2.2.0.25truefalse0100023 - Document - Risk/Return Summary - Janus Triton Fund (Class A, C, S, I, R & T Shares {Unlabeled}falsefalsetrue1falsefalseUSDtruefalse{dei_DocumentInformationDocumentAxis} : Janus Triton Fund [Member] {dei_LegalEntityAxis} : Growth & Core - Class A, C, S, I, R and T Shares [Member] 1/29/2010 - 1/28/2011 USD ($) $TwelveMonthsEnded_28Jan2011_Prospectus_Five_Member_S000010485_Memberhttp://www.sec.gov/CIK0000277751duration2010-01-29T00:00:002011-01-28T00:00:00falsefalsejif277751_S000010485Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsejif277751_ProspectusFiveMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$1false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://janus.com/role/riskreturnsummaryjanustritonfund1falsefalsefalse00Janus Triton Fund [Member] | Growth & Core - Class A, C, S, I, R and T Shares [Member]Janus Triton Fund [Member] | Growth & Core - Class A, C, S, I, R and T Shares [Member]falsefalsefalsefalsefalse1falsefalseUSDtruefalse{dei_DocumentInformationDocumentAxis} : Janus Triton Fund [Member] {dei_LegalEntityAxis} : Growth & Core - Class A, C, S, I, R and T Shares [Member] 1/29/2010 - 1/28/2011 USD ($) $TwelveMonthsEnded_28Jan2011_Prospectus_Five_Member_S000010485_Memberhttp://www.sec.gov/CIK0000277751duration2010-01-29T00:00:002011-01-28T00:00:00falsefalsejif277751_S000010485Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsejif277751_ProspectusFiveMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseJanus Triton Fund [Member] | Growth & Core - Class A, C, S, I, R and T Shares [Member]3false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00FUND SUMMARY Janus Triton FundfalsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 falsefalseRisk/Return [Heading]4false0rr_ObjectiveHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00INVESTMENT OBJECTIVEfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective [Heading]5false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Janus Triton Fund seeks long-term growth of capitalfalsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective, Primary [Text Block]6false0rr_ExpenseHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00FEES AND EXPENSES OF THE FUNDfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Summary Fee Table Includes the following information, in plain English under rule 421(d) under the Securities Act, after Item 2 Fees and expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold shared 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 $[_____] in [name of fund family] funds. Shareholder Fees (fees paid directly from your investment) Example This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a "New Fund" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. The following Instructions apply to New Funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpense [Heading]7false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This table describes the fees and expenses that you may pay if you buy and hold Shares of the Fund. Each share class has different expenses, but represents an investment in the same Fund.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis table describes the fees and expenses that you may pay if you buy and hold shared 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 $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown.The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. Modify the narrative explanation to state that Fund shares are sold on a national securities exchange at the end of the time periods indicated, and that brokerage commissions for buying and selling Fund shares through a broker are not reflected.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseExpense Narrative [Text Block]8false0rr_ExpenseBreakpointDiscountsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00For Class&#160;A Shares, 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 Fund or in other Janus mutual funds. More information about these and other discounts, as well as eligibility requirements for each share class, is available from your financial professional and in the &#8220;Purchases&#8221; section on page&#160;75 of the Fund&#8217;s Prospectus and in the &#8220;Purchases&#8221; section on page&#160;85 of the Fund&#8217;s Statement of Additional Information.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInclude the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown.The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseExpense Breakpoint Discounts [Text]9false0rr_ExpenseBreakpointMinimumInvestmentRequiredAmountrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse5000050000falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThis element represents the minimum level of investment required to qualify for discounted sales charges or fund expenses (SEC Form N-1A 2006-09-14 A.3.instructions.1.b).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseExpense Breakpoint, Minimum Investment Required [Amount]10false0rr_ShareholderFeesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00SHAREHOLDER FEES (fees paid directly from your investment)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringShareholder Fees (fees paid directly from your investment).