XML 54 R3.htm IDEA: XBRL DOCUMENT v3.24.4
Label Element Value
Loomis Sayles Growth Fund  
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading Loomis Sayles Growth Fund
Objective [Heading] rr_ObjectiveHeading Investment Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
The Fund’s investment goal is long-term growth of capital.
Expense [Heading] rr_ExpenseHeading Fund Fees & Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
The following table describes 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 this table. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Natixis Funds Complex. More information about these and other discounts is available from your financial professional and in the section “How Sales Charges Are Calculated” on page 48 of the Prospectus, in Appendix A to the Prospectus and on page 110 in the section “Reduced Sales Charges” of the Statement of Additional Information (“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)
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination January 31, 2026
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 for you if your 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 its most recently ended fiscal year, the Fund’s portfolio turnover rate was 10% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 10.00%
Expenses Deferred Charges [Text Block] rr_ExpensesDeferredChargesTextBlock A 1.00% contingent deferred sales charge (“CDSC”) may apply to certain purchases of Class A shares of $1,000,000 or more that are redeemed within eighteen months of the date of purchase.
Expense Breakpoint Discounts [Text] rr_ExpenseBreakpointDiscounts You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Natixis Funds Complex.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other expenses for Class T shares are estimated for the current fiscal year.
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 (except where indicated). The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same, except that the examples for the Class A, Class C, Class T, and Class Y shares are based on the Total Annual Fund Operating Expenses After Fee Waiver and/or Reimbursement assuming that such waiver and/or reimbursement will only be in place through the date noted above and on the Total Annual Fund Operating Expenses for the remaining periods. The example for Class C shares for the ten-year period reflects the conversion to Class A shares after eight years. The example does not take into account brokerage commissions and other fees to financial intermediaries that you may pay on your purchases and sales of shares of the Fund. 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 If shares are redeemed:
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption If shares are not redeemed:
Strategy [Heading] rr_StrategyHeading Investments, Risks and Performance Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
Under normal market conditions, the Fund will invest primarily in equity securities, including common stocks, convertible securities and warrants. The Fund focuses on stocks of large capitalization companies, but the Fund may invest in companies of any size.
The Fund normally invests across a wide range of sectors and industries. The Fund’s portfolio manager employs a growth style of equity management, which means that the Fund seeks to invest in companies with sustainable competitive advantages versus others, long-term structural growth drivers that will lead to above-average future cash flow growth, attractive cash flow returns on invested capital, and management teams focused on creating long-term value for shareholders. The Fund’s portfolio manager also aims to invest in companies when they trade at a significant discount to the estimate of intrinsic value (i.e., companies with share prices trading significantly below what the portfolio manager believes the share price should be).
The Fund will consider selling a portfolio investment when the portfolio manager believes an unfavorable structural change occurs within a given business or the markets in which it operates, a critical underlying investment assumption is flawed, when a more attractive reward-to-risk opportunity becomes available, when the current price fully reflects intrinsic value, or for other investment reasons which the portfolio manager deems appropriate.
The Fund may also invest up to 20% of its assets in foreign securities, including depositary receipts and emerging market securities. Although certain equity securities purchased by the Fund may be issued by domestic companies incorporated outside of the United States, the Adviser does not consider these securities to be foreign if they are included in the U.S. equity indices published by S&P Global Ratings or Russell Investments or if the security’s country of risk defined by Bloomberg is the United States. The Fund may also invest in affiliated and unaffiliated mutual funds and exchange-traded funds, to the extent permitted by the Investment Company Act of 1940. The Fund may also engage in foreign currency transactions (including foreign currency forwards and foreign currency futures) for hedging purposes, invest in options for hedging and investment purposes and invest in interests in real estate investment trusts (“REITs”), and securities issued pursuant to Rule 144A under the Securities Act of 1933 (“Rule 144A securities”) and other privately placed investments such as private equity investments. Except as provided above or as required by applicable law, the Fund is not limited in the percentage of its assets that it may invest in these instruments.
