2.2.0.25truefalse0100001 - Document - Risk/Return Summary - Gamco Westwood Small Cap Equity Fund (Class AAA) {Unlabeled}falsefalsetrue1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : GAMCO Westwood Small Cap Equity Fund [Member] {dei_LegalEntityAxis} : Prospectus, Class AAA Shares [Member] 1/29/2010 - 1/31/2011 TwelveMonthsEnded_31Jan2011_S000001085_Member_Prospectus_One_Memberhttp://www.sec.gov/CIK0000796229duration2010-01-29T00:00:002011-01-31T00:00:00falsefalsewebax_S000001085Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_S000001085Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsewebax_ProspectusOneMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli01false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://gabelli.com/role/riskreturnsummarygamcowestwoodsmallcapequityfundclassaaa1falsefalsefalse00GAMCO Westwood Small Cap Equity Fund [Member] | Prospectus, Class AAA Shares [Member]GAMCO Westwood Small Cap Equity Fund [Member] | Prospectus, Class AAA Shares [Member]falsefalsefalsefalsefalse1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : GAMCO Westwood Small Cap Equity Fund [Member] {dei_LegalEntityAxis} : Prospectus, Class AAA Shares [Member] 1/29/2010 - 1/31/2011 TwelveMonthsEnded_31Jan2011_S000001085_Member_Prospectus_One_Memberhttp://www.sec.gov/CIK0000796229duration2010-01-29T00:00:002011-01-31T00:00:00falsefalsewebax_S000001085Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_S000001085Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsewebax_ProspectusOneMemberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalseGAMCO Westwood Small Cap Equity Fund [Member] | Prospectus, Class AAA Shares [Member]3false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00GAMCO WESTWOOD SMALLCAP EQUITY FUND (the &#8220;SmallCap Equity Fund&#8221;)falsefalsefalsefalsefalseOtherxbrli: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.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Investment Objective</i>falsefalsefalsefalsefalseOtherxbrli: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.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The SmallCap Equity Fund seeks to provide long(term capital appreciation by investing primarily in smaller capitalization equity securities.falsefalsefalsefalsefalseOtherus-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.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Fees and Expenses of the SmallCap Equity Fund:</i>falsefalsefalsefalsefalseOtherxbrli: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 Class&#160;AAA Shares of the SmallCap Equity 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_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]9false0rr_ShareholderFeesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;" &gt;~ http://gabelli.com/role/ShareholderFeesGamcoWestwoodSmallCapEquityFundClassAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact webax_S000001085_Member * row rr_DocumentInformationDocumentAxis compact webax_Prospectus_One_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;" &gt;~ http://gabelli.com/role/ShareholderFeesGamcoWestwoodSmallCapEquityFundClassAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact webax_S000001085_Member * row rr_DocumentInformationDocumentAxis compact webax_Prospectus_One_Member * ~&lt;/div&gt; </div>falsehttp://gabelli.com/role/ShareholderFeesGamcoWestwoodSmallCapEquityFundClassAAAfalsefalse0200101 - Schedule - Shareholder Fees - Gamco Westwood Small Cap Equity Fund (Class AAA)truefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-31T00:00:00falsefalseGAMCO Westwood Small Cap Equity Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_S000001085Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseProspectus, Class AAA Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberfalsefalseClass AAA, GAMCO Westwood Small Cap Equity Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_C000002934Memberrr_ProspectusShareClassAxisexplicitMemberGAMCO Westwood Small Cap Equity Fund [Member]Prospectus, Class AAA Shares [Member]Class AAA, GAMCO Westwood Small Cap Equity Fund [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPricerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr: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 (Load) Imposed on Purchases (as a percentage of offering price)0rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPricetruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalseMaximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)2falseRowprimaryElement*5false0rr_MaximumDeferredSalesChargeOverOtherrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr: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. 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"Redemption Fee" includes a fee charged for any redemption of the Fund's shares, but does not include a deferred sales charge (load) imposed upon redemption.