S 000010267 Summary1 [Member] Prospectus Summary Prospectus Summary S 000010267 [Member] Lazard US Equity Concentrated Portfolio Lazard US Equity Concentrated Portfolio C 000028367 [Member] Institutional Institutional C 000028366 [Member] Open Open C 000134188 [Member] R6 R6 cik0000874964_SP500Index1Member [Member] S&P 500 Index S&P 500 Index cik0000874964_SP500Index2Member [Member] S&P 500 Index S&P 500 Index cik0000874964_Russell1000ValueSP500LinkedIndex3Member [Member] Russell 1000 Value/S&P 500 Linked Index Russell 1000 Value/S&P 500 Linked Index S 000010266 Summary2 [Member] Prospectus Summary Prospectus Summary S 000010266 [Member] Lazard US Equity Focus Portfolio Lazard US Equity Focus Portfolio C 000028365 [Member] Institutional Institutional C 000028364 [Member] Open Open C 000134187 [Member] R6 R6 cik0000874964_SP500Index4Member [Member] S&P 500 Index S&P 500 Index cik0000874964_SP500Index5Member [Member] S&P 500 Index S&P 500 Index S 000068926 Summary3 [Member] Prospectus Summary Prospectus Summary S 000068926 [Member] Lazard US Sustainable Equity Portfolio Lazard US Sustainable Equity Portfolio C 000220247 [Member] Institutional Institutional C 000220245 [Member] Open Open C 000220246 [Member] R6 R6 cik0000874964_SP500Index6Member [Member] S&P 500 Index S&P 500 Index S 000010269 Summary4 [Member] Prospectus Summary Prospectus Summary S 000010269 [Member] Lazard US Small-Mid Cap Equity Portfolio Lazard US Small-Mid Cap Equity Portfolio C 000028371 [Member] Institutional Institutional C 000028370 [Member] Open Open C 000134190 [Member] R6 R6 cik0000874964_Russell2500Index7Member [Member] Russell 2500 Index Russell 2500 Index cik0000874964_Russell2500Index8Member [Member] Russell 2500 Index Russell 2500 Index cik0000874964_Russell2500Index9Member [Member] Russell 2500 Index Russell 2500 Index cik0000874964_Russell20002500LinkedIndex10Member [Member] Russell 2000/2500 Linked Index Russell 2000/2500 Linked Index cik0000874964_Russell20002500LinkedIndex11Member [Member] Russell 2000/2500 Linked Index Russell 2000/2500 Linked Index S 000074073 Summary5 [Member] Prospectus Summary Prospectus Summary S 000074073 [Member] Lazard US Systematic Small Cap Equity Portfolio Lazard US Systematic Small Cap Equity Portfolio C 000231513 [Member] Institutional Institutional C 000231514 [Member] Open Open C 000231515 [Member] R6 R6 cik0000874964_Russell2000Index12Member [Member] Russell 2000 Index Russell 2000 Index S 000010271 Summary6 [Member] Prospectus Summary Prospectus Summary S 000010271 [Member] Lazard International Equity Portfolio Lazard International Equity Portfolio C 000028375 [Member] Institutional Institutional C 000028374 [Member] Open Open C 000134191 [Member] R6 R6 cik0000874964_MSCIEAFEIndex13Member [Member] MSCI EAFE Index MSCI EAFE Index cik0000874964_MSCIEAFEIndex14Member [Member] MSCI EAFE Index MSCI EAFE Index cik0000874964_MSCIEAFEIndex15Member [Member] MSCI EAFE Index MSCI EAFE Index S 000010272 Summary7 [Member] Prospectus Summary Prospectus Summary S 000010272 [Member] Lazard International Equity Select Portfolio Lazard International Equity Select Portfolio C 000028377 [Member] Institutional Institutional C 000028376 [Member] Open Open C 000134192 [Member] R6 R6 cik0000874964_MSCIAllCountryWorldIndexex-US16Member [Member] MSCI All Country World Index ex-US MSCI All Country World Index