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subsection table falsefalseShareholder Fees Caption [Text]11false0rr_ShareholderFeesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;" &gt;~ http://janus.com/role/ShareholderFeesJanusTritonFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact jif277751_S000010485_Member * row dei_LegalEntityAxis compact jif277751_Prospectus_Five_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;" &gt;~ http://janus.com/role/ShareholderFeesJanusTritonFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact jif277751_S000010485_Member * row dei_LegalEntityAxis compact jif277751_Prospectus_Five_Member * ~&lt;/div&gt; </div>falsehttp://janus.com/role/ShareholderFeesJanusTritonFundfalsefalse0200123 - Schedule - Shareholder Fees - Janus Triton Fund (Class A, C, S, I, R & T Shares)truefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass A, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077722Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class A, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$2falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass C, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077723Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - 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Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$4falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass I, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077724Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class I, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$5falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass R, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077725Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class R, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$6falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass T, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000028947Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class T, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_ShareholderFeesColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class&#160;Afalsefalsefalsetruefalse2falsefalsefalse00Class&#160;Cfalsefalsefalsetruefalse3falsefalsefalse00Class Sfalsefalsefalsetruefalse4falsefalsefalse00Class Ifalsefalsefalsetruefalse5falsefalsefalse00Class Rfalsefalsefalsetruefalse6falsefalsefalse00Class TfalsefalsefalsetruefalseOtherus-types:textBlockItemTypestringShareholder Fees (fees paid directly from your investment).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subsection table falsefalseShareholder Fees Column [Text]0rr_ShareholderFeesColumnNametruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class&#160;AClass&#160;Afalsefalsefalsetruefalse2falsefalsefalse00Class&#160;CClass&#160;Cfalsefalsefalsetruefalse3falsefalsefalse00Class SClass Sfalsefalsefalsetruefalse4falsefalsefalse00Class IClass Ifalsefalsefalsetruefalse5falsefalsefalse00Class RClass Rfalsefalsefalsetruefalse6falsefalsefalse00Class TClass TfalsefalsefalsetruefalseOthernanafalsefalseShareholder Fees Column [Text]2falseRowprimaryElement*5false0rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPricerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.05750.0575falsefalsefalsetruefalse2truetruetrue0.00000.0000falsefalsefalsetruefalse3truetruetrue0.00000.0000falsefalsefalsetruefalse4truetruetrue0.00000.0000falsefalsefalsetruefalse5truetruetrue0.00000.0000falsefalsefalsetruefalse6truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureMaximum Deferred Sales Charge (Load) (as a percentage of ____) A.3.instructions.2.a.i "Maximum Deferred Sales Charge (Load)" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). A.3.instructions.2.a.ii If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read "Maximum Sales Charge (Load)" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection table falsefalseMaximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)0rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPricetruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.05750.0575falsefalsefalsetruefalse2truetruetrue0.00000.0000falsefalsefalsetruefalse3truetruetrue0.00000.0000falsefalsefalsetruefalse4truetruetrue0.00000.0000falsefalsefalsetruefalse5truetruetrue0.00000.0000falsefalsefalsetruefalse6truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalseMaximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)3falseRowprimaryElement*6false0rr_MaximumDeferredSalesChargeOverOtherrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00000.0000falsefalsefalsetruefalse2truetruetrue0.01000.0100falsefalsefalsetruefalse3truetruetrue0.00000.0000falsefalsefalsetruefalse4truetruetrue0.00000.0000falsefalsefalsetruefalse5truetruetrue0.00000.0000falsefalsefalsetruefalse6truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureMaximum Deferred Sales Charge (Load) (as a percentage of ____) "Maximum Deferred Sales Charge (Load)" includes the maximum total deferred sales charge (load) payable upon redemption, in installments, or both, expressed as a percentage of the amount or amounts stated in response to Item 7(a), except that, for a sales charge (load) based on net asset value at the time of purchase, show the sales charge (load) as a percentage of the offering price at the time of purchase. A Fund may include in a footnote to the table, if applicable, a tabular presentation showing the amount of deferred sales charges (loads) over time or a narrative explanation of the sales charges (loads) (e.g., __% in the first year after purchase, declining to __% in the __ year and eliminated thereafter). If more than one type of sales charge (load) is imposed (e.g., a deferred sales charge (load) and a front-end sales charge (load)), the first caption in the table should read "Maximum Sales Charge (Load)" and show the maximum cumulative percentage. Show the percentage amounts and the terms of each sales charge (load) comprising that figure on separate lines below.