778rr_ExpenseExampleYear05
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Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,786rr_ExpenseExampleYear10
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1 Year rr_AverageAnnualReturnYear01 3.01%rr_AverageAnnualReturnYear01
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5 Years rr_AverageAnnualReturnYear05 7.27%rr_AverageAnnualReturnYear05
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10 Years rr_AverageAnnualReturnYear10 6.00%rr_AverageAnnualReturnYear10
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Life of Portfolio rr_AverageAnnualReturnSinceInception 3.76%rr_AverageAnnualReturnSinceInception
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Inception Date rr_AverageAnnualReturnInceptionDate Feb. 24, 1998
R6 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 0.55%rr_ManagementFeesOverAssets
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/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.16%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
[2]
Total Annual Portfolio Operating Expenses rr_ExpensesOverAssets 0.71%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.21%)rr_FeeWaiverOrReimbursementOverAssets
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
[1]
Total Annual Portfolio Operating Expenses After Fee Waiver and Expense Reimbursement rr_NetExpensesOverAssets 0.50%rr_NetExpensesOverAssets
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
[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 51rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 206rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 374rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 863rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
1 Year rr_AverageAnnualReturnYear01 3.31%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
5 Years rr_AverageAnnualReturnYear05 7.63%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
10 Years rr_AverageAnnualReturnYear10 6.29%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
Life of Portfolio rr_AverageAnnualReturnSinceInception 4.32%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= cik0000874964_S000010265Member
/ rr_ProspectusShareClassAxis
= cik0000874964_C000134186Member
[1] Reflects a contractual agreement by the Investment Manager to waive its fee and, if necessary, reimburse the Portfolio through May 1, 2016, to the extent Total Annual Portfolio Operating Expenses exceed .55%, .85% and .50% 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.