497

Natixis Funds Trust II

Exhibit Index

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
Prospectus:	rr_ProspectusTable
Document Type	dei_DocumentType	497
Document Period End Date	dei_DocumentPeriodEndDate	Dec. 31, 2018
Registrant Name	dei_EntityRegistrantName	Natixis Funds Trust II
Central Index Key	dei_EntityCentralIndexKey	0000052136
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	May 03, 2019
Document Effective Date	dei_DocumentEffectiveDate	May 03, 2019
Prospectus Date	rr_ProspectusDate	May 01, 2019

XML

(Natixis Oakmark Fund)

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Investment Goal </b></div>

The Fund seeks long-term capital appreciation.

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Fund Fees & Expenses </b></div>

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 83 of the Prospectus, in Appendix A to the Prospectus and on page 138 in the section "Reduced Sales Charges" of the Statement of Additional Information ("SAI").

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Shareholder Fees </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> (fees paid directly from your investment) </b></div>

Shareholder Fees - (Natixis Oakmark Fund)	Class A		Class C	Class N	Class T	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%		none	none	2.50%	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	none	[1]	1.00%	none	none	none
Redemption fees	none		none	none	none	none

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Annual Fund Operating Expenses </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>(expenses that you pay each year as a percentage of the value of your investment) </b></div>

Annual Fund Operating Expenses - (Natixis Oakmark Fund)		Class A	Class C	Class N	Class T		Class Y
Management fees		0.68%	0.68%	0.68%	0.68%		0.68%
Distribution and/or service (12b-1) fees		0.25%	1.00%	none	0.25%		none
Other expenses		0.20%	0.20%	3.11%	0.20%	[1]	0.20%
Total annual fund operating expenses		1.13%	1.88%	3.79%	1.13%		0.88%
Fee waiver and/or expense reimbursement	[2],[3]	none	none	3.04%	none		none
Total annual fund operating expenses after fee waiver and/or expense reimbursement		1.13%	1.88%	0.75%	1.13%		0.88%

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Example </b></div>

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 for Class N is based on the Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement assuming that such waiver and/or reimbursement will only be in place through the date noted above and on the Total Annual Fund Operating Expenses for the remaining periods. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>If shares are redeemed:</b></div>

Expense Example - (Natixis Oakmark Fund) - USD ($)	1 Year	3 Years	5 Years	10 Years
Class A	684	913	1,161	1,871
Class C	291	591	1,016	2,201
Class N	77	876	1,696	3,832
Class T	362	600	857	1,590
Class Y	90	281	488	1,084

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>If shares are not redeemed:</b></div>

Expense Example, No Redemption - (Natixis Oakmark Fund)	1 Year	3 Years	5 Years	10 Years
Class C | USD ($)	191	591	1,016	2,201

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Portfolio Turnover </b></div>

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 39% of the average value of its portfolio.

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Investments, Risks and Performance </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Principal Investment Strategies </b></div>

Under normal market conditions, the Fund primarily invests in common stocks of U.S. companies. The Fund generally invests in securities of larger capitalization companies in any industry. Harris Associates L.P. ("Harris Associates") uses a value investment philosophy in selecting equity securities, including common stocks. This value investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic value. By "intrinsic 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 what Harris Associates believes is a company's intrinsic value presents the best opportunity to achieve the Fund's investment objectives.

Harris Associates uses this value investment philosophy to identify companies that it believes have discounted stock prices compared to what Harris Associates believes are the companies' intrinsic 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 company management ownership.

Once Harris Associates identifies a stock that it believes is selling at a significant discount to Harris Associates' estimate of intrinsic value and that the issuer has one or more of 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 value or the issuer's fundamentals change. Harris Associates monitors each holding and adjusts its price targets as warranted to reflect changes in the issuer's fundamentals. The Fund's portfolio typically holds 30 to 60 stocks.

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Principal Investment Risks </b></div>

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 generally take precedence over the claims of those who own preferred stock or 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.

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

Market/Issuer Risk: The market value of the Fund's investments will move up and down, sometimes rapidly and unpredictably, based upon overall market and economic conditions, as well as a number of reasons that directly relate to the issuers of the Fund's investments, such as management performance, financial condition and demand for the issuers' goods and services.

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Risk/Return Bar Chart and Table </b></div>

The following bar chart and table 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, ten-year, and life-of-class 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 im.natixis.com and/or by calling the Fund toll-free at 800-225-5478.

The chart does not reflect any sales charge that you may be required to pay when you buy or redeem the Fund's shares. A sales charge will reduce your return.

