The First Trust Dow Jones Global Select Dividend Index Fund (the "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 Dow Jones Global Select Dividend Index(SM) (the "Index").

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The 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, which are not reflected in the table below.

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The 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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 20% of the average value of its portfolio.

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

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.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels until February 28, 2015, and thereafter at 0.85% to represent the imposition of the 12b-1 fee of 0.25% per annum of the Fund's average daily net assets. The example assumes that First Trust's agreement to waive fees and/or pay the Fund's expenses to the extent necessary to prevent the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes, and extraordinary expenses) from exceeding 0.60% of average daily net assets per year will be terminated following February 28, 2015. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (plus the amount of any borrowings for investment purposes) in common stocks or in depositary receipts representing securities in the Index. First Trust Advisors L.P. ("First Trust" or the "Advisor") seeks to match the performance of the Index (before the Fund's fees and expenses).

The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. First Trust 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.

The Index is an indicated annual dividend yield weighted index of 100 stocks selected from the developed-market portion of the Dow Jones World Index(SM). Indicated annual dividend yield is a stock's unadjusted indicated annual dividend (not including any special dividends) divided by its unadjusted price. The Index is compiled and maintained by Dow Jones & Company, Inc. ("Dow Jones" or the "Index Provider"). The Index universe consists of all dividend-paying companies in the Dow Jones World Developed Index which are subjected to eligibility screens for dividend quality and liquidity before being selected for inclusion in the Index. Component securities are weighted on indicated annual dividend yield. Weights of individual securities are capped at 10%. The Index is rebalanced and reconstituted annually in December. The Fund will make changes to its portfolio holdings when changes are made by the Index Provider in the composition of the Index.

The Fund intends to invest entirely in securities included in the Index; however, there may also be instances in which the Fund may be underweighted or overweighted in certain securities in the Index, not invested in certain securities included in the Index, purchases securities not in the Index that are appropriate to substitute for certain securities in the Index or utilizes various combinations of the above techniques in seeking to track the Index.

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

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. There can be no assurance that the Fund's investment objective will be achieved.

CURRENCY RISK. The Fund may hold investments that are denominated in non-U.S. currencies, or in securities that provide exposure to such currencies, currency exchange rates or interest rates denominated in such currencies. Changes in currency exchange rates and the relative value of non-U.S. currencies will affect the value of the Fund's investment and the value of Fund shares. Currency exchange rates can be very volatile and can change quickly and unpredictably. As a result, the value of an investment in the Fund may change quickly and without warning and you may lose money.

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 shares into depositary receipts and vice versa. Such restrictions may cause shares of the underlying issuer to trade at a discount or premium to the market price of the depositary receipts.

EQUITY SECURITIES RISK. Because the Fund invests in equity securities, the value of the Fund's shares will fluctuate with changes in the value of these equity securities. Equity securities prices fluctuate for several reasons, including changes in investors' perceptions of the financial condition of an issuer or the general condition of the relevant stock market, such as current market volatility, or when political or economic events affecting the issuers occur. In addition, common stock prices may be particularly sensitive to rising interest rates, as the cost of capital rises and borrowing costs increase.

EUROPE RISK. The Fund invests a material portion of its assets in securities issued by companies operating in Europe. Investments in a single region, even though representing a number of different countries within the region, may be affected by common economic forces and other factors. The Fund is subject to greater risks of adverse events which occur in the European region and may experience greater volatility than a fund that is more broadly diversified geographically. Political or economic disruptions in European countries, even in countries in which the Fund is not invested, may adversely affect security values and thus the Fund's holdings. A significant number of countries in Europe are member states in the European Union (the "EU"), and the member states no longer control their own monetary policies by directing independent interest rates for their currencies. In these member states, the authority to direct monetary policies, including money supply and official interest rates for the Euro, is exercised by the European Central Bank. Furthermore, the European sovereign debt crisis has had, and continues to have, a significant negative impact on the economies of certain European countries and their future economic outlooks.

INDEX CORRELATION 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.

MARKET RISK. Market risk is the risk that a particular security owned by the Fund or shares of the Fund 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 securities prices. Overall Fund share values could decline generally or could underperform other investments.

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.

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. As a result, the Fund may be more susceptible to a single adverse economic or regulatory occurrence affecting one or more of these issuers, experience increased volatility and be highly concentrated in certain issuers.

NON-U.S. SECURITIES RISK. Non-U.S. 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.

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 if the Index is so concentrated. Therefore, the Fund will generally not sell a security because its issuer is in financial trouble, unless that security is removed or is anticipated to be removed from the Index.

