2.4.0.8020000 - Document - Risk/Return Summary {Unlabeled} - FPA International Value Fundfalsefalsefalse1false falsefalseS000035260Memberhttp://www.sec.gov/CIK0000924727duration2013-09-20T00:00:002013-09-20T00:00:001false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00FPA International Value Fundfalsefalsefalse1false truefalseS000035260Memberhttp://www.sec.gov/CIK0000924727duration2013-09-20T00:00:002013-09-20T00:00:00falsefalseFPA International Value Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000924727_S000035260Memberdei_LegalEntityAxisexplicitMembernanafalse0FPA International Value Fund2false 4rr_RiskReturnHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00FPA International Value Fundfalsefalsefalsexbrli:stringItemTypestringRisk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicatedReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 false0Risk/Return [Heading]3false 4ck0000924727_SupplementTextBlockck0000924727_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 FPA FUNDS TRUST'S FPA INTERNATIONAL VALUE FUND SUPPLEMENT DATED SEPTEMBER 20, 2013, TO PROSPECTUS DATED APRIL 30, 2013 On September 20, 2013, shareholders of FPA Funds Trust's FPA International Value Fund (the "Fund") approved a proposal to change the Fund from a diversified fund to a non-diversified fund. The Fund's Prospectus is revised as described below: falsefalsefalsenonnum:textBlockItemTypenaNo authoritative reference available.No definition available.false0Supplement [Text Block]4false 4rr_RiskHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The following is added to the section in the summary portion of the Fund's Prospectus entitled "Principal Investment Risks" and to the section of the Fund's Prospectus entitled "Principal Risks" under the section "INVESTMENT OBJECTIVE, PRINCIPAL INVESTMENT STRATEGIES, AND PRINCIPAL RISKS":falsefalsefalsexbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 1 false0Risk [Heading]5false 4rr_RiskNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Risks Associated with Non-Diversification. The Fund is non-diversified, which generally means that it may invest a greater percentage of its total assets in the securities of fewer issuers than a "diversified" fund. This increases the risk that a change in the value of any one investment held by the Fund could affect the overall value of the Fund more than it would affect that of a diversified fund holding a greater number of investments. Accordingly, the Fund's value will likely be more volatile than the value of a more diversified fund. falsefalsefalsenonnum:textBlockItemTypenaNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 1 -Subparagraph i -Clause instruction false0Risk Narrative [Text Block]falseRisk/Return Summary - FPA International Value Fund (FPA International Value Fund)UnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://fpafunds.com/20130920/role/DocumentRiskReturnSummaryUnlabeledFPAInternationalValueFund15