485BPOS

Registration Nos. 2-11101

811-00242

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933	¨
Pre-Effective Amendment No.	¨
Post-Effective Amendment No. 166	x

and/or

REGISTRATION STATEMENT

UNDER

THE INVESTMENT COMPANY ACT OF 1940	¨
Amendment No. 97	x

(Check appropriate box or boxes.)

NATIXIS FUNDS TRUST II

(Exact Name of Registrant as Specified in Charter)

399 Boylston Street, Boston, Massachusetts 02116

(Address of principal executive offices)(Zip Code)

(617) 449-2810

Registrant’s Telephone Number, including Area Code

Copy to:

Coleen Downs Dinneen, Esq.	John M. Loder, Esq.
NGAM Distribution, L.P.	Ropes & Gray
399 Boylston Street	800 Boylston Street
Boston, Massachusetts 02116	Boston, Massachusetts 02119
(Name and Address of Agent for Service)

Approximate Date of Public Offering

It is proposed that this filing will become effective (check appropriate box):

x Immediately upon filing pursuant to paragraph (b)

¨ On              pursuant to paragraph (b)

¨ 60 days after filing pursuant to paragraph (a)(1)

¨ On (date) pursuant to paragraph (a)(1)

¨ 75 days after filing pursuant to paragraph (a)(2)

¨ on (date) pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following box:

¨ This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

NATIXIS FUNDS TRUST II

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all of the requirements for effectiveness of this registration statement under Rule 485(b) under the Securities Act and has duly caused this Post-Effective Amendment No. 166 to its Registration Statement to be signed on its behalf by the undersigned, duly authorized, in the City of Boston, and the Commonwealth of Massachusetts on the 22^nd day of May, 2012.

NATIXIS FUNDS TRUST II
By:	/s/ David L. Giunta
	David L. Giunta
	President and Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, as amended, this amendment to the Registration Statement has been signed below by the following persons in the capacities and on the date indicated.

Signature	Title	Date
/s/ David L. Giunta
David L. Giunta	President, Chief Executive Officer and Trustee	May 22, 2012
/s/ Michael C. Kardok
Michael C. Kardok	Treasurer	May 22, 2012
Graham T. Allison, Jr.*
Graham T. Allison, Jr.	Trustee	May 22, 2012
Charles D. Baker*
Charles D. Baker	Trustee	May 22, 2012
Robert J. Blanding *
Robert J. Blanding	Trustee	May 22, 2012
Daniel M. Cain *
Daniel M. Cain	Trustee	May 22, 2012
Kenneth A. Drucker *
Kenneth A. Drucker	Trustee	May 22, 2012
John T. Hailer *
John T. Hailer	Trustee	May 22, 2012

Wendell J. Knox *
Wendell J. Knox	Trustee	May 22, 2012
Sandra O. Moose *
Sandra O. Moose	Trustee, Chairperson of the Board	May 22, 2012
Erik Sirri *
Erik Sirri	Trustee	May 22, 2012
Peter Smail *
Peter Smail	Trustee	May 22, 2012
Cynthia L. Walker *
Cynthia L. Walker	Trustee	May 22, 2012

*By:	/s/ Coleen Downs Dinneen
	Coleen Downs Dinneen Attorney-In-Fact 1,2,3,4,5,6,7 May 22, 2012

¹  Powers of Attorney for Graham T. Allison, Jr., Robert J. Blanding, Daniel M. Cain, John T. Hailer and Sandra O. Moose are incorporated by reference to exhibit (q) to PEA No. 124 to the Registration Statement filed on December 2, 2004.

²  Power of Attorney for Cynthia L. Walker is incorporated by reference to exhibit (q)(2) to PEA No. 128 to the Registration Statement filed on January 30, 2006.

³  Power of Attorney for Kenneth A. Drucker is incorporated by reference to exhibit (q)(4) to PEA No. 136 to the Registration Statement filed on July 17, 2008.

⁴  Power of Attorney for Wendell J. Knox is incorporated by reference to exhibit (q)(4) to PEA No. 143 to the Registration Statement filed on July 15, 2009.

⁵  Power of Attorney for Erik Sirri is incorporated by reference to exhibit (q)(5) to PEA No. 146 to the Registration Statement filed on March 1, 2010.

⁶  Power of Attorney for Peter Smail is incorporated by reference to exhibit (q)(6) to PEA No. 146 to the Registration Statement filed on March 1, 2010.

⁷  Power of Attorney for Charles D. Baker is incorporated by reference to exhibit (q)(7) to PEA No. 154 to the Registration Statement filed on February 25, 2011.

Natixis Funds Trust II

Exhibit Index

Exhibits for Item 28 of Form N-1A

Exhibit	Exhibit Description
EX-101.INS	XBRL Instance Document
EX-101.SCH	XBRL Taxonomy Extension Schema Document
EX-101.CAL	XBRL Taxonomy Extension Calculation Linkbase
EX-101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX-101.LAB	XBRL Taxonomy Extension Labels Linkbase
EX-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Prospectus Date	rr_ProspectusDate	May 01, 2012
Registrant Name	dei_EntityRegistrantName	Natixis Funds Trust II
Loomis Sayles Absolute Strategies Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Loomis Sayles Absolute Strategies Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Goal
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide an attractive absolute total return, complemented by prudent investment management designed to manage risks and protect investor capital.
Objective, Secondary [Text Block]	rr_ObjectiveSecondaryTextBlock	The secondary goal of the Fund is to achieve these returns with relatively low volatility.
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 and hold shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in the Natixis Fund 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 70 of the Prospectus and on page 103 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	April 30, 2013
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 141% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	141.00%
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 $100,000 in the Natixis Fund Complex.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	100,000
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods (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. 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	The Fund has an absolute return investment objective, which means that it is not managed relative to an index and that it attempts to achieve positive total returns over a full market cycle. The Fund intends to pursue its objective by utilizing a flexible investment approach that allocates investments across a global range of investment opportunities related to credit, currencies and interest rates, while employing risk management strategies to mitigate downside risk. The Fund may invest up to 100% of its total assets in below investment-grade fixed-income securities (also known as "junk bonds") and derivatives that have returns related to the returns on below investment-grade fixed-income securities, although it is expected that, under normal market conditions, the Fund's net exposure ( i.e. , long exposures obtained through direct investments in securities and in derivatives minus short exposures obtained through derivatives) to below investment-grade fixed-income assets generally will not exceed 50% of the Fund's total assets. Under normal market conditions, the Fund also may invest up to 50% of its total assets in investments denominated in non-U.S. currencies and related derivatives, including up to 20% in investments denominated in emerging market currencies and related derivatives. The Fund expects that its exposure to these asset classes will often be obtained substantially through the use of derivative instruments. The Fund defines an "emerging market currency" as a currency of a country that carries a sovereign debt quality rating that is rated below investment-grade by either Standard & Poor's Ratings Group ("S&P") or Moody's Investors Service, Inc. ("Moody's"), or is unrated by both S&P and Moody's. Currency positions that are intended to hedge the Fund's non-U.S. currency exposure ( i.e. , currency positions that are not made for investment purposes) will offset positions in the same currency that are made for investment purposes when calculating the limitation on investments in non-U.S. and emerging market currency investments because the Fund believes that hedging a currency position is likely to negate some or all of the currency risk associated with the original currency position. The Fund does not have limits on the duration of its portfolio, and the Fund's duration will change over time. In selecting investments for the Fund, the Adviser develops long-term portfolio themes driven by macro-economic indicators. These include secular global economic trends, demographic trends and labor supply, analysis of global capital flows and assessments of geopolitical factors. The Adviser then develops shorter-term portfolio strategies based on factors including, but not limited to, economic, credit and Federal Reserve cycles, and top-down sector valuations and bottom-up security valuations. The Adviser employs active risk management, with a focus on credit, interest rate and currency risks. Additionally, the portfolio managers will use risk management tools in constructing and optimizing the portfolio and seek to manage risk on an ongoing basis. The portfolio management team expects to actively evaluate each investment idea based upon its return potential, its level of risk and its fit within the team's overall macro strategy when deciding whether to buy or sell investments, with the goal of continually optimizing the Fund's portfolio. The Fund will pursue its investment goal by obtaining long investment exposures through direct cash investments and derivatives and short investment exposures substantially through derivatives. A "long" investment exposure is an investment that rises in value with a rise in the value of an asset, asset class or index and declines in value with a decline in the value of that asset, asset class or index. A "short" investment exposure is an investment that rises in value with a decline in the value of an asset, asset class or index and declines in value with a rise in the value of that asset, asset class or index. The Fund's long and short investment exposures may, at times, each reach 100% of the assets invested in the Fund (excluding instruments primarily used for duration management or yield curve management and short-term investments (such as cash and money market instruments)), although these exposures may be higher or lower at any given time. Fixed-Income Investments. In connection with its principal investment strategies, the Fund may invest in a broad range of U.S. and non-U.S. fixed-income securities, including, but not limited to, corporate bonds, municipal securities, U.S. and non-U.S. government securities (including their agencies, instrumentalities and sponsored entities), securities of supranational entities, emerging market securities, commercial and residential mortgage-backed securities, collateralized mortgage obligations, other mortgage-related securities (such as adjustable rate mortgage securities), asset-backed securities, bank loans, convertible bonds, Rule 144A securities, real estate investment trusts ("REITs"), zero-coupon securities, step coupon securities, pay-in-kind ("PIK") securities, inflation-linked bonds, variable and floating rate securities, private placements and commercial paper. Non-U.S. Currency Investments. Under normal market conditions, the Fund may engage in a broad range of transactions involving non-U.S. and emerging market currencies, including, but not limited to, purchasing and selling forward currency exchange contracts in non-U.S. or emerging market currencies, investing in non-U.S. currency futures contracts, investing in options on non-U.S. currencies and non-U.S. currency futures, investing in cross-currency instruments (such as swaps), investing directly in non-U.S. currencies and investing in securities denominated in non-U.S. currencies. The Fund may engage in non-U.S. currency transactions for investment or for hedging purposes. Derivative Investments. For investment and hedging purposes, the Fund may invest substantially in a broad range of derivatives instruments and sometimes the majority of its investment returns will derive from its derivative investments. These derivative instruments include, but are not limited to, futures contracts (such as treasury futures and index futures), forward contracts, options (such as options on futures contracts, options on securities, interest rate/bond options, currency options, options on swaps and over-the-counter ("OTC") options), warrants (such as non-U.S. currency warrants) and swap transactions (such as interest rate swaps, total return swaps and index swaps). In addition, the Fund may invest in credit derivative products that may be used to manage default risk and credit exposure. Examples of such products include, but are not limited to, credit default swap index products (such as LCDX, CMBX and ABX index products), single name credit default swaps, loan credit default swaps and asset-backed credit default swaps. The Fund may, at times, invest substantially all of its assets in derivatives and securities used to support its obligations under those derivatives. Derivative instruments (such as those listed above) can be used to acquire or to transfer the risk and returns of a security or other asset without buying or selling the security or asset. The Fund's strategy may be highly dependent on the use of derivatives, and to the extent that they become unavailable or unattractive the Fund may be unable to fully implement its investment strategy. The Fund is non-diversified, which means that it is not limited to a percentage of assets that it may invest in any one issuer. Because the Fund may invest in the securities of a limited number of issuers, an investment in the Fund may involve a higher degree of risk than would be present in a diversified portfolio. The Fund expects to engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund's return, and realization of greater short-term capital gains, distributions of which are taxable as ordinary income to taxable shareholders. Trading costs and tax effects associated with frequent trading may adversely affect the Fund"s performance. The percentage limitations set forth herein are not investment restrictions and the Fund may exceed these limits from time to time. In addition, when calculating these exposures, the Fund may use the market value, the notional value, an adjusted notional value or some other measure of the value of a derivative in order to reflect what the Adviser believes to be the most accurate assessment of the Fund's real economic exposure. The total notional value of the Fund's derivative instruments may significantly exceed the total value of the Fund's assets. Although the Fund seeks positive total returns over time, the Fund's investment returns may be volatile over short periods of time. The Fund may outperform the overall securities market during periods of flat or negative performance and may underperform during periods of strong market performance. There can be no assurance that the Fund's returns over time or during any period will be positive.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund. Agency Securities Risk: Agency securities are subject to fixed-income securities risk. Certain debt securities issued or guaranteed by agencies of the U.S. government are guaranteed as to the payment of principal and interest by the relevant entity but have not been backed by the full faith and credit of the U.S. government. Instead, they have been supported only by the discretionary authority of the U.S. government to purchase the agency's obligations. An event affecting the guaranteeing entity could adversely affect the payment of principal or interest or both on the security and, therefore, these types of securities should be considered to be riskier than U.S. government securities. Below Investment-Grade Fixed-Income Securities Risk: This is the risk that the Fund's investments in below investment-grade fixed-income securities, also known as "junk bonds," may be subject to greater risks than other fixed-income securities, including being subject to greater levels of interest rate risk, credit risk (including a greater risk of default) and liquidity risk. The ability of the issuer to make principal and interest payments is predominantly speculative for below investment-grade fixed-income securities. Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with over-the-counter ("OTC") derivative transactions, such as foreign currency transactions. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its direct counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains. 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 a significant portion of its assets in currency-related instruments and may invest in securities or other instruments denominated in, or receive revenues in, foreign currencies. The Adviser may elect not to hedge currency risk, which may cause the Fund to incur losses that would not have been incurred had the risk been hedged. Derivatives Risk: Derivatives are subject to changes in the value of the underlying asset or indices on which such transactions 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 markets 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 which would have occurred had derivatives not been used. The Fund's use of derivatives, such as futures, forward contracts, options, warrants, foreign currency transactions, swaps and credit default swaps, involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward contracts, swaps 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 perfectly with relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, a number of broker-dealers and other financial institutions have recently experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. There can be no assurance that the Fund's derivative counterparties will be able to avoid experiencing similar financial difficulties, possibly resulting in losses to the Fund. Emerging Markets Risk: Investing in emerging markets companies, which may be smaller and have shorter operating histories than companies in developed markets, involves risks in addition to, and greater than, those generally associated with investing in companies in developed foreign markets. The extent of economic development, political stability, market depth, infrastructure, capitalization and regulatory oversight in emerging market economies is generally less than in more developed markets. Fixed-Income Securities Risk: Fixed-income securities are subject to credit risk, interest rate risk and liquidity risk. You may lose money on your investment due to unpredictable drops in a security's value or periods of below-average performance in a given security or in the securities market as a whole. In addition, an economic downturn or period of rising interest rates could adversely affect the market of these securities and reduce the Fund's ability to sell them. Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund's investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity. Inflation/Deflation Risk: Inflation risk is the risk that the value of assets or income from investments will be worth less in the future as inflation decreases the present value of future payments. Deflation risk is the risk that prices throughout the economy decline over time (the opposite of inflation). Deflation may have an adverse effect on the creditworthiness of issuers and may make issuer default more likely, which may result in a decline in the value of the Fund's portfolio. Because the Fund seeks positive returns that exceed the rate of inflation over time, if the portfolio managers' inflation forecasts are incorrect, the Fund may be more severely impacted than other funds. Interest Rate Risk: Changes in interest rates may cause the value of the Fund's investments to decrease. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. A period of low interest rates may cause the Fund to have a low or negative yield, potentially reducing the value of your investment. The value of zero-coupon and pay-in-kind ("PIK") bonds may be more sensitive to fluctuations in interest rates than other fixed-income securities. Rule 144A securities and structured notes may be more illiquid than other fixed-income securities. Issuer Risk: The value of the Fund's investments may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods and services. Leverage Risk: Use of derivative instruments may involve leverage. Leverage is the risk associated with securities or practices that multiply small index, market or asset price movements into larger changes in value. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. The use of leverage increases the impact of gains and losses on a fund's returns, and may lead to significant losses if investments are not successful. However, the Adviser will attempt to ensure that at all times the Fund has sufficient liquid assets to enable it to satisfy its obligations under its derivative contracts. Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell, possibly preventing the Fund from selling these illiquid securities at an advantageous price or time. A lack of liquidity also may cause the value of investments to decline. Illiquid investments also may be difficult to value. Management Risk: A strategy used by the Fund's portfolio managers may fail to produce the intended result. Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer's financial condition, as well as overall market and economic conditions. The Fund's portfolio managers will attempt to reduce this risk by implementing various volatility management strategies and techniques. However, there is no guarantee that such strategies and techniques will produce the intended result. Mortgage-Related and Asset-Backed Securities Risk: In addition to the risks associated with investments in fixed-income securities generally (for example, credit, liquidity and valuation risk), mortgage-related and asset-backed securities are subject to the risks of the mortgages and assets underlying the securities as well as prepayment risk, the risk that the securities may be prepaid and result in the reinvestment of the prepaid amounts in securities with lower yields than the prepaid obligations. Conversely, there is a risk that an unexpected rise in interest rates will extend the life of a mortgage-related or asset-backed security beyond the expected prepayment time, typically reducing the security's value. The Fund also may incur a loss when there is a prepayment of securities that were purchased at a premium. The Fund's investments in other asset-backed securities are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets. Non-Diversification Risk: Compared with other mutual funds, the Fund may invest a greater percentage of its assets in a particular issuer and may invest in fewer issuers. Therefore, the Fund may have more risk because changes in the value of a single security or the impact of a single economic, political or regulatory occurrence may have a greater adverse impact on the Fund's NAV. Short Exposure Risk: A short exposure through a derivative may present various risks, including credit/counterparty risk and leverage risk. If the value of the asset, asset class or index on which the Fund has obtained a short investment exposure increases, the Fund will incur a loss. Unlike a direct cash investment like a stock, bond or exchange-traded fund, where the potential loss is limited to the purchase price, the potential risk of loss from a short exposure is theoretically unlimited. Moreover, there can be no assurance that securities necessary to cover a short position will be available for purchase.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk: Compared with other mutual funds, the Fund may invest a greater percentage of its assets in a particular issuer and may invest in fewer issuers. Therefore, the Fund may have more risk because changes in the value of a single security or the impact of a single economic, political or regulatory occurrence may have a greater adverse impact on the Fund's NAV.
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 the Fund's performance in the first full year and by showing how the Fund's average annual returns for the one-year and life-of-Fund periods compare to those of a broad measure of market performance. 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 ngam.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.
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 the Fund's performance in the first full year and by showing how the Fund's average annual returns for the one-year and life-of-Fund periods compare to those of a broad measure of market performance. 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 ngam.natixis.com and/or by calling the Fund toll-free at 800-225-5478.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-225-5478
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	ngam.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 A Shares
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: First Quarter 2011, 1.33% Lowest Quarterly Return: Third Quarter 2011, -4.69%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
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	After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one–year period and life-of-Fund period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	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 Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one–year period and life-of-Fund period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.
Loomis Sayles Absolute Strategies Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	4.50%
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	0.70%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses-Fee/expense recovery	rr_Component1OtherExpensesOverAssets	none	[1]
Other expenses-Remainder of other expenses	rr_Component2OtherExpensesOverAssets	0.22%
Total other expenses	rr_OtherExpensesOverAssets	0.22%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.17%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.17%
1 year	rr_ExpenseExampleYear01	564
3 years	rr_ExpenseExampleYear03	805
5 years	rr_ExpenseExampleYear05	1,065
10 years	rr_ExpenseExampleYear10	1,806
2011	rr_AnnualReturn2011	(3.90%)
Past 1 Year	rr_AverageAnnualReturnYear01	(8.20%)
Life of Fund	rr_AverageAnnualReturnSinceInception	(7.52%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 15, 2010
Loomis Sayles Absolute Strategies 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	0.70%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses-Fee/expense recovery	rr_Component1OtherExpensesOverAssets	none	[1]
Other expenses-Remainder of other expenses	rr_Component2OtherExpensesOverAssets	0.21%
Total other expenses	rr_OtherExpensesOverAssets	0.21%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.91%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.91%
1 year	rr_ExpenseExampleYear01	294
3 years	rr_ExpenseExampleYear03	600
5 years	rr_ExpenseExampleYear05	1,032
10 years	rr_ExpenseExampleYear10	2,233
1 year	rr_ExpenseExampleNoRedemptionYear01	194
3 years	rr_ExpenseExampleNoRedemptionYear03	600
5 years	rr_ExpenseExampleNoRedemptionYear05	1,032
10 years	rr_ExpenseExampleNoRedemptionYear10	2,233
Past 1 Year	rr_AverageAnnualReturnYear01	(5.62%)
Life of Fund	rr_AverageAnnualReturnSinceInception	(4.22%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 15, 2010
Loomis Sayles Absolute Strategies 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	0.70%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses-Fee/expense recovery	rr_Component1OtherExpensesOverAssets	none	[1]
Other expenses-Remainder of other expenses	rr_Component2OtherExpensesOverAssets	0.22%
Total other expenses	rr_OtherExpensesOverAssets	0.22%
Total annual fund operating expenses	rr_ExpensesOverAssets	0.92%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	0.92%
1 year	rr_ExpenseExampleYear01	94
3 years	rr_ExpenseExampleYear03	293
5 years	rr_ExpenseExampleYear05	509
10 years	rr_ExpenseExampleYear10	1,131
Past 1 Year	rr_AverageAnnualReturnYear01	(3.78%)
Life of Fund	rr_AverageAnnualReturnSinceInception	(3.24%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 15, 2010
Return After Taxes on Distributions | Loomis Sayles Absolute Strategies Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(9.20%)
Life of Fund	rr_AverageAnnualReturnSinceInception	(8.49%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 15, 2010
Return After Taxes on Distributions & Sale of Fund Shares | Loomis Sayles Absolute Strategies Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(5.29%)
Life of Fund	rr_AverageAnnualReturnSinceInception	(6.92%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 15, 2010
3-month London Interbank Offered Rate (LIBOR) | Loomis Sayles Absolute Strategies Fund
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	0.27%
Life of Fund	rr_AverageAnnualReturnSinceInception	0.27%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jan. 01, 2011