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph a -Clause i -Subsection instructions falsefalseMaximum Deferred Sales Charge (as a percentage)0rr_MaximumDeferredSalesChargeOverOthertruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00000.0000falsefalsefalsetruefalse2truetruetrue0.01000.0100falsefalsefalsetruefalse3truetruetrue0.00000.0000falsefalsefalsetruefalse4truetruetrue0.00000.0000falsefalsefalsetruefalse5truetruetrue0.00000.0000falsefalsefalsetruefalse6truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalseMaximum Deferred Sales Charge (as a percentage)63Shareholder Fees - Janus Triton Fund (Class A, C, S, I, R & T Shares) Janus Triton Fund [Member] Growth & Core - Class A, C, S, I, R and T Shares [Member]UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ShareholderFeesData.No authoritative reference available.falsefalseShareholder Fees [Table]12false0rr_OperatingExpensesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalseOperating Expenses Caption [Text]13false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;" &gt;~ http://janus.com/role/AnnualFundOperatingExpensesJanusTritonFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row rr_DocumentInformationDocumentAxis compact jif277751_S000010485_Member * row dei_LegalEntityAxis compact jif277751_Prospectus_Five_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;" &gt;~ http://janus.com/role/AnnualFundOperatingExpensesJanusTritonFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row rr_DocumentInformationDocumentAxis compact jif277751_S000010485_Member * row dei_LegalEntityAxis compact jif277751_Prospectus_Five_Member * ~&lt;/div&gt; </div>falsehttp://janus.com/role/AnnualFundOperatingExpensesJanusTritonFundfalsefalse0200223 - Schedule - Annual Fund Operating Expenses - Janus Triton Fund (Class A, C, S, I, R & T Shares)truefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass A, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077722Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class A, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$2falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass C, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077723Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class C, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$3falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass S, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077726Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class S, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$4falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass I, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077724Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class I, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$5falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass R, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077725Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class R, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$6falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass T, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000028947Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class T, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_OperatingExpensesColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class&#160;Afalsefalsefalsetruefalse2falsefalsefalse00Class&#160;Cfalsefalsefalsetruefalse3falsefalsefalse00Class Sfalsefalsefalsetruefalse4falsefalsefalse00Class Ifalsefalsefalsetruefalse5falsefalsefalse00Class Rfalsefalsefalsetruefalse6falsefalsefalse00Class TfalsefalsefalsetruefalseOtherus-types:textBlockItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalseOperating Expenses Column [Text]0rr_OperatingExpensesColumnNametruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class&#160;AClass&#160;Afalsefalsefalsetruefalse2falsefalsefalse00Class&#160;CClass&#160;Cfalsefalsefalsetruefalse3falsefalsefalse00Class SClass Sfalsefalsefalsetruefalse4falsefalsefalse00Class IClass Ifalsefalsefalsetruefalse5falsefalsefalse00Class RClass Rfalsefalsefalsetruefalse6falsefalsefalse00Class TClass TfalsefalsefalsetruefalseOthernanafalsefalseOperating Expenses Column [Text]2falseRowprimaryElement*5false0rr_ManagementFeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00640.0064falsefalsefalsetruefalse2truetruetrue0.00640.0064falsefalsefalsetruefalse3truetruetrue0.00640.0064falsefalsefalsetruefalse4truetruetrue0.00640.0064falsefalsefalsetruefalse5truetruetrue0.00640.0064falsefalsefalsetruefalse6truetruetrue0.00640.0064falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureManagement Fees include investment advisory fees (including any fees based on the Fund's performance), any other management fees payable to the investment adviser or its affiliates, and administrative fees payable to the investment adviser or its affiliates that are not included as "Other Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph a -Subsection instructions falsefalseManagement Fees0rr_ManagementFeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00640.0064falsefalsefalsetruefalse2truetruetrue0.00640.0064falsefalsefalsetruefalse3truetruetrue0.00640.0064falsefalsefalsetruefalse4truetruetrue0.00640.0064falsefalsefalsetruefalse5truetruetrue0.00640.0064falsefalsefalsetruefalse6truetruetrue0.00640.0064falsefalsefalsetruefalseOthernanafalsefalseManagement Fees3falseRowprimaryElement*6false0rr_DistributionAndService12b1FeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00250.0025falsefalsefalsetruefalse2truetruetrue0.01000.0100falsefalsefalsetruefalse3truetruetrue0.00250.0025falsefalsefalsetruefalse4truetruetrue0.00000.0000falsefalsefalsetruefalse5truetruetrue0.00500.0050falsefalsefalsetruefalse6truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureDistribution [and/or Service] (12b-1) Fees" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalseDistribution/Service (12b-1) Fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00250.0025falsefalsefalsetruefalse2truetruetrue0.01000.0100falsefalsefalsetruefalse3truetruetrue0.00250.0025falsefalsefalsetruefalse4truetruetrue0.00000.0000falsefalsefalsetruefalse5truetruetrue0.00500.0050falsefalsefalsetruefalse6truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalseDistribution/Service (12b-1) Fees4falseRowprimaryElement*7false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00180.0018falsefalsefalsetruefalse2truetruetrue0.00150.0015falsefalsefalsetruefalse3truetruetrue0.00340.0034falsefalsefalsetruefalse4truetruetrue0.00070.0007falsefalsefalsetruefalse5truetruetrue0.00320.0032falsefalsefalsetruefalse6truetruetrue0.00360.0036falsefalsefalsetruefalseOtherrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions falsefalseOther Expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00180.0018falsefalsefalsetruefalse2truetruetrue0.00150.0015falsefalsefalsetruefalse3truetruetrue0.00340.0034falsefalsefalsetruefalse4truetruetrue0.00070.0007falsefalsefalsetruefalse5truetruetrue0.00320.0032falsefalsefalsetruefalse6truetruetrue0.00360.0036falsefalsefalsetruefalseOthernanafalsefalseOther