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph b -Subsection instructions falsefalseRedemption Fee (as a percentage of amount redeemed)0rr_RedemptionFeeOverRedemptiontruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.02000.0200falsefalsefalsetruefalseOthernanafalsefalseRedemption Fee (as a percentage of amount redeemed)5falseRowprimaryElement*8false0rr_ExchangeFeeOverRedemptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureExchange Fee includes the maximum fee charged for any exchange or transfer of interest from the Fund to another fund. The Fund may include in a footnote to the table, if applicable, a tabular presentation of the range of exchange fees or a narrative explanation of the fees.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 2 -Subparagraph c -Subsection instructions falsefalseExchange Fee0rr_ExchangeFeeOverRedemptiontruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalseExchange Fee15Shareholder Fees - Gamco Westwood Small Cap Equity Fund (Class AAA) UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ShareholderFeesData.No authoritative reference available.falsefalseShareholder Fees [Table]10false0rr_OperatingExpensesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Fund&#160;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]11false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;" &gt;~ http://gabelli.com/role/AnnualFundOperatingExpensesGamcoWestwoodSmallCapEquityFundClassAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact webax_Prospectus_One_Member * row rr_DocumentInformationDocumentAxis compact webax_S000001085_Member * ~</div>falsefalse<div> &lt;div style="display:none;" &gt;~ http://gabelli.com/role/AnnualFundOperatingExpensesGamcoWestwoodSmallCapEquityFundClassAAA column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_LegalEntityAxis compact webax_Prospectus_One_Member * row rr_DocumentInformationDocumentAxis compact webax_S000001085_Member * ~</div>falsehttp://gabelli.com/role/AnnualFundOperatingExpensesGamcoWestwoodSmallCapEquityFundClassAAAfalsefalse0200201 - Schedule - Annual Fund Operating Expenses - Gamco Westwood Small Cap Equity Fund (Class AAA)truefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-31T00:00:00falsefalseGAMCO Westwood Small Cap Equity Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_S000001085Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseProspectus, Class AAA Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_ProspectusOneMemberdei_LegalEntityAxisexplicitMembertruefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberGAMCO Westwood Small Cap Equity Fund [Member]Prospectus, Class AAA Shares [Member]Share ClassesStandard0falseUSDfalsefalse$2falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-01-29T00:00:002011-01-31T00:00:00falsefalseGAMCO Westwood Small Cap Equity Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_S000001085Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseProspectus, Class AAA Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberfalsefalseClass AAA, GAMCO Westwood Small Cap Equity Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_C000002934Memberrr_ProspectusShareClassAxisexplicitMemberGAMCO Westwood Small Cap Equity Fund [Member]Prospectus, Class AAA Shares [Member]Class AAA, GAMCO Westwood Small Cap Equity Fund [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_OperatingExpensesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Fund&#160;Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalseOtherxbrli: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]0rr_OperatingExpensesCaptiontruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Fund&#160;Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):Annual Fund&#160;Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseOperating Expenses Caption [Text]2falseRowprimaryElement*6false0rr_ManagementFeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01000.0100falsefalsefalsetruefalseOtherrr: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_ManagementFeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.01000.0100falsefalsefalsetruefalseOthernanafalsefalseManagement Fees3falseRowprimaryElement*7false0rr_DistributionAndService12b1FeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00250.0025falsefalsefalsetruefalseOtherrr: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 and Service (Rule 12b-1) Expenses0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00250.0025falsefalsefalsetruefalseOthernanafalsefalseDistribution and Service (Rule 12b-1) Expenses4falseRowprimaryElement*8false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.00740.0074falsefalsefalsetruefalseOtherrr: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 truefalseOther Expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00740.0074falsefalsefalsetruefalseOthernanafalsefalseOther Expenses5falseRowprimaryElement*9false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01990.0199falsefalsefalsetruefalseOtherrr: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 truefalseTotal Annual Fund Operating Expenses0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.01990.0199falsefalsefalsetruefalseOthernanafalsefalseTotal Annual Fund Operating Expenses6falseRowprimaryElement*10false0rr_FeeWaiverOrReimbursementOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruetrue00falsefalsefalsetruefalse2truetruetrue-0.0049-0.0049[1]falsefalsefalsetruefalseOtherrr:NonPositivePure4TypepureTotal Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseFee Waiver or