TELECOMMUNICATION COMPANIES RISK. The Fund invests in telecommunication companies. Telecommunication companies are subject to risks, such as a market characterized by increasing competition and regulation by the Federal Communications Commission and various state regulatory authorities, the need to commit substantial capital to meet increasing competition, particularly in formulating new products and services using new technology and technological innovations that may make various products and services obsolete.

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value for the past six years as well as the average annual Fund and Index returns for the one year, five year and since inception periods ended December 31, 2013. The bar chart and table provide an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year-to-year and by showing how the Fund's average annual total returns based on net asset value compare to those of the Index and two broad-based securities market indices. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

Returns before taxes do not reflect the effects of any income or capital gains taxes. All after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of any state or local tax. Returns after taxes on distributions reflect the taxed return on the payment of dividends and capital gains. Returns after taxes on distributions and sale of shares assume you sold your shares at period end, and, therefore, are also adjusted for any capital gains or losses incurred. Returns for the market indices do not include expenses, which are deducted from Fund returns, or taxes.

Your own actual after-tax returns will depend on your specific tax situation and may differ from what is shown here. After-tax returns are not relevant to investors who hold Fund shares in tax-deferred accounts such as individual retirement accounts (IRAs) or employee-sponsored retirement plans.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the six-year period ended December 31, 2013, the Fund's highest and lowest calendar quarter returns were 38.58% and -29.38%, respectively, for the quarters ended June 30, 2009 and December 31, 2008. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.61%

Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement

rr_NetExpensesOverAssets

0.60%

3 Years

rr_ExpenseExampleNoRedemptionYear03

239

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

1,028

Annual Return 2009

rr_AnnualReturn2009

64.28%

Annual Return 2011

rr_AnnualReturn2011

(2.17%)

Annual Return 2013

rr_AnnualReturn2013

17.90%

5 Years

rr_AverageAnnualReturnYear05

19.68%

Inception Date

rr_AverageAnnualReturnInceptionDate

Nov. 21, 2007

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

17.64%

1 Year

rr_AverageAnnualReturnYear01

9.99%

Since Inception

rr_AverageAnnualReturnSinceInception

1.68%

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

20.14%

1 Year

rr_AverageAnnualReturnYear01

27.46%

Since Inception

rr_AverageAnnualReturnSinceInception

4.11%

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

15.20%

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust FTSE EPRA/NAREIT Developed Markets Real Estate Index Fund (the "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 FTSE EPRA/NAREIT Developed Index (the "Index").

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The 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, which are not reflected in the table below.

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The 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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 13% of the average value of its portfolio.

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

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.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels until February 28, 2015, and thereafter at 0.85% to represent the imposition of the 12b-1 fee of 0.25% per annum of the Fund's average daily net assets. The example assumes that First Trust's agreement to waive fees and/or pay the Fund's expenses to the extent necessary to prevent the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes, and extraordinary expenses) from exceeding 0.60% of average daily net assets per year will be terminated following February 28, 2015. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (plus the amount of any borrowings for investment purposes) in common stocks or in depositary receipts representing securities in the Index. First Trust Advisors L.P. ("First Trust" or the "Advisor") seeks to match the performance of the Index (before the Fund's fees and expenses).

The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. First Trust 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.

The Index is compiled and maintained by FTSE International Limited ("FTSE" or the "Index Provider"). The Index is modified market cap weighted based on free float market capitalization and tracks the performance of listed real estate companies or real estate investment trusts ("REITs") in North America, Europe and Asia. The Index is rebalanced and reconstituted quarterly in March, June, September and December. The Fund will make changes to its portfolio holdings when changes are made by FTSE in the composition of the Index. The Index is designed to measure the stock performance of companies engaged in specific real estate activities in the North American, European and Asian real estate markets. Specific real estate activities include the ownership, trading and development of income-producing real estate.

The Fund intends to invest entirely in securities included in the Index; however, there may also be instances in which the Fund may be underweighted or overweighted in certain securities in the Index, not invested in certain securities included in the Index, purchases securities not in the Index that are appropriate to substitute for certain securities in the Index or utilizes various combinations of the above techniques in seeking to track the Index.

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

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. There can be no assurance that the Fund's investment objective will be achieved.

ASIA RISK. The Fund invests, in part, in securities issued by companies operating in Asia, and is therefore subject to certain risks associated specifically with Asia. For example, some of the currencies of these countries have experienced devaluations relative to the U.S. dollar, and adjustments have been made periodically in certain of such currencies. Certain countries, such as Indonesia, face serious exchange constraints. Jurisdictional disputes also exist, for example, between South Korea and North Korea. The Tokyo stock market, as measured by the Tokyo Stock Price Index, has been volatile. Declines in the Tokyo stock market have made the country's banks and financial institutions vulnerable. Furthermore, the natural disasters that have impacted Japan and the ongoing recovery efforts have had a negative affect on Japan's economy, and may continue to do so.

