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.