Expenses5falseRowprimaryElement*8false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.01070.0107[1]falsefalsefalsetruefalse2truetruetrue0.01790.0179[1]falsefalsefalsetruefalse3truetruetrue0.01230.0123[1]falsefalsefalsetruefalse4truetruetrue0.00710.0071[1]falsefalsefalsetruefalse5truetruetrue0.01460.0146[1]falsefalsefalsetruefalse6truetruetrue0.01000.0100[1]falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph d -Subsection instructions falsefalseTotal Annual Fund Operating Expenses0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1truetruetrue0.01070.0107falsefalsefalsetruefalse2truetruetrue0.01790.0179falsefalsefalsetruefalse3truetruetrue0.01230.0123falsefalsefalsetruefalse4truetruetrue0.00710.0071falsefalsefalsetruefalse5truetruetrue0.01460.0146falsefalsefalsetruefalse6truetruetrue0.01000.0100falsefalsefalsetruefalseOthernanafalsefalseTotal Annual Fund Operating Expenses1Janus Capital has contractually agreed to waive the Fund's total annual fund operating expenses (excluding the distribution and shareholder servicing fees - applicable to Class A Shares, Class C Shares, Class S Shares, and Class R Shares; administrative services fees payable pursuant to the Transfer Agency Agreement - applicable to Class S Shares, Class R Shares, and Class T Shares; brokerage commissions, interest, dividends, taxes, and extraordinary expenses including, but not limited to, acquired fund fees and expenses) to 1.05% until at least February 1, 2012. The contractual waiver may be terminated or modified at any time prior to this date only at the discretion of the Board of Trustee.65Annual Fund Operating Expenses - Janus Triton Fund (Class A, C, S, I, R & T Shares) Janus Triton Fund [Member] Growth & Core - Class A, C, S, I, R and T Shares [Member]UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Table]14false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00EXAMPLE:falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example [Heading]15false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The following Example is based on expenses without waivers. The 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 reinvest all dividends and distributions. The Example also assumes that your investment has a 5% return each year and that the Fund&#8217;s operating expenses without waivers remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection example falsefalseExpense Example Narrative [Text Block]16false0rr_ExpenseExampleByYearCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00If Shares are redeemed:falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example by, Year, Caption [Text]17false0rr_ExpenseExampleWithRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://janus.com/role/ExpenseExampleJanusTritonFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact jif277751_S000010485_Member * row dei_LegalEntityAxis compact jif277751_Prospectus_Five_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://janus.com/role/ExpenseExampleJanusTritonFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact jif277751_S000010485_Member * row dei_LegalEntityAxis compact jif277751_Prospectus_Five_Member * ~&lt;/div&gt; </div>truehttp://janus.com/role/ExpenseExampleJanusTritonFundfalsefalse0200323 - Schedule - Expense Example - Janus Triton Fund (Class A, C, S, I, R & T Shares) {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_ExpenseExampleByYearColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class A Sharesfalsefalsefalsetruefalse2falsefalsefalse00Class C Sharesfalsefalsefalsetruefalse3falsefalsefalse00Class S Sharesfalsefalsefalsetruefalse4falsefalsefalse00Class I Sharesfalsefalsefalsetruefalse5falsefalsefalse00Class R Sharesfalsefalsefalsetruefalse6falsefalsefalse00Class T SharesfalsefalsefalsetruefalseOtherus-types:textBlockItemTypestringThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, By Year, Column [Text]falseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue678678falsefalsefalsetruefalse2truefalsetrue282282falsefalsefalsetruefalse3truefalsetrue125125falsefalsefalsetruefalse4truefalsetrue7373falsefalsefalsetruefalse5truefalsetrue149149falsefalsefalsetruefalse6truefalsetrue102102falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalse1 YearfalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue896896falsefalsefalsetruefalse2truefalsetrue563563falsefalsefalsetruefalse3truefalsetrue390390falsefalsefalsetruefalse4truefalsetrue227227falsefalsefalsetruefalse5truefalsetrue462462falsefalsefalsetruefalse6truefalsetrue318318falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse3 YearsfalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue11311131falsefalsefalsetruefalse2truefalsetrue970970falsefalsefalsetruefalse3truefalsetrue676676falsefalsefalsetruefalse4truefalsetrue395395falsefalsefalsetruefalse5truefalsetrue797797falsefalsefalsetruefalse6truefalsetrue552552falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse5 YearsfalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue18061806falsefalsefalsetruefalse2truefalsetrue21052105falsefalsefalsetruefalse3truefalsetrue14891489falsefalsefalsetruefalse4truefalsetrue883883falsefalsefalsetruefalse5truefalsetrue17461746falsefalsefalsetruefalse6truefalsetrue12251225falsefalsefalsetruefalseMonetaryrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse10 YearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*Rowdei_LegalEntityAxisAxis*RowunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass A, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077722Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class A, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class A SharesClass A Sharesfalsefalsefalsetruefalse2truefalsetrue678678falsefalsefalsetruefalse3truefalsetrue896896falsefalsefalsetruefalse4truefalsetrue11311131falsefalsefalsetruefalse5truefalsetrue18061806falsefalsefalsetruefalseOthernanafalsefalseClass A, Janus