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b>Total Returns for Class Y Shares</b> </div>

Highest Quarterly Return:
Second Quarter 2009, 24.26%

Lowest Quarterly Return:
Fourth Quarter 2018, -17.07%

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b>Average Annual Total Returns </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b> (for the periods ended December 31, 2018) </b></div>

Average Annual Total Returns - (Natixis Oakmark Fund)	Past 1 Year	Past 5 Years	Past 10 Years	Life of Class N	Inception Date
Class Y	(12.76%)	5.86%	13.29%
Class Y | Return After Taxes on Distributions	(14.75%)	4.05%	12.17%
Class Y | Return After Taxes on Distributions and Sale of Fund Shares	(6.10%)	4.43%	11.08%
Class A	(18.02%)	4.34%	12.33%
Class C	(14.40%)	4.80%	12.16%
Class N	(12.60%)			0.55%	May 01, 2017
Class T	(15.17%)	5.06%	12.72%
S&P 500® Index	(4.38%)	8.49%	13.12%	5.03%	May 01, 2017

The Fund did not have Class T shares outstanding during the periods shown above. The returns of Class T shares would have been substantially similar to the returns of the Fund's other share classes because they would have been invested in the same portfolio of securities and would only differ to the extent the other share classes did not have the same expenses. Performance of Class T shares shown above is that of Class A shares, which have the same expenses as Class T shares, restated to reflect the different sales load applicable to Class T shares.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, or individual retirement accounts. The after-tax returns are shown for only one class of the Fund. The Return After Taxes on Distributions and Sale of Fund Shares for the 1-year period exceeds the Return Before Taxes due to an assumed tax benefit from losses on a sale of Fund shares at the end of the measurement period. After-tax returns for the other classes of the Fund will vary. Index performance reflects no deduction for fees, expenses or taxes.

(Vaughan Nelson Value Opportunity Fund)

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Investment Goal </b></div>

The Fund seeks long-term capital appreciation.

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Fund Fees & Expenses </b></div>

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 83 of the Prospectus, in Appendix A to the Prospectus and on page 138 in the section "Reduced Sales Charges" of the Statement of Additional Information ("SAI").

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Shareholder Fees </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> (fees paid directly from your investment) </b></div>

Shareholder Fees - (Vaughan Nelson Value Opportunity Fund)	Class A		Class C	Class N	Class T	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	5.75%		none	none	2.50%	none
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	none	[1]	1.00%	none	none	none
Redemption fees	none		none	none	none	none

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Annual Fund Operating Expenses </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>(expenses that you pay each year as a percentage of the value of your investment) </b></div>

Annual Fund Operating Expenses - (Vaughan Nelson Value Opportunity Fund)		Class A	Class C	Class N	Class T		Class Y
Management fees		0.80%	0.80%	0.80%	0.80%		0.80%
Distribution and/or service (12b-1) fees		0.25%	1.00%	none	0.25%		none
Other expenses		0.19%	0.18%	0.08%	0.19%	[1]	0.19%
Acquired Fund Fees and Expenses	[2]	0.21%	0.21%	0.21%	0.21%		0.21%
Total annual fund operating expenses		1.45%	2.19%	1.09%	1.45%		1.20%
Fee waiver and/or expense reimbursement	[3]	none	none	none	none		none
Total annual fund operating expenses after fee waiver and/or expense reimbursement		1.45%	2.19%	1.09%	1.45%		1.20%

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Example </b></div>

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:

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>If shares are redeemed:</b></div>

Expense Example - (Vaughan Nelson Value Opportunity Fund) - USD ($)	1 Year	3 Years	5 Years	10 Years
Class A	714	1,007	1,322	2,210
Class C	322	685	1,175	2,524
Class N	111	347	601	1,329
Class T	394	697	1,022	1,942
Class Y	122	381	660	1,455

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>If shares are not redeemed:</b></div>

Expense Example, No Redemption - (Vaughan Nelson Value Opportunity Fund)	1 Year	3 Years	5 Years	10 Years
Class C | USD ($)	222	685	1,175	2,524

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Portfolio Turnover </b></div>

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 44% of the average value of its portfolio.

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Investments, Risks and Performance </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Principal Investment Strategies </b></div>

Under normal market conditions, the Fund 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 December 31, 2018, it was $472.5 million to $33.6 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, real estate investment trusts ("REITs") or other trusts and similar securities representing direct or indirect ownership interests in business organizations.

Vaughan Nelson Investment Management, L.P. ("Vaughan Nelson") invests in medium-capitalization companies with a focus on those companies meeting Vaughan Nelson's return expectations. 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 return on capital 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, in the opinion of Vaughan Nelson, is made up of quality companies with the potential to provide significant increases in share price over a three year period.
• Vaughan Nelson will generally sell a security when it reaches Vaughan Nelson's price target or when the issuer shows a change in financial condition, competitive pressures, poor management decisions or internal or external forces reducing future expected returns from those expected at the time of investment.