Risk [Heading] rr_RiskHeading Principal Investment Risks
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Risk/Return Bar Chart and Table
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
The bar chart and table shown below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year-to-year and by showing how the Fund’s average annual returns for the one-year, five-year and ten-year periods compare to those of a broad-based securities market index that reflects the performance of the overall market applicable to the Fund and an additional index that represents the market sectors in which the Fund primarily invests. Performance for Class C shares includes the automatic conversion to Class A shares after eight years, where applicable. The Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated performance information is available online at im.natixis.com and/or by calling the Fund toll-free at 800-225-5478.
The chart does not reflect any sales charge that you may be required to pay when you buy or redeem the Fund’s shares. A sales charge will reduce your return. To the extent that a class of shares was subject to the waiver or reimbursement of certain expenses during a period, had such expenses not been waived or reimbursed during the period, total returns would have been lower.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart and table shown below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year-to-year and by showing how the Fund’s average annual returns for the one-year, five-year and ten-year periods compare to those of a broad-based securities market index that reflects the performance of the overall market applicable to the Fund and an additional index that represents the market sectors in which the Fund primarily invests.
Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The Fund did not have Class T shares outstanding during the periods shown above.
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone 800-225-5478
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress im.natixis.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Total Returns for Class Y Shares
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads The chart does not reflect any sales charge that you may be required to pay when you buy or redeem the Fund’s shares. A sales charge will reduce your return.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock Highest Quarterly Returns: Second Quarter 2020, 23.88%Lowest Quarterly Return: Second Quarter 2022, -22.80%
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns(for the periods ended December 31, 2024)
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes Index performance 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 federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown for only one class of the Fund.After-tax returns for the other classes of the Fund will vary.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock
The Fund did not have Class T shares outstanding during the periods shown above. The returns of Class T shares would have been substantially similar to the returns of the Fund’s other share classes because they would have been invested in the same portfolio of securities and would only differ to the extent the other share classes did not have the same expenses. Performance of Class T shares shown above is that of Class A shares, which have the same expenses as Class T shares, restated to reflect the different sales load applicable to Class T shares.
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. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, or individual retirement accounts. The after-tax returns are shown for only one class of the Fund. After-tax returns for the other classes of the Fund will vary. Index performance reflects no deduction for fees, expenses or taxes.
Loomis Sayles Growth Fund | Risk Lose Money [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock You may lose money by investing in the Fund.
Loomis Sayles Growth Fund | Risk Not Insured [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Fund shares are not bank deposits and are not guaranteed, endorsed or insured by the Federal Deposit Insurance Corporation or any other government agency, and are subject to investment risks, including possible loss of the principal invested.
Loomis Sayles Growth Fund | Equity Securities Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Equity Securities Risk: The value of the Fund’s investments in equity securities could be subject to unpredictable declines in the value of individual securities and periods of below-average performance in individual securities or in the equity market as a whole. Growth stocks are generally more sensitive to market movements than other types of stocks primarily because their stock prices are based heavily on future expectations. If the Adviser’s assessment of the prospects for a company’s growth is wrong, or if the Adviser’s judgment of how other investors will value the company’s growth is wrong, then the price
of the company’s stock may fall or not approach the value that the Adviser has placed on it. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer’s bonds generally take precedence over the claims of those who own preferred stock or common stock. 
Loomis Sayles Growth Fund | Market Issuer Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Market/Issuer Risk: The market value of the Fund’s investments will move up and down, sometimes rapidly and unpredictably, based upon overall market and economic conditions, as well as a number of reasons that directly relate to the issuers of the Fund’s investments, such as management performance, financial condition and demand for the issuers’ goods and services.
Loomis Sayles Growth Fund | Management Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Management Risk: A strategy used by the Fund’s portfolio manager may fail to produce the intended result. 