Triton Fund [Member]2falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*Rowdei_LegalEntityAxisAxis*RowunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass C, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077723Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - 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Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class S, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Class S SharesClass S Sharesfalsefalsefalsetruefalse2truefalsetrue125125falsefalsefalsetruefalse3truefalsetrue390390falsefalsefalsetruefalse4truefalsetrue676676falsefalsefalsetruefalse5truefalsetrue14891489falsefalsefalsetruefalseOthernanafalsefalseClass S, Janus Triton Fund [Member]4falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*Rowdei_LegalEntityAxisAxis*RowunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass I, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000077724Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - 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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]24false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund pursues its investment objective by investing primarily in common stocks selected for their growth potential. In pursuing that objective, the Fund invests in equity securities of small- and medium-sized companies. Generally, small- and medium-sized companies have a market capitalization of less than $10 billion. Market capitalization is a commonly used measure of the size and value of a company.</p> <p>The portfolio managers apply a &#8220;bottom up&#8221; approach in choosing investments. In other words, the portfolio managers look at companies one at a time to determine if a company is an attractive investment opportunity and if it is consistent with the Fund&#8217;s investment policies.</p><p>The Fund may invest in foreign equity and debt securities, which may include investments in emerging markets.</p><p>The Fund may lend portfolio securities on a short-term or long-term basis, in an amount equal to up to 1/3 of its total assets as determined at the time of the loan origination.</p>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]25false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL INVESTMENT RISKSfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk [Heading]26false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The biggest risk is that the Fund&#8217;s returns will vary, and you could lose money. The Fund is designed for long-term investors seeking an equity portfolio, including common stocks. Common stocks tend to be more volatile than many other investment choices.</p><p><b><i>Market Risk.</i></b> The value of the Fund&#8217;s portfolio may decrease if the value of an individual company or multiple companies in the portfolio decreases or if the portfolio managers&#8217; belief about a company&#8217;s intrinsic worth is incorrect. Further, regardless of how well individual companies perform, the value of the Fund&#8217;s portfolio could also decrease if there are deteriorating economic or market conditions. It is important to understand that the value of your investment may fall, sometimes sharply, in response to changes in the market, and you could lose money.</p><p><b><i>Small- and Mid-Sized Companies Risk.</i></b> The Fund&#8217;s investments in securities issued by small- and mid-sized companies, which tend to be smaller, start-up companies offering emerging products or services, may involve greater risks than are customarily associated with larger, more established companies. Securities issued by small- and mid-sized companies tend to be more volatile and somewhat more speculative than securities issued by larger or more established companies and may underperform as compared to the securities of larger companies.</p><p><b><i>Growth Securities Risk.</i></b> Securities of companies perceived to be &#8220;growth&#8221; companies may be more volatile than other stocks and may involve special risks. The price of a &#8220;growth&#8221; security may be impacted if the company does not realize its anticipated potential or if there is a shift in the market to favor other types of securities.</p><p><b><i>Foreign Exposure Risk.</i></b> The Fund may have significant exposure to foreign markets, including emerging markets, which can be more volatile than the U.S. markets. As a result, its returns and net asset value may be affected to a large degree by fluctuations in currency exchange rates or political or economic conditions in a particular country. A market swing in one or more countries or regions where the Fund has invested a significant amount of its assets may have a greater effect on the Fund&#8217;s performance than it would in a more geographically diversified portfolio. The Fund&#8217;s investments in emerging market countries may involve risks greater than, or in addition to, the risks of investing in more developed countries.</p><p><b><i>Securities Lending Risk.</i></b> The Fund may seek to earn additional income through lending its securities to certain qualified broker-dealers and institutions. There is the risk that when portfolio securities are lent, the securities may not be returned on a timely basis, and the Fund may experience delays and costs in recovering the security or gaining access to the collateral provided to the Fund to collateralize the loan. If the Fund is unable to recover a security on loan, the Fund may use the collateral to purchase replacement securities in the market. There is a risk that the value of the collateral could decrease below the cost of the replacement security by the time the replacement investment is made, resulting in a loss to the Fund.</p><p><i>An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.</i></p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative [Text Block]27false0rr_RiskLoseMoneyrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The biggest risk is that the Fund&#8217;s returns will vary, and you could lose money.