[1] 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 1.30%, 2.05% and 1.05% of the Fund's average daily net assets for Class A, C and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 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 1.30%, 2.05% and 1.05% of the Fund's average daily net assets for Class A, C and Y shares, respectively. 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.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	Natixis Funds Trust II
Prospectus Date	rr_ProspectusDate	May 01, 2012
Vaughan Nelson Value Opportunity Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Vaughan Nelson Value Opportunity Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Goal
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks long-term capital appreciation.
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 and hold shares of the Fund. 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 Fund 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 90 of the Prospectus and on page 122 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	April 30, 2013
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 75% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	75.00%
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 Fund Complex.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	50,000
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods (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. 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	The Fund, under normal market conditions, will invest primarily in companies that, at the time of purchase, have market capitalizations either within the capitalization range of the Russell Midcap Value Index, an unmanaged index that measures the performance of companies with lower price-to-book ratios and lower forecasted growth values within the broader Russell Midcap Index, or of $15 billion or less. While the market capitalization range for the Russell Midcap Value Index fluctuates, at March 31, 2012, it was $123.9 million to $22.8 billion. However, the Fund does not have any market capitalization limits and may invest in companies with smaller or larger capitalizations. Equity securities may take the form of stock in corporations, limited partnership interests, interests in limited liability companies, REITs or other trusts and similar securities. Vaughan Nelson Investment Management, L.P. (“Vaughan Nelson”) invests in medium-capitalization companies with a focus on absolute return. Vaughan Nelson uses a bottom-up value oriented investment process in constructing the Fund’s portfolio. Vaughan Nelson seeks companies with the following characteristics, although not all of the companies selected will have these attributes: Companies earning a positive economic margin with stable-to-improving returns. Companies valued at a discount to their asset value. Companies with an attractive and sustainable dividend level. In selecting investments for the Fund, Vaughan Nelson generally employs the following strategies: Vaughan Nelson employs a value-driven investment philosophy that selects stocks selling at a relatively low value based on business fundamentals, economic margin analysis and discounted cash flow models. Vaughan Nelson selects companies that it believes are out of favor or misunderstood. Vaughan Nelson narrows the investment universe by using value-driven screens to create a research universe of companies with market capitalizations between $1 billion and $20 billion. Vaughan Nelson uses fundamental analysis to construct a portfolio that it believes has attractive return potential. Vaughan Nelson will generally sell a stock when it reaches Vaughan Nelson’s price target or when the issuer shows a deteriorating financial condition due to increased competitive pressures or internal or external forces reducing future expected returns. The Fund may also: Invest in convertible preferred stock and convertible debt securities. Invest in foreign securities, including emerging markets securities. Invest in other investment companies, to the extent permitted by the Investment Company Act of 1940. Invest in real estate investment trusts (“REITs”). Invest in securities offered in initial public offerings (“IPOs”) and Rule 144A securities. Engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund’s returns, and realization of short-term capital gains, distributions of which are taxable to shareholders who are individuals as ordinary income. Trading costs and tax effects associated with frequent trading may adversely affect the Fund’s performance.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund. Emerging Markets Risk: Investing in emerging markets companies, which may be smaller and have shorter operating histories than companies in developed markets, involves risks in addition to, and greater than, those generally associated with investing in companies in developed foreign markets. The extent of economic development, political stability, market depth, infrastructure, capitalization and regulatory oversight in emerging market economies is generally less than in more developed markets. 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. Securities issued in IPOs tend to involve greater market risk than other equity securities due, in part, to public perception and the lack of publicly available information and trading history. Rule Fund Summary 144A securities may be less liquid than other equity securities. Value stocks can perform differently from the market as a whole and from other types of stocks. Value stocks also present the risk that their lower valuations fairly reflect their business prospects and that investors will not agree that the stocks represent favorable investment opportunities, and they may fall out of favor with investors and underperform growth stocks during any given period. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer’s bonds and preferred stock generally take precedence over the claims of those who own common stock. Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund’s investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity. Investments in Other Investment Companies Risk: The Fund will indirectly bear the management, service and other fees of any other investment companies in which it invests in addition to its own expenses. 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 can affect the performance of the Fund, may increase realized capital gains, may accelerate the realization of taxable income to shareholders and may increase transaction costs. 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. Management Risk: A strategy used by the Fund’s portfolio managers may fail to produce the intended result. Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer’s financial condition, as well as overall market and economic conditions. 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.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose money by investing in the Fund.
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 the changes in the Fund’s performance from year-to-year and by showing how the Fund’s average annual returns for the one-year and life-of-fund periods compare to those of a broad measure of market performance. 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 ngam.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.
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 how the Fund's average annual returns for the one-year and life-of-fund periods compare to those of a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-225-5478
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	ngam.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 A 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 Return: Third Quarter 2009, 21.30% Lowest Quarterly Return: Third Quarter 2011, -21.15%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
Index No Deduction for Fees, Expenses, Taxes [Text]	rr_IndexNoDeductionForFeesExpensesTaxes	Index performance returns reflect 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 deferred 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 class of the Fund will vary.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The Return After Taxes on Distributions & Sale of Fund Shares for the 1-year period exceeds the Return Before Taxes due to an assumed tax benefit from tax losses on a sale of Fund shares at the end of the measurement period.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	Prior to May 1, 2012, Class Y shares were offered in a separate prospectus and given that Class Y shares are now offered in this multi-class prospectus, Total Returns, Return After Taxes on Distributions and Return After Taxes on Distributions & Sale of Fund Shares are now presented for Class A 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 deferred 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 class of the Fund will vary. Index performance reflects no deduction for fees, expenses or taxes. The Return After Taxes on Distributions & Sale of Fund Shares for the 1-year period exceeds the Return Before Taxes due to an assumed tax benefit from tax losses on a sale of Fund shares at the end of the measurement period.
Vaughan Nelson Value Opportunity 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
Redemption fees	rr_RedemptionFeeOverRedemption	none
Management fees	rr_ManagementFeesOverAssets	0.80%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses-Fee/expense recovery	rr_Component1OtherExpensesOverAssets	0.01%	[1]
Other expenses-Remainder of other expenses	rr_Component2OtherExpensesOverAssets	0.34%
Total other expenses	rr_OtherExpensesOverAssets	0.35%
Acquired fund fess and expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.16%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.56%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.56%
1 year	rr_ExpenseExampleYear01	725
3 years	rr_ExpenseExampleYear03	1,039
5 years	rr_ExpenseExampleYear05	1,376
10 years	rr_ExpenseExampleYear10	2,325
2009	rr_AnnualReturn2009	30.98%
2010	rr_AnnualReturn2010	19.64%
2011	rr_AnnualReturn2011	(2.71%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	21.30%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(21.15%)
Past 1 Year	rr_AverageAnnualReturnYear01	(8.30%)
Life of Fund	rr_AverageAnnualReturnSinceInception	10.78%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 31, 2008
Vaughan Nelson Value Opportunity 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	0.80%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses-Fee/expense recovery	rr_Component1OtherExpensesOverAssets	0.01%	[1]
Other expenses-Remainder of other expenses	rr_Component2OtherExpensesOverAssets	0.34%
Total other expenses	rr_OtherExpensesOverAssets	0.35%
Acquired fund fess and expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.16%
Total annual fund operating expenses	rr_ExpensesOverAssets	2.31%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	2.31%
1 year	rr_ExpenseExampleYear01	334
3 years	rr_ExpenseExampleYear03	721
5 years	rr_ExpenseExampleYear05	1,235
10 years	rr_ExpenseExampleYear10	2,646
1 year	rr_ExpenseExampleNoRedemptionYear01	234
3 years	rr_ExpenseExampleNoRedemptionYear03	721
5 years	rr_ExpenseExampleNoRedemptionYear05	1,235
10 years	rr_ExpenseExampleNoRedemptionYear10	2,646
Past 1 Year	rr_AverageAnnualReturnYear01	(4.41%)
Life of Fund	rr_AverageAnnualReturnSinceInception	12.04%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 31, 2008
Vaughan Nelson Value Opportunity 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	0.80%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses-Fee/expense recovery	rr_Component1OtherExpensesOverAssets	0.01%	[1]
Other expenses-Remainder of other expenses	rr_Component2OtherExpensesOverAssets	0.34%
Total other expenses	rr_OtherExpensesOverAssets	0.35%
Acquired fund fess and expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.16%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.31%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.31%
1 year	rr_ExpenseExampleYear01	133
3 years	rr_ExpenseExampleYear03	415
5 years	rr_ExpenseExampleYear05	718
10 years	rr_ExpenseExampleYear10	1,579
Past 1 Year	rr_AverageAnnualReturnYear01	(2.53%)
Life of Fund	rr_AverageAnnualReturnSinceInception	13.14%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 31, 2008
Return After Taxes on Distributions | Vaughan Nelson Value Opportunity Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(8.91%)
Life of Fund	rr_AverageAnnualReturnSinceInception	10.38%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 31, 2008
Return After Taxes on Distributions & Sale of Fund Shares | Vaughan Nelson Value Opportunity Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(4.81%)
Life of Fund	rr_AverageAnnualReturnSinceInception	9.18%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 31, 2008
Russell Midcap Value Index | Vaughan Nelson Value Opportunity Fund
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(1.38%)
Life of Fund	rr_AverageAnnualReturnSinceInception	14.99%
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 31, 2008

[1] The Fund's investment adviser has given a binding contractual undertaking to the Fund to limit the amount of the Fund's total annual fund operating expenses to 1.40%, 2.15% and 1.15% of the Fund's average daily net assets for Class A, Class C and Class Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 and may be terminated before then only with the consent of the Fund's Board of Trustees. The Fund's investment 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 1.40%, 2.15% and 1.15% of the Fund's average daily net assets for Class A, Class C and Class Y shares, respectively. 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.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	Natixis Funds Trust II
Prospectus Date	rr_ProspectusDate	May 01, 2012
ASG Managed Futures Strategy Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	ASG Managed Futures Strategy Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Goal
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund pursues an absolute return strategy that seeks to provide capital appreciation.
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 and hold shares of the Fund. 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 Fund 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 70 of the Prospectus and on page 103 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	April 30, 2013
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. Due to the short-term nature of the Fund’s investment portfolio, the Fund does not calculate a portfolio turnover rate.
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 Fund Complex.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	50,000
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	(restated to reflect current expenses)
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 example is based on Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and on the Total Annual Fund Operating Expenses for the remaining years. 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	The Fund seeks to generate positive absolute returns over time. Under normal market conditions, AlphaSimplex typically will make extensive use of a variety of derivative instruments, including futures and forward contracts, to capture the exposures suggested by its absolute return strategy while also seeking to add value through volatility management. These market exposures, which are expected to change over time, may include, for example, exposures to the returns of U.S. and non-U.S. equity and fixed income securities indices (including both broad- and narrow-based securities indices), currencies and commodities. AlphaSimplex uses proprietary quantitative models to identify price trends in equity, fixed income, currency and commodity instruments across time periods of various lengths. AlphaSimplex believes that asset prices may show persistent trending behavior due to a number of behavioral biases among market participants as well as certain risk-management policies that will identify assets to purchase in upward-trending markets and identify assets to sell in downward-trending markets. AlphaSimplex believes that following trends across a widely diversified set of assets, combined with active risk management, may allow it to earn a positive expected return over time. The Fund may have both “short” and “long” exposures within an asset class based upon AlphaSimplex’s analysis of multiple time horizons to identify trends in a particular asset class. A “short”exposure will benefit when the underlying asset class decreases in price. A “long” exposure will benefit when the underlying asset class increases in price. AlphaSimplex will scale the notional exposure of the Fund’s futures and currency forward positions with the objective of targeting a relatively stable level of annualized volatility for the Fund’s overall portfolio. AlphaSimplex will have great flexibility to allocate the Fund’s derivatives exposure among various securities, indices, currencies, commodities and other instruments; the amount of the Fund’s assets that may be allocated to derivative strategies and among these various instruments is expected to vary over time. Under normal market conditions, it is expected that no more than 25% of the Fund’s total assets will be dedicated to initial and variation margin payments relating to the Fund’s derivative transactions. The gross notional value of the Fund’s derivative investments, however, will generally exceed 25% of the Fund’s total assets, and may significantly exceed the total value of the Fund’s assets. The Fund expects that under normal market conditions it will invest at least 75% of its total assets in money market and other short-term, high quality securities (such as bankers’ acceptances, certificates of deposit, commercial paper, loan participations, repurchase agreements and time deposits) (the “Money Market Portion”) managed by Reich & Tang Asset Management, LLC (“Reich & Tang”), although the Fund may invest less than this percentage. The Adviser will determine the percentage of the Fund’s assets that will be invested in the Money Market Portion at any time. The assets allocated to the Money Market Portion will be used primarily to support the Fund’s investments in derivatives and, secondarily, to provide the Fund with incremental income and liquidity. Although the Fund will invest a significant portion of its assets in money market instruments, the Fund is not a “money market” fund and the value of the Money Market Portion as well as the value of the Fund’s shares may decrease. The Fund is not subject to the portfolio quality, maturity and net asset value requirements applicable to money market funds, and the Fund will not seek to maintain a stable net asset value. The Fund will concentrate its investments in the financial services industry, which means it will normally invest at least 25% of its total assets in securities and other obligations (for example, bank certificates of deposit, repurchase agreements and time deposits) of issuers in such industry. Reich &Tang will only invest the assets of the Money Market Portion in high quality securities which are denominated in U.S. dollars, and will select securities for investment based on various factors, including the security’s maturity and rating. Reich &Tang will invest primarily in (i) short-term obligations issued or guaranteed by the United States government, its agencies or instrumentalities (“U.S. Government Obligations”); (ii) securities issued by foreign governments, their political subdivisions, agencies or instrumentalities; (iii) certificates of deposit, time deposits and bankers’ acceptances issued by domestic banks, foreign branches of domestic banks, foreign subsidiaries of domestic banks and domestic and foreign branches of foreign banks; (iv) variable amount master demand notes; (v) participation interests in loans extended by banks to companies; (vi) commercial paper or similar debt obligations; and (vii) repurchase agreements. Although the Fund does not intend to invest in physical commodities directly, the Fund expects to obtain investment exposure to commodities and commodity-related derivatives by investing in a wholly-owned subsidiary organized under the laws of the Cayman Islands that will make commodity-related investments (the “Commodity Subsidiary”). Under normal market conditions, no more than 10% of the Fund’s total assets will be dedicated to initial and variation margin payments relating to these transactions. Although the Fund seeks positive absolute returns over time, it is likely that the Fund’s investment returns may be volatile over short periods of time. The Fund may outperform the overall securities market during periods of flat or negative market performance and may underperform during periods of strong market performance. There can be no assurance that the Fund’s returns over time or during any period will be positive or that the Fund will outperform the overall security markets over time or during any particular period. The Fund may engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund’s return, and realization of greater short-term capital gains, distributions of which are taxable as ordinary income to taxable shareholders. Trading costs and tax effects associated with frequent trading may adversely affect the Fund’s performance. Due to the short-term nature of the Fund’s investment portfolio, the Fund does not calculate a portfolio turnover rate. The Fund’s trading in derivatives is active and frequent. Active and frequent trading of derivatives, like active and frequent trading of securities, will result in transaction costs which reduce fund returns. The percentage limitations set forth herein are not investment restrictions and the Fund may exceed these limits from time to time.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund. Commodity Risk: This is the risk that exposure to the commodities markets may subject the Fund to greater volatility than investments in traditional securities. The value of physical commodities or commodity-linked derivative instruments may be affected by changes in overall market movements, commodity price volatility, changes in interest rates, currency fluctuations, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. Recent rulemaking by the Commodity Futures Trading Commission (“CFTC”) may affect the Fund’s ability to pursue its investment strategies or increase the Fund’s expenses. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Commodity Subsidiary Risk: Investing in the Commodity Subsidiary will indirectly expose the Fund to the risks associated with the Commodity Subsidiary’s investments, such as commodity investment risk. The Commodity Subsidiary is not registered under the Investment Company Act of 1940 (the “1940 Act”) and is not subject to all of the investor protections of the 1940 Act. Recent rulemaking by the CFTC may affect the Fund’s ability to use the Commodity Subsidiary to pursue its investment strategies. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Changes in the laws of the United States and/or the Cayman Islands, under which the Fund and the Commodity Subsidiary, respectively, are organized, could negatively affect the Fund and its shareholders. Concentrated Investment Risk: The Fund is particularly vulnerable to events affecting companies in the financial services industry because the Fund concentrates its investments in securities and other obligations of issuers in such industry. Examples of risks affecting the financial services industry include changes in governmental regulation, issues relating to the availability and cost of capital, changes in interest rates and/or monetary policy and price competition. In addition, financial services companies are often more highly leveraged than other companies, making them inherently riskier. As a result, the Fund’s shares may rise and fall in value more rapidly and to a greater extent than shares of a fund that does not concentrate or focus in a particular industry or economic sector. The financial services industry has recently experienced high volatility and a number of issuer failures and the value of many of these securities has significantly declined. As a result, the risk associated with investing in the Fund may be increased as compared to a fund that does not concentrate in the financial services industry. Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with over-the-counter (“OTC”) derivative transactions, such as foreign currency transactions. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its direct counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains. Currency Risk: Fluctuations in the exchange rates between different currencies may negatively affect an investment. 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. Derivatives Risk: Derivatives are subject to changes in the value of the underlying asset or indices on which such transactions 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 markets 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 which would have occurred had derivatives not been used. The Fund’s use of derivatives, such as futures, forward contracts, and other foreign currency transactions and commodity-linked derivatives involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward 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 perfectly with relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, a number of broker-dealers and other financial institutions have recently experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. There can be no assurance that the Fund’s derivative counterparties will be able to avoid experiencing similar financial difficulties, possibly resulting in losses to the Fund. 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. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer’s bonds and preferred stock generally take precedence over the claims of those who own common stock. Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund’s investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity. Interest Rate Risk: Changes in interest rates may cause the value of the Fund’s investments to decrease. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. A period of low interest rates may cause the Fund to have a low or negative yield, potentially reducing the value of your investment. Issuer Risk: The value of the Fund’s investments may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods and services. 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 can affect the performance of the Fund, may increase realized capital gains, may accelerate the realization of taxable income to shareholders and may increase transaction costs. 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. Leverage Risk: Use of derivative instruments may involve leverage. Leverage is the risk associated with securities or practices that multiply small index, market or asset price movements into larger changes in value. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. The use of leverage increases the impact of gains and losses on a fund’s returns, and may lead to significant losses if investments are not successful. However, the Adviser will attempt to ensure that at all times the Fund has sufficient liquid assets to enable it to satisfy its obligations under its derivative contracts. Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell, possibly preventing the Fund from selling these illiquid securities at an advantageous price or time. A lack of liquidity also may cause the value of investments to decline. Illiquid investments also may be difficult to value. Management Risk: A strategy used by the Fund’s portfolio managers may fail to produce the intended result. The Adviser utilizes various proprietary quantitative models to identify investment opportunities. There is a possibility that one or all of the quantitative models may fail to identify profitable opportunities at any time. Furthermore, they may incorrectly identify opportunities and these misidentified opportunities may lead to substantial losses. Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer’s financial condition, as well as overall market and economic conditions. The Fund’s portfolio managers will attempt to reduce this risk by implementing various volatility management strategies and techniques. However, there is no guarantee that such strategies and techniques will produce the intended result. U.S. Government Securities Risk: Investments in certain U.S. government securities may not be supported by the full faith and credit of the U.S. government. Accordingly, no assurance can be given that the U.S. government will provide financial support to U.S. government agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. The maximum potential liability of the issuers of some U.S. government securities held by the Fund may greatly exceed their current resources, and it is possible that these issuers will not have the funds to meet their payment obligations in the future. In such a case, the Fund would have to look principally to the agency, instrumentality or sponsored enterprise issuing or guaranteeing the security for ultimate repayment, and the Fund may not be able to assert a claim against the U.S. government itself in the event the agency, instrumentality or sponsored enterprise does not meet its commitment. Concerns about the capacity of the U.S. government to meet its obligations may raise the interest rates payable on its securities, negatively impacting the price of such securities already held by the Fund. Valuation Risk: This is the risk that the Fund has valued certain securities at a higher price than the price at which they can be sold. This risk may be especially pronounced for investments, such as derivatives that may be illiquid or may become illiquid.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose money by investing in the Fund.
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 the Fund’s performance in the first full year and by showing how the Fund’s average annual returns for the one-year and life-of-Fund periods compare to those of a broad measure of market performance. 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 ngam.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.
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 the Fund’s performance in the first full year and by showing how the Fund’s average annual returns for the one-year and life-of-Fund periods compare to those of a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-225-5478
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	ngam.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 A 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 Return: First Quarter 2011,1.79% Lowest Quarterly Return: Fourth Quarterly 2011, -1.69%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
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 Fund shares through tax-deferred 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 Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	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 Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.
ASG Managed Futures Strategy 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
Redemption fees	rr_RedemptionFeeOverRedemption	none
Management fees	rr_ManagementFeesOverAssets	1.25%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.27%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.77%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.06%	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.71%
1 year	rr_ExpenseExampleYear01	739
3 years	rr_ExpenseExampleYear03	1,095
5 years	rr_ExpenseExampleYear05	1,474
10 years	rr_ExpenseExampleYear10	2,534
2011	rr_AnnualReturn2011	0.25%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Mar. 31, 2011
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	1.79%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(1.69%)
Past 1 Year	rr_AverageAnnualReturnYear01	(5.53%)
Life of Fund	rr_AverageAnnualReturnSinceInception	5.00%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 30, 2010
ASG Managed Futures Strategy 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	1.25%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	0.30%
Total annual fund operating expenses	rr_ExpensesOverAssets	2.55%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.09%	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	2.46%
1 year	rr_ExpenseExampleYear01	349
3 years	rr_ExpenseExampleYear03	785
5 years	rr_ExpenseExampleYear05	1,347
10 years	rr_ExpenseExampleYear10	2,879
1 year	rr_ExpenseExampleNoRedemptionYear01	249
3 years	rr_ExpenseExampleNoRedemptionYear03	785
5 years	rr_ExpenseExampleNoRedemptionYear05	1,347
Expense Example, No Redemption, 10 Years	rr_ExpenseExampleNoRedemptionYear10	2,879
Past 1 Year	rr_AverageAnnualReturnYear01	(1.48%)
Life of Fund	rr_AverageAnnualReturnSinceInception	8.61%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 30, 2010
ASG Managed Futures Strategy 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	1.25%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.32%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.57%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.11%	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.46%
1 year	rr_ExpenseExampleYear01	149
3 years	rr_ExpenseExampleYear03	485
5 years	rr_ExpenseExampleYear05	845
10 years	rr_ExpenseExampleYear10	1,858
Past 1 Year	rr_AverageAnnualReturnYear01	0.57%
Life of Fund	rr_AverageAnnualReturnSinceInception	9.68%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 30, 2010
Return After Taxes on Distributions | ASG Managed Futures Strategy Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(6.46%)
Life of Fund	rr_AverageAnnualReturnSinceInception	2.83%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 30, 2010
Return After Taxes on Distributions & Sale of Fund Shares | ASG Managed Futures Strategy Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(3.60%)
Life of Fund	rr_AverageAnnualReturnSinceInception	3.12%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 30, 2010
FTSE StableRisk Trend Composite Index (Calculated from August 1, 2010) | ASG Managed Futures Strategy Fund
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	2.12%
Life of Fund	rr_AverageAnnualReturnSinceInception	16.01%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 30, 2010

[1] AlphaSimplex Group, LLC ("AlphaSimplex" 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 1.70%, 2.45% and 1.45% of the Fund's average daily net assets for Class A, C and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 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 1.70%, 2.45% and 1.45% of the Fund's average daily net assets for Class A, C and Y shares, respectively. 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 fee/expense was waived/reimbursed.

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Vaughan Nelson Value Opportunity Fund

Vaughan Nelson Value Opportunity Fund

Investment Goal

The Fund seeks long-term capital appreciation.

Fund Fees & Expenses

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 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 Fund 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 90 of the Prospectus and on page 122 in the section "Reduced Sales Charges" of the Statement of Additional Information ("SAI").

Shareholder Fees(fees paid directly from your investment)

Shareholder Fees Vaughan Nelson Value Opportunity Fund	Class A	Class C	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%	none	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	none	1.00%	none
Redemption fees	none	none	none

Annual Fund Operating Expenses(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Vaughan Nelson Value Opportunity Fund		Class A	Class C	Class Y
Management fees		0.80%	0.80%	0.80%
Distribution and/or service (12b-1) fees		0.25%	1.00%	none
Other expenses-Fee/expense recovery	[1]	0.01%	0.01%	0.01%
Other expenses-Remainder of other expenses		0.34%	0.34%	0.34%
Total other expenses		0.35%	0.35%	0.35%
Acquired fund fess and expenses		0.16%	0.16%	0.16%
Total annual fund operating expenses		1.56%	2.31%	1.31%
Fee waiver and/or expense reimbursement	[1]	none	none	none
Total annual fund operating expenses after fee waiver and/or expense reimbursement		1.56%	2.31%	1.31%

Example

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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

If shares are redeemed

Expense Example Vaughan Nelson Value Opportunity Fund (USD $)	1 year	3 years	5 years	10 years
Class A	725	1,039	1,376	2,325
Class C	334	721	1,235	2,646
Class Y	133	415	718	1,579

If shares are not redeemed

Expense Example, No Redemption (USD $)	1 year	3 years	5 years	10 years
Vaughan Nelson Value Opportunity Fund Class C	234	721	1,235	2,646

Portfolio Turnover

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 75% of the average value of its portfolio.

Investments, Risks and Performance Principal Investment Strategies

The Fund, under normal market conditions, will invest primarily in companies that, at the time of purchase, have market capitalizations either within the capitalization range of the Russell Midcap Value Index, an unmanaged index that measures the performance of companies with lower price-to-book ratios and lower forecasted growth values within the broader Russell Midcap Index, or of $15 billion or less. While the market capitalization range for the Russell Midcap Value Index fluctuates, at March 31, 2012, it was $123.9 million to $22.8 billion. However, the Fund does not have any market capitalization limits and may invest in companies with smaller or larger capitalizations. Equity securities may take the form of stock in corporations, limited partnership interests, interests in limited liability companies, REITs or other trusts and similar securities.

Vaughan Nelson Investment Management, L.P. (“Vaughan Nelson”) invests in medium-capitalization companies with a focus on absolute return. Vaughan Nelson uses a bottom-up value oriented investment process in constructing the Fund’s portfolio. Vaughan Nelson seeks companies with the following characteristics, although not all of the companies selected will have these attributes:

• Companies earning a positive economic margin with stable-to-improving returns.
• Companies valued at a discount to their asset value.
• Companies with an attractive and sustainable dividend level.

In selecting investments for the Fund, Vaughan Nelson generally employs the following strategies:

• Vaughan Nelson employs a value-driven investment philosophy that selects stocks selling at a relatively low value based on business fundamentals, economic margin analysis and discounted cash flow models. Vaughan Nelson selects companies that it believes are out of favor or misunderstood.
• Vaughan Nelson narrows the investment universe by using value-driven screens to create a research universe of companies with market capitalizations between $1 billion and $20 billion.
• Vaughan Nelson uses fundamental analysis to construct a portfolio that it believes has attractive return potential.
• Vaughan Nelson will generally sell a stock when it reaches Vaughan Nelson’s price target or when the issuer shows a deteriorating financial condition due to increased competitive pressures or internal or external forces reducing future expected returns.

The Fund may also:

• Invest in convertible preferred stock and convertible debt securities.
• Invest in foreign securities, including emerging markets securities.
• Invest in other investment companies, to the extent permitted by the Investment Company Act of 1940.
• Invest in real estate investment trusts (“REITs”).
• Invest in securities offered in initial public offerings (“IPOs”) and Rule 144A securities.
• Engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund’s returns, and realization of short-term capital gains, distributions of which are taxable to shareholders who are individuals as ordinary income. Trading costs and tax effects associated with frequent trading may adversely affect the Fund’s performance.

Principal Risks

The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund.

Emerging Markets Risk: Investing in emerging markets companies, which may be smaller and have shorter operating histories than companies in developed markets, involves risks in addition to, and greater than, those generally associated with investing in companies in developed foreign markets. The extent of economic development, political stability, market depth, infrastructure, capitalization and regulatory oversight in emerging market economies is generally less than in more developed markets.

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. Securities issued in IPOs tend to involve greater market risk than other equity securities due, in part, to public perception and the lack of publicly available information and trading history. Rule Fund Summary 144A securities may be less liquid than other equity securities. Value stocks can perform differently from the market as a whole and from other types of stocks. Value stocks also present the risk that their lower valuations fairly reflect their business prospects and that investors will not agree that the stocks represent favorable investment opportunities, and they may fall out of favor with investors and underperform growth stocks during any given period. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer’s bonds and preferred stock generally take precedence over the claims of those who own common stock.

Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund’s investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity.

Investments in Other Investment Companies Risk: The Fund will indirectly bear the management, service and other fees of any other investment companies in which it invests in addition to its own expenses.

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 can affect the performance of the Fund, may increase realized capital gains, may accelerate the realization of taxable income to shareholders and may increase transaction costs. 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.

Management Risk: A strategy used by the Fund’s portfolio managers may fail to produce the intended result.

Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer’s financial condition, as well as overall market and economic conditions.

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.

Risk/Return Bar Chart and Table

The bar chart and table shown below provide some indication of the risks of investing in the Fund by showing the changes in the Fund’s performance from year-to-year and by showing how the Fund’s average annual returns for the one-year and life-of-fund periods compare to those of a broad measure of market performance. 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 ngam.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.

Total Returns for Class A Shares

Highest Quarterly Return:
Third Quarter 2009, 21.30%

Lowest Quarterly Return:
Third Quarter 2011, -21.15%

Average Annual Total Returns
(for the periods ended December 31, 2011)

Average Annual Total Returns Vaughan Nelson Value Opportunity Fund	Past 1 Year	Life of Fund	Inception Date
Class A	(8.30%)	10.78%	Oct. 31, 2008
Class C	(4.41%)	12.04%	Oct. 31, 2008
Class Y	(2.53%)	13.14%	Oct. 31, 2008
Return After Taxes on Distributions Class A	(8.91%)	10.38%	Oct. 31, 2008
Return After Taxes on Distributions & Sale of Fund Shares Class A	(4.81%)	9.18%	Oct. 31, 2008
Russell Midcap Value Index	(1.38%)	14.99%	Oct. 31, 2008

Prior to May 1, 2012, Class Y shares were offered in a separate prospectus and given that Class Y shares are now offered in this multi-class prospectus, Total Returns, Return After Taxes on Distributions and Return After Taxes on Distributions & Sale of Fund Shares are now presented for Class A 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 deferred 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 class of the Fund will vary. Index performance reflects no deduction for fees, expenses or taxes. The Return After Taxes on Distributions & Sale of Fund Shares for the 1-year period exceeds the Return Before Taxes due to an assumed tax benefit from tax losses on a sale of Fund shares at the end of the measurement period.

[1] The Fund's investment adviser has given a binding contractual undertaking to the Fund to limit the amount of the Fund's total annual fund operating expenses to 1.40%, 2.15% and 1.15% of the Fund's average daily net assets for Class A, Class C and Class Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 and may be terminated before then only with the consent of the Fund's Board of Trustees. The Fund's investment 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 1.40%, 2.15% and 1.15% of the Fund's average daily net assets for Class A, Class C and Class Y shares, respectively. 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.

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Harris Associates Large Cap Value Fund

Harris Associates Large Cap Value Fund

Investment Goal

The Fund seeks opportunities for long-term capital growth and income.

Fund Fees & Expenses

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 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 Fund 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 90 of the Prospectus and on page 122 in the section “Reduced Sales Charges” of the Statement of Additional Information (“SAI”).

Shareholder Fees(fees paid directly from your investment)

Shareholder Fees Harris Associates Large Cap Value Fund	Class A	Class B	Class C	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%	none	none	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	none	5.00%	1.00%	none
Redemption fees	none	none	none	none

Annual Fund Operating Expenses(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Harris Associates Large Cap Value Fund		Class A	Class B	Class C	Class Y
Management fees		0.70%	0.70%	0.70%	0.70%
Distribution and/or service (12b-1) fees		0.25%	1.00%	1.00%	none
Other expenses-Fee/expense recovery	[1]	0.01%	0.01%	0.01%	0.01%
Other expenses-Remainder of other expenses		0.34%	0.34%	0.34%	0.34%
Total other expenses		0.35%	0.35%	0.35%	0.35%
Total annual fund operating expenses		1.30%	2.05%	2.05%	1.05%
Fee waiver and/or expense reimbursement	[1]	none	none	none	none
Total annual fund operating expenses after fee waiver and/or expense reimbursement		1.30%	2.05%	2.05%	1.05%

Example

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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

If shares are redeemed:

Expense Example Harris Associates Large Cap Value Fund (USD $)	1 year	3 years	5 years	10 years
Class A	700	963	1,247	2,053
Class B	708	943	1,303	2,187
Class C	308	643	1,103	2,379
Class Y	107	334	579	1,283

If shares are not redeemed:

Expense Example, No Redemption Harris Associates Large Cap Value Fund (USD $)	1 year	3 years	5 years	10 years
Class B	208	643	1,103	2,187
Class C	208	643	1,103	2,379

Portfolio Turnover

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 36% of the average value of its portfolio.

Investments, Risks and Performance Principal Investment Strategies

Under normal market conditions, the Fund will invest substantially all of its assets in common stock of large- and mid-capitalization companies in any industry. The Fund will invest at least 80% of its net assets (plus any borrowings made for investment purposes) in companies that have market capitalizations within the capitalization range of the Russell 1000 Index, a nationally recognized index of large-capitalization companies. While the market capitalization range for this index fluctuates, at March 31, 2012, it was $124 million to $557 billion.

Harris Associates L.P. (“Harris Associates”) uses a value investment philosophy in selecting equity securities, including common stocks. This philosophy is based upon the belief that, over time, a company's stock price converges with the company's true business value. By “true business value,” Harris Associates means its estimate of the price a knowledgeable buyer would pay to acquire the entire business. Harris Associates believes that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objectives. Harris Associates usually sells a stock when the price approaches its estimated worth or the company's fundamentals change.

Harris Associates uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, Harris Associates looks for the following characteristics, although not all of the companies selected will have these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of manager ownership.

Once Harris Associates determines that a security is selling at what it believes to be a significant discount and that the issuer has the additional qualities mentioned above, Harris Associates generally will consider buying that security for the Fund. Harris Associates usually sells a security when the price approaches its estimated worth. Harris Associates also monitors each holding and adjusts those price targets as warranted to reflect changes in the issuer's fundamentals. The Fund's portfolio typically holds 30 to 60 stocks.

The Fund may also invest in foreign securities traded in U.S. markets (through depositary receipt programs such as American Depositary Receipts (“ADRs”) or non-U.S. stocks traded in U.S. markets). ADRs are securities issued by a U.S. bank that represent shares of a foreign company.

The Fund may also engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund's returns, and realization of short-term capital gains, distributions of which are taxable to shareholders who are individuals as ordinary income. Trading costs and tax effects associated with frequent trading may adversely affect the Fund's performance.

Principal Risks

The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund.

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. Value stocks can perform differently from the market as a whole and from other types of stocks. Value stocks also present the risk that their lower valuations fairly reflect their business prospects and that investors will not agree that the stocks represent favorable investment opportunities, and they may fall out of favor with investors and underperform growth stocks during any given period. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer's bonds and preferred stock generally take precedence over the claims of those who own common stock.

Focused Investment Risk: Because the Fund may invest in a small number of industries or securities, it may have more risk because the impact of a single economic, political or regulatory occurrence may have a greater adverse impact on the Fund's net asset value.

Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund's investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity.

Management Risk: A strategy used by the Fund's portfolio managers may fail to produce the intended result.

Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer's financial condition, as well as overall market and economic conditions.

Risk/Return Bar Chart and Table Shares

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 measure of market performance. 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 ngam.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.

Total Returns for Class A Shares

Highest Quarterly Return:
Second Quarter 2009, 24.17%

Lowest Quarterly Return:
Fourth Quarter 2008, -27.03%

Class B total returns in the table below do not reflect the automatic conversion of Class B shares to Class A shares after eight years.

Average Annual Total Returns
(for the periods ended December 31, 2011)

Average Annual Total Returns Harris Associates Large Cap Value Fund	Past 1 Year	Past 5 Years	Past 10 Years
Class A	(7.20%)	(2.68%)	1.43%
Class B	(7.23%)	(2.64%)	1.26%
Class C	(3.25%)	(2.25%)	1.26%
Class Y	(1.40%)	(1.20%)	2.40%
Return After Taxes on Distributions Class A	(7.28%)	(2.78%)	1.37%
Return After Taxes on Distributions & Sale of Fund Shares Class A	(4.56%)	(2.27%)	1.22%
Russell 1000 Value Index	0.39%	(2.64%)	3.89%

Prior to May 1, 2012, Class Y shares were offered in a separate prospectus and given that Class Y shares are now offered in this multi-class prospectus, Total Returns, Return After Taxes on Distributions and Return After Taxes on Distributions & Sale of Fund Shares are now presented for Class A shares.

The Fund's current subadviser assumed that function on July 1, 2002. The performance results shown above, for the periods prior to July 1, 2002, reflect results achieved by different subadvisers under different investment strategies.

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 Fund shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, 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. The Return After Taxes on Distributions & Sale of Fund Shares for the 1-year and 5-year periods exceeds the Return Before Taxes due to an assumed tax benefit from tax losses on a sale of Fund shares at the end of the measurement period.

[1] The Fund's investment adviser has given a binding contractual undertaking to the Fund to limit the amount of the Fund's total annual fund operating expenses to 1.30%, 2.05%, 2.05% and 1.05% of the Fund's average daily net assets for Class A, Class B, Class C and Class Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 and may be terminated before then only with the consent of the Fund's Board of Trustees. The Fund's investment 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 1.30%, 2.05%, 2.05% and 1.05% of the Fund's average daily net assets for Class A, Class B, Class C and Class Y shares, respectively. 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.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	Natixis Funds Trust II
Prospectus Date	rr_ProspectusDate	May 01, 2012
ASG Diversifying Strategies Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	ASG Diversifying Strategies Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Goal
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund pursues an absolute return strategy that seeks to provide capital appreciation.
Objective, Secondary [Text Block]	rr_ObjectiveSecondaryTextBlock	The secondary goal of the Fund is to achieve these returns while maintaining a low or negative correlation over time with the returns of major equity indices.
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 and hold shares of the Fund. 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 Fund 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 70 of the Prospectus and on page 103 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	April 30, 2013
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. Due to the short-term nature of the Fund’s investment portfolio, the Fund does not calculate a portfolio turnover rate.
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 example is based on Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and on the Total Annual Fund Operating Expenses for the remaining years. 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	The Fund seeks to generate positive absolute returns over time rather than track the performance of any particular index. In selecting investments for the Fund, the Adviser uses multiple quantitative investment models and strategies (for example, relative value fixed income strategies and multi-market trend strategies) each of which has an absolute return objective. Each model and strategy may involve a broad range of market exposures. These models may include, for example, models that base investment decisions on fixed income spreads and models which seek to identify trends across various asset classes. The Adviser uses quantitative and qualitative judgments in the determination of weighting among the models and strategies. Although the Fund seeks positive absolute returns over time, it is likely that the Fund's investment returns may be volatile over short periods of time. The Fund may outperform the overall securities market during periods of flat or negative market performance and may underperform during periods of strong market performance. There can be no assurance that the Fund's returns over time or during any period will be positive or that the Fund will outperform the overall security markets over time or during any particular period. Under normal market conditions, the Adviser typically will make extensive use of a variety of derivative instruments, in particular futures and forward contracts, to capture the exposures suggested by its absolute return strategies while also adding value through volatility management and correlation management. These market exposures, which are expected to change over time, may include, for example, exposures to the returns of equity and fixed income securities, currencies and commodities. The Adviser will scale the notional exposure of the Fund's futures and currency forward positions with the objective of targeting a relatively stable level of annualized volatility for the Fund's overall portfolio. The Adviser may also use exchange-traded futures contracts on broad U.S. or international equity indices to decrease any undesired correlation with the returns of the major equity indices. The Adviser will have great flexibility to allocate the Fund's derivatives exposure among various securities, indices, currencies, commodities and other instruments; the amount of the Fund's assets that may be allocated to derivative strategies and among these various instruments is expected to vary over time. When buying and selling securities and other instruments for the Fund, and in determining the amount of assets to be allocated to the Money Market Portion (as defined below), the Adviser will also consider the following factors: (i) the Fund's obligations under its various derivative positions; (ii) redemption requests; (iii) yield management; (iv) credit management and (v) volatility management. The Fund may invest in non-U.S. securities and instruments and securities and instruments traded outside the United States and expects to engage in non-U.S. currency transactions. Under normal market conditions, it is expected that no more than 25% of the Fund's total assets will be dedicated to initial and variation margin payments relating to the Fund's derivative transactions. The gross notional value of the Fund's derivative investments, however, will generally exceed 25% of the Fund's total assets, and may significantly exceed the total value of the Fund's assets. The Fund expects that under normal market conditions it will invest at least 75% of its total assets in money market and other short-term, high quality securities (the "Money Market Portion") managed by Reich & Tang Asset Management, LLC (the "Subadviser"), although the Fund may invest less than this percentage. The Adviser will determine the percentage of the Fund's assets that will be invested in the Money Market Portion at any time. The assetsallocated to the Money Market Portion will be used primarily to support the Fund's investments in derivatives and similar instruments and, secondarily, to provide the Fund with incremental income and liquidity. Although the Fund will invest a significant portion of its assets in money market instruments, the Fund is not a "money market" fund and the value of the Money Market Portion as well as the value of the Fund's shares may decrease. The Fund is not subject to the portfolio quality, maturity and net asset value requirements applicable to money market funds, and the Fund will not seek to maintain a stable net asset value. The Subadviser will only invest the assets of the Money Market Portion in high quality securities which are denominated in U.S. dollars, and will select securities for investment based on various factors, including the security's maturity and rating. The Subadviser will invest primarily in (i) short-term obligations issued or guaranteed by the United States government, its agencies or instrumentalities ("U.S. Government Obligations"); (ii) securities issued by foreign governments, their political subdivisions, agencies or instrumentalities; (iii) certificates of deposit, time deposits and bankers' acceptances issued by domestic banks, foreign branches of domestic banks, foreign subsidiaries of domestic banks, and domestic and foreign branches of foreign banks; (iv) variable amount master demand notes; (v) participation interests in loans extended by banks to companies; (vi) commercial paper or similar debt obligations; and (vii) repurchase agreements. Although the Fund does not intend to invest in physical commodities directly, the Fund expects to obtain investment exposure to commodity-related derivatives through a wholly-owned subsidiary organized under the laws of the Cayman Islands that will make commodity-related investments (the "Commodity Subsidiary"). Under normal market conditions, no more than 10% of the Fund's total assets will be dedicated to initial and variation margin payments relating to these transactions. The Fund will concentrate its investments in the financial services industry, which means it will normally invest at least 25% of its total assets in securities and other obligations (for example, bank certificates of deposit) of issuers in such industry. The Fund may engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund's return, and realization of greater short-term capital gains, distributions of which are taxable as ordinary income to taxable shareholders. Trading costs and tax effects associated with frequent trading may adversely affect the Fund's performance. Due to the short-term nature of the Fund's investment portfolio, the Fund does not calculate a portfolio turnover rate. The Fund's trading in derivatives is active and frequent. Active and frequent trading of derivatives, like active and frequent trading of securities, will result in transaction costs which reduce fund returns. The percentage limitations set forth herein are not investment restrictions and the Fund may exceed these limits from time to time.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund. Allocation and Correlation Risk: This is the risk that the Adviser's judgments about, and allocations between, asset classes and market exposures may adversely affect the Fund's performance. This risk can be increased by the use of derivatives to increase allocations to various market exposures. This is because derivatives can create investment leverage, which will magnify the impact to the Fund of its investment in any underperforming market exposure. Commodity Risk: This is the risk that exposure to the commodities markets may subject the Fund to greater volatility than investments in traditional securities. The value of physical commodities or commodity-linked derivative instruments may be affected by changes in overall market movements, commodity price volatility, changes in interest rates, currency fluctuations, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. Recent rulemaking by the Commodity Futures Trading Commission ("CFTC")may affect the Fund's ability to pursue its investment strategies or increase the Fund's expenses. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Commodity Subsidiary Risk: Investing in the Commodity Subsidiary will indirectly expose the Fund to the risks associated with the Commodity Subsidiary's investments, such as commodity investment risk. The Commodity Subsidiary is not registered under the Investment Company Act of 1940 (the "1940 Act") and is not subject to all of the investor protections of the 1940 Act. Recent rulemaking by the CFTC may affect the Fund&s ability to use the Commodity Subsidiary to pursue its investment strategies. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Changes in the laws of the United States and/or the Cayman Islands, under which the Fund and the Commodity Subsidiary, respectively, are organized, could negatively affect the Fund and its shareholders. Concentrated Investment Risk: The Fund is particularly vulnerable to events affecting companies in the financial services industry because the Fund concentrates its investments in securities and other obligations of issuers in such industry. Examples of risks affecting the financial services industry include changes in governmental regulation, issues relating to the availability and cost of capital, changes in interest rates and/or monetary policy and price competition. In addition, financial services companies are often more highly leveraged than other companies, making them inherently riskier. As a result, the Fund's shares may rise and fall in value more rapidly and to a greater extent than shares of a fund that does not concentrate or focus in a particular industry or economic sector. The financial services industry has recently experienced high volatility and a number of issuer failures and the value of many of these securities has significantly declined. As a result, the risk associated with investing in the Fund may be increased as compared to a fund that does not concentrate in the financial services industry. Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with over-the-counter ("OTC")derivative transactions, such as foreign currency transactions. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its direct counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains. Currency Risk: Fluctuations in the exchange rates between different currencies may negatively affect an investment. 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. Derivatives Risk: Derivatives are subject to changes in the value of the underlying asset or indices on which such transactions 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 markets 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 which would have occurred had derivatives not been used. The Fund's use of derivatives, such as futures, forward contracts, and other foreign currency transactions and commodity-linked derivatives involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward 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 perfectly with relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, a number of broker-dealers and other financial institutions have recently experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. There can be no assurance that the Fund's derivative counterparties will be able to avoid experiencing similar financial difficulties, possibly resulting in losses to the Fund. 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. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer's bonds and preferred stock generally take precedence over the claims of those who own common stock. Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund's investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity. Interest Rate Risk: Changes in interest rates may cause the value of the Fund's investments to decrease. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. A period of low interest rates may cause the Fund to have a low or negative yield, potentially reducing the value of your investment. Issuer Risk: The value of the Fund's investments may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods and services. Leverage Risk: Use of derivative instruments may involve leverage. Leverage is the risk associated with securities or practices that multiply small index, market or asset price movements into larger changes in value. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. The use of leverage increases the impact of gains and losses on a fund's returns, and may lead to significant losses if investments are not successful. However, the Adviser will attempt to ensure that at all times the Fund has sufficient liquid assets to enable it to satisfy its obligations under its derivative contracts. Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell, possibly preventing the Fund from selling these illiquid securities at an advantageous price or time. A lack of liquidity also may cause the value of investments to decline. Illiquid investments also may be difficult to value. Management Risk: A strategy used by the Fund's portfolio managers may fail to produce the intended result. The Adviser utilizes various proprietary quantitative models to identify investment opportunities. There is a possibility that one or all of the quantitative models may fail to identify profitable opportunities at any time. Furthermore, they may incorrectly identify opportunities and these misidentified opportunities may lead to substantial losses. Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer's financial condition, as well as overall market and economic conditions. The Fund's portfolio managers will attempt to reduce this risk by implementing various volatility management strategies and techniques. However, there is no guarantee that such strategies and techniques will produce the intended result. U.S. Government Securities Risk: Investments in certain U.S. government securities may not be supported by the full faith and credit of the U.S. government. Accordingly, no assurance can be given that the U.S. government will provide financial support to U.S. government agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. The maximum potential liability of the issuers of some U.S. government securities held by the Fund may greatly exceed their current resources, and it is possible that these issuers will not have the funds to meet their payment obligations in the future. In such a case, the Fund would have to look principally to the agency, instrumentality or sponsored enterprise issuing or guaranteeing the security for ultimate repayment, and the Fund may not be able to assert a claim against the U.S. government itself in the event the agency, instrumentality or sponsored enterprise does not meet its commitment. Concerns about the capacity of the U.S. government to meet its obligations may raise the interest rates payable on its securities, negatively impacting the price of such securities already held by the Fund. Valuation Risk: This is the risk that the Fund has valued certain securities at a higher price than the price at which they can be sold. This risk may be especially pronounced for investments, such as derivatives that may be illiquid or may become illiquid.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose money by investing in the Fund.
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 and life-of-Fund periods compare with those of two broad measure of market performance. 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 ngam.natixis.com and/or by calling the Fund toll-free at 800-225-5478. The bar 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.
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 and life-of-Fund periods compare with those of a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-225-5478
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	ngam.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 A
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	The bar chart does not reflect any sales charge that you may be required to pay when you buy or redeem the Fund's shares.
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarterly Return: Third Quarter 2010, 13.89% Lowest Quarterly Return: Fourth Quarter 2010, -4.18%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
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 Fund shares through tax-deferred 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	Prior to May 1, 2012, Class Y shares were offered in a separate prospectus and given that Class Y shares are now offered in this multi-class prospectus, Total Returns, Return After Taxes on Distributions and Return After Taxes on Distributions & Sale of Fund Shares are now presented for Class A 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 Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.
ASG Diversifying Strategies 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
Redemption fees	rr_RedemptionFeeOverRedemption	none
Management fees	rr_ManagementFeesOverAssets	1.25%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.30%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.80%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.08%	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.72%
1 year	rr_ExpenseExampleYear01	740
3 years	rr_ExpenseExampleYear03	1,102
5 years	rr_ExpenseExampleYear05	1,487
10 years	rr_ExpenseExampleYear10	2,563
Annual Return 2010	rr_AnnualReturn2010	8.46%
Annual Return 2011	rr_AnnualReturn2011	(2.75%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2010
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	13.89%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2010
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(4.18%)
1 Year	rr_AverageAnnualReturnYear01	(8.36%)
Since Inception	rr_AverageAnnualReturnSinceInception	2.70%
Inception Date	rr_AverageAnnualReturnInceptionDate	Aug. 03, 2009
ASG Diversifying Strategies 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	1.25%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	0.30%
Total annual fund operating expenses	rr_ExpensesOverAssets	2.55%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.08%	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	2.47%
1 year	rr_ExpenseExampleYear01	350
3 years	rr_ExpenseExampleYear03	786
5 years	rr_ExpenseExampleYear05	1,348
10 years	rr_ExpenseExampleYear10	2,879
1 year	rr_ExpenseExampleNoRedemptionYear01	250
3 years	rr_ExpenseExampleNoRedemptionYear03	786
5 years	rr_ExpenseExampleNoRedemptionYear05	1,348
10 years	rr_ExpenseExampleNoRedemptionYear10	2,879
1 Year	rr_AverageAnnualReturnYear01	(4.37%)
Since Inception	rr_AverageAnnualReturnSinceInception	4.44%
Inception Date	rr_AverageAnnualReturnInceptionDate	Aug. 03, 2009
ASG Diversifying Strategies 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	1.25%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.30%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.55%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.08%	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.47%
1 year	rr_ExpenseExampleYear01	150
3 years	rr_ExpenseExampleYear03	482
5 years	rr_ExpenseExampleYear05	837
10 years	rr_ExpenseExampleYear10	1,839
1 Year	rr_AverageAnnualReturnYear01	(2.48%)
Since Inception	rr_AverageAnnualReturnSinceInception	5.46%
Inception Date	rr_AverageAnnualReturnInceptionDate	Aug. 03, 2009
After Taxes on Distributions | ASG Diversifying Strategies Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(9.66%)
Since Inception	rr_AverageAnnualReturnSinceInception	0.79%
Inception Date	rr_AverageAnnualReturnInceptionDate	Aug. 03, 2009
Return After Taxes on Distributions & Sale of Fund Shares | ASG Diversifying Strategies Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(5.44%)
Since Inception	rr_AverageAnnualReturnSinceInception	1.34%
Inception Date	rr_AverageAnnualReturnInceptionDate	Aug. 03, 2009
3-month London Interbank Offered Rate (LIBOR) | ASG Diversifying Strategies Fund
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	0.27%	[2]
Since Inception	rr_AverageAnnualReturnSinceInception	0.33%	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Aug. 01, 2009
HFRI Fund of Funds Composite Index | ASG Diversifying Strategies Fund
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(5.51%)
Since Inception	rr_AverageAnnualReturnSinceInception	1.73%
Inception Date	rr_AverageAnnualReturnInceptionDate	Aug. 01, 2009

[1] AlphaSimplex Group, LLC ("AlphaSimplex" 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 1.70%, 2.45% and 1.45% of the Fund's average daily net assets for Class A, C and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 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 1.70%, 2.45% and 1.45% of the Fund's average daily net assets for Class A, C and Y shares, respectively. 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 fee/expense was waived/reimbursed.

[2] Prior to May 1, 2012, the Fund's prospectus listed the Fund's primary benchmark as HFRI Fund of Funds Composite Index, an unmanaged, equally-weighted hedge fund index. 3-month London Interbank Offered Rate (LIBOR) is now listed as the Fund's primary benchmark because AlphaSimplex believes that 3-month LIBOR provides an appropriate comparison in light of the Fund's absolute return strategy.

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ASG Diversifying Strategies Fund

ASG Diversifying Strategies Fund

Investment Goal

The Fund pursues an absolute return strategy that seeks to provide capital appreciation.