Loomis Sayles Growth Fund | Liquidity Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Liquidity Risk: Liquidity risk is the risk that the Fund may be unable to find a buyer for its investments when it seeks to sell them or to receive the price it expects. Decreases in the number of financial institutions willing to make markets in the Fund’s investments or in their capacity or willingness to transact may increase the Fund’s exposure to this risk. Events that may lead to increased redemptions, such as market disruptions or increases in interest rates, may also negatively impact the liquidity of the Fund’s investments when it needs to dispose of them. Markets may become illiquid quickly. If the Fund is forced to sell its investments at an unfavorable time and/or under adverse conditions in order to meet redemption requests, such sales could negatively affect the Fund. During times of market turmoil, there may be no buyers or sellers for securities in certain asset classes and dealers may be unwilling or unable to make a market for certain securities.  Securities acquired in a private placement, such as Rule 144A securities and privately negotiated credit and other investments, are generally subject to significant liquidity risk because they are subject to strict restrictions on resale and there may be no liquid secondary market or ready purchaser for such securities. In other circumstances, liquid investments may become illiquid. Derivatives, and particularly over-the-counter (“OTC”) derivatives, are generally subject to liquidity risk as well. Derivatives, and particularly over-the-counter (“OTC”) derivatives, are generally subject to liquidity risk as well. Liquidity issues may also make it difficult to value the Fund’s investments. The Fund may invest in liquid investments that become illiquid due to financial distress, or geopolitical events such as sanctions, trading halts or wars.
Loomis Sayles Growth Fund | Foreign Securities Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit/counterparty and information risks. The Fund’s investments in foreign securities also are subject to foreign currency fluctuations and other foreign currency-related risks. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity.
Loomis Sayles Growth Fund | Emerging Markets Risks [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Emerging Markets Risk: In addition to the risks of investing in foreign investments generally, emerging markets investments are subject to greater risks arising from political or economic instability, war, nationalization or confiscatory taxation, currency exchange or repatriation restrictions, sanctions by other countries (such as the United States or the European Union), new or inconsistent government treatment of or restrictions on issuers and instruments, and an issuer’s unwillingness or inability to make dividend, principal or interest payments on its securities. Emerging markets companies may be smaller and have shorter operating histories than companies in developed markets.
Loomis Sayles Growth Fund | Small and Mid Capitalization Companies Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Small- and Mid-Capitalization Companies Risk: Compared to large-capitalization companies, small- and mid-capitalization companies are more likely to have limited product lines, markets or financial resources. Stocks of these companies often trade less frequently and in limited volume and their prices may fluctuate more than stocks of large-capitalization companies. As a result, it may be relatively more difficult for the Fund to buy and sell securities of small- and mid-capitalization companies.
Loomis Sayles Growth Fund | Credit Counterparty Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Credit/Counterparty Risk: Credit/counterparty risk is the risk that the issuer or guarantor of a fixed-income security, or the counterparty to a derivative or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. As a result, the Fund may sustain losses or be unable or delayed in its ability to realize gains. The Fund will be subject to credit/counterparty risk with respect to the counterparties to its derivatives transactions. This risk will be heightened to the extent the Fund enters into derivatives transactions with a single counterparty (or affiliated counterparties that are part of the same organization), causing the Fund to have significant exposure to such counterparty. Many of the protections afforded to participants on organized exchanges and clearing houses, such as the performance guarantee given by a central clearing house, are not available in connection with OTC derivatives transactions, such as foreign currency transactions. For centrally cleared derivatives, such as cleared swaps, futures and many options, the primary credit/counterparty risk is the creditworthiness of the Fund’s clearing broker and the central clearing house itself. 
Loomis Sayles Growth Fund | Currency Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Currency Risk: Fluctuations in the exchange rates between different currencies may negatively affect an investment. The Fund may be subject to currency risk because it may invest in currency-related instruments and may invest in securities or other instruments denominated in, or that generate income denominated in, foreign currencies. The Fund may elect not to hedge currency risk, or may hedge such risk imperfectly, which may cause the Fund to incur losses that would not have been incurred had the risk been hedged.  
Loomis Sayles Growth Fund | Cybersecurity and Technology Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Cybersecurity and Technology Risk: The Fund, its service providers, and other market participants increasingly depend on complex information technology and communications systems, which are subject to a number of different threats and risks that could adversely affect the Fund and its shareholders. Cybersecurity and other operational and technology issues may result in financial losses to the Fund and its shareholders.