CURRENCY RISK. The Fund may hold investments that are denominated in non-U.S. currencies, or in securities that provide exposure to such currencies, currency exchange rates or interest rates denominated in such currencies. Changes in currency exchange rates and the relative value of non-U.S. currencies will affect the value of the Fund's investment and the value of Fund shares. Currency exchange rates can be very volatile and can change quickly and unpredictably. As a result, the value of an investment in the Fund may change quickly and without warning and you may lose money.

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 shares into depositary receipts and vice versa. Such restrictions may cause shares of the underlying issuer to trade at a discount or premium to the market price of the depositary receipts.

EQUITY SECURITIES RISK. Because the Fund invests in equity securities, the value of the Fund's shares will fluctuate with changes in the value of these equity securities. Equity securities prices fluctuate for several reasons, including changes in investors' perceptions of the financial condition of an issuer or the general condition of the relevant stock market, such as current market volatility, or when political or economic events affecting the issuers occur. In addition, common stock prices may be particularly sensitive to rising interest rates, as the cost of capital rises and borrowing costs increase.

FINANCIALS COMPANIES RISK. Financial companies are especially subject to the adverse effects of economic recession, currency exchange rates, government regulation, decreases in the availability of capital, volatile interest rates, portfolio concentrations in geographic markets and in commercial and residential real estate loans, and competition from new entrants in their fields of business.

INDEX CORRELATION 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.

INTEREST RATE RISK. The Fund is subject to interest rate risk. Increases in interest rates typically lower the present value of a REIT's future earnings stream, and may make financing property purchases and improvements more costly. Because the market price of REIT stocks may change based upon investors' collective perceptions of future earnings, the value of the Fund will generally decline when investors anticipate or experience rising interest rates.

MARKET RISK. Market risk is the risk that a particular security owned by the Fund or shares of the Fund 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 securities prices. Overall Fund share values could decline generally or could underperform other investments.

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.

NON-U.S. SECURITIES RISK. Non-U.S. 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.

REAL ESTATE INVESTMENT RISK. The Fund invests in companies in the real estate industry, including REITs. Therefore, the Fund is subject to the risks associated with investing in real estate, which may include, but are not limited to, fluctuations in the value of underlying properties; defaults by borrowers or tenants; market saturation; changes in general and local economic conditions; decreases in market rates for rents; increases in competition, property taxes, capital expenditures or operating expenses; and other economic, political or regulatory occurrences affecting companies in the real estate industry.

The Fund invests in real estate companies that may be adversely impacted by the downturn in the subprime mortgage lending market in the United States. Subprime loans have higher defaults and losses than prime loans. Subprime loans also have higher serious delinquency rates than prime loans. The downturn in the subprime mortgage lending market may have far-reaching consequences into many aspects and geographic regions of the real estate business, and consequently, the value of the Fund may decline in response to such developments.

REIT INVESTMENT RISK. In addition to risks related to investments in real estate generally, investing in REITs involves certain other risks related to their structure and focus, which include, but are not limited to, dependency upon management skills, limited diversification, the risks of locating and managing financing for projects, heavy cash flow dependency, possible default by borrowers, the costs and potential losses of self-liquidation of one or more holdings, the risk of a possible lack of mortgage funds and associated interest rate risks, overbuilding, property vacancies, increases in property taxes and operating expenses, changes in zoning laws, losses due to environmental damages, changes in neighborhood values and appeal to purchases, the possibility of failing to maintain exemptions from registration under the 1940 Act and, in many cases, relatively small market capitalization, which may result in less market liquidity and greater price volatility.

REITs are also subject to the risk that the real estate market may experience an economic downturn generally, which may have a material effect on the real estate in which the REITs invest and their underlying portfolio securities.

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 if the Index is so concentrated. Therefore, the Fund will generally not sell a security because its issuer is in financial trouble, unless that security is removed or is anticipated to be removed from the Index.

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value for the past six years as well as the average annual Fund and Index returns for the one year, five year and since inception periods ended December 31, 2013. The bar chart and table provide an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year-to-year and by showing how the Fund's average annual total returns based on net asset value compare to those of the Index, the S&P Global REIT Index, which is a broad-based securities market index, and a specialized securities market index. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

Returns before taxes do not reflect the effects of any income or capital gains taxes. All after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of any state or local tax. Returns after taxes on distributions reflect the taxed return on the payment of dividends and capital gains. Returns after taxes on distributions and sale of shares assume you sold your shares at period end, and, therefore, are also adjusted for any capital gains or losses incurred. Returns for the market indices do not include expenses, which are deducted from Fund returns, or taxes.