The secondary goal of the Fund is to achieve these returns while maintaining a low or negative correlation over time with the returns of major equity indices.

Fund Fees & Expenses

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 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 Fund 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 70 of the Prospectus and on page 103 in the section “Reduced Sales Charges” of the Statement of Additional Information (“SAI”).

Shareholder Fees
(fees paid directly from your investment)

Shareholder Fees ASG Diversifying Strategies Fund	Class A	Class C	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%	none	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	none	1.00%	none
Redemption fees	none	none	none

Annual Fund Operating Expenses
(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses ASG Diversifying Strategies Fund		Class A	Class C	Class Y
Management fees		1.25%	1.25%	1.25%
Distribution and/or service (12b-1) fees		0.25%	1.00%	none
Other expenses		0.30%	0.30%	0.30%
Total annual fund operating expenses		1.80%	2.55%	1.55%
Fee waiver and/or expense reimbursement	[1]	0.08%	0.08%	0.08%
Total annual fund operating expenses after fee waiver and/or expense reimbursement		1.72%	2.47%	1.47%

Example

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 example is based on Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and on the Total Annual Fund Operating Expenses for the remaining years. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

If shares are redeemed:

Expense Example ASG Diversifying Strategies Fund (USD $)	1 year	3 years	5 years	10 years
Class A	740	1,102	1,487	2,563
Class C	350	786	1,348	2,879
Class Y	150	482	837	1,839

If shares are not redeemed:

Expense Example, No Redemption (USD $)	1 year	3 years	5 years	10 years
ASG Diversifying Strategies Fund Class C	250	786	1,348	2,879

Portfolio Turnover

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. Due to the short-term nature of the Fund’s investment portfolio, the Fund does not calculate a portfolio turnover rate.

Investments, Risks and Performance Principal Investment Strategies

The Fund seeks to generate positive absolute returns over time rather than track the performance of any particular index. In selecting investments for the Fund, the Adviser uses multiple quantitative investment models and strategies (for example, relative value fixed income strategies and multi-market trend strategies) each of which has an absolute return objective. Each model and strategy may involve a broad range of market exposures. These models may include, for example, models that base investment decisions on fixed income spreads and models which seek to identify trends across various asset classes. The Adviser uses quantitative and qualitative judgments in the determination of weighting among the models and strategies. Although the Fund seeks positive absolute returns over time, it is likely that the Fund's investment returns may be volatile over short periods of time. The Fund may outperform the overall securities market during periods of flat or negative market performance and may underperform during periods of strong market performance. There can be no assurance that the Fund's returns over time or during any period will be positive or that the Fund will outperform the overall security markets over time or during any particular period.

Under normal market conditions, the Adviser typically will make extensive use of a variety of derivative instruments, in particular futures and forward contracts, to capture the exposures suggested by its absolute return strategies while also adding value through volatility management and correlation management. These market exposures, which are expected to change over time, may include, for example, exposures to the returns of equity and fixed income securities, currencies and commodities. The Adviser will scale the notional exposure of the Fund's futures and currency forward positions with the objective of targeting a relatively stable level of annualized volatility for the Fund's overall portfolio. The Adviser may also use exchange-traded futures contracts on broad U.S. or international equity indices to decrease any undesired correlation with the returns of the major equity indices. The Adviser will have great flexibility to allocate the Fund's derivatives exposure among various securities, indices, currencies, commodities and other instruments; the amount of the Fund's assets that may be allocated to derivative strategies and among these various instruments is expected to vary over time. When buying and selling securities and other instruments for the Fund, and in determining the amount of assets to be allocated to the Money Market Portion (as defined below), the Adviser will also consider the following factors: (i) the Fund's obligations under its various derivative positions; (ii) redemption requests; (iii) yield management; (iv) credit management and (v) volatility management. The Fund may invest in non-U.S. securities and instruments and securities and instruments traded outside the United States and expects to engage in non-U.S. currency transactions.

Under normal market conditions, it is expected that no more than 25% of the Fund's total assets will be dedicated to initial and variation margin payments relating to the Fund's derivative transactions. The gross notional value of the Fund's derivative investments, however, will generally exceed 25% of the Fund's total assets, and may significantly exceed the total value of the Fund's assets. The Fund expects that under normal market conditions it will invest at least 75% of its total assets in money market and other short-term, high quality securities (the "Money Market Portion") managed by Reich & Tang Asset Management, LLC (the "Subadviser"), although the Fund may invest less than this percentage. The Adviser will determine the percentage of the Fund's assets that will be invested in the Money Market Portion at any time. The assetsallocated to the Money Market Portion will be used primarily to support the Fund's investments in derivatives and similar instruments and, secondarily, to provide the Fund with incremental income and liquidity. Although the Fund will invest a significant portion of its assets in money market instruments, the Fund is not a "money market" fund and the value of the Money Market Portion as well as the value of the Fund's shares may decrease. The Fund is not subject to the portfolio quality, maturity and net asset value requirements applicable to money market funds, and the Fund will not seek to maintain a stable net asset value.

The Subadviser will only invest the assets of the Money Market Portion in high quality securities which are denominated in U.S. dollars, and will select securities for investment based on various factors, including the security's maturity and rating. The Subadviser will invest primarily in (i) short-term obligations issued or guaranteed by the United States government, its agencies or instrumentalities ("U.S. Government Obligations"); (ii) securities issued by foreign governments, their political subdivisions, agencies or instrumentalities; (iii) certificates of deposit, time deposits and bankers' acceptances issued by domestic banks, foreign branches of domestic banks, foreign subsidiaries of domestic banks, and domestic and foreign branches of foreign banks; (iv) variable amount master demand notes; (v) participation interests in loans extended by banks to companies; (vi) commercial paper or similar debt obligations; and (vii) repurchase agreements.

Although the Fund does not intend to invest in physical commodities directly, the Fund expects to obtain investment exposure to commodity-related derivatives through a wholly-owned subsidiary organized under the laws of the Cayman Islands that will make commodity-related investments (the "Commodity Subsidiary"). Under normal market conditions, no more than 10% of the Fund's total assets will be dedicated to initial and variation margin payments relating to these transactions.

The Fund will concentrate its investments in the financial services industry, which means it will normally invest at least 25% of its total assets in securities and other obligations (for example, bank certificates of deposit) of issuers in such industry.

The Fund may engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund's return, and realization of greater short-term capital gains, distributions of which are taxable as ordinary income to taxable shareholders. Trading costs and tax effects associated with frequent trading may adversely affect the Fund's performance. Due to the short-term nature of the Fund's investment portfolio, the Fund does not calculate a portfolio turnover rate. The Fund's trading in derivatives is active and frequent. Active and frequent trading of derivatives, like active and frequent trading of securities, will result in transaction costs which reduce fund returns.

The percentage limitations set forth herein are not investment restrictions and the Fund may exceed these limits from time to time.

Principal Risks

The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund.

Allocation and Correlation Risk: This is the risk that the Adviser's judgments about, and allocations between, asset classes and market exposures may adversely affect the Fund's performance. This risk can be increased by the use of derivatives to increase allocations to various market exposures. This is because derivatives can create investment leverage, which will magnify the impact to the Fund of its investment in any underperforming market exposure.

Commodity Risk: This is the risk that exposure to the commodities markets may subject the Fund to greater volatility than investments in traditional securities. The value of physical commodities or commodity-linked derivative instruments may be affected by changes in overall market movements, commodity price volatility, changes in interest rates, currency fluctuations, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. Recent rulemaking by the Commodity Futures Trading Commission ("CFTC")may affect the Fund's ability to pursue its investment strategies or increase the Fund's expenses. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain.

Commodity Subsidiary Risk: Investing in the Commodity Subsidiary will indirectly expose the Fund to the risks associated with the Commodity Subsidiary's investments, such as commodity investment risk. The Commodity Subsidiary is not registered under the Investment Company Act of 1940 (the "1940 Act") and is not subject to all of the investor protections of the 1940 Act. Recent rulemaking by the CFTC may affect the Fund&s ability to use the Commodity Subsidiary to pursue its investment strategies. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Changes in the laws of the United States and/or the Cayman Islands, under which the Fund and the Commodity Subsidiary, respectively, are organized, could negatively affect the Fund and its shareholders.

Concentrated Investment Risk: The Fund is particularly vulnerable to events affecting companies in the financial services industry because the Fund concentrates its investments in securities and other obligations of issuers in such industry. Examples of risks affecting the financial services industry include changes in governmental regulation, issues relating to the availability and cost of capital, changes in interest rates and/or monetary policy and price competition. In addition, financial services companies are often more highly leveraged than other companies, making them inherently riskier. As a result, the Fund's shares may rise and fall in value more rapidly and to a greater extent than shares of a fund that does not concentrate or focus in a particular industry or economic sector. The financial services industry has recently experienced high volatility and a number of issuer failures and the value of many of these securities has significantly declined. As a result, the risk associated with investing in the Fund may be increased as compared to a fund that does not concentrate in the financial services industry.

Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with over-the-counter ("OTC")derivative transactions, such as foreign currency transactions. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its direct counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains.

Currency Risk: Fluctuations in the exchange rates between different currencies may negatively affect an investment. 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.

Derivatives Risk: Derivatives are subject to changes in the value of the underlying asset or indices on which such transactions 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 markets 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 which would have occurred had derivatives not been used. The Fund's use of derivatives, such as futures, forward contracts, and other foreign currency transactions and commodity-linked derivatives involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward 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 perfectly with relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, a number of broker-dealers and other financial institutions have recently experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. There can be no assurance that the Fund's derivative counterparties will be able to avoid experiencing similar financial difficulties, possibly resulting in losses to the Fund.

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. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer's bonds and preferred stock generally take precedence over the claims of those who own common stock.

Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund's investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity.

Interest Rate Risk: Changes in interest rates may cause the value of the Fund's investments to decrease. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. A period of low interest rates may cause the Fund to have a low or negative yield, potentially reducing the value of your investment.

Issuer Risk: The value of the Fund's investments may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods and services.

Leverage Risk: Use of derivative instruments may involve leverage. Leverage is the risk associated with securities or practices that multiply small index, market or asset price movements into larger changes in value. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. The use of leverage increases the impact of gains and losses on a fund's returns, and may lead to significant losses if investments are not successful. However, the Adviser will attempt to ensure that at all times the Fund has sufficient liquid assets to enable it to satisfy its obligations under its derivative contracts.

Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell, possibly preventing the Fund from selling these illiquid securities at an advantageous price or time. A lack of liquidity also may cause the value of investments to decline. Illiquid investments also may be difficult to value.

Management Risk: A strategy used by the Fund's portfolio managers may fail to produce the intended result. The Adviser utilizes various proprietary quantitative models to identify investment opportunities. There is a possibility that one or all of the quantitative models may fail to identify profitable opportunities at any time. Furthermore, they may incorrectly identify opportunities and these misidentified opportunities may lead to substantial losses.

Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer's financial condition, as well as overall market and economic conditions. The Fund's portfolio managers will attempt to reduce this risk by implementing various volatility management strategies and techniques. However, there is no guarantee that such strategies and techniques will produce the intended result.

U.S. Government Securities Risk: Investments in certain U.S. government securities may not be supported by the full faith and credit of the U.S. government. Accordingly, no assurance can be given that the U.S. government will provide financial support to U.S. government agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. The maximum potential liability of the issuers of some U.S. government securities held by the Fund may greatly exceed their current resources, and it is possible that these issuers will not have the funds to meet their payment obligations in the future. In such a case, the Fund would have to look principally to the agency, instrumentality or sponsored enterprise issuing or guaranteeing the security for ultimate repayment, and the Fund may not be able to assert a claim against the U.S. government itself in the event the agency, instrumentality or sponsored enterprise does not meet its commitment. Concerns about the capacity of the U.S. government to meet its obligations may raise the interest rates payable on its securities, negatively impacting the price of such securities already held by the Fund.

Valuation Risk: This is the risk that the Fund has valued certain securities at a higher price than the price at which they can be sold. This risk may be especially pronounced for investments, such as derivatives that may be illiquid or may become illiquid.

Risk/Return Bar Chart and Table

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 and life-of-Fund periods compare with those of two broad measure of market performance. 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 ngam.natixis.com and/or by calling the Fund toll-free at 800-225-5478.

The bar 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.

Total Returns for Class A

Highest Quarterly Return:
Third Quarter 2010, 13.89%

Lowest Quarterly Return:
Fourth Quarter 2010, -4.18%

Average Annual Total Returns
(for the periods ended December 31, 2011)

Average Annual Total Returns ASG Diversifying Strategies Fund	Past 1 Year		Life of Fund		Inception Date
Class A	(8.36%)		2.70%		Aug. 03, 2009
Class C	(4.37%)		4.44%		Aug. 03, 2009
Class Y	(2.48%)		5.46%		Aug. 03, 2009
Return After Taxes on Distributions Class A	(9.66%)		0.79%		Aug. 03, 2009
Return After Taxes on Distributions & Sale of Fund Shares Class A	(5.44%)		1.34%		Aug. 03, 2009
3-month London Interbank Offered Rate (LIBOR)	0.27%	[1]	0.33%	[1]	Aug. 01, 2009
HFRI Fund of Funds Composite Index	(5.51%)		1.73%		Aug. 01, 2009

Prior to May 1, 2012, Class Y shares were offered in a separate prospectus and given that Class Y shares are now offered in this multi-class prospectus, Total Returns, Return After Taxes on Distributions and Return After Taxes on Distributions & Sale of Fund Shares are now presented for Class A 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 Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.

[1] AlphaSimplex Group, LLC ("AlphaSimplex" 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 1.70%, 2.45% and 1.45% of the Fund's average daily net assets for Class A, C and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 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 1.70%, 2.45% and 1.45% of the Fund's average daily net assets for Class A, C and Y shares, respectively. 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 fee/expense was waived/reimbursed.

[1] Prior to May 1, 2012, the Fund's prospectus listed the Fund's primary benchmark as HFRI Fund of Funds Composite Index, an unmanaged, equally-weighted hedge fund index. 3-month London Interbank Offered Rate (LIBOR) is now listed as the Fund's primary benchmark because AlphaSimplex believes that 3-month LIBOR provides an appropriate comparison in light of the Fund's absolute return strategy.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	Natixis Funds Trust II
Prospectus Date	rr_ProspectusDate	May 01, 2012
ASG Global Alternatives Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	ASG Global Alternatives Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Goal
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund pursues an absolute return strategy that seeks to provide capital appreciation consistent with the risk-return characteristics of a diversified portfolio of hedge funds.
Objective, Secondary [Text Block]	rr_ObjectiveSecondaryTextBlock	The secondary goal of the Fund is to achieve these returns with less volatility than major equity indices.
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 and hold shares of the Fund. 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 Fund 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 70 of the Prospectus and on page 103 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	April 30, 2013
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. Due to the short-term nature of the Fund’s investment portfolio, the Fund does not calculate a portfolio turnover rate.
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 Fund Complex.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	50,000
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods (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 example is based on Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and on the Total Annual Fund Operating Expenses for the remaining years. 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	The Fund seeks to achieve long and short exposure to global equity, bond, currency and commodity markets through a wide range of derivative instruments and direct investments. Under normal market conditions, the Adviser typically will make extensive use of derivative instruments, in particular futures and forward contracts on global equity and fixed income securities, securities indices (including both broad- and narrow-based securities indices), currencies, commodities and other instruments. These investments are intended to provide the Fund with risk and return characteristics similar to those of a diversified portfolio of hedge funds. The Fund seeks to generate absolute returns over time rather than track the performance of any particular index of hedge fund returns. In selecting investments for the Fund, the Adviser uses quantitative models to estimate the market exposures that drive the aggregate returns of a diverse set of hedge funds. These market exposures may include, for example, exposures to the returns of stocks, fixed income securities (including U.S. and non-U.S. government securities), currencies and commodities. In estimating these market exposures, the Adviser analyzes the returns of hedge funds included in one or more commercially available databases selected by the Adviser (for example, the Lipper TASS hedge fund database), and seeks to use a variety of derivative instruments to capture such exposures in the aggregate while adding value through dynamic allocation among market exposures and volatility management. The Adviser will have great flexibility to allocate the Fund’s derivatives exposure among various securities, indices, currencies, commodities and other instruments; the amount of the Fund’s assets that may be allocated to derivative strategies and among these various instruments is expected to vary over time. When buying and selling securities and other instruments for the Fund, and in determining the amount of assets to be allocated to the Money Market Portion (as defined below), the Adviser will also consider the following factors: (i) the Fund’s obligations under its various derivative positions; (ii) redemption requests; (iii) yield management; (iv) credit management and (v) volatility management. The Fund will not invest directly in hedge funds. The Fund may invest in non-U.S. securities and instruments and securities and instruments traded outside the United States, and expects to engage in non-U.S. currency transactions. Under normal market conditions, it is expected that no more than 25% of the Fund’s total assets will be dedicated to initial and variation margin payments relating to the Fund’s derivative transactions. The gross notional value of the Fund’s derivative investments, however, will generally exceed 25% of the Fund’s assets, and may significantly exceed the total value of the Fund’s assets. The Fund expects that under normal market conditions it will invest at least 75% of its total assets in money market and other short-term, high quality securities (the “Money Market Portion”) managed by Reich & Tang Asset Management, LLC (the “Subadviser”), although the Fund may invest less than this percentage. The Adviser will determine the percentage of the Fund’s assets that will be invested in the Money Market Portion at any time. The assets allocated to the Money Market Portion will be used primarily to finance the Fund’s investments in derivatives and similar instruments and, secondarily, to provide the Fund with incremental income and liquidity. Although the Fund will invest a significant portion of its assets in money market instruments, the Fund is not a “money market” fund and the value of the Money Market Portion as well as the value of the Fund’s shares may decrease. The Fund is not subject to the portfolio quality, maturity and net asset value requirements applicable to money market funds, and the Fund will not seek to maintain a stable net asset value. The Subadviser will only invest the assets of the Money Market Portion in high quality securities which are denominated in U.S. dollars, and will select securities for investment based on various factors, including the security’s maturity and rating. The Subadviser will invest primarily in (i) short-term obligations issued or guaranteed by the United States government, its agencies or instrumentalities (“U.S. Government Obligations”); (ii) securities issued by foreign governments, their political subdivisions or agencies or instrumentalities; (iii) certificates of deposit, time deposits and bankers’ acceptances issued by domestic banks, foreign branches of domestic banks, foreign subsidiaries of domestic banks, and domestic and foreign branches of foreign banks; (iv) variable amount master demand notes; (v) participation interests in loans extended by banks to companies; (vi) commercial paper or similar debt obligations; and (vii) repurchase agreements. Although the Fund does not intend to invest in physical commodities directly, the Fund expects to obtain investment exposure to commodity-related derivatives through a wholly-owned subsidiary organized under the laws of the Cayman Islands that will make commodity-related investments (the “Commodity Subsidiary”). Under normal market conditions, no more than 10% of the Fund’s total assets will be dedicated to initial and variation margin payments relating to these transactions. The Fund will concentrate its investments in the financial services industry, which means it will normally invest at least 25% of its total assets in securities and other obligations (for example, bank certificates of deposit) of issuers in such industry. The Fund may engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund’s return, and realization of greater short-term capital gains, distributions of which are taxable as ordinary income to taxable shareholders. Trading costs and tax effects associated with frequent trading may adversely affect the Fund’s performance. Due to the short-term nature of the Fund’s investment portfolio, the Fund does not calculate a portfolio turnover rate. The Fund’s trading in derivatives is active and frequent. Active and frequent trading of derivatives, like active and frequent trading of securities, will result in transaction costs which reduce fund returns. The percentage limitations set forth herein are not investment restrictions and the Fund may exceed these limits from time to time.
Strategy Portfolio Concentration [Text]	rr_StrategyPortfolioConcentration	The Fund will concentrate its investments in the financial services industry, which means it will normally invest at least 25% of its total assets in securities and other obligations (for example, bank certificates of deposit) of issuers in such industry.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund. Commodity Risk: This is the risk that exposure to the commodities markets may subject the Fund to greater volatility than investments in traditional securities. The value of physical commodities or commodity-linked derivative instruments may be affected by changes in overall market movements, commodity price volatility, changes in interest rates, currency fluctuations, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. Recent rulemaking by the Commodity Futures Trading Commission (“CFTC”) may affect the Fund’s ability to pursue its investment strategies or increase the Fund’s expenses. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Commodity Subsidiary Risk: Investing in the Commodity Subsidiary will indirectly expose the Fund to the risks associated with the Commodity Subsidiary’s investments, such as commodity investment risk. The Commodity Subsidiary is not registered under the Investment Company Act of 1940 (the “1940 Act”) and is not subject to all of the investor protections of the 1940 Act. Recent rulemaking by the CFTC may affect the Fund’s ability to use the Commodity Subsidiary to pursue its investment strategies. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Changes in the laws of the United States and/or the Cayman Islands, under which the Fund and the Commodity Subsidiary, respectively, are organized, could negatively affect the Fund and its shareholders. Concentrated Investment Risk: The Fund is particularly vulnerable to events affecting companies in the financial services industry because the Fund concentrates its investments in securities and other obligations of issuers in such industry. Examples of risks affecting the financial services industry include changes in governmental regulation, issues relating to the availability and cost of capital, changes in interest rates and/or monetary policy and price competition. In addition, financial services companies are often more highly leveraged than other companies, making them inherently riskier. As a result, the Fund’s shares may rise and fall in value more rapidly and to a greater extent than shares of a fund that does not concentrate or focus in a particular industry or economic sector. The financial services industry has recently experienced high volatility and a number of issuer failures and the value of many of these securities has significantly declined. As a result, the risk associated with investing in the Fund may be increased as compared to a fund that does not concentrate in the financial services industry. Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with over-the-counter (“OTC”) derivative transactions, such as foreign currency transactions. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its direct counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains. Currency Risk: Fluctuations in the exchange rates between different currencies may negatively affect an investment. 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. Derivatives Risk: Derivatives are subject to changes in the value of the underlying asset or indices on which such transactions 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 markets 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 which would have occurred had derivatives not been used. The Fund’s use of derivatives, such as futures, forward contracts, and other foreign currency transactions and commodity-linked derivatives involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward 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 perfectly with relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, a number of broker-dealers and other financial institutions have recently experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. There can be no assurance that the Fund’s derivative counterparties will be able to avoid experiencing similar financial difficulties, possibly resulting in losses to the Fund. 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. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer’s bonds and preferred stock generally take precedence over the claims of those who own common stock. Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund’s investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity. Hedge Fund Risk: Hedge funds are typically unregulated private investment pools available only to sophisticated investors. They are often illiquid and highly leveraged. Although the Fund will not invest directly in hedge funds, because the Fund’s investments are intended to provide exposure to the factors that drive hedge fund returns, an investment in the Fund will be subject to many of the same risks associated with an investment in a diversified portfolio of hedge funds. Therefore, the Fund’s performance may be lower than the returns of the broader stock market and the Fund’s net asset value may fluctuate substantially over time. Index/Tracking Error Risk: Although the Fund does not seek to track any particular index, the Fund seeks to analyze the factors that drive hedge fund returns, as determined by reference to one or more indices. These indices may not provide an accurate representation of hedge fund returns generally, and the Adviser’s strategy may not successfully identify or be able to replicate factors that drive returns. There is a risk that hedge fund return data provided by third party hedge fund index providers may be inaccurate or may not accurately reflect hedge fund returns due to survivorship bias, self-reporting bias or other biases. Interest Rate Risk: Changes in interest rates may cause the value of the Fund’s investments to decrease. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. A period of low interest rates may cause the Fund to have a low or negative yield, potentially reducing the value of your investment. Issuer Risk: The value of the Fund’s investments may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods and services. Leverage Risk: Use of derivative instruments may involve leverage. Leverage is the risk associated with securities or practices that multiply small index, market or asset price movements into larger changes in value. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. The use of leverage increases the impact of gains and losses on a fund’s returns, and may lead to significant losses if investments are not successful. However, the Adviser will attempt to ensure that at all times the Fund has sufficient liquid assets to enable it to satisfy its obligations under its derivative contracts. Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell, possibly preventing the Fund from selling these illiquid securities at an advantageous price or time. A lack of liquidity also may cause the value of investments to decline. Illiquid investments also may be difficult to value. Management Risk: A strategy used by the Fund’s portfolio managers may fail to produce the intended result. The Adviser utilizes various proprietary quantitative models to identify investment opportunities. There is a possibility that one or all of the quantitative models may fail to identify profitable opportunities at any time. Furthermore, they may incorrectly identify opportunities and these misidentified opportunities may lead to substantial losses. Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer’s financial condition, as well as overall market and economic conditions. The Fund’s portfolio managers will attempt to reduce this risk by implementing various volatility management strategies and techniques. However, there is no guarantee that such strategies and techniques will produce the intended result. U.S. Government Securities Risk: Investments in certain U.S. government securities may not be supported by the full faith and credit of the U.S. government. Accordingly, no assurance can be given that the U.S. government will provide financial support to U.S. government agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. The maximum potential liability of the issuers of some U.S. government securities held by the Fund may greatly exceed their current resources, and it is possible that these issuers will not have the funds to meet their payment obligations in the future. In such a case, the Fund would have to look principally to the agency, instrumentality or sponsored enterprise issuing or guaranteeing the security for ultimate repayment, and the Fund may not be able to assert a claim against the U.S. government itself in the event the agency, instrumentality or sponsored enterprise does not meet its commitment. Concerns about the capacity of the U.S. government to meet its obligations may raise the interest rates payable on its securities, negatively impacting the price of such securities already held by the Fund. Valuation Risk: This is the risk that the Fund has valued certain securities at a higher price than the price at which they can be sold. This risk may be especially pronounced for investments, such as derivatives that may be illiquid or may become illiquid.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose money by investing in the Fund.
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 and life-of-Fund periods compare with those of a broad measure of market performance. 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 ngam.natixis.com and/or by calling the Fund toll-free at 800-225-5478. The bar 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.
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 and life-of-Fund periods compare with those of a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-225-5478
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	ngam.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 A
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	The bar 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 Return: Third Quarter 2010, 7.26% Lowest Quarterly Return: Third Quarter 2011, -7.47%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
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 Fund shares through tax-deferred 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 Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	Prior to May 1, 2012, Class Y shares were offered in a separate prospectus and given that Class Y shares are now offered in this multi-class prospectus, Total Returns, Return After Taxes on Distributions and Return After Taxes on Distributions & Sale of Fund Shares are now presented for Class A 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 Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.
ASG Global Alternatives 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
Redemption fees	rr_RedemptionFeeOverRedemption	none
Management fees	rr_ManagementFeesOverAssets	1.15%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.21%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.61%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.61%
1 year	rr_ExpenseExampleYear01	729
3 years	rr_ExpenseExampleYear03	1,054
5 years	rr_ExpenseExampleYear05	1,401
10 years	rr_ExpenseExampleYear10	2,376
2009	rr_AnnualReturn2009	8.95%
2010	rr_AnnualReturn2010	6.94%
2011	rr_AnnualReturn2011	(3.29%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2010
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	7.26%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(7.47%)
Past 1 Year	rr_AverageAnnualReturnYear01	(8.85%)
Life of Fund	rr_AverageAnnualReturnSinceInception	1.00%
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2008
ASG Global Alternatives 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	1.15%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	0.21%
Total annual fund operating expenses	rr_ExpensesOverAssets	2.36%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	2.36%
1 year	rr_ExpenseExampleYear01	339
3 years	rr_ExpenseExampleYear03	736
5 years	rr_ExpenseExampleYear05	1,260
10 years	rr_ExpenseExampleYear10	2,696
1 year	rr_ExpenseExampleNoRedemptionYear01	239
3 years	rr_ExpenseExampleNoRedemptionYear03	736
5 years	rr_ExpenseExampleNoRedemptionYear05	1,260
10 years	rr_ExpenseExampleNoRedemptionYear10	2,696
Past 1 Year	rr_AverageAnnualReturnYear01	(4.96%)
Life of Fund	rr_AverageAnnualReturnSinceInception	2.11%
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2008
ASG Global Alternatives 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	1.15%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.22%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.37%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.01%	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.36%
1 year	rr_ExpenseExampleYear01	138
3 years	rr_ExpenseExampleYear03	433
5 years	rr_ExpenseExampleYear05	749
10 years	rr_ExpenseExampleYear10	1,645
Past 1 Year	rr_AverageAnnualReturnYear01	(3.00%)
Life of Fund	rr_AverageAnnualReturnSinceInception	3.12%
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2008
Return After Taxes on Distributions | ASG Global Alternatives Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(8.96%)
Life of Fund	rr_AverageAnnualReturnSinceInception	0.45%
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2008
Return After Taxes on Distributions & Sale of Fund Shares | ASG Global Alternatives Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(5.68%)
Life of Fund	rr_AverageAnnualReturnSinceInception	0.61%
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2008
HFRI Fund of Funds Composite Index | ASG Global Alternatives Fund
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(5.51%)	[2]
Life of Fund	rr_AverageAnnualReturnSinceInception	0.04%	[2]
Inception Date	rr_AverageAnnualReturnInceptionDate	Oct. 30, 2008