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 REITs.
• Invest in securities offered in initial public offerings ("IPOs") and securities issued pursuant to Rule 144A under the Securities Act of 1933 ("Rule 144A securities").

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Principal Investment Risks </b></div>

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: In addition to the risks of investing in foreign investments generally, emerging markets investments are subject to greater risks arising from political or economic instability, nationalization or confiscatory taxation, currency exchange restrictions, sanctions by the U.S. government and an issuer's unwillingness or inability to make principal or interest payments on its obligations. Emerging markets companies may be smaller and have shorter operating histories than companies in 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 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 generally take precedence over the claims of those who own preferred stock or common stock. Equity securities may take the form of stock in corporations, limited partnership interests, interests in limited liability companies, REITs or other trusts and other similar securities representing direct or indirect ownership interests in business organizations.

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

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

Liquidity Risk: Liquidity risk is the risk that the Fund may be unable to find a buyer for its investments when it seeks to sell them or to receive the price it expects. Decreases in the number of financial institutions willing to make markets in the Fund's investments or in their capacity or willingness to transact may increase the Fund's exposure to this risk. Events that may lead to increased redemptions, such as market disruptions or increases in interest rates, may also negatively impact the liquidity of the Fund's investments when it needs to dispose of them. If the Fund is forced to sell its investments at an unfavorable time and/or under adverse conditions in order to meet redemption requests, such sales could negatively affect the Fund. Securities acquired in a private placement, such as Rule 144A securities, are generally subject to greater liquidity risk because they are subject to strict restrictions on resale and there may be no liquid secondary market or ready purchaser for such securities. Liquidity issues may also make it difficult to value the Fund's investments.

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

Market/Issuer Risk: The market value of the Fund's investments will move up and down, sometimes rapidly and unpredictably, based upon overall market and economic conditions, as well as a number of reasons that directly relate to the issuers of the Fund's investments, such as management performance, financial condition and demand for the issuers' goods and services.

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.

Small- and Mid-Capitalization Companies Risk: Compared to large-capitalization companies, small- and mid-capitalization companies are more likely to have limited product lines, markets or financial resources. Stocks of these companies often trade less frequently and in limited volume and their prices may fluctuate more than stocks of large-capitalization companies. As a result, it may be relatively more difficult for the Fund to buy and sell securities of small- and mid-capitalization companies.

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Risk/Return Bar Chart and Table </b></div>

The following bar chart and table 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, life-of-fund and life-of-class periods (as applicable) 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 im.natixis.com and/or by calling the Fund toll-free at 800-225-5478.

The chart does not reflect any sales charge that you may be required to pay when you buy or redeem the Fund's shares. A sales charge will reduce your return.

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b>Total Returns for Class Y Shares</b> </div>

Highest Quarterly Return:
Third Quarter 2009, 21.36%

Lowest Quarterly Return:
Third Quarter 2011, -21.12%

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b>Average Annual Total Returns </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b> (for the periods ended December 31, 2018) </b></div>

Average Annual Total Returns - (Vaughan Nelson Value Opportunity Fund)	Past 1 Year	Past 5 Years	Past 10 Years	Life of Class N	Inception Date
Class Y	(15.85%)	1.66%	10.62%
Class Y | Return After Taxes on Distributions	(17.62%)	0.46%	9.61%
Class Y | Return After Taxes on Distributions and Sale of Fund Shares	(8.08%)	1.29%	8.75%
Class A	(20.92%)	0.20%	9.68%
Class C	(17.47%)	0.64%	9.52%
Class N	(15.78%)	1.73%		5.56%	May 01, 2013
Class T	(18.20%)	0.88%	10.06%
Russell MidCap® Value Index	(12.29%)	5.44%	13.03%	7.74%	May 01, 2013

The Fund did not have Class T shares outstanding during the periods shown above. The returns of Class T shares would have been substantially similar to the returns of the Fund's other share classes because they would have been invested in the same portfolio of securities and would only differ to the extent the other share classes did not have the same expenses. Performance of Class T shares shown above is that of Class A shares, which have the same expenses as Class T shares, restated to reflect the different sales load applicable to Class T shares.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, or individual retirement accounts. The after-tax returns are shown for only one class of the Fund. The Return After Taxes on Distributions and Sale of Fund Shares for the 1-year period exceeds the Return Before Taxes due to an assumed tax benefit from losses on a sale of Fund shares at the end of the measurement period. After-tax returns for the other classes of the Fund will vary. Index performance reflects no deduction for fees, expenses or taxes.

[1] A 1.00% contingent deferred sales charge ("CDSC") may apply to certain purchases of Class A shares of $1,000,000 or more that are redeemed within eighteen months of the date of purchase.

[1] Other expenses are estimated for the current fiscal year.

