2.2.0.25truefalse004008 - Document - Risk/Return Summary {Unlabeled} (Loomis Sayles Global Markets Fund) (Class Y)falsefalsefalse1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Institutional Class Member {dei_LegalEntityAxis} : S000006698 Member 2/1/2011 - 2/1/2011 Duration_2_1_2011_To_2_1_20112http://www.sec.gov/CIK0000872649duration2011-02-01T00:00:002011-02-01T00:00:00falsefalseClass Ydei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicik000087264_InstitutionalClassMemberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseLoomis Sayles Global Markets Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicik000087264_S000006698Memberdei_LegalEntityAxisexplicitMember1false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://www.funds.natixis.com/role/documentriskreturnsummaryunlabeledloomissaylesglobalmarketsfundserviceclass1falsefalsefalse00Class Y | Loomis Sayles Global Markets FundClass Y | Loomis Sayles Global Markets Fundfalsefalsefalsefalsefalse1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : Institutional Class Member {dei_LegalEntityAxis} : S000006698 Member 2/1/2011 - 2/1/2011 Duration_2_1_2011_To_2_1_20112http://www.sec.gov/CIK0000872649duration2011-02-01T00:00:002011-02-01T00:00:00falsefalseClass Ydei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldicik000087264_InstitutionalClassMemberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseLoomis Sayles Global Markets Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldicik000087264_S000006698Memberdei_LegalEntityAxisexplicitMemberOthernaNo definition available.No authoritative reference available.falsefalseClass Y | Loomis Sayles Global Markets Fund3false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<font class="_mt"><font style="font-family: Times New Roman;" class="_mt" size="2"><b>Principal Investment Strategies</b></font></font>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy [Heading]4false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> <div class="MetaData"> <p style="margin-top: 6px; margin-bottom: 0px;"><font style="font-family: Times New Roman;" class="_mt" size="2">Under normal market conditions, the Fund will invest at least 80% of its net assets (plus any borrowings made for investment purposes) in equity and fixed-income securities of U.S. and foreign issuers. Equity securities purchased by the Fund may include common stocks, preferred stocks, depositary receipts, warrants, securities convertible into common or preferred stocks, interests in real estate investment trusts ("REITs") and/or real estate-related securities and other equity-like interests in an issuer. The Fund will invest a significant portion of its assets outside the U.S., including securities of issuers located in countries with emerging securities markets. </font></p> <p style="margin-top: 12px; margin-bottom: 0px;"><font style="font-family: Times New Roman;" class="_mt" size="2">In deciding which domestic and international equity securities to buy and sell, the Adviser generally looks for companies that it believes have the potential for superior earnings growth relative to their current value. The Adviser also looks for companies that appear to be undervalued relative to the intrinsic value of the companies' assets or cash flows. </font></p> <p style="margin-top: 12px; margin-bottom: 0px;"><font style="font-family: Times New Roman;" class="_mt" size="2">In deciding which domestic and international fixed-income securities to buy and sell, the Adviser generally looks for securities that it believes are undervalued and have the potential for credit upgrades. The Fund may also invest in foreign currencies, collateralized mortgage obligations, zero-coupon securities, when-issued securities, real estate investment trusts ("REITs"), Rule 144A securities and mortgage-related securities. The Fund may also engage in active and frequent trading of securities and engage in options or foreign currency transactions for hedging and investment purposes and futures transactions, foreign currency transactions, swap transactions (including credit default swaps) and other derivative transactions.</font></p></div> </div>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy Narrative [Text Block]13Risk/Return Summary (Loomis Sayles Global Markets Fund) (Class Y) (Class Y, Loomis Sayles Global Markets Fund)UnKnownUnKnownUnKnownUnKnownfalsetrue