Reimbursement0rr_FeeWaiverOrReimbursementOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue-0.0049-0.0049falsefalsefalsetruefalseOthernanafalsefalseFee Waiver or Reimbursement7falseRowprimaryElement*11false0rr_NetExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01500.0150[1]falsefalsefalsetruefalseOtherrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 11 -Subsection table falsefalseNet Expenses (as a percentage of Assets)0rr_NetExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.01500.0150falsefalsefalsetruefalseOthernanafalsefalseNet Expenses (as a percentage of Assets)1The Adviser has contractually agreed to waive its investment advisory fees and/or to reimburse expenses of the SmallCap Equity Fund to the extent necessary to maintain the Total Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement (excluding brokerage, acquired fund fees and expenses, interest, taxes, and extraordinary expenses) at no more than 1.50%. The fee waiver and expense reimbursement arrangement will continue until at least January 31, 2012 and may not be terminated by the Fund or the Adviser before such time. Thereafter, this arrangement may only be terminated or amended to increase the expense cap as of January 31 of each calendar year, provided that in the case of a termination by the Adviser, the Adviser will provide the Board with written notice of its intention to terminate the arrangement prior to the expiration of its then current term. 27Annual Fund Operating Expenses - Gamco Westwood Small Cap Equity Fund (Class AAA) GAMCO Westwood Small Cap Equity Fund [Member]UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*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]12false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Expense Example</i>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]13false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>This example is intended to help you compare the cost of investing in Class&#160;AAA Shares of the SmallCap Equity Fund with the cost of investing in other mutual funds.</p><p>The example assumes that you invest $10,000 in the SmallCap Equity Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the SmallCap Equity Fund&#8217;s operating expenses remain the same (taking into account the expense limitation for one year). 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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$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue577577falsefalsefalsetruefalseMonetaryrr: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$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue10271027falsefalsefalsetruefalseMonetaryrr: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$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue22772277falsefalsefalsetruefalseMonetaryrr: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. 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Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover [Heading]16false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The SmallCap Equity Fund pays transaction costs, such as commissions, when it buys and sells securities (or &#8220;turns over&#8221; its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when the SmallCap Equity Fund&#8217;s shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the SmallCap Equity Fund&#8217;s performance. During the most recent fiscal year, the SmallCap Equity Fund&#8217;s portfolio turnover rate was 28% of the average value of its portfolio.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover [Text Block]17false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Principal Investment Strategies</i>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]18false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Under normal market conditions, the SmallCap Equity Fund invests at least 80% of its net assets (which includes, for purposes of this test, the amount of any borrowings for investment purposes) in a portfolio of common stocks of smaller companies. The Adviser characterizes small capitalization companies as those companies with a market capitalization (defined as shares outstanding times current market price) between $100&#160;million and $2.5&#160;billion at the time of the SmallCap Equity Fund&#8217;s initial investment. The Adviser may change this characterization at any time in the future based upon the market capitalizations of the securities included in the Russell 2000&#174; Index. The Adviser closely monitors the issuers and will sell a stock if the stock achieves its price objective and has limited further potential for price increase, the forecasted price/earnings ratio exceeds the future forecasted growth rate, and/or the issuer suffers a negative change in its fundamental outlook.</p><p>The SmallCap Equity Fund may also invest up to 25% of its total assets in foreign equity securities and in EDRs or ADRs. The SmallCap Equity Fund may also invest in foreign debt securities.