[1] AlphaSimplex Group, LLC ("AlphaSimplex" 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 1.60%, 2.35% and 1.35% of the Fund's average daily net assets for Class A, C and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 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 1.60%, 2.35% and 1.35% of the Fund's average daily net assets for Class A, C and Y shares, respectively. 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 fee/expense was waived/reimbursed.

[2] Calculated from October 1, 2008

XML

Document and Entity Information	12 Months Ended
	May 01, 2012
Risk/Return:
Document Type	485BPOS
Document Period End Date	Dec. 31, 2011
Registrant Name	Natixis Funds Trust II
Central Index Key	0000052136
Amendment Flag	false
Document Creation Date	Apr. 27, 2012
Document Effective Date	May 01, 2012
Prospectus Date	May 01, 2012

XML

ASG Managed Futures Strategy Fund

ASG Managed Futures Strategy Fund

Investment Goal

The Fund pursues an absolute return strategy that seeks to provide capital appreciation.

Fund Fees & Expenses

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 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 Fund 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 70 of the Prospectus and on page 103 in the section “Reduced Sales Charges” of the Statement of Additional Information (“SAI”).

Shareholder Fees(fees paid directly from your investment)

Shareholder Fees ASG Managed Futures Strategy Fund	Class A	Class C	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%	none	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	none	1.00%	none
Redemption fees	none	none	none

Annual Fund Operating Expenses(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses ASG Managed Futures Strategy Fund		Class A	Class C	Class Y
Management fees		1.25%	1.25%	1.25%
Distribution and/or service (12b-1) fees		0.25%	1.00%	none
Other expenses		0.27%	0.30%	0.32%
Total annual fund operating expenses		1.77%	2.55%	1.57%
Fee waiver and/or expense reimbursement	[1]	0.06%	0.09%	0.11%
Total annual fund operating expenses after fee waiver and/or expense reimbursement		1.71%	2.46%	1.46%

Example

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 example is based on Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and on the Total Annual Fund Operating Expenses for the remaining years. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

If shares are redeemed:

Expense Example ASG Managed Futures Strategy Fund (USD $)	1 year	3 years	5 years	10 years
Class A	739	1,095	1,474	2,534
Class C	349	785	1,347	2,879
Class Y	149	485	845	1,858

If shares are not redeemed:

Expense Example, No Redemption (USD $)	1 year	3 years	5 years	10 years
ASG Managed Futures Strategy Fund Class C	249	785	1,347	2,879

Portfolio Turnover

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. Due to the short-term nature of the Fund’s investment portfolio, the Fund does not calculate a portfolio turnover rate.

Investments, Risks and Performance Principal Investment Strategies

The Fund seeks to generate positive absolute returns over time. Under normal market conditions, AlphaSimplex typically will make extensive use of a variety of derivative instruments, including futures and forward contracts, to capture the exposures suggested by its absolute return strategy while also seeking to add value through volatility management. These market exposures, which are expected to change over time, may include, for example, exposures to the returns of U.S. and non-U.S. equity and fixed income securities indices (including both broad- and narrow-based securities indices), currencies and commodities. AlphaSimplex uses proprietary quantitative models to identify price trends in equity, fixed income, currency and commodity instruments across time periods of various lengths. AlphaSimplex believes that asset prices may show persistent trending behavior due to a number of behavioral biases among market participants as well as certain risk-management policies that will identify assets to purchase in upward-trending markets and identify assets to sell in downward-trending markets. AlphaSimplex believes that following trends across a widely diversified set of assets, combined with active risk management, may allow it to earn a positive expected return over time. The Fund may have both “short” and “long” exposures within an asset class based upon AlphaSimplex’s analysis of multiple time horizons to identify trends in a particular asset class. A “short”exposure will benefit when the underlying asset class decreases in price. A “long” exposure will benefit when the underlying asset class increases in price. AlphaSimplex will scale the notional exposure of the Fund’s futures and currency forward positions with the objective of targeting a relatively stable level of annualized volatility for the Fund’s overall portfolio. AlphaSimplex will have great flexibility to allocate the Fund’s derivatives exposure among various securities, indices, currencies, commodities and other instruments; the amount of the Fund’s assets that may be allocated to derivative strategies and among these various instruments is expected to vary over time.

Under normal market conditions, it is expected that no more than 25% of the Fund’s total assets will be dedicated to initial and variation margin payments relating to the Fund’s derivative transactions. The gross notional value of the Fund’s derivative investments, however, will generally exceed 25% of the Fund’s total assets, and may significantly exceed the total value of the Fund’s assets. The Fund expects that under normal market conditions it will invest at least 75% of its total assets in money market and other short-term, high quality securities (such as bankers’ acceptances, certificates of deposit, commercial paper, loan participations, repurchase agreements and time deposits) (the “Money Market Portion”) managed by Reich & Tang Asset Management, LLC (“Reich & Tang”), although the Fund may invest less than this percentage. The Adviser will determine the percentage of the Fund’s assets that will be invested in the Money Market Portion at any time. The assets allocated to the Money Market Portion will be used primarily to support the Fund’s investments in derivatives and, secondarily, to provide the Fund with incremental income and liquidity. Although the Fund will invest a significant portion of its assets in money market instruments, the Fund is not a “money market” fund and the value of the Money Market Portion as well as the value of the Fund’s shares may decrease. The Fund is not subject to the portfolio quality, maturity and net asset value requirements applicable to money market funds, and the Fund will not seek to maintain a stable net asset value. The Fund will concentrate its investments in the financial services industry, which means it will normally invest at least 25% of its total assets in securities and other obligations (for example, bank certificates of deposit, repurchase agreements and time deposits) of issuers in such industry.

Reich &Tang will only invest the assets of the Money Market Portion in high quality securities which are denominated in U.S. dollars, and will select securities for investment based on various factors, including the security’s maturity and rating.

Reich &Tang will invest primarily in (i) short-term obligations issued or guaranteed by the United States government, its agencies or instrumentalities (“U.S. Government Obligations”); (ii) securities issued by foreign governments, their political subdivisions, agencies or instrumentalities; (iii) certificates of deposit, time deposits and bankers’ acceptances issued by domestic banks, foreign branches of domestic banks, foreign subsidiaries of domestic banks and domestic and foreign branches of foreign banks; (iv) variable amount master demand notes; (v) participation interests in loans extended by banks to companies; (vi) commercial paper or similar debt obligations; and (vii) repurchase agreements.

Although the Fund does not intend to invest in physical commodities directly, the Fund expects to obtain investment exposure to commodities and commodity-related derivatives by investing in a wholly-owned subsidiary organized under the laws of the Cayman Islands that will make commodity-related investments (the “Commodity Subsidiary”). Under normal market conditions, no more than 10% of the Fund’s total assets will be dedicated to initial and variation margin payments relating to these transactions.

Although the Fund seeks positive absolute returns over time, it is likely that the Fund’s investment returns may be volatile over short periods of time. The Fund may outperform the overall securities market during periods of flat or negative market performance and may underperform during periods of strong market performance. There can be no assurance that the Fund’s returns over time or during any period will be positive or that the Fund will outperform the overall security markets over time or during any particular period.

The Fund may engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund’s return, and realization of greater short-term capital gains, distributions of which are taxable as ordinary income to taxable shareholders. Trading costs and tax effects associated with frequent trading may adversely affect the Fund’s performance. Due to the short-term nature of the Fund’s investment portfolio, the Fund does not calculate a portfolio turnover rate. The Fund’s trading in derivatives is active and frequent. Active and frequent trading of derivatives, like active and frequent trading of securities, will result in transaction costs which reduce fund returns.

The percentage limitations set forth herein are not investment restrictions and the Fund may exceed these limits from time to time.

Principal Risks

The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund.

Commodity Risk: This is the risk that exposure to the commodities markets may subject the Fund to greater volatility than investments in traditional securities. The value of physical commodities or commodity-linked derivative instruments may be affected by changes in overall market movements, commodity price volatility, changes in interest rates, currency fluctuations, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. Recent rulemaking by the Commodity Futures Trading Commission (“CFTC”) may affect the Fund’s ability to pursue its investment strategies or increase the Fund’s expenses. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain.

Commodity Subsidiary Risk: Investing in the Commodity Subsidiary will indirectly expose the Fund to the risks associated with the Commodity Subsidiary’s investments, such as commodity investment risk. The Commodity Subsidiary is not registered under the Investment Company Act of 1940 (the “1940 Act”) and is not subject to all of the investor protections of the 1940 Act. Recent rulemaking by the CFTC may affect the Fund’s ability to use the Commodity Subsidiary to pursue its investment strategies. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Changes in the laws of the United States and/or the Cayman Islands, under which the Fund and the Commodity Subsidiary, respectively, are organized, could negatively affect the Fund and its shareholders.

Concentrated Investment Risk: The Fund is particularly vulnerable to events affecting companies in the financial services industry because the Fund concentrates its investments in securities and other obligations of issuers in such industry. Examples of risks affecting the financial services industry include changes in governmental regulation, issues relating to the availability and cost of capital, changes in interest rates and/or monetary policy and price competition. In addition, financial services companies are often more highly leveraged than other companies, making them inherently riskier. As a result, the Fund’s shares may rise and fall in value more rapidly and to a greater extent than shares of a fund that does not concentrate or focus in a particular industry or economic sector. The financial services industry has recently experienced high volatility and a number of issuer failures and the value of many of these securities has significantly declined. As a result, the risk associated with investing in the Fund may be increased as compared to a fund that does not concentrate in the financial services industry.

Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with over-the-counter (“OTC”) derivative transactions, such as foreign currency transactions. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its direct counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains.

Currency Risk: Fluctuations in the exchange rates between different currencies may negatively affect an investment. 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.

Derivatives Risk: Derivatives are subject to changes in the value of the underlying asset or indices on which such transactions 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 markets 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 which would have occurred had derivatives not been used. The Fund’s use of derivatives, such as futures, forward contracts, and other foreign currency transactions and commodity-linked derivatives involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward 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 perfectly with relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, a number of broker-dealers and other financial institutions have recently experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. There can be no assurance that the Fund’s derivative counterparties will be able to avoid experiencing similar financial difficulties, possibly resulting in losses to the Fund.

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. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer’s bonds and preferred stock generally take precedence over the claims of those who own common stock.

Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund’s investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity.

Interest Rate Risk: Changes in interest rates may cause the value of the Fund’s investments to decrease. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. A period of low interest rates may cause the Fund to have a low or negative yield, potentially reducing the value of your investment.

Issuer Risk: The value of the Fund’s investments may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods and services.

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 can affect the performance of the Fund, may increase realized capital gains, may accelerate the realization of taxable income to shareholders and may increase transaction costs. 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.

Leverage Risk: Use of derivative instruments may involve leverage. Leverage is the risk associated with securities or practices that multiply small index, market or asset price movements into larger changes in value. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. The use of leverage increases the impact of gains and losses on a fund’s returns, and may lead to significant losses if investments are not successful. However, the Adviser will attempt to ensure that at all times the Fund has sufficient liquid assets to enable it to satisfy its obligations under its derivative contracts.

Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell, possibly preventing the Fund from selling these illiquid securities at an advantageous price or time. A lack of liquidity also may cause the value of investments to decline. Illiquid investments also may be difficult to value.

Management Risk: A strategy used by the Fund’s portfolio managers may fail to produce the intended result. The Adviser utilizes various proprietary quantitative models to identify investment opportunities. There is a possibility that one or all of the quantitative models may fail to identify profitable opportunities at any time. Furthermore, they may incorrectly identify opportunities and these misidentified opportunities may lead to substantial losses.

Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer’s financial condition, as well as overall market and economic conditions. The Fund’s portfolio managers will attempt to reduce this risk by implementing various volatility management strategies and techniques. However, there is no guarantee that such strategies and techniques will produce the intended result.

U.S. Government Securities Risk: Investments in certain U.S. government securities may not be supported by the full faith and credit of the U.S. government. Accordingly, no assurance can be given that the U.S. government will provide financial support to U.S. government agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. The maximum potential liability of the issuers of some U.S. government securities held by the Fund may greatly exceed their current resources, and it is possible that these issuers will not have the funds to meet their payment obligations in the future. In such a case, the Fund would have to look principally to the agency, instrumentality or sponsored enterprise issuing or guaranteeing the security for ultimate repayment, and the Fund may not be able to assert a claim against the U.S. government itself in the event the agency, instrumentality or sponsored enterprise does not meet its commitment. Concerns about the capacity of the U.S. government to meet its obligations may raise the interest rates payable on its securities, negatively impacting the price of such securities already held by the Fund.

Valuation Risk: This is the risk that the Fund has valued certain securities at a higher price than the price at which they can be sold. This risk may be especially pronounced for investments, such as derivatives that may be illiquid or may become illiquid.

Risk/Return Bar Chart and Table

The bar chart and table shown below provide some indication of the risks of investing in the Fund by showing the Fund’s performance in the first full year and by showing how the Fund’s average annual returns for the one-year and life-of-Fund periods compare to those of a broad measure of market performance. 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 ngam.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.

Total Returns for Class A Shares

Highest Quarterly Return:
First Quarter 2011,1.79%

Lowest Quarterly Return:
Fourth Quarterly 2011, -1.69%

Average Annual Total Returns
(for the periods ended December 31, 2011)

Average Annual Total Returns ASG Managed Futures Strategy Fund	Past 1 Year	Life of Fund	Inception Date
Class A	(5.53%)	5.00%	Jul. 30, 2010
Class C	(1.48%)	8.61%	Jul. 30, 2010
Class Y	0.57%	9.68%	Jul. 30, 2010
Return After Taxes on Distributions Class A	(6.46%)	2.83%	Jul. 30, 2010
Return After Taxes on Distributions & Sale of Fund Shares Class A	(3.60%)	3.12%	Jul. 30, 2010
FTSE StableRisk Trend Composite Index (Calculated from August 1, 2010)	2.12%	16.01%	Jul. 30, 2010

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 Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.

[1] AlphaSimplex Group, LLC ("AlphaSimplex" 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 1.70%, 2.45% and 1.45% of the Fund's average daily net assets for Class A, C and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 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 1.70%, 2.45% and 1.45% of the Fund's average daily net assets for Class A, C and Y shares, respectively. 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 fee/expense was waived/reimbursed.

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Loomis Sayles Multi-Asset Real Return Fund

Loomis Sayles Multi-Asset Real Return Fund

Investment Goal

The Fund seeks to maximize real returns consistent with prudent investment management.

Fund Fees & Expenses

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in the Natixis Fund 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 70 of the Prospectus and on page 103 in the section "Reduced Sales Charges" of the Statement of Additional Information ("SAI").

Shareholder Fees(fees paid directly from your investment)

Shareholder Fees Loomis Sayles Multi-Asset Real Return Fund	Class A	Class C	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	4.50%	none	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	none	1.00%	none
Redemption fees	none	none	none

Annual Fund Operating Expenses(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Loomis Sayles Multi-Asset Real Return Fund		Class A	Class C	Class Y
Management fees		0.75%	0.75%	0.75%
Distribution and/or service (12b-1) fees		0.25%	1.00%	none
Other expenses		0.93%	0.79%	0.86%
Acquired fund fess and expenses		0.08%	0.08%	0.08%
Total annual fund operating expenses		2.01%	2.62%	1.69%
Fee waiver and/or expense reimbursement	[1]	0.58%	0.44%	0.51%
Total annual fund operating expenses after fee waiver and/or expense reimbursement		1.43%	2.18%	1.18%

Example

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 example is based on Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and on the Total Annual Fund Operating Expenses for the remaining years. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

If shares are redeemed:

Expense Example Loomis Sayles Multi-Asset Real Return Fund (USD $)	1 year	3 years	5 years	10 years
Class A	589	999	1,433	2,638
Class C	321	773	1,351	2,921
Class Y	120	483	870	1,955

If shares are not redeemed:

Expense Example, No Redemption (USD $)	1 year	3 years	5 years	10 years
Loomis Sayles Multi-Asset Real Return Fund Class C	221	773	1,351	2,921

Portfolio Turnover

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 732% of the average value of its portfolio.

Investments, Risks and Performance Principal Investment Strategies

The Fund will pursue its investment goal primarily through exposure to investments in fixed-income securities, equity securities, currencies and commodity-linked instruments. The Fund expects that its exposure to these asset classes will often be obtained substantially through the use of derivative instruments. The Fund is designed for investors seeking "real returns" (i.e ., total returns that exceed the rate of inflation over a full market cycle regardless of market conditions). Although the Fund seeks positive total returns over time, the Fund's investment returns may be volatile over short periods of time. The Fund may outperform the overall securities market during periods of flat or negative market performance and may underperform during periods of strong market performance. There can be no assurance that the Fund's returns over time or during any period will be positive or that the Fund will provide returns in excess of inflation over time or during any particular period. The Fund does not have limits on the duration of its portfolio, and the Fund's duration will change over time.

In selecting investments for the Fund, the Adviser seeks to draw on its macroeconomic research in global inflationary cycles to identify and to implement investment opportunities that it believes will outpace inflation in a variety of inflationary environments.

Using a global asset allocation analysis, the portfolio managers seek to identify the relative return potential of various asset classes. This analysis is intended to provide the foundation for weighting the asset classes as a whole to develop a portfolio with superior risk and return characteristics in the view of the Adviser. The Adviser expects to use a bottom-up investment process to generate investment ideas consistent with the expectations for the asset classes. Additionally, the portfolio managers will use risk management tools to construct the portfolio and manage risk and volatility on an ongoing basis with an objective of targeting a relatively stable level of annualized volatility for the Fund's overall portfolio. The portfolio management team expects to actively evaluate each investment idea based upon its return potential, its level of risk and its fit within the team's overall macro strategy when deciding whether to buy or sell investments, with the goal of continually optimizing the Fund's portfolio.

The Fund will pursue its investment goal by obtaining long investment exposures through direct cash investments and derivatives and short investment exposures substantially through derivatives. A "long" investment exposure is an investment that rises in value with a rise in the value of an asset, asset class or index and declines in value with a decline in the value of that asset, asset class or index. A "short" investment exposure is an investment that rises in value with a decline in the value of an asset, asset class or index and declines in value with a rise in the value of that asset, asset class or index. The Fund's long and short investment exposures may, at times, each reach 100% of the assets invested in the Fund (excluding instruments primarily used for duration management or yield curve management and short-term investments (such as cash and money market instruments)), although these exposures may be higher or lower at any given time.

Fixed-Income Investments. Under normal market conditions, the Fund expects to invest at least 50% of its net assets in fixed-income securities and derivatives that have returns related to the returns on fixed-income securities. At times, the Fund expects to gain this exposure substantially through the use of derivatives. The Fund may invest in a broad range of U.S. and non-U.S. fixed-income securities, including, but not limited to, corporate bonds, municipal securities, U.S. and non-U.S. government securities (including their agencies, instrumentalities and sponsored entities), securities of supranational entities, partnership securities, commercial and residential mortgage-backed securities, other mortgage-related securities (such as adjustable rate mortgage securities), asset-backed securities, bank loans, depositary receipts, convertible bonds, Rule 144A securities, real estate investment trusts ("REITs"), zero-coupon securities, step coupon securities, stripped securities, pay-in-kind ("PIK") securities, inflation-linked bonds, variable and floating rate securities, when-issued securities, private placements, privatizations, hybrid instruments, structured investments, repurchase agreements and commercial paper. The Fund may invest in securities of any maturity, market sector or credit quality, including below investment-grade fixed-income securities (also known as "junk bonds"). Below investment-grade fixed-income securities are below investment-grade quality (i.e., none of the three major rating agencies (Moody's Investors Service, Inc. ("Moody's"), Fitch Investors Service, Inc. ("Fitch") or Standard & Poor's Ratings Group ("S&P")) have rated the securities in one of their top four ratings categories) or, if the security is unrated, the Adviser has determined it to be of comparable quality.

Equity Investments. Although the Fund expects that in normal market conditions it will have net long equity exposures, in the Adviser's sole discretion the Fund may have net short equity exposures of up to 35% of the Fund's total assets and gross short equity exposures of up to 70% of the Fund's total assets. At times, the Fund expects to gain this exposure substantially through the use of derivatives. For these purposes, a short equity position is a position that will decline in value with a rise of the equity markets. A gross short equity position represents the total of all short positions without regard to any offsetting long positions. A net short equity position is the total of all short positions offset by any long positions (e.g., a direct investment in a stock). The Adviser may have net short equity exposures for investment or hedging purposes, including but not limited to macro hedges to protect the Fund's entire portfolio or more targeted hedges to neutralize specific components of the Fund's equity market exposure. The Fund may invest in a broad range of U.S. and non-U.S. equity securities, including, but not limited to, common and preferred stocks, convertible preferred stocks, depositary receipts, warrants, rights, Rule 144A securities, private placements, privatizations and hybrid instruments. The Fund may invest in securities of issuers of any market capitalization. In addition to direct investment in securities and other instruments, the Fund may invest in other funds, including exchange-traded funds ("ETFs"), unit investment trusts, and other pooled investment vehicles that may or may not be registered under the 1940 Act. The Fund may invest in REITs and U.S. and non-U.S. real estate companies.