[2] Natixis Advisors, L.P. ("Natixis Advisors") has given a binding contractual undertaking to the Fund to reimburse any and all transfer agency expenses for Class N shares. This undertaking is in effect through May 31, 2020 and may be terminated before then only with the consent of the Fund's Board of Trustees.

[3] 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%, 1.00%, 1.30% and 1.05% of the Fund's average daily net assets for Class A, C, N, T 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, 2020 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 the applicable expense limitations for Class A, C, N, T and Y shares. 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.

[1] A 1.00% contingent deferred sales charge ("CDSC") may apply to certain purchases of Class A shares of $1,000,000 or more that are redeemed within eighteen months of the date of purchase.

[1] Other expenses are estimated for the current fiscal year.

[2] The expense information shown in the table above differs from the expense information disclosed in the Fund's financial highlights table because the financial highlights table reflects the operating expenses of the Fund and does not include acquired fund fees and expenses.

[3] 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%, 1.10%, 1.40% and 1.15% of the Fund's average daily net assets for Class A, C, N, T 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, 2020 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 the applicable expense limitations for Class A, C, N, T and Y shares. 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

(Natixis Oakmark Fund)

Prospectus:

rr_ProspectusTable

Objective [Heading]

rr_ObjectiveHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Investment Goal </b></div>

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Fund Fees & Expenses </b></div>

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 83 of the Prospectus, in Appendix A to the Prospectus and on page 138 in the section "Reduced Sales Charges" of the Statement of Additional Information ("SAI").

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

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Shareholder Fees </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> (fees paid directly from your investment) </b></div>

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Annual Fund Operating Expenses </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>(expenses that you pay each year as a percentage of the value of your investment) </b></div>

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

April 30, 2020

Expenses Deferred Charges [Text Block]

rr_ExpensesDeferredChargesTextBlock

A 1.00% contingent deferred sales charge ("CDSC") may apply to certain purchases of Class A shares of $1,000,000 or more that are redeemed within eighteen months of the date of purchase.

Expense Example [Heading]

rr_ExpenseExampleHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Example </b></div>

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 for Class N is based on the Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement assuming that such waiver and/or reimbursement will only be in place through the date noted above and on the Total Annual Fund Operating Expenses for the remaining periods. 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

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>If shares are redeemed:</b></div>

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>If shares are not redeemed:</b></div>

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Portfolio Turnover </b></div>

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 39% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

39.00%

Strategy [Heading]

rr_StrategyHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Investments, Risks and Performance </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Principal Investment Strategies </b></div>

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Under normal market conditions, the Fund primarily invests in common stocks of U.S. companies. The Fund generally invests in securities of larger capitalization companies in any industry. Harris Associates L.P. ("Harris Associates") uses a value investment philosophy in selecting equity securities, including common stocks. This value investment philosophy is based upon the belief that, over time, a company's stock price converges with the company's intrinsic value. By "intrinsic 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 what Harris Associates believes is a company's intrinsic value presents the best opportunity to achieve the Fund's investment objectives.

Harris Associates uses this value investment philosophy to identify companies that it believes have discounted stock prices compared to what Harris Associates believes are the companies' intrinsic 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 company management ownership.

Once Harris Associates identifies a stock that it believes is selling at a significant discount to Harris Associates' estimate of intrinsic value and that the issuer has one or more of 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 value or the issuer's fundamentals change. Harris Associates monitors each holding and adjusts its price targets as warranted to reflect changes in the issuer's fundamentals. The Fund's portfolio typically holds 30 to 60 stocks.

Risk [Heading]

rr_RiskHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Principal Investment Risks </b></div>

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 generally take precedence over the claims of those who own preferred stock or 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.

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

Market/Issuer Risk: The market value of the Fund's investments will move up and down, sometimes rapidly and unpredictably, based upon overall market and economic conditions, as well as a number of reasons that directly relate to the issuers of the Fund's investments, such as management performance, financial condition and demand for the issuers' goods and services.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Risk/Return Bar Chart and Table </b></div>

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table 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, ten-year, and life-of-class 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 im.natixis.com and/or by calling the Fund toll-free at 800-225-5478.

The chart does not reflect any sales charge that you may be required to pay when you buy or redeem the Fund's shares. A sales charge will reduce your return.

Bar Chart [Heading]

rr_BarChartHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b>Total Returns for Class Y Shares</b> </div>

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, 24.26%

Lowest Quarterly Return:
Fourth Quarter 2018, -17.07%

Performance Table Heading

rr_PerformanceTableHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b>Average Annual Total Returns </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b> (for the periods ended December 31, 2018) </b></div>

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

The Fund did not have Class T shares outstanding during the periods shown above. The returns of Class T shares would have been substantially similar to the returns of the Fund's other share classes because they would have been invested in the same portfolio of securities and would only differ to the extent the other share classes did not have the same expenses. Performance of Class T shares shown above is that of Class A shares, which have the same expenses as Class T shares, restated to reflect the different sales load applicable to Class T shares.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, or individual retirement accounts. The after-tax returns are shown for only one class of the Fund. The Return After Taxes on Distributions and Sale of Fund Shares for the 1-year period exceeds the Return Before Taxes due to an assumed tax benefit from losses on a sale of Fund shares at the end of the measurement period. After-tax returns for the other classes of the Fund will vary. Index performance reflects no deduction for fees, expenses or taxes.