Loomis Sayles Growth Fund | Derivatives Risks [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Derivatives Risk: Derivative instruments (such as those in which the Fund may invest, including foreign currency forwards, foreign currency futures and options) are subject to changes in the value of the underlying assets or indices on which such instruments are based. There is no guarantee that the use of derivatives will be effective or that suitable transactions will be available. Even a small investment in derivatives may give rise to leverage risk and can have a significant impact on the Fund’s exposure to securities market values, interest rates or currency exchange rates. It is possible that the Fund’s liquid assets may be insufficient to support its obligations under its derivatives positions. The use of derivatives for other than hedging purposes may be considered a speculative activity, and involves greater risks than are involved in hedging. The use of derivatives may cause the Fund to incur losses greater than those that would have occurred had derivatives not been used. The Fund’s use of derivatives involves other risks, such as credit/counterparty risk relating to the other party to a derivative contract (which is greater for forward currency contracts and other OTC derivatives), the risk of difficulties in pricing and valuation,
the risk that changes in the value of a derivative may not correlate as expected with changes in the value of relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than any amounts paid or margin transferred to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivative position at an advantageous time or price. The Fund’s derivative counterparties may experience financial difficulties or otherwise be unwilling or unable to honor their obligations, possibly resulting in losses to the Fund.
Loomis Sayles Growth Fund | Investments in Other Investment Companies Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Investments in Other Investment Companies Risk: The Fund will indirectly bear the management, service and other fees of any other investment companies, including exchange-traded funds, in which it invests in addition to its own expenses.
Loomis Sayles Growth Fund | Large Investor Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Large Investor Risk: Ownership of shares of the Fund may be concentrated in one or a few large investors. Such investors may redeem shares in large quantities or on a frequent basis. Redemptions by a large investor may require the Fund to sell investments at unfavorable times or prices, may increase realized capital gains, including short-term capital gains taxable as ordinary income, may accelerate the realization of taxable income to shareholders, may increase transaction costs, and may otherwise negatively impact fund performance. These transactions potentially limit the use of any capital loss carryforwards and certain other losses to offset future realized capital gains (if any). Such transactions may also increase the Fund’s expenses.
Loomis Sayles Growth Fund | Leverage Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
Leverage Risk: Leverage is the risk associated with securities or investment practices (e.g., borrowing and the use of certain derivatives) that multiply small index, market or asset-price movements into larger changes in value. The use of leverage increases the impact of gains and losses on the Fund’s returns, and may lead to significant losses if investments are not successful.
Loomis Sayles Growth Fund | REITs Risk [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock
REITs Risk: Investments in the real estate industry, including REITs, are particularly sensitive to economic downturns and are sensitive to factors such as changes in real estate values, property taxes and tax laws, interest rates, cash flow of underlying real estate assets, occupancy rates, government regulations affecting zoning, land use and rents and the management skill and creditworthiness of the issuer. Companies in the real estate industry also may be subject to liabilities under environmental and hazardous waste laws. In addition, the value of a REIT is affected by changes in the value of the properties owned by the REIT or mortgage loans held by the REIT. REITs are also subject to default and prepayment risk. Many REITs are highly leveraged, increasing their risk. The Fund will indirectly bear its proportionate share of expenses, including management fees, paid by each REIT in which it invests in addition to the expenses of the Fund. REITs are also subject to the possibilities of failing to qualify for the favorable tax treatment available to REITs under the Internal Revenue Code of 1986, as amended, and failing to maintain their exemptions from registration under the investment Company Act of 1940.