ex-US cik0000874964_MSCIEAFEACWIex-USLinkedIndex17Member [Member] MSCI EAFE/ACWI ex-US Linked Index MSCI EAFE/ACWI ex-US Linked Index S 000049415 Summary8 [Member] Prospectus Summary Prospectus Summary S 000049415 [Member] Lazard International Equity Advantage Portfolio Lazard International Equity Advantage Portfolio C 000156255 [Member] Institutional Institutional C 000156256 [Member] Open Open C 000156257 [Member] R6 R6 cik0000874964_MSCIAllCountryWorldex-USIndex18Member [Member] MSCI All Country World ex-US Index MSCI All Country World ex-US Index cik0000874964_MSCIEAFEIndex19Member [Member] MSCI EAFE Index MSCI EAFE Index S 000064063 Summary9 [Member] Prospectus Summary Prospectus Summary S 000064063 [Member] Lazard International Quality Growth Portfolio Lazard International Quality Growth Portfolio C 000207194 [Member] Institutional Institutional C 000207192 [Member] Open Open C 000207193 [Member] R6 R6 cik0000874964_MSCIAllCountryWorldex-USIndex20Member [Member] MSCI All Country World ex-US Index MSCI All Country World ex-US Index cik0000874964_MSCIAllCountryWorldex-USGrowthIndex21Member [Member] MSCI All Country World ex-US Growth Index MSCI All Country World ex-US Growth Index S 000010273 Summary10 [Member] Prospectus Summary Prospectus Summary S 000010273 [Member] Lazard International Strategic Equity Portfolio Lazard International Strategic Equity Portfolio C 000028379 [Member] Institutional Institutional C 000028378 [Member] Open Open C 000134193 [Member] R6 R6 cik0000874964_MSCIEAFEIndex22Member [Member] MSCI EAFE Index MSCI EAFE Index cik0000874964_MSCIEAFEIndex23Member [Member] MSCI EAFE Index MSCI EAFE Index cik0000874964_MSCIEAFEIndex24Member [Member] MSCI EAFE Index MSCI EAFE Index S 000010263 Summary11 [Member] Prospectus Summary Prospectus Summary S 000010263 [Member] Lazard International Small Cap Equity Portfolio Lazard International Small Cap Equity Portfolio C 000028359 [Member] Institutional Institutional C 000028358 [Member] Open Open C 000134184 [Member] R6 R6 cik0000874964_MSCIEAFESmallCapIndex25Member [Member] MSCI EAFE Small Cap Index MSCI EAFE Small Cap Index cik0000874964_MSCIEAFESmallCapIndex26Member [Member] MSCI EAFE Small Cap Index MSCI EAFE Small Cap Index cik0000874964_MSCIEAFESmallCapIndex27Member [Member] MSCI EAFE Small Cap Index MSCI EAFE Small Cap Index S 000043739 Summary12 [Member] Prospectus Summary Prospectus Summary S 000043739 [Member] Lazard Global Equity Select Portfolio Lazard Global Equity Select Portfolio C 000135644 [Member] Institutional Institutional C 000135645 [Member] Open Open C 000135646 [Member] R6 R6 cik0000874964_MSCIAllCountryWorldIndex28Member [Member] MSCI All Country World Index MSCI All Country World Index S 000049416 Summary13 [Member] Prospectus Summary Prospectus Summary S 000049416 [Member] Lazard Managed Equity Volatility Portfolio Lazard Managed Equity Volatility Portfolio C 000156258 [Member] Institutional Institutional C 000156259 [Member] Open Open C 000156260 [Member] R6 R6 cik0000874964_MSCIWorldIndex29Member [Member] MSCI World Index MSCI World Index S 000046422 Summary14 [Member] Prospectus Summary Prospectus Summary S 000046422 [Member] Lazard Global Strategic Equity Portfolio Lazard Global Strategic Equity Portfolio C 000145068 [Member] Institutional Institutional C 000145069 [Member] Open Open C 000145070 [Member] R6 R6 