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-advantaged arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, or individual retirement accounts.

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.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table 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, ten-year, and life-of-class periods compare to those of a broad measure of market performance.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

The after-tax returns are shown for only one class of the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

im.natixis.com

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-225-5478

(Natixis Oakmark Fund) | S&P 500® Index

Prospectus:

rr_ProspectusTable

Past 1 Year

rr_AverageAnnualReturnYear01

(4.38%)

Past 5 Years

rr_AverageAnnualReturnYear05

8.49%

Past 10 Years

rr_AverageAnnualReturnYear10

13.12%

Life of Class N

rr_AverageAnnualReturnSinceInception

5.03%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 01, 2017

(Natixis Oakmark Fund) | Class A

Prospectus:

rr_ProspectusTable

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Redemption fees

rr_RedemptionFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.68%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.20%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.13%

Fee waiver and/or expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2],[3]

Total annual fund operating expenses after fee waiver and/or expense reimbursement

rr_NetExpensesOverAssets

1.13%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 684

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

913

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,161

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,871

Past 1 Year

rr_AverageAnnualReturnYear01

(18.02%)

Past 5 Years

rr_AverageAnnualReturnYear05

4.34%

Past 10 Years

rr_AverageAnnualReturnYear10

12.33%

(Natixis Oakmark Fund) | Class C

Prospectus:

rr_ProspectusTable

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

0.68%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.20%

Total annual fund operating expenses

rr_ExpensesOverAssets

1.88%

Fee waiver and/or expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2],[3]

Total annual fund operating expenses after fee waiver and/or expense reimbursement

rr_NetExpensesOverAssets

1.88%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 291

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

591

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,016

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,201

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

191

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

591

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,016

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 2,201

Past 1 Year

rr_AverageAnnualReturnYear01

(14.40%)

Past 5 Years

rr_AverageAnnualReturnYear05

4.80%

Past 10 Years

rr_AverageAnnualReturnYear10

12.16%

(Natixis Oakmark Fund) | Class N

Prospectus:

rr_ProspectusTable

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

0.68%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.11%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.79%

Fee waiver and/or expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

3.04%

^[2],[3]

Total annual fund operating expenses after fee waiver and/or expense reimbursement

rr_NetExpensesOverAssets

0.75%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 77

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

876

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,696

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 3,832

Past 1 Year

rr_AverageAnnualReturnYear01

(12.60%)

Life of Class N

rr_AverageAnnualReturnSinceInception

0.55%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 01, 2017

(Natixis Oakmark Fund) | Class T

Prospectus:

rr_ProspectusTable

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

2.50%

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)

rr_MaximumDeferredSalesChargeOverOther

none

Redemption fees

rr_RedemptionFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.68%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.20%

^[4]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.13%

Fee waiver and/or expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2],[3]

Total annual fund operating expenses after fee waiver and/or expense reimbursement

rr_NetExpensesOverAssets

1.13%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 362

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

600

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

857

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,590

Past 1 Year

rr_AverageAnnualReturnYear01

(15.17%)

Past 5 Years

rr_AverageAnnualReturnYear05

5.06%

Past 10 Years

rr_AverageAnnualReturnYear10

12.72%

(Natixis Oakmark Fund) | Class Y

Prospectus:

rr_ProspectusTable

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

0.68%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.20%

Total annual fund operating expenses

rr_ExpensesOverAssets

0.88%

Fee waiver and/or expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2],[3]

Total annual fund operating expenses after fee waiver and/or expense reimbursement

rr_NetExpensesOverAssets

0.88%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 90

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

281

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

488

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,084

Annual Return 2009

rr_AnnualReturn2009

44.39%

Annual Return 2010

rr_AnnualReturn2010

13.47%

Annual Return 2011

rr_AnnualReturn2011

(1.40%)

Annual Return 2012

rr_AnnualReturn2012

17.33%

Annual Return 2013

rr_AnnualReturn2013

38.21%

Annual Return 2014

rr_AnnualReturn2014

10.70%

Annual Return 2015

rr_AnnualReturn2015

(4.18%)

Annual Return 2016

rr_AnnualReturn2016

18.69%

Annual Return 2017

rr_AnnualReturn2017

21.05%

Annual Return 2018

rr_AnnualReturn2018

(12.76%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest Quarterly Return: Second Quarter 2009, 24.26%

