2.2.0.25truefalse010000 - Document - Risk/Return Summary {Unlabeled}falsefalsetrue1falsefalseUSDtruefalse{dei_DocumentInformationDocumentAxis} : First Trust NASDAQ CEA Smartphone Index Fund [Member] 2/2/2010 - 2/18/2011 USD ($) $TwelveMonthsEnded_18Feb2011_S000030172_Memberhttp://www.sec.gov/CIK0001364608duration2010-02-02T00:00:002011-02-18T00:00:00falsefalseftetf1364608_S000030172Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiftetf1364608_S000030172Memberdei_DocumentInformationDocumentAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$3false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00SUMMARY INFORMATIONfalsefalsefalsefalsefalseOtherxbrli: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.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund seeks investment results that correspond generally to the price and yield (before the Fund's fees and expenses) of an equity index called the NASDAQ OMX CEA Smartphone Index(SM) (the "Index").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.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.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The following table describes the fees and expenses you may pay if you buy and hold Shares of the Fund. Investors purchasing and selling Shares may be subject to costs (including customary brokerage commissions) charged by their broker.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 style="display:none">~ http://ftportfolios.com/role/ShareholderFees column compact * column rr_ProspectusShareClassAxis compact * row compact * row dei_LegalEntityAxis compact ftetf1364608_S000030172_Member ~</div>falsefalse<div style="display:none">~ http://ftportfolios.com/role/ShareholderFees column compact * column rr_ProspectusShareClassAxis compact * row compact * row dei_LegalEntityAxis compact ftetf1364608_S000030172_Member ~</div>falsehttp://ftportfolios.com/role/ShareholderFeesfalsefalse020010 - Schedule - Shareholder Feestruefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2010-02-02T00:00:002011-02-18T00:00:00falsefalseFirst Trust NASDAQ CEA Smartphone Index Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiftetf1364608_S000030172Memberdei_DocumentInformationDocumentAxisexplicitMemberFirst Trust NASDAQ CEA Smartphone Index 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)11Shareholder Fees UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*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 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 style="display:none">~ http://ftportfolios.com/role/AnnualFundOperatingExpenses column compact * column rr_ProspectusShareClassAxis compact * row compact * row dei_LegalEntityAxis compact ftetf1364608_S000030172_Membe ~</div>falsefalse<div style="display:none">~ http://ftportfolios.com/role/AnnualFundOperatingExpenses column compact * column rr_ProspectusShareClassAxis compact * row compact * row dei_LegalEntityAxis compact ftetf1364608_S000030172_Membe ~</div>falsehttp://ftportfolios.com/role/AnnualFundOperatingExpensesfalsefalse020020 - Schedule - Annual Fund Operating Expensestruefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*ColumnunitUnit*duration2010-02-02T00:00:002011-02-18T00:00:00falsefalseFirst Trust NASDAQ CEA Smartphone Index Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiftetf1364608_S000030172Memberdei_DocumentInformationDocumentAxisexplicitMemberFirst Trust NASDAQ CEA Smartphone Index Fund [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_ManagementFeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00700.0070falsefalsefalsetruefalseOtherrr: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_ManagementFeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00700.0070falsefalsefalsetruefalseOthernanafalsefalseManagement Fees2falseRowprimaryElement*5false0rr_DistributionAndService12b1FeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr: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 and Service (12b-1) Fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalseDistribution and Service (12b-1) Fees3falseRowprimaryElement*6false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truetruetrue0.00000.0000falsefalsefalsetruefalseOtherrr: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_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalseOther Expenses4falseRowprimaryElement*7false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00700.0070falsefalsefalsetruefalseOtherrr: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_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruetrue0.00700.0070falsefalsefalsetruefalseOthernanafalsefalseTotal Annual Fund Operating Expenses14Annual Fund Operating Expenses UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*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.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00EXAMPLEfalsefalsefalsefalsefalseOtherxbrli: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>The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling Shares of the Fund in the secondary market.