Non-U.S. Currency Investments. Under normal market conditions, the Fund expects to invest up to 30% of its total assets in investments in non-U.S. currencies, securities denominated in non-U.S. currencies and related derivative transactions. The Fund may engage in a broad range of transactions involving non-U.S. currencies, including, but not limited to, purchasing and selling forward currency exchange contracts in non-U.S. currencies, investing in non-U.S. currency futures contracts, investing in options on non-U.S. currencies and non-U.S. currency futures, cross-hedging between two or more currencies, investing directly in non-U.S. currencies and investing in securities denominated in non-U.S. currencies, including securities of emerging market issuers. The Fund may engage in non-U.S. currency transactions for investment or for hedging purposes. Currency positions that are intended to hedge the Fund's non-U.S. currency exposure (i.e., currency positions that are not made for investment purposes) will offset positions in the same currency that are made for investment purposes when calculating the 30% limitation in investments in non-U.S. currency investments because the Fund believes that hedging a currency position is likely to negate some or all of the currency risk associated with the original currency position.

Commodity Investments. Under normal market conditions, the Fund expects that up to 25% of its total assets will be invested in commodity-linked instruments. Commodities are assets that have tangible properties, such as oil, metals, and agricultural products. A "commodity-linked instrument" is an instrument whose value is linked to the price movement of a commodity, a commodity index, or a commodity option or futures contract. An investment in a commodity-linked instrument does not generally provide a claim to the tangible underlying commodity. The Fund and a wholly-owned subsidiary organized under the laws of the Cayman Islands (the "Commodity Subsidiary") may invest in a broad range of commodity-linked instruments, including, but not limited to, commodity-linked derivatives (such as commodity-linked swaps, futures, options or options on futures), commodity-linked debt (including leveraged or unleveraged notes that are derivative debt instruments with principal and/or coupon payments linked to the performance of commodities) or commodity-linked ETFs (i.e., ETFs that have their value derived from the price movement of an underlying commodity). The Fund also may invest in equity and fixed-income securities of issuers in commodity-related industries. These investments will not be counted toward the 25% limitation on investments in commodity-linked instruments, but rather will be considered investments in equity securities or fixed-income securities, as appropriate. The Fund expects to obtain its investment exposure to commodity-linked instruments in whole or in significant part indirectly by investing in the Commodity Subsidiary, although in certain circumstances it is possible that the Fund may also invest directly in certain commodity-linked instruments. The Commodity Subsidiary is advised by the Adviser and will invest primarily in commodity-linked instruments and fixed-income securities and other investments that serve as collateral for its derivative positions. The Fund may invest up to 25% of its total assets in the Commodity Subsidiary.

Derivative Investments. The Fund may invest substantially in a broad range of derivative instruments for both hedging and investment purposes, including, but not limited to, futures contracts (such as futures that provide for physical delivery, treasury futures, single stock futures, and index futures), forward contracts, options (such as options on futures contracts, options on securities, options on securities indices, interest rate/bond options, currency options, options on swaps and exchange-traded and over-the-counter options), warrants (such as index warrants), swap transactions (such as interest rate swaps, total return swaps, index swaps and equity swaps), structured notes, foreign currency transactions, commodity-linked derivatives and credit default swaps. The Fund may, at times, invest substantially all of its assets in derivatives and securities used to support its obligations under those derivatives. Derivative instruments (such as those listed above) can be used to acquire or to transfer the risk and returns of a security or other asset without buying or selling the security or asset. The Fund's strategy may be highly dependent on the use of derivatives, and to the extent that they become unavailable or unattractive the Fund may be unable to fully implement its investment strategy.

The Fund is non-diversified, which means that it is not limited to a percentage of assets that it may invest in any one issuer. Because the Fund may invest in the securities of a limited number of issuers, an investment in the Fund may involve a higher degree of risk than would be present in a diversified portfolio.

The Fund expects to engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund's return, and realization of greater short-term capital gains, distributions of which are taxable as ordinary income to taxable shareholders. Trading costs and tax effects associated with frequent trading may adversely affect the Fund's performance.

The percentage limitations set forth herein are not investment restrictions and the Fund may exceed these limits from time to time. In addition, when calculating these exposures, the Fund may use the market value, the notional value, an adjusted notional value or some other measure of the value of a derivative in order to reflect what the Adviser believes to be the most accurate assessment of the Fund's real economic exposure. The total notional value of the Fund's derivative instruments may significantly exceed the total value of the Fund's assets.

Although the Fund will not concentrate more than 25% of its total assets in issuers in any one industry, it may maintain aggregate exposure of more than 25% of its total assets to commodity-linked and commodity-related investments, and therefore may be significantly exposed to commodity-related risks.

Principal Risks

The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund.

Agency Securities Risk: Agency securities are subject to fixed-income securities risk. Certain debt securities issued or guaranteed by agencies of the U.S. government are guaranteed as to the payment of principal and interest by the relevant entity but have not been backed by the full faith and credit of the U.S. government. Instead, they have been supported only by the discretionary authority of the U.S. government to purchase the agency's obligations. An event affecting the guaranteeing entity could adversely affect the payment of principal or interest or both on the security and, therefore, these types of securities should be considered to be riskier than U.S. government securities.

Below Investment-Grade Fixed-Income Securities Risk: This is the risk that the Fund's investments in below investment-grade fixed-income securities, also known as "junk bonds," may be subject to greater risks than other fixed-income securities, including being subject to greater levels of interest rate risk, credit risk (including a greater risk of default) and liquidity risk. The ability of the issuer to make principal and interest payments is predominantly speculative for below investment-grade fixed-income securities.

Commodity Risk: This is the risk that exposure to the commodities markets may subject the Fund to greater volatility than investments in traditional securities. The value of physical commodities or commodity-linked derivative instruments may be affected by changes in overall market movements, commodity price volatility, changes in interest rates, currency fluctuations, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. Recent rulemaking by the Commodity Futures Trading Commission ("CFTC") may affect the Fund's ability to pursue its investment strategies or increase the Fund's expenses. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain.

Commodity Subsidiary Risk: Investing in the Commodity Subsidiary will indirectly expose the Fund to the risks associated with the Commodity Subsidiary's investments, such as commodity investment risk. The Commodity Subsidiary is not registered under the Investment Company Act of 1940 (the "1940 Act") and is not subject to all of the investor protections of the 1940 Act. Recent rulemaking by the CFTC may affect the Fund's ability to use the Commodity Subsidiary to pursue its investment strategies. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Changes in the laws of the United States and/or the Cayman Islands, under which the Fund and the Commodity Subsidiary, respectively, are organized, could negatively affect the Fund and its shareholders.

Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with over-the-counter ("OTC") derivative transactions, such as foreign currency transactions. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its direct counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains.

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 a significant portion of its assets in currency-related instruments and may invest in securities or other instruments denominated in, or receive revenues in, foreign currencies. The Adviser may elect not to hedge currency risk, which may cause the Fund to incur losses that would not have been incurred had the risk been hedged.

Derivatives Risk: Derivatives are subject to changes in the value of the underlying asset or indices on which such transactions 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 markets 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 which would have occurred had derivatives not been used. The Fund's use of derivatives, such as futures, forward contracts, and other foreign currency transactions and commodity-linked derivatives involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward 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 perfectly with relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, a number of broker-dealers and other financial institutions have recently experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. There can be no assurance that the Fund's derivative counterparties will be able to avoid experiencing similar financial difficulties, possibly resulting in losses to the Fund.

Emerging Markets Risk: Investing in emerging markets companies, which may be smaller and have shorter operating histories than companies in developed markets, involves risks in addition to, and greater than, those generally associated with investing in companies in developed foreign markets. The extent of economic development, political stability, market depth, infrastructure, capitalization and regulatory oversight in emerging market economies is generally less than in more developed markets.

Equity Securities Risk: The value of the Fund's investments in equity securities could be subject to unpredictable declines in the value of the individual securities and periods of below average performance in individual securities or the equity market as a whole. Rule 144A equity securities may be less liquid than other equity securities. Small-capitalization and emerging growth companies may be subject to more abrupt price movements, limited markets and less liquidity than larger, more established companies, which could adversely affect the value of the Fund's portfolio. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer's bonds and preferred stock generally take precedence over the claims of those who own common stock.

Fixed-Income Securities Risk: Fixed-income securities are subject to credit risk, interest rate risk and liquidity risk. You may lose money on your investment due to unpredictable drops in a security's value or periods of below-average performance in a given security or in the securities market as a whole. In addition, an economic downturn or period of rising interest rates could adversely affect the market of these securities and reduce the Fund's ability to sell them.

Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund's investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity.

Inflation/Deflation Risk: Inflation risk is the risk that the value of assets or income from investments will be worth less in the future as inflation decreases the present value of future payments. Deflation risk is the risk that prices throughout the economy decline over time (the opposite of inflation). Deflation may have an adverse effect on the creditworthiness of issuers and may make issuer default more likely, which may result in a decline in the value of the Fund's portfolio. Because the Fund seeks positive returns that exceed the rate of inflation over time, if the portfolio managers' inflation forecasts are incorrect, the Fund may be more severely impacted than other funds.

Interest Rate Risk: Changes in interest rates may cause the value of the Fund's investments to decrease. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. A period of low interest rates may cause the Fund to have a low or negative yield, potentially reducing the value of your investment. The value of zero-coupon and pay-in-kind ("PIK") bonds may be more sensitive to fluctuations in interest rates than other fixed-income securities. Rule 144A securities may be more illiquid than other fixed-income securities.

Investments in Other Investment Companies Risk: The Fund will indirectly bear the management, service and other fees of any other investment companies in which it invests in addition to its own expenses.

Issuer Risk: The value of the Fund's investments may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods and services.

Leverage Risk: Use of derivative instruments may involve leverage. Leverage is the risk associated with securities or practices that multiply small index, market or asset price movements into larger changes in value. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. The use of leverage increases the impact of gains and losses on a fund's returns, and may lead to significant losses if investments are not successful. However, the Adviser will attempt to ensure that at all times the Fund has sufficient liquid assets to enable it to satisfy its obligations under its derivative contracts.

Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell, possibly preventing the Fund from selling these illiquid securities at an advantageous price or time. A lack of liquidity also may cause the value of investments to decline. Illiquid investments also may be difficult to value.

Management Risk: A strategy used by the Fund's portfolio managers may fail to produce the intended result.

Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer's financial condition, as well as overall market and economic conditions. The Fund's portfolio managers will attempt to reduce this risk by implementing various volatility management strategies and techniques. However, there is no guarantee that such strategies and techniques will produce the intended result.

Mortgage-Related and Asset-Backed Securities Risk: In addition to the risks associated with investments in fixed-income securities generally (for example, credit, liquidity and valuation risk), mortgage-related and asset-backed securities are subject to the risks of the mortgages and assets underlying the securities as well as prepayment risk, the risk that the securities may be prepaid and result in the reinvestment of the prepaid amounts in securities with lower yields than the prepaid obligations. Conversely, there is a risk that an unexpected rise in interest rates will extend the life of a mortgage-related or asset-backed security beyond the expected prepayment time, typically reducing the security's value. The Fund also may incur a loss when there is a prepayment of securities that were purchased at a premium. The Fund's investments in other asset-backed securities are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets.

Non-Diversification Risk: Compared with other mutual funds, the Fund may invest a greater percentage of its assets in a particular issuer and may invest in fewer issuers. Therefore, the Fund may have more risk because changes in the value of a single security or the impact of a single economic, political or regulatory occurrence may have a greater adverse impact on the Fund's NAV.

Short Exposure Risk: A short exposure through a derivative may present various risks, including credit/counterparty risk and leverage risk. If the value of the asset, asset class or index on which the Fund has obtained a short investment exposure increases, the Fund will incur a loss. Unlike a direct cash investment like a stock, bond or exchange-traded fund, where the potential loss is limited to the purchase price, the potential risk of loss from a short exposure is theoretically unlimited. Moreover, there can be no assurance that securities necessary to cover a short position will be available for purchase.

Risk/Return Bar Chart and Table

The bar chart and table shown below provide some indication of the risks of investing in the Fund by showing the Fund's performance in the first full year and by showing how the Fund's average annual returns for the one-year and life-of-Fund periods compare to those of a broad measure of market performance. 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 ngam.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.

Total Returns for Class A Shares

Highest Quarterly Return:
First Quarter 2011, 0.69%

Lowest Quarterly Return:
Third Quarter 2011, -4.25%

Average Annual Total Returns
(for the periods ended December 31, 2011)

Average Annual Total Returns Loomis Sayles Multi-Asset Real Return Fund	Past 1 Year	Life of Fund	Inception Date
Class A	(10.02%)	(6.53%)	Sep. 30, 2010
Class C	(7.36%)	(3.76%)	Sep. 30, 2010
Class Y	(5.52%)	(2.82%)	Sep. 30, 2010
Return After Taxes on Distributions Class A	(10.65%)	(7.25%)	Sep. 30, 2010
Return After Taxes on Distributions & Sale of Fund Shares Class A	(6.46%)	(5.92%)	Sep. 30, 2010
Barclays U.S. TIPS Index	13.56%	10.14%	Sep. 30, 2010

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 Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period and life-of-Fund period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.

[1] 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 1.35%, 2.10% and 1.10% of the Fund's average daily net assets for Class A, C and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 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 1.35%, 2.10% and 1.10% of the Fund's average daily net assets for Class A, C and Y shares, respectively. The Fund will not be obligated to repay any such waived/reimbursed fees or expenses more than one year after the end of the fiscal year in which the fees or expenses were waived/reimbursed.

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Loomis Sayles Absolute Strategies Fund

Loomis Sayles Absolute Strategies Fund

Investment Goal

The Fund seeks to provide an attractive absolute total return, complemented by prudent investment management designed to manage risks and protect investor capital.

The secondary goal of the Fund is to achieve these returns with relatively low volatility.

Fund Fees & Expenses

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in the Natixis Fund 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 70 of the Prospectus and on page 103 in the section "Reduced Sales Charges" of the Statement of Additional Information ("SAI").

Shareholder Fees(fees paid directly from your investment)

Shareholder Fees Loomis Sayles Absolute Strategies Fund	Class A	Class C	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	4.50%	none	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	none	1.00%	none
Redemption fees	none	none	none

Annual Fund Operating Expenses(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Loomis Sayles Absolute Strategies Fund		Class A	Class C	Class Y
Management fees		0.70%	0.70%	0.70%
Distribution and/or service (12b-1) fees		0.25%	1.00%	none
Other expenses-Fee/expense recovery	[1]	none	none	none
Other expenses-Remainder of other expenses		0.22%	0.21%	0.22%
Total other expenses		0.22%	0.21%	0.22%
Total annual fund operating expenses		1.17%	1.91%	0.92%
Fee waiver and/or expense reimbursement	[1]	none	none	none
Total annual fund operating expenses after fee waiver and/or expense reimbursement		1.17%	1.91%	0.92%

Example

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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

If shares are redeemed:

Expense Example Loomis Sayles Absolute Strategies Fund (USD $)	1 year	3 years	5 years	10 years
Class A	564	805	1,065	1,806
Class C	294	600	1,032	2,233
Class Y	94	293	509	1,131

If shares are not redeemed:

Expense Example, No Redemption (USD $)	1 year	3 years	5 years	10 years
Loomis Sayles Absolute Strategies Fund Class C	194	600	1,032	2,233

Portfolio Turnover

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 141% of the average value of its portfolio.

Investments, Risks and Performance Principal Investment Strategies

The Fund has an absolute return investment objective, which means that it is not managed relative to an index and that it attempts to achieve positive total returns over a full market cycle. The Fund intends to pursue its objective by utilizing a flexible investment approach that allocates investments across a global range of investment opportunities related to credit, currencies and interest rates, while employing risk management strategies to mitigate downside risk. The Fund may invest up to 100% of its total assets in below investment-grade fixed-income securities (also known as "junk bonds") and derivatives that have returns related to the returns on below investment-grade fixed-income securities, although it is expected that, under normal market conditions, the Fund's net exposure ( i.e. , long exposures obtained through direct investments in securities and in derivatives minus short exposures obtained through derivatives) to below investment-grade fixed-income assets generally will not exceed 50% of the Fund's total assets. Under normal market conditions, the Fund also may invest up to 50% of its total assets in investments denominated in non-U.S. currencies and related derivatives, including up to 20% in investments denominated in emerging market currencies and related derivatives. The Fund expects that its exposure to these asset classes will often be obtained substantially through the use of derivative instruments. The Fund defines an "emerging market currency" as a currency of a country that carries a sovereign debt quality rating that is rated below investment-grade by either Standard & Poor's Ratings Group ("S&P") or Moody's Investors Service, Inc. ("Moody's"), or is unrated by both S&P and Moody's. Currency positions that are intended to hedge the Fund's non-U.S. currency exposure ( i.e. , currency positions that are not made for investment purposes) will offset positions in the same currency that are made for investment purposes when calculating the limitation on investments in non-U.S. and emerging market currency investments because the Fund believes that hedging a currency position is likely to negate some or all of the currency risk associated with the original currency position. The Fund does not have limits on the duration of its portfolio, and the Fund's duration will change over time.

In selecting investments for the Fund, the Adviser develops long-term portfolio themes driven by macro-economic indicators. These include secular global economic trends, demographic trends and labor supply, analysis of global capital flows and assessments of geopolitical factors. The Adviser then develops shorter-term portfolio strategies based on factors including, but not limited to, economic, credit and Federal Reserve cycles, and top-down sector valuations and bottom-up security valuations. The Adviser employs active risk management, with a focus on credit, interest rate and currency risks. Additionally, the portfolio managers will use risk management tools in constructing and optimizing the portfolio and seek to manage risk on an ongoing basis. The portfolio management team expects to actively evaluate each investment idea based upon its return potential, its level of risk and its fit within the team's overall macro strategy when deciding whether to buy or sell investments, with the goal of continually optimizing the Fund's portfolio.

The Fund will pursue its investment goal by obtaining long investment exposures through direct cash investments and derivatives and short investment exposures substantially through derivatives. A "long" investment exposure is an investment that rises in value with a rise in the value of an asset, asset class or index and declines in value with a decline in the value of that asset, asset class or index. A "short" investment exposure is an investment that rises in value with a decline in the value of an asset, asset class or index and declines in value with a rise in the value of that asset, asset class or index. The Fund's long and short investment exposures may, at times, each reach 100% of the assets invested in the Fund (excluding instruments primarily used for duration management or yield curve management and short-term investments (such as cash and money market instruments)), although these exposures may be higher or lower at any given time.

Fixed-Income Investments. In connection with its principal investment strategies, the Fund may invest in a broad range of U.S. and non-U.S. fixed-income securities, including, but not limited to, corporate bonds, municipal securities, U.S. and non-U.S. government securities (including their agencies, instrumentalities and sponsored entities), securities of supranational entities, emerging market securities, commercial and residential mortgage-backed securities, collateralized mortgage obligations, other mortgage-related securities (such as adjustable rate mortgage securities), asset-backed securities, bank loans, convertible bonds, Rule 144A securities, real estate investment trusts ("REITs"), zero-coupon securities, step coupon securities, pay-in-kind ("PIK") securities, inflation-linked bonds, variable and floating rate securities, private placements and commercial paper.

Non-U.S. Currency Investments. Under normal market conditions, the Fund may engage in a broad range of transactions involving non-U.S. and emerging market currencies, including, but not limited to, purchasing and selling forward currency exchange contracts in non-U.S. or emerging market currencies, investing in non-U.S. currency futures contracts, investing in options on non-U.S. currencies and non-U.S. currency futures, investing in cross-currency instruments (such as swaps), investing directly in non-U.S. currencies and investing in securities denominated in non-U.S. currencies. The Fund may engage in non-U.S. currency transactions for investment or for hedging purposes.

Derivative Investments. For investment and hedging purposes, the Fund may invest substantially in a broad range of derivatives instruments and sometimes the majority of its investment returns will derive from its derivative investments. These derivative instruments include, but are not limited to, futures contracts (such as treasury futures and index futures), forward contracts, options (such as options on futures contracts, options on securities, interest rate/bond options, currency options, options on swaps and over-the-counter ("OTC") options), warrants (such as non-U.S. currency warrants) and swap transactions (such as interest rate swaps, total return swaps and index swaps). In addition, the Fund may invest in credit derivative products that may be used to manage default risk and credit exposure. Examples of such products include, but are not limited to, credit default swap index products (such as LCDX, CMBX and ABX index products), single name credit default swaps, loan credit default swaps and asset-backed credit default swaps. The Fund may, at times, invest substantially all of its assets in derivatives and securities used to support its obligations under those derivatives. Derivative instruments (such as those listed above) can be used to acquire or to transfer the risk and returns of a security or other asset without buying or selling the security or asset. The Fund's strategy may be highly dependent on the use of derivatives, and to the extent that they become unavailable or unattractive the Fund may be unable to fully implement its investment strategy.

The Fund is non-diversified, which means that it is not limited to a percentage of assets that it may invest in any one issuer. Because the Fund may invest in the securities of a limited number of issuers, an investment in the Fund may involve a higher degree of risk than would be present in a diversified portfolio.

The Fund expects to engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund's return, and realization of greater short-term capital gains, distributions of which are taxable as ordinary income to taxable shareholders. Trading costs and tax effects associated with frequent trading may adversely affect the Fund"s performance.

The percentage limitations set forth herein are not investment restrictions and the Fund may exceed these limits from time to time. In addition, when calculating these exposures, the Fund may use the market value, the notional value, an adjusted notional value or some other measure of the value of a derivative in order to reflect what the Adviser believes to be the most accurate assessment of the Fund's real economic exposure. The total notional value of the Fund's derivative instruments may significantly exceed the total value of the Fund's assets.

Although the Fund seeks positive total returns over time, the Fund's investment returns may be volatile over short periods of time. The Fund may outperform the overall securities market during periods of flat or negative performance and may underperform during periods of strong market performance. There can be no assurance that the Fund's returns over time or during any period will be positive.

Principal Risks

The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund.

Agency Securities Risk: Agency securities are subject to fixed-income securities risk. Certain debt securities issued or guaranteed by agencies of the U.S. government are guaranteed as to the payment of principal and interest by the relevant entity but have not been backed by the full faith and credit of the U.S. government. Instead, they have been supported only by the discretionary authority of the U.S. government to purchase the agency's obligations. An event affecting the guaranteeing entity could adversely affect the payment of principal or interest or both on the security and, therefore, these types of securities should be considered to be riskier than U.S. government securities.

Below Investment-Grade Fixed-Income Securities Risk: This is the risk that the Fund's investments in below investment-grade fixed-income securities, also known as "junk bonds," may be subject to greater risks than other fixed-income securities, including being subject to greater levels of interest rate risk, credit risk (including a greater risk of default) and liquidity risk. The ability of the issuer to make principal and interest payments is predominantly speculative for below investment-grade fixed-income securities.

Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with over-the-counter ("OTC") derivative transactions, such as foreign currency transactions. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its direct counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains.

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 a significant portion of its assets in currency-related instruments and may invest in securities or other instruments denominated in, or receive revenues in, foreign currencies. The Adviser may elect not to hedge currency risk, which may cause the Fund to incur losses that would not have been incurred had the risk been hedged.

Derivatives Risk: Derivatives are subject to changes in the value of the underlying asset or indices on which such transactions 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 markets 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 which would have occurred had derivatives not been used. The Fund's use of derivatives, such as futures, forward contracts, options, warrants, foreign currency transactions, swaps and credit default swaps, involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward contracts, swaps 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 perfectly with relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, a number of broker-dealers and other financial institutions have recently experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. There can be no assurance that the Fund's derivative counterparties will be able to avoid experiencing similar financial difficulties, possibly resulting in losses to the Fund.

Emerging Markets Risk: Investing in emerging markets companies, which may be smaller and have shorter operating histories than companies in developed markets, involves risks in addition to, and greater than, those generally associated with investing in companies in developed foreign markets. The extent of economic development, political stability, market depth, infrastructure, capitalization and regulatory oversight in emerging market economies is generally less than in more developed markets.

Fixed-Income Securities Risk: Fixed-income securities are subject to credit risk, interest rate risk and liquidity risk. You may lose money on your investment due to unpredictable drops in a security's value or periods of below-average performance in a given security or in the securities market as a whole. In addition, an economic downturn or period of rising interest rates could adversely affect the market of these securities and reduce the Fund's ability to sell them.

Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund's investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity.

Inflation/Deflation Risk: Inflation risk is the risk that the value of assets or income from investments will be worth less in the future as inflation decreases the present value of future payments. Deflation risk is the risk that prices throughout the economy decline over time (the opposite of inflation). Deflation may have an adverse effect on the creditworthiness of issuers and may make issuer default more likely, which may result in a decline in the value of the Fund's portfolio. Because the Fund seeks positive returns that exceed the rate of inflation over time, if the portfolio managers' inflation forecasts are incorrect, the Fund may be more severely impacted than other funds.

Interest Rate Risk: Changes in interest rates may cause the value of the Fund's investments to decrease. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. A period of low interest rates may cause the Fund to have a low or negative yield, potentially reducing the value of your investment. The value of zero-coupon and pay-in-kind ("PIK") bonds may be more sensitive to fluctuations in interest rates than other fixed-income securities. Rule 144A securities and structured notes may be more illiquid than other fixed-income securities.

Issuer Risk: The value of the Fund's investments may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods and services.

Leverage Risk: Use of derivative instruments may involve leverage. Leverage is the risk associated with securities or practices that multiply small index, market or asset price movements into larger changes in value. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. The use of leverage increases the impact of gains and losses on a fund's returns, and may lead to significant losses if investments are not successful. However, the Adviser will attempt to ensure that at all times the Fund has sufficient liquid assets to enable it to satisfy its obligations under its derivative contracts.

Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell, possibly preventing the Fund from selling these illiquid securities at an advantageous price or time. A lack of liquidity also may cause the value of investments to decline. Illiquid investments also may be difficult to value.

Management Risk: A strategy used by the Fund's portfolio managers may fail to produce the intended result.

Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer's financial condition, as well as overall market and economic conditions. The Fund's portfolio managers will attempt to reduce this risk by implementing various volatility management strategies and techniques. However, there is no guarantee that such strategies and techniques will produce the intended result.

Mortgage-Related and Asset-Backed Securities Risk: In addition to the risks associated with investments in fixed-income securities generally (for example, credit, liquidity and valuation risk), mortgage-related and asset-backed securities are subject to the risks of the mortgages and assets underlying the securities as well as prepayment risk, the risk that the securities may be prepaid and result in the reinvestment of the prepaid amounts in securities with lower yields than the prepaid obligations. Conversely, there is a risk that an unexpected rise in interest rates will extend the life of a mortgage-related or asset-backed security beyond the expected prepayment time, typically reducing the security's value. The Fund also may incur a loss when there is a prepayment of securities that were purchased at a premium. The Fund's investments in other asset-backed securities are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets.

Non-Diversification Risk: Compared with other mutual funds, the Fund may invest a greater percentage of its assets in a particular issuer and may invest in fewer issuers. Therefore, the Fund may have more risk because changes in the value of a single security or the impact of a single economic, political or regulatory occurrence may have a greater adverse impact on the Fund's NAV.

Short Exposure Risk: A short exposure through a derivative may present various risks, including credit/counterparty risk and leverage risk. If the value of the asset, asset class or index on which the Fund has obtained a short investment exposure increases, the Fund will incur a loss. Unlike a direct cash investment like a stock, bond or exchange-traded fund, where the potential loss is limited to the purchase price, the potential risk of loss from a short exposure is theoretically unlimited. Moreover, there can be no assurance that securities necessary to cover a short position will be available for purchase.

Risk/Return Bar Chart and Table

The bar chart and table shown below provide some indication of the risks of investing in the Fund by showing the Fund's performance in the first full year and by showing how the Fund's average annual returns for the one-year and life-of-Fund periods compare to those of a broad measure of market performance. 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 ngam.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.

Total Returns for Class A Shares

Highest Quarterly Return:
First Quarter 2011, 1.33%

Lowest Quarterly Return:
Third Quarter 2011, -4.69%

Average Annual Total Returns
(for the periods ended December 31, 2011)

Average Annual Total Returns Loomis Sayles Absolute Strategies Fund	Past 1 Year	Life of Fund	Inception Date
Class A	(8.20%)	(7.52%)	Dec. 15, 2010
Class C	(5.62%)	(4.22%)	Dec. 15, 2010
Class Y	(3.78%)	(3.24%)	Dec. 15, 2010
Return After Taxes on Distributions Class A	(9.20%)	(8.49%)	Dec. 15, 2010
Return After Taxes on Distributions & Sale of Fund Shares Class A	(5.29%)	(6.92%)	Dec. 15, 2010
3-month London Interbank Offered Rate (LIBOR)	0.27%	0.27%	Jan. 01, 2011

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 Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one–year period and life-of-Fund period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.

[1] 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 1.30%, 2.05% and 1.05% of the Fund's average daily net assets for Class A, C and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 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 1.30%, 2.05% and 1.05% of the Fund's average daily net assets for Class A, C and Y shares, respectively. 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.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	Natixis Funds Trust II
Prospectus Date	rr_ProspectusDate	May 01, 2012
Harris Associates Large Cap Value Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Harris Associates Large Cap Value Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Goal
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks opportunities for long-term capital growth and income.
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 and hold shares of the Fund. 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 Fund 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 90 of the Prospectus and on page 122 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	April 30, 2013
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 36% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	36.00%
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 Fund Complex.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	50,000
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods (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. 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 substantially all of its assets in common stock of large- and mid-capitalization companies in any industry. The Fund will invest at least 80% of its net assets (plus any borrowings made for investment purposes) in companies that have market capitalizations within the capitalization range of the Russell 1000 Index, a nationally recognized index of large-capitalization companies. While the market capitalization range for this index fluctuates, at March 31, 2012, it was $124 million to $557 billion. Harris Associates L.P. (“Harris Associates”) uses a value investment philosophy in selecting equity securities, including common stocks. This philosophy is based upon the belief that, over time, a company's stock price converges with the company's true business value. By “true business value,” Harris Associates means its estimate of the price a knowledgeable buyer would pay to acquire the entire business. Harris Associates believes that investing in securities priced significantly below their true business value presents the best opportunity to achieve the Fund's investment objectives. Harris Associates usually sells a stock when the price approaches its estimated worth or the company's fundamentals change. Harris Associates uses this value philosophy to identify companies that it believes have discounted stock prices compared to the companies' true business values. In assessing such companies, Harris Associates looks for the following characteristics, although not all of the companies selected will have these attributes: (1) free cash flows and intelligent investment of excess cash; (2) earnings that are growing and are reasonably predictable; and (3) high level of manager ownership. Once Harris Associates determines that a security is selling at what it believes to be a significant discount and that the issuer has the additional qualities mentioned above, Harris Associates generally will consider buying that security for the Fund. Harris Associates usually sells a security when the price approaches its estimated worth. Harris Associates also monitors each holding and adjusts those price targets as warranted to reflect changes in the issuer's fundamentals. The Fund's portfolio typically holds 30 to 60 stocks. The Fund may also invest in foreign securities traded in U.S. markets (through depositary receipt programs such as American Depositary Receipts (“ADRs”) or non-U.S. stocks traded in U.S. markets). ADRs are securities issued by a U.S. bank that represent shares of a foreign company. The Fund may also engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund's returns, and realization of short-term capital gains, distributions of which are taxable to shareholders who are individuals as ordinary income. Trading costs and tax effects associated with frequent trading may adversely affect the Fund's performance.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund. 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. Value stocks can perform differently from the market as a whole and from other types of stocks. Value stocks also present the risk that their lower valuations fairly reflect their business prospects and that investors will not agree that the stocks represent favorable investment opportunities, and they may fall out of favor with investors and underperform growth stocks during any given period. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer's bonds and preferred stock generally take precedence over the claims of those who own common stock. Focused Investment Risk: Because the Fund may invest in a small number of industries or securities, it may have more risk because the impact of a single economic, political or regulatory occurrence may have a greater adverse impact on the Fund's net asset value. Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund's investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity. Management Risk: A strategy used by the Fund's portfolio managers may fail to produce the intended result. Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer's financial condition, as well as overall market and economic conditions.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose money by investing in the Fund.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Risk/Return Bar Chart and Table Shares
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 measure of market performance. 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 ngam.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.
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 measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-225-5478
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	ngam.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 A 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 Return: Second Quarter 2009, 24.17% Lowest Quarterly Return: Fourth Quarter 2008, -27.03% Class B total returns in the table below do not reflect the automatic conversion of Class B shares to Class A shares after eight years.
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
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 Fund shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, 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 Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The Return After Taxes on Distributions & Sale of Fund Shares for the 1-year and 5-year periods exceeds the Return Before Taxes due to an assumed tax benefit from tax losses on a sale of Fund shares at the end of the measurement period.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	Prior to May 1, 2012, Class Y shares were offered in a separate prospectus and given that Class Y shares are now offered in this multi-class prospectus, Total Returns, Return After Taxes on Distributions and Return After Taxes on Distributions & Sale of Fund Shares are now presented for Class A shares. The Fund's current subadviser assumed that function on July 1, 2002. The performance results shown above, for the periods prior to July 1, 2002, reflect results achieved by different subadvisers under different investment strategies. 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 Fund shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, 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. The Return After Taxes on Distributions & Sale of Fund Shares for the 1-year and 5-year periods exceeds the Return Before Taxes due to an assumed tax benefit from tax losses on a sale of Fund shares at the end of the measurement period.
Harris Associates Large Cap Value 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
Redemption fees	rr_RedemptionFeeOverRedemption	none
Management fees	rr_ManagementFeesOverAssets	0.70%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses-Fee/expense recovery	rr_Component1OtherExpensesOverAssets	0.01%	[1]
Other expenses-Remainder of other expenses	rr_Component2OtherExpensesOverAssets	0.34%
Total other expenses	rr_OtherExpensesOverAssets	0.35%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.30%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.30%
1 year	rr_ExpenseExampleYear01	700
3 years	rr_ExpenseExampleYear03	963
5 years	rr_ExpenseExampleYear05	1,247
10 years	rr_ExpenseExampleYear10	2,053
2002	rr_AnnualReturn2002	(20.03%)
2003	rr_AnnualReturn2003	30.04%
2004	rr_AnnualReturn2004	9.14%
2005	rr_AnnualReturn2005	(0.19%)
2006	rr_AnnualReturn2006	16.50%
2007	rr_AnnualReturn2007	(2.94%)
2008	rr_AnnualReturn2008	(40.45%)
2009	rr_AnnualReturn2009	44.03%
2010	rr_AnnualReturn2010	13.08%
2011	rr_AnnualReturn2011	(1.56%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	24.17%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(27.03%)
Past 1 Year	rr_AverageAnnualReturnYear01	(7.20%)
Past 5 Years	rr_AverageAnnualReturnYear05	(2.68%)
Past 10 Years	rr_AverageAnnualReturnYear10	1.43%
Harris Associates Large Cap Value Fund | Class B
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	5.00%
Redemption fees	rr_RedemptionFeeOverRedemption	none
Management fees	rr_ManagementFeesOverAssets	0.70%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses-Fee/expense recovery	rr_Component1OtherExpensesOverAssets	0.01%	[1]
Other expenses-Remainder of other expenses	rr_Component2OtherExpensesOverAssets	0.34%
Total other expenses	rr_OtherExpensesOverAssets	0.35%
Total annual fund operating expenses	rr_ExpensesOverAssets	2.05%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	2.05%
1 year	rr_ExpenseExampleYear01	708
3 years	rr_ExpenseExampleYear03	943
5 years	rr_ExpenseExampleYear05	1,303
10 years	rr_ExpenseExampleYear10	2,187
1 year	rr_ExpenseExampleNoRedemptionYear01	208
3 years	rr_ExpenseExampleNoRedemptionYear03	643
5 years	rr_ExpenseExampleNoRedemptionYear05	1,103
10 years	rr_ExpenseExampleNoRedemptionYear10	2,187
Past 1 Year	rr_AverageAnnualReturnYear01	(7.23%)
Past 5 Years	rr_AverageAnnualReturnYear05	(2.64%)
Past 10 Years	rr_AverageAnnualReturnYear10	1.26%
Harris Associates Large Cap Value 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	0.70%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses-Fee/expense recovery	rr_Component1OtherExpensesOverAssets	0.01%	[1]
Other expenses-Remainder of other expenses	rr_Component2OtherExpensesOverAssets	0.34%
Total other expenses	rr_OtherExpensesOverAssets	0.35%
Total annual fund operating expenses	rr_ExpensesOverAssets	2.05%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	2.05%
1 year	rr_ExpenseExampleYear01	308
3 years	rr_ExpenseExampleYear03	643
5 years	rr_ExpenseExampleYear05	1,103
10 years	rr_ExpenseExampleYear10	2,379
1 year	rr_ExpenseExampleNoRedemptionYear01	208
3 years	rr_ExpenseExampleNoRedemptionYear03	643
5 years	rr_ExpenseExampleNoRedemptionYear05	1,103
10 years	rr_ExpenseExampleNoRedemptionYear10	2,379
Past 1 Year	rr_AverageAnnualReturnYear01	(3.25%)
Past 5 Years	rr_AverageAnnualReturnYear05	(2.25%)
Past 10 Years	rr_AverageAnnualReturnYear10	1.26%
Harris Associates Large Cap Value 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	0.70%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses-Fee/expense recovery	rr_Component1OtherExpensesOverAssets	0.01%	[1]
Other expenses-Remainder of other expenses	rr_Component2OtherExpensesOverAssets	0.34%
Total other expenses	rr_OtherExpensesOverAssets	0.35%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.05%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.05%
1 year	rr_ExpenseExampleYear01	107
3 years	rr_ExpenseExampleYear03	334
5 years	rr_ExpenseExampleYear05	579
10 years	rr_ExpenseExampleYear10	1,283
Past 1 Year	rr_AverageAnnualReturnYear01	(1.40%)
Past 5 Years	rr_AverageAnnualReturnYear05	(1.20%)
Past 10 Years	rr_AverageAnnualReturnYear10	2.40%
Return After Taxes on Distributions | Harris Associates Large Cap Value Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(7.28%)
Past 5 Years	rr_AverageAnnualReturnYear05	(2.78%)
Past 10 Years	rr_AverageAnnualReturnYear10	1.37%
Return After Taxes on Distributions & Sale of Fund Shares | Harris Associates Large Cap Value Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(4.56%)
Past 5 Years	rr_AverageAnnualReturnYear05	(2.27%)
Past 10 Years	rr_AverageAnnualReturnYear10	1.22%
Russell 1000 Value Index | Harris Associates Large Cap Value Fund
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	0.39%
Past 5 Years	rr_AverageAnnualReturnYear05	(2.64%)
Past 10 Years	rr_AverageAnnualReturnYear10	3.89%

[1] The Fund's investment adviser has given a binding contractual undertaking to the Fund to limit the amount of the Fund's total annual fund operating expenses to 1.30%, 2.05%, 2.05% and 1.05% of the Fund's average daily net assets for Class A, Class B, Class C and Class Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 and may be terminated before then only with the consent of the Fund's Board of Trustees. The Fund's investment 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 1.30%, 2.05%, 2.05% and 1.05% of the Fund's average daily net assets for Class A, Class B, Class C and Class Y shares, respectively. 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.

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Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Prospectus Date	rr_ProspectusDate	May 01, 2012
Registrant Name	dei_EntityRegistrantName	Natixis Funds Trust II
Loomis Sayles Multi-Asset Real Return Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Loomis Sayles Multi-Asset Real Return Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Goal
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to maximize real returns consistent with prudent investment management.
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 and hold shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in the Natixis Fund 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 70 of the Prospectus and on page 103 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	April 30, 2013
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 732% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	732.00%
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 $100,000 in the Natixis Fund Complex.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	100,000
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	(restated to reflect current expenses)
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 example is based on Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and on the Total Annual Fund Operating Expenses for the remaining years. 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	The Fund will pursue its investment goal primarily through exposure to investments in fixed-income securities, equity securities, currencies and commodity-linked instruments. The Fund expects that its exposure to these asset classes will often be obtained substantially through the use of derivative instruments. The Fund is designed for investors seeking "real returns" (i.e ., total returns that exceed the rate of inflation over a full market cycle regardless of market conditions). Although the Fund seeks positive total returns over time, the Fund's investment returns may be volatile over short periods of time. The Fund may outperform the overall securities market during periods of flat or negative market performance and may underperform during periods of strong market performance. There can be no assurance that the Fund's returns over time or during any period will be positive or that the Fund will provide returns in excess of inflation over time or during any particular period. The Fund does not have limits on the duration of its portfolio, and the Fund's duration will change over time. In selecting investments for the Fund, the Adviser seeks to draw on its macroeconomic research in global inflationary cycles to identify and to implement investment opportunities that it believes will outpace inflation in a variety of inflationary environments. Using a global asset allocation analysis, the portfolio managers seek to identify the relative return potential of various asset classes. This analysis is intended to provide the foundation for weighting the asset classes as a whole to develop a portfolio with superior risk and return characteristics in the view of the Adviser. The Adviser expects to use a bottom-up investment process to generate investment ideas consistent with the expectations for the asset classes. Additionally, the portfolio managers will use risk management tools to construct the portfolio and manage risk and volatility on an ongoing basis with an objective of targeting a relatively stable level of annualized volatility for the Fund's overall portfolio. The portfolio management team expects to actively evaluate each investment idea based upon its return potential, its level of risk and its fit within the team's overall macro strategy when deciding whether to buy or sell investments, with the goal of continually optimizing the Fund's portfolio. The Fund will pursue its investment goal by obtaining long investment exposures through direct cash investments and derivatives and short investment exposures substantially through derivatives. A "long" investment exposure is an investment that rises in value with a rise in the value of an asset, asset class or index and declines in value with a decline in the value of that asset, asset class or index. A "short" investment exposure is an investment that rises in value with a decline in the value of an asset, asset class or index and declines in value with a rise in the value of that asset, asset class or index. The Fund's long and short investment exposures may, at times, each reach 100% of the assets invested in the Fund (excluding instruments primarily used for duration management or yield curve management and short-term investments (such as cash and money market instruments)), although these exposures may be higher or lower at any given time. Fixed-Income Investments. Under normal market conditions, the Fund expects to invest at least 50% of its net assets in fixed-income securities and derivatives that have returns related to the returns on fixed-income securities. At times, the Fund expects to gain this exposure substantially through the use of derivatives. The Fund may invest in a broad range of U.S. and non-U.S. fixed-income securities, including, but not limited to, corporate bonds, municipal securities, U.S. and non-U.S. government securities (including their agencies, instrumentalities and sponsored entities), securities of supranational entities, partnership securities, commercial and residential mortgage-backed securities, other mortgage-related securities (such as adjustable rate mortgage securities), asset-backed securities, bank loans, depositary receipts, convertible bonds, Rule 144A securities, real estate investment trusts ("REITs"), zero-coupon securities, step coupon securities, stripped securities, pay-in-kind ("PIK") securities, inflation-linked bonds, variable and floating rate securities, when-issued securities, private placements, privatizations, hybrid instruments, structured investments, repurchase agreements and commercial paper. The Fund may invest in securities of any maturity, market sector or credit quality, including below investment-grade fixed-income securities (also known as "junk bonds"). Below investment-grade fixed-income securities are below investment-grade quality (i.e., none of the three major rating agencies (Moody's Investors Service, Inc. ("Moody's"), Fitch Investors Service, Inc. ("Fitch") or Standard & Poor's Ratings Group ("S&P")) have rated the securities in one of their top four ratings categories) or, if the security is unrated, the Adviser has determined it to be of comparable quality. Equity Investments. Although the Fund expects that in normal market conditions it will have net long equity exposures, in the Adviser's sole discretion the Fund may have net short equity exposures of up to 35% of the Fund's total assets and gross short equity exposures of up to 70% of the Fund's total assets. At times, the Fund expects to gain this exposure substantially through the use of derivatives. For these purposes, a short equity position is a position that will decline in value with a rise of the equity markets. A gross short equity position represents the total of all short positions without regard to any offsetting long positions. A net short equity position is the total of all short positions offset by any long positions (e.g., a direct investment in a stock). The Adviser may have net short equity exposures for investment or hedging purposes, including but not limited to macro hedges to protect the Fund's entire portfolio or more targeted hedges to neutralize specific components of the Fund's equity market exposure. The Fund may invest in a broad range of U.S. and non-U.S. equity securities, including, but not limited to, common and preferred stocks, convertible preferred stocks, depositary receipts, warrants, rights, Rule 144A securities, private placements, privatizations and hybrid instruments. The Fund may invest in securities of issuers of any market capitalization. In addition to direct investment in securities and other instruments, the Fund may invest in other funds, including exchange-traded funds ("ETFs"), unit investment trusts, and other pooled investment vehicles that may or may not be registered under the 1940 Act. The Fund may invest in REITs and U.S. and non-U.S. real estate companies. Non-U.S. Currency Investments. Under normal market conditions, the Fund expects to invest up to 30% of its total assets in investments in non-U.S. currencies, securities denominated in non-U.S. currencies and related derivative transactions. The Fund may engage in a broad range of transactions involving non-U.S. currencies, including, but not limited to, purchasing and selling forward currency exchange contracts in non-U.S. currencies, investing in non-U.S. currency futures contracts, investing in options on non-U.S. currencies and non-U.S. currency futures, cross-hedging between two or more currencies, investing directly in non-U.S. currencies and investing in securities denominated in non-U.S. currencies, including securities of emerging market issuers. The Fund may engage in non-U.S. currency transactions for investment or for hedging purposes. Currency positions that are intended to hedge the Fund's non-U.S. currency exposure (i.e., currency positions that are not made for investment purposes) will offset positions in the same currency that are made for investment purposes when calculating the 30% limitation in investments in non-U.S. currency investments because the Fund believes that hedging a currency position is likely to negate some or all of the currency risk associated with the original currency position. Commodity Investments. Under normal market conditions, the Fund expects that up to 25% of its total assets will be invested in commodity-linked instruments. Commodities are assets that have tangible properties, such as oil, metals, and agricultural products. A "commodity-linked instrument" is an instrument whose value is linked to the price movement of a commodity, a commodity index, or a commodity option or futures contract. An investment in a commodity-linked instrument does not generally provide a claim to the tangible underlying commodity. The Fund and a wholly-owned subsidiary organized under the laws of the Cayman Islands (the "Commodity Subsidiary") may invest in a broad range of commodity-linked instruments, including, but not limited to, commodity-linked derivatives (such as commodity-linked swaps, futures, options or options on futures), commodity-linked debt (including leveraged or unleveraged notes that are derivative debt instruments with principal and/or coupon payments linked to the performance of commodities) or commodity-linked ETFs (i.e., ETFs that have their value derived from the price movement of an underlying commodity). The Fund also may invest in equity and fixed-income securities of issuers in commodity-related industries. These investments will not be counted toward the 25% limitation on investments in commodity-linked instruments, but rather will be considered investments in equity securities or fixed-income securities, as appropriate. The Fund expects to obtain its investment exposure to commodity-linked instruments in whole or in significant part indirectly by investing in the Commodity Subsidiary, although in certain circumstances it is possible that the Fund may also invest directly in certain commodity-linked instruments. The Commodity Subsidiary is advised by the Adviser and will invest primarily in commodity-linked instruments and fixed-income securities and other investments that serve as collateral for its derivative positions. The Fund may invest up to 25% of its total assets in the Commodity Subsidiary. Derivative Investments. The Fund may invest substantially in a broad range of derivative instruments for both hedging and investment purposes, including, but not limited to, futures contracts (such as futures that provide for physical delivery, treasury futures, single stock futures, and index futures), forward contracts, options (such as options on futures contracts, options on securities, options on securities indices, interest rate/bond options, currency options, options on swaps and exchange-traded and over-the-counter options), warrants (such as index warrants), swap transactions (such as interest rate swaps, total return swaps, index swaps and equity swaps), structured notes, foreign currency transactions, commodity-linked derivatives and credit default swaps. The Fund may, at times, invest substantially all of its assets in derivatives and securities used to support its obligations under those derivatives. Derivative instruments (such as those listed above) can be used to acquire or to transfer the risk and returns of a security or other asset without buying or selling the security or asset. The Fund's strategy may be highly dependent on the use of derivatives, and to the extent that they become unavailable or unattractive the Fund may be unable to fully implement its investment strategy. The Fund is non-diversified, which means that it is not limited to a percentage of assets that it may invest in any one issuer. Because the Fund may invest in the securities of a limited number of issuers, an investment in the Fund may involve a higher degree of risk than would be present in a diversified portfolio. The Fund expects to engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund's return, and realization of greater short-term capital gains, distributions of which are taxable as ordinary income to taxable shareholders. Trading costs and tax effects associated with frequent trading may adversely affect the Fund's performance. The percentage limitations set forth herein are not investment restrictions and the Fund may exceed these limits from time to time. In addition, when calculating these exposures, the Fund may use the market value, the notional value, an adjusted notional value or some other measure of the value of a derivative in order to reflect what the Adviser believes to be the most accurate assessment of the Fund's real economic exposure. The total notional value of the Fund's derivative instruments may significantly exceed the total value of the Fund's assets. Although the Fund will not concentrate more than 25% of its total assets in issuers in any one industry, it may maintain aggregate exposure of more than 25% of its total assets to commodity-linked and commodity-related investments, and therefore may be significantly exposed to commodity-related risks.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund. Agency Securities Risk: Agency securities are subject to fixed-income securities risk. Certain debt securities issued or guaranteed by agencies of the U.S. government are guaranteed as to the payment of principal and interest by the relevant entity but have not been backed by the full faith and credit of the U.S. government. Instead, they have been supported only by the discretionary authority of the U.S. government to purchase the agency's obligations. An event affecting the guaranteeing entity could adversely affect the payment of principal or interest or both on the security and, therefore, these types of securities should be considered to be riskier than U.S. government securities. Below Investment-Grade Fixed-Income Securities Risk: This is the risk that the Fund's investments in below investment-grade fixed-income securities, also known as "junk bonds," may be subject to greater risks than other fixed-income securities, including being subject to greater levels of interest rate risk, credit risk (including a greater risk of default) and liquidity risk. The ability of the issuer to make principal and interest payments is predominantly speculative for below investment-grade fixed-income securities. Commodity Risk: This is the risk that exposure to the commodities markets may subject the Fund to greater volatility than investments in traditional securities. The value of physical commodities or commodity-linked derivative instruments may be affected by changes in overall market movements, commodity price volatility, changes in interest rates, currency fluctuations, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. Recent rulemaking by the Commodity Futures Trading Commission ("CFTC") may affect the Fund's ability to pursue its investment strategies or increase the Fund's expenses. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Commodity Subsidiary Risk: Investing in the Commodity Subsidiary will indirectly expose the Fund to the risks associated with the Commodity Subsidiary's investments, such as commodity investment risk. The Commodity Subsidiary is not registered under the Investment Company Act of 1940 (the "1940 Act") and is not subject to all of the investor protections of the 1940 Act. Recent rulemaking by the CFTC may affect the Fund's ability to use the Commodity Subsidiary to pursue its investment strategies. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Changes in the laws of the United States and/or the Cayman Islands, under which the Fund and the Commodity Subsidiary, respectively, are organized, could negatively affect the Fund and its shareholders. Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with over-the-counter ("OTC") derivative transactions, such as foreign currency transactions. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its direct counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains. 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 a significant portion of its assets in currency-related instruments and may invest in securities or other instruments denominated in, or receive revenues in, foreign currencies. The Adviser may elect not to hedge currency risk, which may cause the Fund to incur losses that would not have been incurred had the risk been hedged. Derivatives Risk: Derivatives are subject to changes in the value of the underlying asset or indices on which such transactions 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 markets 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 which would have occurred had derivatives not been used. The Fund's use of derivatives, such as futures, forward contracts, and other foreign currency transactions and commodity-linked derivatives involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward 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 perfectly with relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, a number of broker-dealers and other financial institutions have recently experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. There can be no assurance that the Fund's derivative counterparties will be able to avoid experiencing similar financial difficulties, possibly resulting in losses to the Fund. Emerging Markets Risk: Investing in emerging markets companies, which may be smaller and have shorter operating histories than companies in developed markets, involves risks in addition to, and greater than, those generally associated with investing in companies in developed foreign markets. The extent of economic development, political stability, market depth, infrastructure, capitalization and regulatory oversight in emerging market economies is generally less than in more developed markets. Equity Securities Risk: The value of the Fund's investments in equity securities could be subject to unpredictable declines in the value of the individual securities and periods of below average performance in individual securities or the equity market as a whole. Rule 144A equity securities may be less liquid than other equity securities. Small-capitalization and emerging growth companies may be subject to more abrupt price movements, limited markets and less liquidity than larger, more established companies, which could adversely affect the value of the Fund's portfolio. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer's bonds and preferred stock generally take precedence over the claims of those who own common stock. Fixed-Income Securities Risk: Fixed-income securities are subject to credit risk, interest rate risk and liquidity risk. You may lose money on your investment due to unpredictable drops in a security's value or periods of below-average performance in a given security or in the securities market as a whole. In addition, an economic downturn or period of rising interest rates could adversely affect the market of these securities and reduce the Fund's ability to sell them. Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund's investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity. Inflation/Deflation Risk: Inflation risk is the risk that the value of assets or income from investments will be worth less in the future as inflation decreases the present value of future payments. Deflation risk is the risk that prices throughout the economy decline over time (the opposite of inflation). Deflation may have an adverse effect on the creditworthiness of issuers and may make issuer default more likely, which may result in a decline in the value of the Fund's portfolio. Because the Fund seeks positive returns that exceed the rate of inflation over time, if the portfolio managers' inflation forecasts are incorrect, the Fund may be more severely impacted than other funds. Interest Rate Risk: Changes in interest rates may cause the value of the Fund's investments to decrease. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. A period of low interest rates may cause the Fund to have a low or negative yield, potentially reducing the value of your investment. The value of zero-coupon and pay-in-kind ("PIK") bonds may be more sensitive to fluctuations in interest rates than other fixed-income securities. Rule 144A securities may be more illiquid than other fixed-income securities. Investments in Other Investment Companies Risk: The Fund will indirectly bear the management, service and other fees of any other investment companies in which it invests in addition to its own expenses. Issuer Risk: The value of the Fund's investments may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods and services. Leverage Risk: Use of derivative instruments may involve leverage. Leverage is the risk associated with securities or practices that multiply small index, market or asset price movements into larger changes in value. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. The use of leverage increases the impact of gains and losses on a fund's returns, and may lead to significant losses if investments are not successful. However, the Adviser will attempt to ensure that at all times the Fund has sufficient liquid assets to enable it to satisfy its obligations under its derivative contracts. Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell, possibly preventing the Fund from selling these illiquid securities at an advantageous price or time. A lack of liquidity also may cause the value of investments to decline. Illiquid investments also may be difficult to value. Management Risk: A strategy used by the Fund's portfolio managers may fail to produce the intended result. Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer's financial condition, as well as overall market and economic conditions. The Fund's portfolio managers will attempt to reduce this risk by implementing various volatility management strategies and techniques. However, there is no guarantee that such strategies and techniques will produce the intended result. Mortgage-Related and Asset-Backed Securities Risk: In addition to the risks associated with investments in fixed-income securities generally (for example, credit, liquidity and valuation risk), mortgage-related and asset-backed securities are subject to the risks of the mortgages and assets underlying the securities as well as prepayment risk, the risk that the securities may be prepaid and result in the reinvestment of the prepaid amounts in securities with lower yields than the prepaid obligations. Conversely, there is a risk that an unexpected rise in interest rates will extend the life of a mortgage-related or asset-backed security beyond the expected prepayment time, typically reducing the security's value. The Fund also may incur a loss when there is a prepayment of securities that were purchased at a premium. The Fund's investments in other asset-backed securities are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets. Non-Diversification Risk: Compared with other mutual funds, the Fund may invest a greater percentage of its assets in a particular issuer and may invest in fewer issuers. Therefore, the Fund may have more risk because changes in the value of a single security or the impact of a single economic, political or regulatory occurrence may have a greater adverse impact on the Fund's NAV. Short Exposure Risk: A short exposure through a derivative may present various risks, including credit/counterparty risk and leverage risk. If the value of the asset, asset class or index on which the Fund has obtained a short investment exposure increases, the Fund will incur a loss. Unlike a direct cash investment like a stock, bond or exchange-traded fund, where the potential loss is limited to the purchase price, the potential risk of loss from a short exposure is theoretically unlimited. Moreover, there can be no assurance that securities necessary to cover a short position will be available for purchase.
Risk Lose Money [Text]	rr_RiskLoseMoney	You may lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-Diversification Risk: Compared with other mutual funds, the Fund may invest a greater percentage of its assets in a particular issuer and may invest in fewer issuers. Therefore, the Fund may have more risk because changes in the value of a single security or the impact of a single economic, political or regulatory occurrence may have a greater adverse impact on the Fund's NAV.
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 the Fund's performance in the first full year and by showing how the Fund's average annual returns for the one-year and life-of-Fund periods compare to those of a broad measure of market performance. 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 ngam.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.
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 the Fund’s performance in the first full year and by showing how the Fund’s average annual returns for the one-year and life-of-Fund periods compare to those of a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-225-5478
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	ngam.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 A 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 Return: First Quarter 2011, 0.69% Lowest Quarterly Return: Third Quarter 2011, -4.25%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
Index No Deduction for Fees, Expenses, Taxes [Text]	rr_IndexNoDeductionForFeesExpensesTaxes	Index performance returns reflect 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 Fund shares through tax-deferred 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 Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period and life-of-Fund period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	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 Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period and life-of-Fund period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.
Loomis Sayles Multi-Asset Real Return Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	4.50%
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	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.93%
Acquired fund fess and expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.08%
Total annual fund operating expenses	rr_ExpensesOverAssets	2.01%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.58%	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.43%
1 year	rr_ExpenseExampleYear01	589
3 years	rr_ExpenseExampleYear03	999
5 years	rr_ExpenseExampleYear05	1,433
10 years	rr_ExpenseExampleYear10	2,638
2011	rr_AnnualReturn2011	(5.76%)
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarterly Return:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Mar. 31, 2011
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	0.69%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarterly Return:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(4.25%)
Past 1 Year	rr_AverageAnnualReturnYear01	(10.02%)
Life of Fund	rr_AverageAnnualReturnSinceInception	(6.53%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2010
Loomis Sayles Multi-Asset Real Return 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	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	0.79%
Acquired fund fess and expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.08%
Total annual fund operating expenses	rr_ExpensesOverAssets	2.62%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.44%	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	2.18%
1 year	rr_ExpenseExampleYear01	321
3 years	rr_ExpenseExampleYear03	773
5 years	rr_ExpenseExampleYear05	1,351
10 years	rr_ExpenseExampleYear10	2,921
1 year	rr_ExpenseExampleNoRedemptionYear01	221
3 years	rr_ExpenseExampleNoRedemptionYear03	773
5 years	rr_ExpenseExampleNoRedemptionYear05	1,351
10 years	rr_ExpenseExampleNoRedemptionYear10	2,921
Past 1 Year	rr_AverageAnnualReturnYear01	(7.36%)
Life of Fund	rr_AverageAnnualReturnSinceInception	(3.76%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2010
Loomis Sayles Multi-Asset Real Return 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	0.75%
Distribution and/or service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.86%
Acquired fund fess and expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.08%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.69%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.51%	[1]
Total annual fund operating expenses after fee waiver and/or expense reimbursement	rr_NetExpensesOverAssets	1.18%
1 year	rr_ExpenseExampleYear01	120
3 years	rr_ExpenseExampleYear03	483
5 years	rr_ExpenseExampleYear05	870
10 years	rr_ExpenseExampleYear10	1,955
Past 1 Year	rr_AverageAnnualReturnYear01	(5.52%)
Life of Fund	rr_AverageAnnualReturnSinceInception	(2.82%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2010
Return After Taxes on Distributions | Loomis Sayles Multi-Asset Real Return Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(10.65%)
Life of Fund	rr_AverageAnnualReturnSinceInception	(7.25%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2010
Return After Taxes on Distributions & Sale of Fund Shares | Loomis Sayles Multi-Asset Real Return Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	(6.46%)
Life of Fund	rr_AverageAnnualReturnSinceInception	(5.92%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2010
Barclays U.S. TIPS Index | Loomis Sayles Multi-Asset Real Return Fund
Risk/Return:	rr_RiskReturnAbstract
Past 1 Year	rr_AverageAnnualReturnYear01	13.56%
Life of Fund	rr_AverageAnnualReturnSinceInception	10.14%
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2010