cik0000874964_MSCIAllCountryWorldIndex30Member [Member] MSCI All Country World Index MSCI All Country World Index S 000059092 Summary15 [Member] Prospectus Summary Prospectus Summary S 000059092 [Member] Lazard Equity Franchise Portfolio Lazard Equity Franchise Portfolio C 000193735 [Member] Institutional Institutional C 000193736 [Member] Open Open C 000193737 [Member] R6 R6 cik0000874964_MSCIWorldIndex31Member [Member] MSCI World Index MSCI World Index S 000010264 Summary16 [Member] Prospectus Summary Prospectus Summary S 000010264 [Member] Lazard Emerging Markets Equity Portfolio Lazard Emerging Markets Equity Portfolio C 000028361 [Member] Institutional Institutional C 000028360 [Member] Open Open C 000134185 [Member] R6 R6 cik0000874964_MSCIEmergingMarketsIndex32Member [Member] MSCI Emerging Markets Index MSCI Emerging Markets Index cik0000874964_MSCIEmergingMarketsIndex33Member [Member] MSCI Emerging Markets Index MSCI Emerging Markets Index cik0000874964_MSCIEmergingMarketsIndex34Member [Member] MSCI Emerging Markets Index MSCI Emerging Markets Index S 000042723 Summary17 [Member] Prospectus Summary Prospectus Summary S 000042723 [Member] Lazard Emerging Markets Core Equity Portfolio Lazard Emerging Markets Core Equity Portfolio C 000132106 [Member] Institutional Institutional C 000132107 [Member] Open Open C 000136816 [Member] R6 Shares R6 Shares cik0000874964_MSCIEmergingMarketsIndex35Member [Member] MSCI Emerging Markets Index MSCI Emerging Markets Index cik0000874964_MSCIEmergingMarketsIndex36Member [Member] MSCI Emerging Markets Index MSCI Emerging Markets Index S 000049414 Summary18 [Member] Prospectus Summary Prospectus Summary S 000049414 [Member] Lazard Emerging Markets Equity Advantage Portfolio Lazard Emerging Markets Equity Advantage Portfolio C 000156252 [Member] Institutional Institutional C 000156253 [Member] Open Open C 000156254 [Member] R6 R6 cik0000874964_MSCIEmergingMarketsIndex37Member [Member] MSCI Emerging Markets Index MSCI Emerging Markets Index S 000023480 Summary19 [Member] Prospectus Summary Prospectus Summary S 000023480 [Member] Lazard Developing Markets Equity Portfolio Lazard Developing Markets Equity Portfolio C 000069022 [Member] Institutional Institutional C 000069023 [Member] Open Open C 000134195 [Member] R6 R6 cik0000874964_MSCIEmergingMarketsIndex38Member [Member] MSCI Emerging Markets Index MSCI Emerging Markets Index S 000028828 Summary20 [Member] Prospectus Summary Prospectus Summary S 000028828 [Member] Lazard Emerging Markets Strategic Equity Portfolio Lazard Emerging Markets Strategic Equity Portfolio C 000088404 [Member] Institutional Institutional C 000088405 [Member] Open Open C 000134197 [Member] R6 R6 cik0000874964_MSCIEmergingMarketsIndex39Member [Member] MSCI Emerging Markets Index MSCI Emerging Markets Index S 000079313 Summary21 [Member] Prospectus Summary Prospectus Summary S 000079313 [Member] Lazard US Convertibles Portfolio Lazard US Convertibles Portfolio C 000240316 [Member] Institutional Institutional C 000240317 [Member] Open Open C 000240315 [Member] R6 R6 S 000010265 Summary22 [Member] Prospectus Summary Prospectus Summary S 000010265 [Member] Lazard US Corporate Income Portfolio Lazard US Corporate Income Portfolio C 000028363 [Member] Institutional Institutional C 000028362 [Member] Open Open C 000134186 [Member] R6 R6 