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringSummarize the principal risks of investing in the Fund, including the risks to which the Fund's portfolio as a whole is subject and the circumstances reasonably likely to affect adversely the Fund's net asset value, yield, and total return. Unless the Fund is a Money Market Fund, disclose that loss of money is a risk of investing in the Fund. 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Subsection b falsefalseRisk Lose Money [Text]28false0rr_RiskNotInsuredDepositoryInstitutionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringIf the Fund is advised by or sold through an insured depository institution, state that An investment in the Fund is not a deposit of the bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. A Money Market Fund that is advised by or sold through an insured depository institution should combine the disclosure required by Items 2(c)(1)(ii) and (iii) in a single statement.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph iii -Subsection b falsefalseRisk Not Insured Depository Institution [Text]29false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PERFORMANCE INFORMATIONfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table [Heading]30false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The following information provides some indication of the risks of investing in the Fund by showing how the Fund&#8217;s performance has varied over time. Class&#160;T Shares (formerly named Class&#160;J Shares, the initial share class) of the Fund commenced operations with the Fund&#8217;s inception. Class&#160;A Shares, Class&#160;C Shares, Class&#160;S Shares, Class&#160;I Shares, and Class&#160;R Shares of the Fund commenced operations on July&#160;6, 2009.</p><p>&#8226; The performance shown for Class T Shares is calculated using the fees and expenses of Class T Shares in effect during the periods shown, net of any applicable fee and expense limitations or waivers.</p><p>&#8226; The performance shown for Class A Shares, Class C Shares, Class S Shares, and Class R Shares for periods prior to July 6, 2009, reflects the performance of the Fund&#8217;s former Class J Shares, calculated using the fees and expenses of each respective share class, without the effect of any fee and expense limitations or waivers.</p><p>&#8226; The performance shown for Class I Shares for periods prior to July 6, 2009, reflects the performance of the Fund&#8217;s former Class J Shares, calculated using the fees and expenses of Class J Shares, without the effect of any fee and expense limitations or waivers.</p><p>If Class A Shares, Class C Shares, Class S Shares, Class I Shares, and Class R Shares of the Fund had been available during periods prior to July 6, 2009, the performance shown for each respective share class may have been different. The performance shown for periods following the Fund&#8217;s commencement of Class A Shares, Class C Shares, Class S Shares, Class I Shares, and Class R Shares reflects the fees and expenses of each respective share class, net of any applicable fee and expense limitations or waivers.</p><p>The bar chart depicts the change in performance from year to year during the periods indicated. The bar chart figures do not include any applicable sales charges that an investor may pay when they buy or sell Class A Shares or Class C Shares of the Fund. If sales charges were included, the returns would be lower. The table compares the Fund&#8217;s average annual returns for the periods indicated to broad-based securities market indices. The indices are not actively managed and are not available for direct investment. All figures assume reinvestment of dividends and distributions. For certain periods, the Fund&#8217;s performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.</p><p><i>The Fund&#8217;s past performance (before and after taxes) does not necessarily indicate how it will perform in the future. Updated performance information is available at janus.com/advisor/mutual-funds or by calling 1-877-335-2687.</i></p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalsePerformance Narrative [Text Block]31false0rr_PerformanceInformationIllustratesVariabilityOfReturnsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The following information provides some indication of the risks of investing in the Fund by showing how the Fund&#8217;s performance has varied over time. The bar chart depicts the change in performance from year to year during the periods indicated.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInclude the bar chart and table required by paragraphs (b)(2)(ii) and (iii) of this section. Provide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides 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 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph i -Subsection b falsefalsePerformance Information Illustrates Variability of Returns [Text]32false0rr_PerformanceAdditionalMarketIndexrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The table compares the Fund&#8217;s average annual returns for the periods indicated to broad-based securities market indices. The indices are not actively managed and are not available for direct investment. All figures assume reinvestment of dividends and distributions.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInclude the bar chart and table required by paragraphs (b)(2)(ii) and (iii) of this section. 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Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph i -Subsection b falsefalsePerformance Additional Market Index [Text]33false0rr_BarChartDoesNotReflectSalesLoadsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The bar chart figures do not include any applicable sales charges that an investor may pay when they buy or sell Class A Shares or Class C Shares of the Fund. If sales charges were included, the returns would be lower.