</p> <p>The example assumes that you invest $10,000 in the Fund for the time periods indicated and then you retain the Shares or 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 Fund's net operating expenses remain at current levels until February 18, 2012. Additionally, the example assumes that the Fund imposes a 12b-1 fee of 0.25% per annum of the Fund's average daily net assets following February 18, 2012. Although your actual costs may be higher or lower, based on these assumptions your costs would be:</p>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]14false0rr_ExpenseExampleWithRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://ftportfolios.com/role/ExpenseExample column compact * column rr_ProspectusShareClassAxis compact * row compact * row dei_LegalEntityAxis compact ftetf1364608_S000030172_Membe ~</div>falsefalse<div style="display:none">~ http://ftportfolios.com/role/ExpenseExample column compact * column rr_ProspectusShareClassAxis compact * row compact * row dei_LegalEntityAxis compact ftetf1364608_S000030172_Membe ~</div>truehttp://ftportfolios.com/role/ExpenseExamplefalsefalse020030 - Schedule - Expense Example {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue7272falsefalsefalsetruefalseMonetaryrr: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$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue263263falsefalsefalsetruefalseMonetaryrr: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$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*RowunitUnit*duration2010-02-02T00:00:002011-02-18T00:00:00falsefalseFirst Trust NASDAQ CEA Smartphone Index Fund [Member]dei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiftetf1364608_S000030172Memberdei_DocumentInformationDocumentAxisexplicitMemberFirst Trust NASDAQ CEA Smartphone Index Fund [Member]USDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue7272falsefalsefalsetruefalse2truefalsetrue263263falsefalsefalsetruefalseOthernanafalsefalseFirst Trust NASDAQ CEA Smartphone Index Fund [Member]21Expense Example (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No authoritative reference available.falsefalseExpense Example, With Redemption [Table]15false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PORTFOLIO TURNOVERfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDisclose 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 5 -Subsection instructions falsefalsePortfolio Turnover [Heading]16false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance.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.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL INVESTMENT STRATEGIESfalsefalsefalsefalsefalseOtherxbrli: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>The Fund will normally invest at least 90% of its net assets in common stocks and depositary receipts included in the Index.</p> <p>The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. First Trust Advisors L.P. ("First Trust"), the Fund's investment advisor, seeks a correlation of 0.95 or better (before fees and expenses) between the Fund's performance and the performance of the Index; a figure of 1.00 would represent perfect correlation.</p> <p>The Index is owned by The NASDAQ OMX Group, Inc. (the "Index Provider"). The Index Provider and the Consumer Electronics Association have jointly developed the eligibility and selection criteria and rules for the Index. The Index is calculated and maintained by the Index Provider. The Index is designed to track the performance of companies engaged in the Smartphone segment of the telecommunications and technology sectors. The Index includes companies primarily involved in the building, design and distribution of handsets, hardware, software and mobile networks associated with the development, sale and usage of Smartphones. The Index Provider defines a Smartphone as a wireless, mobile communication device offering advanced capabilities and functionalities, including web access, through the use of an identifiable operating system.</p> <p>The Index uses a modified equal dollar weighting methodology. The Index Provider evaluates the Index components semi-annually in March and September of each year for eligibility, using market data through the end of February and August, respectively. Eligible components for the Index are identified as such using the eligibility criteria set forth in this Prospectus under "Index Information." Changes to the Index are made effective after the close of trading on the third Friday in March and September. The Index is rebalanced quarterly, each March, June, September and December. As of February 15, 2011, there were 79 securities that comprised the Index.</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.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL RISKSfalsefalsefalsefalsefalseOtherxbrli: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>You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.</p> <p>MARKET RISK. Market risk is the risk that a particular stock owned by the Fund, Shares of the Fund or stocks in general may fall in value. Shares are subject to market fluctuations caused by such factors as economic, political, regulatory or market developments, changes in interest rates and perceived trends in stock prices. Overall stock values could decline generally or could underperform other investments. Companies with smaller market capitalizations are generally subject to additional market risk.