cik0000874964_ICEBofAMLBB-BUSCashPayNon-DistressedHighYieldaIndex40Member [Member] ICE BofAML BB-B US Cash Pay Non-Distressed High Yield(a) Index ICE BofAML BB-B US Cash Pay Non-Distressed High Yield(a) Index cik0000874964_ICEBofAMLBB-BUSCashPayNon-DistressedHighYieldaIndex41Member [Member] ICE BofAML BB-B US Cash Pay Non-Distressed High Yield(a) Index ICE BofAML BB-B US Cash Pay Non-Distressed High Yield(a) Index cik0000874964_ICEBofAMLBB-BUSCashPayNon-DistressedHighYieldaIndex42Member [Member] ICE BofAML BB-B US Cash Pay Non-Distressed High Yield(a) Index ICE BofAML BB-B US Cash Pay Non-Distressed High Yield(a) Index S 000031124 Summary23 [Member] Prospectus Summary Prospectus Summary S 000031124 [Member] Lazard US Short Duration Fixed Income Portfolio Lazard US Short Duration Fixed Income Portfolio C 000096533 [Member] Institutional Institutional C 000096534 [Member] Open Open C 000134199 [Member] R6 R6 cik0000874964_BankofAmericaMerrillLynch1-3YearUSTreasuryIndex43Member [Member] Bank of America Merrill Lynch 1-3 Year US Treasury Index Bank of America Merrill Lynch 1-3 Year US Treasury Index S 000035892 Summary24 [Member] Prospectus Summary Prospectus Summary S 000035892 [Member] Lazard Global Fixed Income Portfolio Lazard Global Fixed Income Portfolio C 000110020 [Member] Institutional Institutional C 000110021 [Member] Open Open C 000134204 [Member] R6 R6 cik0000874964_BloombergBarclaysGlobalAggregateIndex44Member [Member] Bloomberg Barclays Global Aggregate Index Bloomberg Barclays Global Aggregate Index S 000027245 Summary25 [Member] Prospectus Summary Prospectus Summary S 000027245 [Member] Lazard Global Listed Infrastructure Portfolio Lazard Global Listed Infrastructure Portfolio C 000082231 [Member] Institutional Institutional C 000082232 [Member] Open Open C 000134196 [Member] R6 R6 cik0000874964_MSCIWorldIndex45Member [Member] MSCI World Index MSCI World Index cik0000874964_MSCIWorldCoreInfrastructureHedgedIndex46Member [Member] MSCI World Core Infrastructure (Hedged) Index MSCI World Core Infrastructure (Hedged) Index S 000056012 Summary26 [Member] Prospectus Summary Prospectus Summary S 000056012 [Member] Lazard Real Assets Portfolio Lazard Real Assets Portfolio C 000176375 [Member] Institutional Institutional C 000176376 [Member] Open Open C 000176377 [Member] R6 R6 cik0000874964_MSCIWorldIndex47Member [Member] MSCI World Index MSCI World Index cik0000874964_MSCIWorldIndex48Member [Member] MSCI World Index MSCI World Index cik0000874964_MSCIWorldIndex49Member [Member] MSCI World Index MSCI World Index cik0000874964_RealAssetsBlendIndex50Member [Member] Real Assets Blend Index Real Assets Blend Index cik0000874964_RealAssetsBlendIndex51Member [Member] Real Assets Blend Index Real Assets Blend Index cik0000874964_RealAssetsBlendIndex52Member [Member] Real Assets Blend Index Real Assets Blend Index cik0000874964_RealAssetsIndex53Member [Member] Real Assets Index Real Assets Index cik0000874964_RealAssetsIndex54Member [Member] Real Assets Index Real Assets Index cik0000874964_RealAssetsIndex55Member [Member] Real Assets Index Real Assets Index S 000047900 Summary27 [Member] Prospectus Summary Prospectus Summary S 000047900 [Member] Lazard Enhanced Opportunities Portfolio Lazard Enhanced Opportunities Portfolio C 000150427 [Member] Institutional Institutional C 000150428 [Member] Open Open C 000150429 [Member] R6 R6 cik0000874964_ICEBofAMLUSConvertibleexMandatoryIndex56Member [Member] ICE BofAML U.S. Convertible ex Mandatory Index ICE BofAML U.S. Convertible ex Mandatory Index cik0000874964_HFRXGlobalHedgeFundIndex57Member [Member] HFRX Global Hedge Fund Index HFRX Global Hedge Fund Index S 000020883 Summary28 [Member] Prospectus Summary Prospectus Summary S 000020883 [Member] Lazard Opportunistic Strategies Portfolio Lazard Opportunistic Strategies Portfolio C 000058929 [Member] Institutional Institutional C 000058930 [Member] Open Open C 000134194 [Member] R6 R6 cik0000874964_MSCIWorldIndex58Member [Member] MSCI World Index MSCI World Index cik0000874964_MSCIWorldIndex59Member [Member] MSCI World Index MSCI World Index cik0000874964_MSCIWorldIndex60Member [Member] MSCI World Index MSCI World Index cik0000874964_GlobalAssetAllocationBlendedIndex61Member [Member] Global Asset Allocation Blended Index Global Asset Allocation Blended Index cik0000874964_GlobalAssetAllocationBlendedIndex62Member [Member] Global Asset Allocation Blended Index Global Asset Allocation Blended Index cik0000874964_GlobalAssetAllocationBlendedIndex63Member [Member] Global Asset Allocation Blended Index Global Asset Allocation Blended Index S 000037196 Summary29 [Member] Prospectus Summary Prospectus Summary S 000037196 [Member] Lazard Global Dynamic Multi-Asset Portfolio Lazard Global Dynamic Multi-Asset Portfolio C 000114570 [Member] Institutional Institutional C 000114571 [Member] Open Open C 000134205 [Member] R6 R6 cik0000874964_MSCIWorldIndex64Member [Member] MSCI World Index MSCI World Index cik0000874964_GDMAIndex65Member [Member] GDMA Index GDMA Index Amendment Flag Amendment Flag Document Creation Date Document Creation Date Prospectus Prospectus Document Effective Date Document Effective Date Document [Axis] Document [Axis] Document Period End Date Document Period End Date Document Type Document Type Entity Central Index Key Entity Central Index Key EntityInvCompanyType EntityInvCompanyType Registrant Name Registrant Name Series [Axis] Series [Axis] After Taxes on Distributions and Sales After Taxes on Distributions and Sales After Taxes on Distributions After Taxes on Distributions Annual Fund Operating Expenses [Table] Annual Fund Operating Expenses [Table] Annual Return 2013 Annual Return 2013 Annual Return 2014 Annual Return 2014 Annual Return 2015 Annual Return 2015 Annual Return 2016 Annual Return 2016 Annual Return 2017 Annual Return 2017 Annual Return 2018 Annual Return 2018 Annual Return 2019 Annual Return 2019 Annual Return 2020 Annual Return 2020 Annual Return 2021 Annual Return 2021 Annual Return 2022 Annual Return 2022 Inception Date Inception Date Label Label Since Inception Since Inception 1 Year 1 Year 5 Years 5 Years 10 Years 10 Years Bar Chart and Performance Table [Heading] Bar Chart and Performance Table [Heading] Bar Chart Closing [Text Block] Bar Chart Closing [Text Block] Bar Chart Does Not Reflect Sales Loads [Text] Bar Chart Does Not Reflect Sales Loads [Text] Bar Chart [Heading] Bar Chart [Heading] Highest Quarterly Return Highest Quarterly Return Highest Quarterly Return, Date Highest Quarterly Return, Date Lowest Quarterly Return Lowest Quarterly Return Lowest Quarterly Return, Date Lowest Quarterly Return, Date Bar Chart [Table] Bar Chart [Table] Expense Example [Heading] Expense Example [Heading] Expense Example Narrative [Text Block] Expense Example Narrative [Text Block] Expense Example, No Redemption [Table] Expense Example, No Redemption [Table] Expense Example, With Redemption [Table] Expense Example, With Redemption [Table] Expense Example, with Redemption, 1 Year 1 Year Expense Example, with Redemption, 3 Years 3 Years Expense Example, with Redemption, 5 Years 5 Years Expense Example, with Redemption, 10 Years 10 Years Expense [Heading] Expense [Heading] Expense Narrative [Text Block] Expense Narrative [Text Block] Fee Waiver or Reimbursement over Assets, Date of Termination Fee Waiver or Reimbursement over Assets, Date of Termination Highest Quarterly Return, Label Label Index No Deduction for Fees, Expenses, Taxes [Text] Index No Deduction for Fees, Expenses, Taxes [Text] Lowest Quarterly Return, Label Label Market Index Performance [Table] Market Index Performance [Table] Objective [Heading] Objective [Heading] Objective, Primary [Text Block] Objective, Primary [Text Block] Operating Expenses Caption [Text] Operating Expenses Caption [Text] Other Expenses, New Fund, Based on Estimates [Text] Other Expenses, New Fund, Based on Estimates [Text] Performance Availability Phone [Text] Performance Availability Phone [Text] Performance Availability Website Address [Text] Performance Availability Website Address [Text] Performance Information Illustrates Variability of Returns [Text] Performance Information Illustrates Variability of Returns [Text] Performance Measure [Axis] Performance Measure [Axis] Before Taxes Before Taxes Performance Narrative [Text Block] Performance Narrative [Text Block] Performance One Year or Less [Text] Performance One Year or Less [Text] Performance Past Does Not Indicate Future [Text] Performance Past Does Not Indicate Future [Text] Performance Table Heading Performance Table Heading Performance Table Narrative Performance Table Narrative Performance Table Not Relevant to Tax Deferred Performance Table Not Relevant to Tax Deferred Performance Table One Class of after Tax Shown [Text] Performance Table One Class of after Tax Shown [Text] Performance [Table] Performance [Table] Performance Table Uses Highest Federal Rate Performance Table Uses Highest Federal Rate Portfolio Turnover [Heading] Portfolio Turnover [Heading] Portfolio Turnover, Rate Portfolio Turnover, Rate Portfolio Turnover [Text Block] Portfolio Turnover [Text Block] Prospectus Date Prospectus Date Share Class [Axis] Share Class [Axis] Prospectus: Prospectus: Risk [Heading] Risk [Heading] Risk Lose Money [Text] Risk Lose Money [Text] Risk Narrative [Text Block] Risk Narrative [Text Block] Risk/Return: Risk/Return: Risk/Return [Heading] Risk/Return [Heading] Shareholder Fees [Table] Shareholder Fees [Table] Strategy [Heading] Strategy [Heading] Strategy Narrative [Text Block] Strategy Narrative [Text Block] Management Fees Distribution and Service (12b-1) Fees Other Expenses Total Other Expenses Total Annual Portfolio Operating Expenses Fee Waiver and/or Expense Reimbursement Fee Waiver and/or Expense Reimbursement Total Annual Portfolio Operating Expenses After Fee Waiver and/or Expense Reimbursement Acquired Fund Fees and Expenses Acquired Fund Fees and Expenses (Underlying Funds) Dividend Expenses on Securities Sold Short Borrowing Expenses on Securities Sold Short Remainder of Other Expenses