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInclude the bar chart and table required by Item 4 (b)(2)(ii) and (iii) of this section. Provide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides 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 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph i -Subsection b falsefalseBar Chart Does Not Reflect Sales Loads [Text]34false0rr_PerformancePastDoesNotIndicateFuturerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>The Fund&#8217;s past performance (before and after taxes) does not necessarily indicate how it will perform in the future.</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringInclude the bar chart and table required by paragraphs (b)(2)(ii) and (iii) of this section. Provide a brief explanation of how the information illustrates the variability of the Fund's returns (e.g., by stating that the information provides 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 1, 5, and 10 years compare with those of a broad measure of market performance). Provide a statement to the effect that the Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph i -Subsection b falsefalsePerformance Past Does Not Indicate Future [Text]35false0rr_PerformanceTableClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Updated performance information is available at janus.com/advisor/mutual-funds or by calling 1-877-335-2687.</i>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also shouldshow the returns of an appropriate broadbased securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Subsection b falsefalsePerformance Table Closing [Text Block]36false0rr_PerformanceAvailabilityWebSiteAddressrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>janus.com/advisor/mutual-funds</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringIf applicable, include a statement explaining that updated performance information is available and providing a Website address and/or toll-free (or collect) telephone number where the updated information may be obtained.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph i -Subsection b falsefalsePerformance Availability Website Address [Text]37false0rr_PerformanceAvailabilityPhonerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>1-877-335-2687</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringIf applicable, include a statement explaining that updated performance information is available and providing a Web site address and/or toll-free (or collect) telephone number where the updated information may be obtained.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph i -Subsection b falsefalsePerformance Availability Phone [Text]38false0rr_BarChartHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Total Returns for Class T Shares (calendar year-end)falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart [Heading]39false0rr_BarChartTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 <div> &lt;div style="display:none;"&gt;~ http://janus.com/role/AnnualTotalReturnsBarChartJanusTritonFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact jif277751_S000010477_Member * row dei_LegalEntityAxis compact jif277751_Prospectus_Five_Member * ~&lt;/div&gt; </div>falsefalseBarChart24.jpg <div> &lt;div style="display:none;"&gt;~ http://janus.com/role/AnnualTotalReturnsBarChartJanusTritonFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact jif277751_S000010477_Member * row dei_LegalEntityAxis compact jif277751_Prospectus_Five_Member * ~&lt;/div&gt; </div>falsehttp://janus.com/role/AnnualTotalReturnsBarChartJanusTritonFundfalsefalse0200523 - Schedule - Annual Total Returns (Bar Chart) - Janus Triton Fund (Class A, C, S, I, R & T Shares)truefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*Columndei_LegalEntityAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseJanus Triton Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_S000010485Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseClass T, Janus Triton Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_C000028947Memberrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberJanus Triton Fund [Member]Class T, Janus Triton Fund [Member]Growth & Core - Class A, C, S, I, R and T Shares [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_AnnualReturn2006rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.15850.1585falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. 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Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberRussell 2500 Growth Index [Member]Inception Period Since, 02-25-2005 [Member]Share ClassesGrowth & Core - Class A, C, S, I, R and T Shares [Member]Standard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsetruefalse00Russell 2500tm Growth IndexRussell 2500tm Growth Indexfalsefalsefalsetruefalse3falsefalsefalse00(reflects no deduction for expenses, fees, or taxes)(reflects no deduction for expenses, fees, or taxes)falsefalsefalsetruefalse4truetruetrue0.28860.2886falsefalsefalsetruefalse5truetruetrue0.05630.0563falsefalsefalsetruefalse6truetruetrue0.06400.0640falsefalsefalsetruefalse7falsetruefalse002005-02-252005-02-25falsefalsetruetruefalseOthernanafalsefalseRussell 2500 Growth Index [Member] Inception Period Since, 02-25-2005 [Member]10falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*Rowdei_LegalEntityAxisAxis*RowunitUnit*duration2010-01-29T00:00:002011-01-28T00:00:00falsefalseRussell 2000 Growth Index [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_Russell2000GrowthIndexMemberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseInception Period Since, 02-25-2005 [Member]rr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_InceptionPeriodEightMemberrr_PerformanceMeasureAxisexplicitMembertruefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberfalsefalseGrowth & Core - Class A, C, S, I, R and T Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijif277751_ProspectusFiveMemberdei_LegalEntityAxisexplicitMemberRussell 2000 Growth Index [Member]Inception Period Since, 02-25-2005 [Member]Share ClassesGrowth & Core - Class A, C, S, I, R and T Shares [Member]Standard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsetruefalse00Russell 2000 Growth IndexRussell 2000 Growth Indexfalsefalsefalsetruefalse3falsefalsefalse00(reflects no deduction for expenses, fees, or taxes)(reflects no deduction for expenses, fees, or taxes)falsefalsefalsetruefalse4truetruetrue0.29090.2909falsefalsefalsetruefalse5truetruetrue0.05300.0530falsefalsefalsetruefalse6truetruetrue0.05720.0572falsefalsefalsetruefalse7falsetruefalse002005-02-252005-02-25falsefalsetruetruefalseOthernanafalsefalseRussell 2000 Growth Index [Member] Inception Period Since, 02-25-2005 [Member]1Calculated assuming maximum permitted sales loads.2The one year return is calculated to include the contingent deferred sales charge.3If the Fund incurs a loss, which generates a tax benefit, the Return After Taxes on Distributions and Sale of Fund Shares may exceed the Fund's other return figures. 