Loomis Sayles Growth Fund | Class A  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable) rr_MaximumDeferredSalesChargeOverOther none [1]
Redemption fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.50%
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other expenses rr_OtherExpensesOverAssets 0.17% [2]
Total annual fund operating expenses rr_ExpensesOverAssets 0.92%
Fee waiver and/or expense reimbursement rr_FeeWaiverOrReimbursementOverAssets 0.01% [3],[4]
Total annual fund operating expenses after fee waiver and/or expense reimbursement rr_NetExpensesOverAssets 0.91%
1 year rr_ExpenseExampleYear01 $ 663
3 years rr_ExpenseExampleYear03 850
5 years rr_ExpenseExampleYear05 1,054
10 years rr_ExpenseExampleYear10 $ 1,640
Past 1 Year rr_AverageAnnualReturnYear01 26.31%
Past 5 Years rr_AverageAnnualReturnYear05 16.47%
Past 10 Years rr_AverageAnnualReturnYear10 15.43%
Loomis Sayles Growth Fund | Class C  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable) rr_MaximumDeferredSalesChargeOverOther 1.00%
Redemption fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.50%
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Other expenses rr_OtherExpensesOverAssets 0.17%
Total annual fund operating expenses rr_ExpensesOverAssets 1.67%
Fee waiver and/or expense reimbursement rr_FeeWaiverOrReimbursementOverAssets 0.01% [3],[4]
Total annual fund operating expenses after fee waiver and/or expense reimbursement rr_NetExpensesOverAssets 1.66%
1 year rr_ExpenseExampleYear01 $ 269
3 years rr_ExpenseExampleYear03 526
5 years rr_ExpenseExampleYear05 906
10 years rr_ExpenseExampleYear10 1,776
1 year rr_ExpenseExampleNoRedemptionYear01 169
3 years rr_ExpenseExampleNoRedemptionYear03 526
5 years rr_ExpenseExampleNoRedemptionYear05 906
10 years rr_ExpenseExampleNoRedemptionYear10 $ 1,776
Past 1 Year rr_AverageAnnualReturnYear01 32.02%
Past 5 Years rr_AverageAnnualReturnYear05 16.96%
Past 10 Years rr_AverageAnnualReturnYear10 15.41%
Loomis Sayles Growth Fund | Class N  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable) rr_MaximumDeferredSalesChargeOverOther none
Redemption fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.50%
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets none
Other expenses rr_OtherExpensesOverAssets 0.07%
Total annual fund operating expenses rr_ExpensesOverAssets 0.57%
Fee waiver and/or expense reimbursement rr_FeeWaiverOrReimbursementOverAssets none [3],[4]
Total annual fund operating expenses after fee waiver and/or expense reimbursement rr_NetExpensesOverAssets 0.57%
1 year rr_ExpenseExampleYear01 $ 58
3 years rr_ExpenseExampleYear03 183
5 years rr_ExpenseExampleYear05 318
10 years rr_ExpenseExampleYear10 $ 714
Past 1 Year rr_AverageAnnualReturnYear01 34.46%
Past 5 Years rr_AverageAnnualReturnYear05 18.25%
Past 10 Years rr_AverageAnnualReturnYear10 16.51%
Loomis Sayles Growth Fund | Class T  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 2.50%
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable) rr_MaximumDeferredSalesChargeOverOther none
Redemption fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.50%
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other expenses rr_OtherExpensesOverAssets 0.17% [2],[5]
Total annual fund operating expenses rr_ExpensesOverAssets 0.92%
Fee waiver and/or expense reimbursement rr_FeeWaiverOrReimbursementOverAssets 0.01% [3],[4]
Total annual fund operating expenses after fee waiver and/or expense reimbursement rr_NetExpensesOverAssets 0.91%
1 year rr_ExpenseExampleYear01 $ 341
3 years rr_ExpenseExampleYear03 535
5 years rr_ExpenseExampleYear05 746
10 years rr_ExpenseExampleYear10 $ 1,352
Past 1 Year rr_AverageAnnualReturnYear01 30.67%
Past 5 Years rr_AverageAnnualReturnYear05 17.26%
Past 10 Years rr_AverageAnnualReturnYear10 15.83%
Loomis Sayles Growth Fund | Class Y  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable) rr_MaximumDeferredSalesChargeOverOther none
Redemption fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.50%
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets none
Other expenses rr_OtherExpensesOverAssets 0.17%
Total annual fund operating expenses rr_ExpensesOverAssets 0.67%
Fee waiver and/or expense reimbursement rr_FeeWaiverOrReimbursementOverAssets 0.01% [3],[4]