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

24.26%

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest Quarterly Return: Fourth Quarter 2018, -17.07%

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(17.07%)

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2018

Past 1 Year

rr_AverageAnnualReturnYear01

(12.76%)

Past 5 Years

rr_AverageAnnualReturnYear05

5.86%

Past 10 Years

rr_AverageAnnualReturnYear10

13.29%

(Natixis Oakmark Fund) | Class Y | Return After Taxes on Distributions

Prospectus:

rr_ProspectusTable

Past 1 Year

rr_AverageAnnualReturnYear01

(14.75%)

Past 5 Years

rr_AverageAnnualReturnYear05

4.05%

Past 10 Years

rr_AverageAnnualReturnYear10

12.17%

(Natixis Oakmark Fund) | Class Y | Return After Taxes on Distributions and Sale of Fund Shares

Prospectus:

rr_ProspectusTable

Past 1 Year

rr_AverageAnnualReturnYear01

(6.10%)

Past 5 Years

rr_AverageAnnualReturnYear05

4.43%

Past 10 Years

rr_AverageAnnualReturnYear10

11.08%

(Vaughan Nelson Value Opportunity Fund)

Prospectus:

rr_ProspectusTable

Objective [Heading]

rr_ObjectiveHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Investment Goal </b></div>

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Fund Fees & Expenses </b></div>

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 83 of the Prospectus, in Appendix A to the Prospectus and on page 138 in the section "Reduced Sales Charges" of the Statement of Additional Information ("SAI").

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

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Shareholder Fees </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> (fees paid directly from your investment) </b></div>

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Annual Fund Operating Expenses </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>(expenses that you pay each year as a percentage of the value of your investment) </b></div>

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

April 30, 2020

Expenses Deferred Charges [Text Block]

rr_ExpensesDeferredChargesTextBlock

A 1.00% contingent deferred sales charge ("CDSC") may apply to certain purchases of Class A shares of $1,000,000 or more that are redeemed within eighteen months of the date of purchase.

Expense Example [Heading]

rr_ExpenseExampleHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Example </b></div>

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

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>If shares are redeemed:</b></div>

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b>If shares are not redeemed:</b></div>

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Portfolio Turnover </b></div>

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 44% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

44.00%

Strategy [Heading]

rr_StrategyHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Investments, Risks and Performance </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Principal Investment Strategies </b></div>

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Under normal market conditions, the Fund 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 December 31, 2018, it was $472.5 million to $33.6 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, real estate investment trusts ("REITs") or other trusts and similar securities representing direct or indirect ownership interests in business organizations.

Vaughan Nelson Investment Management, L.P. ("Vaughan Nelson") invests in medium-capitalization companies with a focus on those companies meeting Vaughan Nelson's return expectations. 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 return on capital 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, in the opinion of Vaughan Nelson, is made up of quality companies with the potential to provide significant increases in share price over a three year period.
• Vaughan Nelson will generally sell a security when it reaches Vaughan Nelson's price target or when the issuer shows a change in financial condition, competitive pressures, poor management decisions or internal or external forces reducing future expected returns from those expected at the time of investment.

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 REITs.
• Invest in securities offered in initial public offerings ("IPOs") and securities issued pursuant to Rule 144A under the Securities Act of 1933 ("Rule 144A securities").

Risk [Heading]

rr_RiskHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Principal Investment Risks </b></div>

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: In addition to the risks of investing in foreign investments generally, emerging markets investments are subject to greater risks arising from political or economic instability, nationalization or confiscatory taxation, currency exchange restrictions, sanctions by the U.S. government and an issuer's unwillingness or inability to make principal or interest payments on its obligations. Emerging markets companies may be smaller and have shorter operating histories than companies in 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 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 generally take precedence over the claims of those who own preferred stock or common stock. Equity securities may take the form of stock in corporations, limited partnership interests, interests in limited liability companies, REITs or other trusts and other similar securities representing direct or indirect ownership interests in business organizations.

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

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

Liquidity Risk: Liquidity risk is the risk that the Fund may be unable to find a buyer for its investments when it seeks to sell them or to receive the price it expects. Decreases in the number of financial institutions willing to make markets in the Fund's investments or in their capacity or willingness to transact may increase the Fund's exposure to this risk. Events that may lead to increased redemptions, such as market disruptions or increases in interest rates, may also negatively impact the liquidity of the Fund's investments when it needs to dispose of them. If the Fund is forced to sell its investments at an unfavorable time and/or under adverse conditions in order to meet redemption requests, such sales could negatively affect the Fund. Securities acquired in a private placement, such as Rule 144A securities, are generally subject to greater liquidity risk because they are subject to strict restrictions on resale and there may be no liquid secondary market or ready purchaser for such securities. Liquidity issues may also make it difficult to value the Fund's investments.