</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]19false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Principal Risks</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk [Heading]20false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p><b>You May Want to Invest in the Fund if:</b></p><p>&#8226; you are a long-term investor</p><p>&#8226; you seek growth of capital</p><p>&#8226; you seek investments in small capitalization growth stocks as part of your overall investment strategy</p><p>The SmallCap Equity Fund&#8217;s share price will fluctuate with changes in the market value of the SmallCap Equity Fund&#8217;s portfolio securities. Your investment in the SmallCap Equity Fund is not guaranteed and you could lose some or all of the amount you invested in the SmallCap Equity Fund.</p><p>Investing in the SmallCap Equity Fund involves the following risks:</p><p><b>&#8226;&#160;Fund and Management Risk.&#160;</b>&#160;If the SmallCap Equity Fund&#8217;s Adviser&#8217;s judgment in selecting securities is incorrect or if the market segment in which the SmallCap Equity Fund invests falls out of favor with investors, the SmallCap Equity Fund could underperform the stock market or its peers. The SmallCap Equity Fund could also fail to meet its investment objective. When you sell SmallCap Equity Fund shares, they may be worth less than what you paid for them.</p><p><b>&#8226;&#160;Equity Risk.</b>&#160;&#160;The principal risk of investing in the SmallCap Equity Fund is equity risk. Equity risk is the risk that the prices of the securities held by the SmallCap Equity Fund will fall due to general market and economic conditions, perceptions regarding the industries in which the companies issuing the securities participate, and the issuer company&#8217;s particular circumstances.</p><p><b>&#8226;&#160;Foreign Securities Risk.</b>&#160;&#160;Foreign securities pose additional risks over U.S.&#160;based securities for a number of reasons. Foreign economic, governmental, and political systems may be less favorable than those of the U.S.&#160;Foreign governments may exercise greater control over their economies, industries, and citizens&#8217; rights. Specific risk factors related to foreign securities include: inflation, structure and regulation of financial markets, liquidity and volatility of investments, currency exchange rates and regulations, and differing accounting standards. Foreign companies may also be subject to significantly higher levels of taxation than U.S. companies, including potentially confiscatory levels of taxation, thereby reducing their earnings potential, and amounts realized on foreign securities may be subject to high levels of foreign taxation for which no U.S. federal income tax deductions or credits will be available to shareholders.</p><p>Foreign securities may be denominated in foreign currencies. Therefore, the value of the SmallCap Equity Fund&#8217;s assets and income in U.S. dollars may be affected by changes in exchange rates and regulations, since exchange rates for foreign currencies change daily. The combination of currency risk and market risk tends to make securities traded in foreign markets more volatile than securities traded exclusively in the U.S. Although the SmallCap Equity Fund values its assets daily in U.S. dollars, it will not convert its holdings of foreign currencies to U.S. dollars daily. Therefore, the SmallCap Equity Fund may be exposed to currency risks over an extended period of time.</p><p><b> &#8226; Small- and Micro-Cap Company Risk.</b> Although small-cap and micro-cap companies may offer greater potential for capital appreciation than larger companies, investing in securities of small-cap and micro-cap companies may involve greater risks than investing in larger, more established issuers. Small-cap and micro-cap companies generally have limited product lines, markets, and financial resources. Their securities may trade less frequently and in more limited volume than the securities of larger, more established companies. Also, small-cap and micro-cap companies are typically subject to greater changes in earnings and business prospects than larger companies. Consequently, small-cap and micro-cap company stock prices tend to rise and fall in value more than other stocks. The risks of investing in micro-cap stocks and companies are even greater than those of investing in small-cap companies.</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]21false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Performance</i>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 and Performance Table [Heading]22false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The bar chart and table provide an indication of the risks of investing in the SmallCap Equity Fund by showing changes in the SmallCap Equity Fund&#8217;s performance from year to year, and by showing how the SmallCap Equity Fund&#8217;s average annual returns for one year, five years, and ten years compare to those of a broad-based securities market index. As with all mutual funds, the SmallCap Equity Fund&#8217;s past performance (before and after taxes) does not predict how the SmallCap Equity Fund will perform in the future. Updated information on the SmallCap Equity Fund&#8217;s results can be obtained by visiting www.gabelli.com.