[1] 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 1.35%, 2.10% and 1.10% of the Fund's average daily net assets for Class A, C and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 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 1.35%, 2.10% and 1.10% of the Fund's average daily net assets for Class A, C and Y shares, respectively. The Fund will not be obligated to repay any such waived/reimbursed fees or expenses more than one year after the end of the fiscal year in which the fees or expenses were waived/reimbursed.

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ASG Global Alternatives Fund

ASG Global Alternatives Fund

Investment Goal

The Fund pursues an absolute return strategy that seeks to provide capital appreciation consistent with the risk-return characteristics of a diversified portfolio of hedge funds.

The secondary goal of the Fund is to achieve these returns with less volatility than major equity indices.

Fund Fees & Expenses

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. 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 Fund 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 70 of the Prospectus and on page 103 in the section “Reduced Sales Charges” of the Statement of Additional Information (“SAI”).

Shareholder Fees(fees paid directly from your investment)

Shareholder Fees ASG Global Alternatives Fund	Class A	Class C	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%	none	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	none	1.00%	none
Redemption fees	none	none	none

Annual Fund Operating Expenses(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses ASG Global Alternatives Fund		Class A	Class C	Class Y
Management fees		1.15%	1.15%	1.15%
Distribution and/or service (12b-1) fees		0.25%	1.00%	none
Other expenses		0.21%	0.21%	0.22%
Total annual fund operating expenses		1.61%	2.36%	1.37%
Fee waiver and/or expense reimbursement	[1]	none	none	0.01%
Total annual fund operating expenses after fee waiver and/or expense reimbursement		1.61%	2.36%	1.36%

Example

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 example is based on Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first year and on the Total Annual Fund Operating Expenses for the remaining years. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

If shares are redeemed:

Expense Example ASG Global Alternatives Fund (USD $)	1 year	3 years	5 years	10 years
Class A	729	1,054	1,401	2,376
Class C	339	736	1,260	2,696
Class Y	138	433	749	1,645

If shares are not redeemed:

Expense Example, No Redemption (USD $)	1 year	3 years	5 years	10 years
ASG Global Alternatives Fund Class C	239	736	1,260	2,696

Portfolio Turnover

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. Due to the short-term nature of the Fund’s investment portfolio, the Fund does not calculate a portfolio turnover rate.

Investments, Risks and Performance Principal Investment Strategies

The Fund seeks to achieve long and short exposure to global equity, bond, currency and commodity markets through a wide range of derivative instruments and direct investments. Under normal market conditions, the Adviser typically will make extensive use of derivative instruments, in particular futures and forward contracts on global equity and fixed income securities, securities indices (including both broad- and narrow-based securities indices), currencies, commodities and other instruments. These investments are intended to provide the Fund with risk and return characteristics similar to those of a diversified portfolio of hedge funds.

The Fund seeks to generate absolute returns over time rather than track the performance of any particular index of hedge fund returns. In selecting investments for the Fund, the Adviser uses quantitative models to estimate the market exposures that drive the aggregate returns of a diverse set of hedge funds. These market exposures may include, for example, exposures to the returns of stocks, fixed income securities (including U.S. and non-U.S. government securities), currencies and commodities. In estimating these market exposures, the Adviser analyzes the returns of hedge funds included in one or more commercially available databases selected by the Adviser (for example, the Lipper TASS hedge fund database), and seeks to use a variety of derivative instruments to capture such exposures in the aggregate while adding value through dynamic allocation among market exposures and volatility management. The Adviser will have great flexibility to allocate the Fund’s derivatives exposure among various securities, indices, currencies, commodities and other instruments; the amount of the Fund’s assets that may be allocated to derivative strategies and among these various instruments is expected to vary over time. When buying and selling securities and other instruments for the Fund, and in determining the amount of assets to be allocated to the Money Market Portion (as defined below), the Adviser will also consider the following factors: (i) the Fund’s obligations under its various derivative positions; (ii) redemption requests; (iii) yield management; (iv) credit management and (v) volatility management. The Fund will not invest directly in hedge funds. The Fund may invest in non-U.S. securities and instruments and securities and instruments traded outside the United States, and expects to engage in non-U.S. currency transactions.

Under normal market conditions, it is expected that no more than 25% of the Fund’s total assets will be dedicated to initial and variation margin payments relating to the Fund’s derivative transactions. The gross notional value of the Fund’s derivative investments, however, will generally exceed 25% of the Fund’s assets, and may significantly exceed the total value of the Fund’s assets. The Fund expects that under normal market conditions it will invest at least 75% of its total assets in money market and other short-term, high quality securities (the “Money Market Portion”) managed by Reich & Tang Asset Management, LLC (the “Subadviser”), although the Fund may invest less than this percentage. The Adviser will determine the percentage of the Fund’s assets that will be invested in the Money Market Portion at any time. The assets allocated to the Money Market Portion will be used primarily to finance the Fund’s investments in derivatives and similar instruments and, secondarily, to provide the Fund with incremental income and liquidity. Although the Fund will invest a significant portion of its assets in money market instruments, the Fund is not a “money market” fund and the value of the Money Market Portion as well as the value of the Fund’s shares may decrease. The Fund is not subject to the portfolio quality, maturity and net asset value requirements applicable to money market funds, and the Fund will not seek to maintain a stable net asset value.

The Subadviser will only invest the assets of the Money Market Portion in high quality securities which are denominated in U.S. dollars, and will select securities for investment based on various factors, including the security’s maturity and rating.

The Subadviser will invest primarily in (i) short-term obligations issued or guaranteed by the United States government, its agencies or instrumentalities (“U.S. Government Obligations”); (ii) securities issued by foreign governments, their political subdivisions or agencies or instrumentalities; (iii) certificates of deposit, time deposits and bankers’ acceptances issued by domestic banks, foreign branches of domestic banks, foreign subsidiaries of domestic banks, and domestic and foreign branches of foreign banks; (iv) variable amount master demand notes; (v) participation interests in loans extended by banks to companies; (vi) commercial paper or similar debt obligations; and (vii) repurchase agreements.

Although the Fund does not intend to invest in physical commodities directly, the Fund expects to obtain investment exposure to commodity-related derivatives through a wholly-owned subsidiary organized under the laws of the Cayman Islands that will make commodity-related investments (the “Commodity Subsidiary”). Under normal market conditions, no more than 10% of the Fund’s total assets will be dedicated to initial and variation margin payments relating to these transactions.

The Fund will concentrate its investments in the financial services industry, which means it will normally invest at least 25% of its total assets in securities and other obligations (for example, bank certificates of deposit) of issuers in such industry. The Fund may engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund’s return, and realization of greater short-term capital gains, distributions of which are taxable as ordinary income to taxable shareholders. Trading costs and tax effects associated with frequent trading may adversely affect the Fund’s performance. Due to the short-term nature of the Fund’s investment portfolio, the Fund does not calculate a portfolio turnover rate. The Fund’s trading in derivatives is active and frequent. Active and frequent trading of derivatives, like active and frequent trading of securities, will result in transaction costs which reduce fund returns.

The percentage limitations set forth herein are not investment restrictions and the Fund may exceed these limits from time to time.

Principal Risks

The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund.

Commodity Risk: This is the risk that exposure to the commodities markets may subject the Fund to greater volatility than investments in traditional securities. The value of physical commodities or commodity-linked derivative instruments may be affected by changes in overall market movements, commodity price volatility, changes in interest rates, currency fluctuations, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. Recent rulemaking by the Commodity Futures Trading Commission (“CFTC”) may affect the Fund’s ability to pursue its investment strategies or increase the Fund’s expenses. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain.

Commodity Subsidiary Risk: Investing in the Commodity Subsidiary will indirectly expose the Fund to the risks associated with the Commodity Subsidiary’s investments, such as commodity investment risk. The Commodity Subsidiary is not registered under the Investment Company Act of 1940 (the “1940 Act”) and is not subject to all of the investor protections of the 1940 Act. Recent rulemaking by the CFTC may affect the Fund’s ability to use the Commodity Subsidiary to pursue its investment strategies. As of the date of this prospectus, the potential impact of the new CFTC rules on the Fund is uncertain. Changes in the laws of the United States and/or the Cayman Islands, under which the Fund and the Commodity Subsidiary, respectively, are organized, could negatively affect the Fund and its shareholders.

Concentrated Investment Risk: The Fund is particularly vulnerable to events affecting companies in the financial services industry because the Fund concentrates its investments in securities and other obligations of issuers in such industry. Examples of risks affecting the financial services industry include changes in governmental regulation, issues relating to the availability and cost of capital, changes in interest rates and/or monetary policy and price competition. In addition, financial services companies are often more highly leveraged than other companies, making them inherently riskier. As a result, the Fund’s shares may rise and fall in value more rapidly and to a greater extent than shares of a fund that does not concentrate or focus in a particular industry or economic sector. The financial services industry has recently experienced high volatility and a number of issuer failures and the value of many of these securities has significantly declined. As a result, the risk associated with investing in the Fund may be increased as compared to a fund that does not concentrate in the financial services industry.

Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with over-the-counter (“OTC”) derivative transactions, such as foreign currency transactions. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its direct counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains.

Currency Risk: Fluctuations in the exchange rates between different currencies may negatively affect an investment. 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.

Derivatives Risk: Derivatives are subject to changes in the value of the underlying asset or indices on which such transactions 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 markets 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 which would have occurred had derivatives not been used. The Fund’s use of derivatives, such as futures, forward contracts, and other foreign currency transactions and commodity-linked derivatives involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward 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 perfectly with relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, a number of broker-dealers and other financial institutions have recently experienced extreme financial difficulty, sometimes resulting in bankruptcy of the institution. There can be no assurance that the Fund’s derivative counterparties will be able to avoid experiencing similar financial difficulties, possibly resulting in losses to the Fund.

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. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer’s bonds and preferred stock generally take precedence over the claims of those who own common stock.

Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund’s investments in foreign securities are subject to foreign currency fluctuations. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity.

Hedge Fund Risk: Hedge funds are typically unregulated private investment pools available only to sophisticated investors. They are often illiquid and highly leveraged. Although the Fund will not invest directly in hedge funds, because the Fund’s investments are intended to provide exposure to the factors that drive hedge fund returns, an investment in the Fund will be subject to many of the same risks associated with an investment in a diversified portfolio of hedge funds. Therefore, the Fund’s performance may be lower than the returns of the broader stock market and the Fund’s net asset value may fluctuate substantially over time.

Index/Tracking Error Risk: Although the Fund does not seek to track any particular index, the Fund seeks to analyze the factors that drive hedge fund returns, as determined by reference to one or more indices. These indices may not provide an accurate representation of hedge fund returns generally, and the Adviser’s strategy may not successfully identify or be able to replicate factors that drive returns. There is a risk that hedge fund return data provided by third party hedge fund index providers may be inaccurate or may not accurately reflect hedge fund returns due to survivorship bias, self-reporting bias or other biases.

Interest Rate Risk: Changes in interest rates may cause the value of the Fund’s investments to decrease. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. A period of low interest rates may cause the Fund to have a low or negative yield, potentially reducing the value of your investment.

Issuer Risk: The value of the Fund’s investments may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods and services.

Leverage Risk: Use of derivative instruments may involve leverage. Leverage is the risk associated with securities or practices that multiply small index, market or asset price movements into larger changes in value. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. The use of leverage increases the impact of gains and losses on a fund’s returns, and may lead to significant losses if investments are not successful. However, the Adviser will attempt to ensure that at all times the Fund has sufficient liquid assets to enable it to satisfy its obligations under its derivative contracts.

Liquidity Risk: Liquidity risk exists when particular investments are difficult to purchase or sell, possibly preventing the Fund from selling these illiquid securities at an advantageous price or time. A lack of liquidity also may cause the value of investments to decline. Illiquid investments also may be difficult to value.

Management Risk: A strategy used by the Fund’s portfolio managers may fail to produce the intended result. The Adviser utilizes various proprietary quantitative models to identify investment opportunities. There is a possibility that one or all of the quantitative models may fail to identify profitable opportunities at any time. Furthermore, they may incorrectly identify opportunities and these misidentified opportunities may lead to substantial losses.

Market Risk: The market value of a security will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer’s financial condition, as well as overall market and economic conditions. The Fund’s portfolio managers will attempt to reduce this risk by implementing various volatility management strategies and techniques. However, there is no guarantee that such strategies and techniques will produce the intended result.

U.S. Government Securities Risk: Investments in certain U.S. government securities may not be supported by the full faith and credit of the U.S. government. Accordingly, no assurance can be given that the U.S. government will provide financial support to U.S. government agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. The maximum potential liability of the issuers of some U.S. government securities held by the Fund may greatly exceed their current resources, and it is possible that these issuers will not have the funds to meet their payment obligations in the future. In such a case, the Fund would have to look principally to the agency, instrumentality or sponsored enterprise issuing or guaranteeing the security for ultimate repayment, and the Fund may not be able to assert a claim against the U.S. government itself in the event the agency, instrumentality or sponsored enterprise does not meet its commitment. Concerns about the capacity of the U.S. government to meet its obligations may raise the interest rates payable on its securities, negatively impacting the price of such securities already held by the Fund.

Valuation Risk: This is the risk that the Fund has valued certain securities at a higher price than the price at which they can be sold. This risk may be especially pronounced for investments, such as derivatives that may be illiquid or may become illiquid.

Risk/Return Bar Chart and Table

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 and life-of-Fund periods compare with those of a broad measure of market performance. 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 ngam.natixis.com and/or by calling the Fund toll-free at 800-225-5478.

The bar 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.

Total Returns for Class A

Highest Quarterly Return:
Third Quarter 2010, 7.26%

Lowest Quarterly Return:
Third Quarter 2011, -7.47%

Average Annual Total Returns
(for the periods ended December 31, 2011)

Average Annual Total Returns ASG Global Alternatives Fund	Past 1 Year		Life of Fund		Inception Date
Class A	(8.85%)		1.00%		Sep. 30, 2008
Class C	(4.96%)		2.11%		Sep. 30, 2008
Class Y	(3.00%)		3.12%		Sep. 30, 2008
Return After Taxes on Distributions Class A	(8.96%)		0.45%		Sep. 30, 2008
Return After Taxes on Distributions & Sale of Fund Shares Class A	(5.68%)		0.61%		Sep. 30, 2008
HFRI Fund of Funds Composite Index	(5.51%)	[1]	0.04%	[1]	Oct. 30, 2008

Prior to May 1, 2012, Class Y shares were offered in a separate prospectus and given that Class Y shares are now offered in this multi-class prospectus, Total Returns, Return After Taxes on Distributions and Return After Taxes on Distributions & Sale of Fund Shares are now presented for Class A 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 Fund shares through tax-deferred 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. The Return After Taxes on Distributions & Sale of Fund Shares for the one-year period exceeds the Return Before Taxes due to an assumed benefit from losses on a sale of Fund shares at the end of the measurement period.

[1] AlphaSimplex Group, LLC ("AlphaSimplex" 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 1.60%, 2.35% and 1.35% of the Fund's average daily net assets for Class A, C and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2013 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 1.60%, 2.35% and 1.35% of the Fund's average daily net assets for Class A, C and Y shares, respectively. 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 fee/expense was waived/reimbursed.

[1] Calculated from October 1, 2008

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	Natixis Funds Trust II
Prospectus Date	rr_ProspectusDate	May 01, 2012
Document Creation Date	dei_DocumentCreationDate	Apr. 27, 2012