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

Market/Issuer Risk: The market value of the Fund's investments will move up and down, sometimes rapidly and unpredictably, based upon overall market and economic conditions, as well as a number of reasons that directly relate to the issuers of the Fund's investments, such as management performance, financial condition and demand for the issuers' goods and services.

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.

Small- and Mid-Capitalization Companies Risk: Compared to large-capitalization companies, small- and mid-capitalization companies are more likely to have limited product lines, markets or financial resources. Stocks of these companies often trade less frequently and in limited volume and their prices may fluctuate more than stocks of large-capitalization companies. As a result, it may be relatively more difficult for the Fund to buy and sell securities of small- and mid-capitalization companies.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"><b> Risk/Return Bar Chart and Table </b></div>

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table 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, life-of-fund and life-of-class periods (as applicable) 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 im.natixis.com and/or by calling the Fund toll-free at 800-225-5478.

The chart does not reflect any sales charge that you may be required to pay when you buy or redeem the Fund's shares. A sales charge will reduce your return.

Bar Chart [Heading]

rr_BarChartHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b>Total Returns for Class Y Shares</b> </div>

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, 21.36%

Lowest Quarterly Return:
Third Quarter 2011, -21.12%

Performance Table Heading

rr_PerformanceTableHeading

<div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b>Average Annual Total Returns </b></div> <div style="font-size:10pt;padding-top:5pt;padding-bottom:0;padding-left:0;"> <b> (for the periods ended December 31, 2018) </b></div>

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

The Fund did not have Class T shares outstanding during the periods shown above. The returns of Class T shares would have been substantially similar to the returns of the Fund's other share classes because they would have been invested in the same portfolio of securities and would only differ to the extent the other share classes did not have the same expenses. Performance of Class T shares shown above is that of Class A shares, which have the same expenses as Class T shares, restated to reflect the different sales load applicable to Class T shares.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, or individual retirement accounts. The after-tax returns are shown for only one class of the Fund. The Return After Taxes on Distributions and Sale of Fund Shares for the 1-year period exceeds the Return Before Taxes due to an assumed tax benefit from losses on a sale of Fund shares at the end of the measurement period. After-tax returns for the other classes of the Fund will vary. Index performance reflects no deduction for fees, expenses or taxes.

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-advantaged arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, or individual retirement accounts.

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.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table 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, life-of-fund and life-of-class periods (as applicable) compare to those of a broad measure of market performance.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

The after-tax returns are shown for only one class of the Fund.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

im.natixis.com

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

800-225-5478

(Vaughan Nelson Value Opportunity Fund) | Russell MidCap® Value Index

Prospectus:

rr_ProspectusTable

Past 1 Year

rr_AverageAnnualReturnYear01

(12.29%)

Past 5 Years

rr_AverageAnnualReturnYear05

5.44%

Past 10 Years

rr_AverageAnnualReturnYear10

13.03%

Life of Class N

rr_AverageAnnualReturnSinceInception

7.74%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 01, 2013

(Vaughan Nelson Value Opportunity Fund) | Class A

Prospectus:

rr_ProspectusTable

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Redemption fees

rr_RedemptionFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.80%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.19%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.21%

^[5]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.45%

Fee waiver and/or expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[6]

Total annual fund operating expenses after fee waiver and/or expense reimbursement

rr_NetExpensesOverAssets

1.45%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 714

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

1,007

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,322

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 2,210

Past 1 Year

rr_AverageAnnualReturnYear01

(20.92%)

Past 5 Years

rr_AverageAnnualReturnYear05

0.20%

Past 10 Years

rr_AverageAnnualReturnYear10

9.68%

(Vaughan Nelson Value Opportunity Fund) | Class C

Prospectus:

rr_ProspectusTable

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

rr_OtherExpensesOverAssets

0.18%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.21%

^[5]

Total annual fund operating expenses

rr_ExpensesOverAssets

2.19%

Fee waiver and/or expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[6]

Total annual fund operating expenses after fee waiver and/or expense reimbursement

rr_NetExpensesOverAssets

2.19%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 322

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

685

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,175

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,524

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

222

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

685

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,175

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 2,524

Past 1 Year

rr_AverageAnnualReturnYear01

(17.47%)

Past 5 Years

rr_AverageAnnualReturnYear05

0.64%

Past 10 Years

rr_AverageAnnualReturnYear10

9.52%

(Vaughan Nelson Value Opportunity Fund) | Class N

Prospectus:

rr_ProspectusTable

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

rr_OtherExpensesOverAssets

0.08%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.21%

^[5]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.09%

Fee waiver and/or expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[6]