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]23false0rr_BarChartHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00GAMCO WESTWOOD SMALLCAP EQUITY FUND <i>(Total returns for Class&#160;AAA Shares for the Years Ended December 31)</i>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]24false0rr_BarChartTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;" &gt;~ http://gabelli.com/role/AnnualTotalReturnsBarChartGamcoWestwoodSmallCapEquityFundClassAAA column period compact * column primary compact * row dei_LegalEntityAxis compact webax_S000001085_Member row rr_ProspectusShareClassAxis compact * row rr_DocumentInformationDocumentAxis compact webax_Prospectus_One_Member ~&lt;/div&gt; </div>falsefalseBarChart2.jpg<div> &lt;div style="display:none;" &gt;~ http://gabelli.com/role/AnnualTotalReturnsBarChartGamcoWestwoodSmallCapEquityFundClassAAA column period compact * column primary compact * row dei_LegalEntityAxis compact webax_S000001085_Member row rr_ProspectusShareClassAxis compact * row rr_DocumentInformationDocumentAxis compact webax_Prospectus_One_Member ~&lt;/div&gt; </div>falsehttp://gabelli.com/role/AnnualTotalReturnsBarChartGamcoWestwoodSmallCapEquityFundClassAAA2.2.0.25truefalse0200501 - Schedule - Annual Total Returns (Bar Chart) - Gamco Westwood Small Cap Equity Fund (Class AAA)truefalsefalse1falsefalseUSDtruefalse{dei_DocumentInformationDocumentAxis} : GAMCO Westwood Small Cap Equity Fund [Member] {dei_LegalEntityAxis} : Prospectus, Class AAA Shares [Member] {rr_ProspectusShareClassAxis} : Class AAA, GAMCO Westwood Small Cap Equity Fund [Member] 1/29/2010 - 1/31/2011 USD ($) $TwelveMonthsEnded_31Jan2011_S000001085_Member_Prospectus_One_Member_C000002934_Memberhttp://www.sec.gov/CIK0000796229duration2010-01-29T00:00:002011-01-31T00:00:00falsefalseGAMCO Westwood Small Cap Equity Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_S000001085Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseProspectus, Class AAA Shares [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_ProspectusOneMemberdei_LegalEntityAxisexplicitMemberfalsefalseClass AAA, GAMCO Westwood Small Cap Equity Fund [Member]rr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiwebax_C000002934Memberrr_ProspectusShareClassAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$1false1false0natruenanaNo definition available.truefalsefalsefalsefalsefalsefalsefalsefalsefalsehttp://gabelli.com/role/annualtotalreturnsbarchartgamcowestwoodsmallcapequityfundclassaaa1falsefalsefalse00falsefalsefalsetruefalseOthernaNo definition available.No authoritative reference available.falsefalseAnnual Total Returns (Bar Chart) - Gamco Westwood Small Cap Equity Fund (Class AAA)0natruenanaNo definition available.truefalsefalsefalsefalsefalsefalsefalsefalsefalsehttp://gabelli.com/role/annualtotalreturnsbarchartgamcowestwoodsmallcapequityfundclassaaa1falsefalsefalse00falsefalsefalsetruefalseOthernaNo definition available.No authoritative reference available.falsefalseAnnual Total Returns (Bar Chart) - Gamco Westwood Small Cap Equity Fund (Class AAA)3true3true0rr_BarChartTableAbstractrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsetruefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseAnnual Total Returns0rr_BarChartTableAbstractrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsetruefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseAnnual Total Returns4false4false0rr_AnnualReturn2001rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.223-0.223falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20010rr_AnnualReturn2001rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.223-0.223falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. 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Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20020rr_AnnualReturn2002rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.299-0.299falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. 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If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20037false7false0rr_AnnualReturn2004rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.1430.143falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20040rr_AnnualReturn2004rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.1430.143falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20048false8false0rr_AnnualReturn2005rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.0960.096falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20050rr_AnnualReturn2005rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.0960.096falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. 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The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20059false9false0rr_AnnualReturn2006rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.2240.224falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. 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The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20060rr_AnnualReturn2006rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.2240.224falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. 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The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20070rr_AnnualReturn2007rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.0190.019falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. 