</p> <p>NON-CORRELATION RISK. The Fund's return may not match the return of the Index for a number of reasons. For example, the Fund incurs operating expenses not applicable to the Index, and may incur costs in buying and selling securities, especially when rebalancing the Fund's portfolio holdings to reflect changes in the composition of the Index. In addition, the Fund's portfolio holdings may not exactly replicate the securities included in the Index or the ratios between the securities included in the Index.</p> <p>REPLICATION MANAGEMENT RISK. The Fund is exposed to additional market risk due to its policy of investing principally in the securities included in the Index. As a result of this policy, securities held by the Fund will generally not be bought or sold in response to market fluctuations and the securities may be issued by companies concentrated in a particular industry. Therefore, the Fund will generally not sell a stock because the stock's issuer is in financial trouble, unless that stock is removed or is anticipated to be removed from the Index.</p> <p>NON-DIVERSIFICATION RISK. The Fund is classified as "non-diversified" under the Investment Company Act of 1940, as amended (the "1940 Act"). As a result, the Fund is only limited as to the percentage of its assets which may be invested in the securities of any one issuer by the diversification requirements imposed by the Internal Revenue Code of 1986, as amended (the "Code"). The Fund may invest a relatively high percentage of its assets in a limited number of issuers.</p> <p>SMARTPHONE INDUSTRY RISK. The Fund will be invested in securities of companies in the smartphone industry. The smartphone industry is characterized by intense competition and new market entrants, which could negatively impact profit margins and overall revenues of the companies involved in the industry.</p> <p>Smartphone companies are generally subject to the risks of rapidly changing technologies, short product life cycles, fierce competition, aggressive pricing and reduced profit margins, the loss of patent, copyright and trademark protections, cyclical market patterns, evolving industry standards, and frequent new product introductions. Smartphone companies are affected by high and continuing costs of research and development due to quickly evolving technologies. Smartphone companies are often reliant upon the relationships with third-parties, which can be unpredictable. Additionally, the Smartphone industry is in the early stages of development and can be extremely volatile.</p> <p>NON-U.S. SECURITIES AND EMERGING MARKETS RISK. The Fund invests in securities of non-U.S. issuers, including non-U.S. dollar-denominated securities traded outside of the United States and U.S. dollar-denominated securities of non-U.S. issuers traded in the United States. Such securities are subject to higher volatility than securities of domestic issuers due to possible adverse political, social or economic developments; restrictions on foreign investment or exchange of securities; lack of liquidity; excessive taxation; government seizure of assets; different legal or accounting standards; and less government supervision and regulation of exchanges in foreign countries. These risks may be heightened for securities of companies located in, or with significant operations in, emerging market countries.</p> <p>DEPOSITARY RECEIPTS RISK. Depositary receipts may be less liquid than the underlying shares in their primary trading market. Any distributions paid to the holders of depositary receipts are usually subject to a fee charged by the depositary. Holders of depositary receipts may have limited voting rights, and investment restrictions in certain countries may adversely impact the value of depositary receipts because such restrictions may limit the ability to convert equity shares into depositary receipts and vice versa. Such restrictions may cause equity shares of the underlying issuer to trade at a discount or premium to the market price of the depositary receipts.</p> <p>CURRENCY RISK. Because the Fund's NAV is determined on the basis of U.S. dollars and the Fund invests in foreign securities, you may lose money if the local currency of a foreign market depreciates against the U.S. dollar, even if the local currency value of the Fund's holdings goes up.</p> <p>INDEX TRACKING RISK. You should anticipate that the value of Fund Shares will decline more or less in correlation with any decline in the value of the Fund's Index.</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.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PERFORMANCEfalsefalsefalsefalsefalseOtherxbrli: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 Fund has not yet commenced operations and, therefore, does not have a performance history. Once available, the Fund's performance information will be available on the Fund's website at www.ftportfolios.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]120Risk/Return Summary (First Trust NASDAQ CEA Smartphone Index Fund [Member])UnKnownUnKnownUnKnownUnKnownfalsetrue