710Average Annual Total Returns - Janus Triton Fund (Class A, C, S, I, R & T Shares) Growth & Core - Class A, C, S, I, R and T Shares [Member]UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*Rowdei_LegalEntityAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to PerformanceTableData.No authoritative reference available.falsefalsePerformance [Table]43false0rr_PerformanceTableNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>After-tax returns are calculated using distributions for the Fund&#8217;s Class T Shares (formerly named Class J Shares, the initial share class). After-tax returns are calculated using the historically highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on your individual tax situation and may differ from those shown in the preceding table. The after-tax return information shown above does not apply to Fund shares held through a tax-deferred account, such as a 401(k) plan or an IRA.</p><p>After-tax returns are only shown for Class T Shares of the Fund. After-tax returns for the other classes of Shares will vary from those shown for Class T Shares due to varying sales charges (as applicable), fees, and expenses among the classes.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a table showing the Fund's (A) average annual total return; (B) average annual total return (after taxes on distributions); and (C) average annual total return (after taxes on distributions and redemption). A Money Market Fund should show only the returns described in clause (A) of the preceding sentence. All returns should be shown for 1-, 5-, and 10- calendar year periods ending on the date of the most recently completed calendar year (or for the life of the Fund, if shorter), but only for periods subsequent to the effective date of the Fund's registration statement. The table also shouldshow the returns of an appropriate broadbased securities market index as defined in Instruction 5 to Item 22(b)(7) for the same periods. A Fund that has been in existence for more than 10 years also may include returns for the life of the Fund. A Money Market Fund may provide the Fund's 7-day yield ending on the date of the most recent calendar year or disclose a toll-free (or collect) telephone number that investors can use to obtain the Fund's current 7-day yield. For a Fund (other than a Money Market Fund or a Fund described in General Instruction C.3.(d)(iii)), provide the information in the following table with the specified captions AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, _____). For a Fund that provides annual total returns for only one calendar year or for a Fund that does not include the bar chart because it does not have annual returns for a full calendar year, modify, as appropriate, the narrative explanation required by paragraph (c)(2)(i) (e.g., by stating that the information gives some indication of the risks of an investment in the Fund by comparing the Fund's performance with a broad measure of market performance).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iv -Subsection b falsefalsePerformance Table Narrative44false0rr_PerformanceTableUsesHighestFederalRaterrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00After-tax returns are calculated using the historically highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringProvide a brief explanation that 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.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Subsection b falsefalsePerformance Table Uses Highest Federal Rate45false0rr_PerformanceTableNotRelevantToTaxDeferredrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Actual after-tax returns depend on your individual tax situation and may differ from those shown in the preceding table. The after-tax return information shown above does not apply to Fund shares held through a tax-deferred account, such as a 401(k) plan or an IRA.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringProvide a brief explanation that the actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iv -Clause B -Subsection b falsefalsePerformance Table Not Relevant to Tax Deferred46false0rr_PerformanceTableOneClassOfAfterTaxShownrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00After-tax returns are only shown for Class T Shares of the Fund. After-tax returns for the other classes of Shares will vary from those shown for Class T Shares due to varying sales charges (as applicable), fees, and expenses among the classes.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringProvide a brief explanation that if the Fund is a Multiple Class Fund that offers more than one Class in the prospectus, after-tax returns are shown for only one Class and after-tax returns for other Classes will vary.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Subsection b Reference 2: 2 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iv -Clause C -Subsection b falsefalsePerformance Table One Class of after Tax Shown [Text]145Risk/Return Summary - Janus Triton Fund (Class A, C, S, I, R & T Shares (Janus Triton Fund [Member], Growth & Core - Class A, C, S, I, R and T Shares [Member], USD $)NoRoundingUnKnownUnKnownUnKnowntruetrue