Total annual fund operating expenses after fee waiver and/or expense reimbursement

rr_NetExpensesOverAssets

1.09%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 111

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

347

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

601

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,329

Past 1 Year

rr_AverageAnnualReturnYear01

(15.78%)

Past 5 Years

rr_AverageAnnualReturnYear05

1.73%

Life of Class N

rr_AverageAnnualReturnSinceInception

5.56%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 01, 2013

(Vaughan Nelson Value Opportunity Fund) | Class T

Prospectus:

rr_ProspectusTable

Maximum sales charge (load) imposed on purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

2.50%

Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)

rr_MaximumDeferredSalesChargeOverOther

none

Redemption fees

rr_RedemptionFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.80%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.19%

^[4]

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.21%

^[5]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.45%

Fee waiver and/or expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[6]

Total annual fund operating expenses after fee waiver and/or expense reimbursement

rr_NetExpensesOverAssets

1.45%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 394

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

697

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,022

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,942

Past 1 Year

rr_AverageAnnualReturnYear01

(18.20%)

Past 5 Years

rr_AverageAnnualReturnYear05

0.88%

Past 10 Years

rr_AverageAnnualReturnYear10

10.06%

(Vaughan Nelson Value Opportunity Fund) | Class Y

Prospectus:

rr_ProspectusTable

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

rr_OtherExpensesOverAssets

0.19%

Acquired Fund Fees and Expenses

rr_AcquiredFundFeesAndExpensesOverAssets

0.21%

^[5]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.20%

Fee waiver and/or expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[6]

Total annual fund operating expenses after fee waiver and/or expense reimbursement

rr_NetExpensesOverAssets

1.20%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 122

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

381

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

660

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,455

Annual Return 2009

rr_AnnualReturn2009

31.37%

Annual Return 2010

rr_AnnualReturn2010

19.96%

Annual Return 2011

rr_AnnualReturn2011

(2.53%)

Annual Return 2012

rr_AnnualReturn2012

16.28%

Annual Return 2013

rr_AnnualReturn2013

41.52%

Annual Return 2014

rr_AnnualReturn2014

11.23%

Annual Return 2015

rr_AnnualReturn2015

(3.47%)

Annual Return 2016

rr_AnnualReturn2016

6.14%

Annual Return 2017

rr_AnnualReturn2017

13.19%

Annual Return 2018

rr_AnnualReturn2018

(15.85%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Highest Quarterly Return: Third Quarter 2009, 21.36%

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

21.36%

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2009

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Lowest Quarterly Return: Third Quarter 2011, -21.12%

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(21.12%)

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Past 1 Year

rr_AverageAnnualReturnYear01

(15.85%)

Past 5 Years

rr_AverageAnnualReturnYear05

1.66%

Past 10 Years

rr_AverageAnnualReturnYear10

10.62%

(Vaughan Nelson Value Opportunity Fund) | Class Y | Return After Taxes on Distributions

Prospectus:

rr_ProspectusTable

Past 1 Year

rr_AverageAnnualReturnYear01

(17.62%)

Past 5 Years

rr_AverageAnnualReturnYear05

0.46%

Past 10 Years

rr_AverageAnnualReturnYear10

9.61%

(Vaughan Nelson Value Opportunity Fund) | Class Y | Return After Taxes on Distributions and Sale of Fund Shares

Prospectus:

rr_ProspectusTable

Past 1 Year

rr_AverageAnnualReturnYear01

(8.08%)

Past 5 Years

rr_AverageAnnualReturnYear05

1.29%

Past 10 Years

rr_AverageAnnualReturnYear10

8.75%

[1] A 1.00% contingent deferred sales charge ("CDSC") may apply to certain purchases of Class A shares of $1,000,000 or more that are redeemed within eighteen months of the date of purchase.

[2] Natixis Advisors, L.P. ("Natixis Advisors") has given a binding contractual undertaking to the Fund to reimburse any and all transfer agency expenses for Class N shares. This undertaking is in effect through May 31, 2020 and may be terminated before then only with the consent of the Fund's Board of Trustees.

[3] 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%, 1.00%, 1.30% and 1.05% of the Fund's average daily net assets for Class A, C, N, T 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, 2020 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 the applicable expense limitations for Class A, C, N, T and Y shares. The Fund will not be obligated to repay any such waived/reimbursed fees and expenses more than one year after the end of the fiscal year in which the fees or expenses were waived/reimbursed.

[4] Other expenses are estimated for the current fiscal year.

[5] The expense information shown in the table above differs from the expense information disclosed in the Fund's financial highlights table because the financial highlights table reflects the operating expenses of the Fund and does not include acquired fund fees and expenses.

[6] 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%, 1.10%, 1.40% and 1.15% of the Fund's average daily net assets for Class A, C, N, T 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, 2020 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 the applicable expense limitations for Class A, C, N, T and Y shares. 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.