Total annual fund operating expenses after fee waiver and/or expense reimbursement rr_NetExpensesOverAssets 0.66%
1 year rr_ExpenseExampleYear01 $ 67
3 years rr_ExpenseExampleYear03 213
5 years rr_ExpenseExampleYear05 372
10 years rr_ExpenseExampleYear10 $ 834
2015 rr_AnnualReturn2015 10.02%
2016 rr_AnnualReturn2016 5.87%
2017 rr_AnnualReturn2017 32.64%
2018 rr_AnnualReturn2018 (2.48%)
2019 rr_AnnualReturn2019 31.72%
2020 rr_AnnualReturn2020 31.77%
2021 rr_AnnualReturn2021 18.65%
2022 rr_AnnualReturn2022 (27.64%)
2023 rr_AnnualReturn2023 51.42%
2024 rr_AnnualReturn2024 34.38%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Quarterly Returns:
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2020
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 23.88%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Quarterly Return:
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Jun. 30, 2022
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (22.80%)
Past 1 Year rr_AverageAnnualReturnYear01 34.38%
Past 5 Years rr_AverageAnnualReturnYear05 18.15%
Past 10 Years rr_AverageAnnualReturnYear10 16.41%
Loomis Sayles Growth Fund | Return After Taxes on Distributions | Class Y  
Risk/Return: rr_RiskReturnAbstract  
Past 1 Year rr_AverageAnnualReturnYear01 32.68%
Past 5 Years rr_AverageAnnualReturnYear05 16.23%
Past 10 Years rr_AverageAnnualReturnYear10 15.11%
Loomis Sayles Growth Fund | Return After Taxes on Distributions and Sale of Fund Shares | Class Y  
Risk/Return: rr_RiskReturnAbstract  
Past 1 Year rr_AverageAnnualReturnYear01 21.59%
Past 5 Years rr_AverageAnnualReturnYear05 14.21%
Past 10 Years rr_AverageAnnualReturnYear10 13.53%
Loomis Sayles Growth Fund | S&P 500® Index  
Risk/Return: rr_RiskReturnAbstract  
Past 1 Year rr_AverageAnnualReturnYear01 25.02%
Past 5 Years rr_AverageAnnualReturnYear05 14.53%
Past 10 Years rr_AverageAnnualReturnYear10 13.10%
Loomis Sayles Growth Fund | Russell 1000® Growth Index  
Risk/Return: rr_RiskReturnAbstract  
Past 1 Year rr_AverageAnnualReturnYear01 33.36%
Past 5 Years rr_AverageAnnualReturnYear05 18.96%
Past 10 Years rr_AverageAnnualReturnYear10 16.78%
[1] A 1.00% contingent deferred sales charge (“CDSC”) may apply to certain purchases of Class A shares of $1,000,000 or more that are redeemed within eighteen months of the date of purchase.
[2] Pursuant to an expense offset arrangement, credits realized as a result of uninvested cash balances may be used to reduce the Fund’s transfer agent expenses. Other expenses are shown net of such reductions of transfer agent expenses of 3bps.
[3] Loomis, Sayles & Company, L.P. (“Loomis Sayles” or the “Adviser”) has given a binding contractual undertaking to the Fund to limit the amount of the Fund’s total annual fund operating expenses to 1.00%, 1.75%, 0.70%, 1.00% and 0.75% of the Fund’s average daily net assets for Class A, C, N, T and Y shares, respectively, exclusive of acquired fund fees and expenses, brokerage expenses, interest expense, taxes, and organizational and extraordinary expenses, such as litigation and indemnification expenses. In addition, Loomis Sayles will waive its management fee on any portion of the Fund’s assets that are invested in the Natixis Loomis Sayles Focused Growth ETF. This undertaking is in effect through January 31, 2026 and may be terminated before then only with the consent of the Fund’s Board of Trustees. The Adviser will be permitted to recover, on a class-by-class basis, management fees waived and/or expenses reimbursed to the extent that expenses in later periods fall below both (1) the class’ applicable expense limitation at the time such amounts were waived/reimbursed and (2) the class’ current applicable expense limitation. The Fund will not be obligated to repay any such waived/reimbursed fees and expenses more than one year after the end of the fiscal year in which the fees or expenses were waived/reimbursed.
[4] The expense information shown in the table above includes acquired fund fees and expenses of less than 0.01%; the ratios may differ from the expense information disclosed in the Fund’s financial highlights table because the financial highlights table reflects the operating expenses of the Fund and does not include acquired fund fees and expenses.
[5] Other expenses for Class T shares are estimated for the current fiscal year.