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Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20090rr_AnnualReturn2009rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.5240.524falsefalsefalsetruefalseOtherxbrli: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. Present the corresponding numerical return adjacent to each bar. 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If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 1 -Subsection b falsefalseColumn0rr_AverageAnnualReturnColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00falsefalsefalsetruefalse2falsetruefalse00GAMCO Westwood SmallCap Equity Fund&#160;Class&#160;AAA SharesGAMCO Westwood SmallCap Equity Fund&#160;Class&#160;AAA Sharesfalsefalsefalsetruefalse3falsetruefalse00GAMCO Westwood SmallCap Equity Fund&#160;Class&#160;AAA SharesGAMCO Westwood SmallCap Equity Fund&#160;Class&#160;AAA Sharesfalsefalsefalsetruefalse4falsetruefalse00GAMCO Westwood SmallCap Equity Fund&#160;Class&#160;AAA SharesGAMCO Westwood SmallCap Equity Fund&#160;Class&#160;AAA Sharesfalsefalsefalsetruefalse5falsetruefalse00IndexIndexfalsefalsefalsetruefalseOtherus-types:textBlockItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 1 -Subsection b falsefalseColumn6false6false0rr_IndexNoDeductionForFeesExpensesTaxesrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5falsefalsefalse00(reflects no deduction for fees, expenses or taxes)falsefalsefalsetruefalseOtherxbrli:stringItemTypestringThe Performance Table includes a parenthetical, indicating that the Index "(reflects no deduction for fees, expenses or taxes)". 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If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseLabel0rr_AverageAnnualReturnLabelrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00falsefalsefalsetruefalse2falsetruefalse00Return Before TaxesReturn Before Taxesfalsefalsefalsetruefalse3falsetruefalse00Return After Taxes on DistributionsReturn After Taxes on Distributionsfalsefalsefalsetruefalse4falsetruefalse00Return After Taxes on Distributions and Sale of Fund&#160;SharesReturn After Taxes on Distributions and Sale of Fund&#160;Sharesfalsefalsefalsetruefalse5falsetruefalse00Russell 2000 IndexRussell 2000 IndexfalsefalsefalsetruefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseLabel8false8false0rr_AverageAnnualReturnYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.31020.3102falsefalsefalsetruefalse3truetruetrue0.31020.3102falsefalsefalsetruefalse4truetruetrue0.20160.2016falsefalsefalsetruefalse5truetruetrue0.26850.2685falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalsePast One Year0rr_AverageAnnualReturnYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.31020.3102falsefalsefalsetruefalse3truetruetrue0.31020.3102falsefalsefalsetruefalse4truetruetrue0.20160.2016falsefalsefalsetruefalse5truetruetrue0.26850.2685falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalsePast One Year9false9false0rr_AverageAnnualReturnYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.07310.0731falsefalsefalsetruefalse3truetruetrue0.07270.0727falsefalsefalsetruefalse4truetruetrue0.06330.0633falsefalsefalsetruefalse5truetruetrue0.04470.0447falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalsePast Five Years0rr_AverageAnnualReturnYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.07310.0731falsefalsefalsetruefalse3truetruetrue0.07270.0727falsefalsefalsetruefalse4truetruetrue0.06330.0633falsefalsefalsetruefalse5truetruetrue0.04470.0447falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalsePast Five Years10false10false0rr_AverageAnnualReturnYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01870.0187falsefalsefalsetruefalse3truetruetrue0.01850.0185falsefalsefalsetruefalse4truetruetrue0.01610.0161falsefalsefalsetruefalse5truetruetrue0.06330.0633falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalsePast Ten Years0rr_AverageAnnualReturnYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruetrue00falsefalsefalsetruefalse2truetruetrue0.01870.0187falsefalsefalsetruefalse3truetruetrue0.01850.0185falsefalsefalsetruefalse4truetruetrue0.01610.0161falsefalsefalsetruefalse5truetruetrue0.06330.0633falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalsePast Ten Years59Average Annual Total Returns - Gamco Westwood Small Cap Equity (Class AAA)UnKnownUnKnownUnKnownUnKnowntruetrueColumnperiodPeriod*ColumnprimaryElement*Columnrr_DocumentInformationDocumentAxisAxiswebax_Prospectus_One_MemberRowdei_LegalEntityAxisAxiswebax_S000001085_MemberRowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowdei_DocumentInformationDocumentAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to PerformanceTableData.No authoritative reference available.falsefalsePerformance [Table]27false0rr_PerformanceTableNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor&#8217;s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.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 Narrative126Risk/Return Summary - Gamco Westwood Small Cap Equity Fund (Class AAA) (GAMCO Westwood Small Cap Equity Fund [Member], Prospectus, Class AAA Shares [Member])UnKnownUnKnownUnKnownUnKnownfalsetrue