Your own actual after-tax returns will depend on your specific tax situation and may differ from what is shown here. After-tax returns are not relevant to investors who hold Fund shares in tax-deferred accounts such as individual retirement accounts (IRAs) or employee-sponsored retirement plans.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the six-year period ended December 31, 2013, the Fund's highest and lowest calendar quarter returns were 35.30% and -32.77%, respectively, for the quarters ended June 30, 2009 and December 31, 2008. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.68%

Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement

rr_NetExpensesOverAssets

0.60%

3 Years

rr_ExpenseExampleNoRedemptionYear03

252

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

1,102

Annual Return 2009

rr_AnnualReturn2009

35.00%

Annual Return 2011

rr_AnnualReturn2011

(6.49%)

Annual Return 2013

rr_AnnualReturn2013

2.97%

5 Years

rr_AverageAnnualReturnYear05

14.80%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 27, 2007

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

13.19%

1 Year

rr_AverageAnnualReturnYear01

1.68%

Since Inception

rr_AverageAnnualReturnSinceInception

(0.60%)

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

16.06%

1 Year

rr_AverageAnnualReturnYear01

1.73%

Since Inception

rr_AverageAnnualReturnSinceInception

0.28%

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

13.49%

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust ISE Cloud Computing Index Fund (the "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 ISE Cloud Computing(TM) Index (the "Index").

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The 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, which are not reflected in the table below.

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The 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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 22% of the average value of its portfolio.

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

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.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels until February 28, 2015, and thereafter at 0.85% to represent the imposition of the 12b-1 fee of 0.25% per annum of the Fund's average daily net assets. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (plus the amount of any borrowings for investment purposes) in common stocks or in depositary receipts representing securities in the Index. First Trust Advisors L.P. ("First Trust" or the "Advisor") seeks to match the performance of the Index (before the Fund's fees and expenses).

The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. First Trust 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.

The Index is owned and was developed by International Securities Exchange, LLC ("ISE" or the "Index Provider"). The Index Provider has contracted with Standard & Poor's to calculate and maintain the Index. The Index is designed to provide a benchmark for investors interested in tracking companies actively involved in the cloud computing industry. The cloud computing industry is a group of companies that offers internet and technology products, services and applications delivered via the Internet rather than traditional computing, which focuses on computer desktop applications. The Index components are reviewed semi-annually for eligibility. As of December 31, 2013, the Index was comprised of 35 securities from companies located in the United States and 5 securities from companies located in Belgium, Canada, Germany, India and Israel.

The Index uses a market capitalization weighted allocation across three categories in the cloud computing industry. The pure play category includes companies that are direct service providers for "the cloud" (i.e., network hardware/software, storage and cloud computing services) or companies with business models that rely on delivering goods and services that utilize cloud computing technology. The non pure play category includes companies that focus outside the cloud computing space but provide goods and services that support the cloud computing space. The technology conglomerate category includes companies that are large, broad-based companies with business models that indirectly utilize or support the use of cloud computing technology.

The Fund intends to invest entirely in securities included in the Index; however, there may also be instances in which the Fund may be underweighted or overweighted in certain securities in the Index, not invested in certain securities included in the Index, purchases securities not in the Index that are appropriate to substitute for certain securities in the Index or utilizes various combinations of the above techniques in seeking to track the Index.

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

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. There can be no assurance that the Fund's investment objective will be achieved.

CLOUD COMPUTING COMPANIES RISK. The Fund invests in securities of cloud computing companies, including companies that provide remote computation, software, data access and storage services. The risks related to investing in such companies include disruption in service caused by hardware or software failure, interruptions or delays in service by third-party data center hosting facilities and maintenance providers, security breaches involving certain private, sensitive, proprietary and confidential information managed and transmitted by cloud computing companies, and privacy concerns and laws, evolving Internet regulation and other foreign or domestic regulations that may limit or otherwise affect the operations of such companies. Also, the business models employed by the companies in the cloud computing industry may not prove to be successful.

CURRENCY RISK. The Fund may hold investments that are denominated in non-U.S. currencies, or in securities that provide exposure to such currencies, currency exchange rates or interest rates denominated in such currencies. Changes in currency exchange rates and the relative value of non-U.S. currencies will affect the value of the Fund's investment and the value of Fund shares. Currency exchange rates can be very volatile and can change quickly and unpredictably. As a result, the value of an investment in the Fund may change quickly and without warning and you may lose money.

EQUITY SECURITIES RISK. Because the Fund invests in equity securities, the value of the Fund's shares will fluctuate with changes in the value of these equity securities. Equity securities prices fluctuate for several reasons, including changes in investors' perceptions of the financial condition of an issuer or the general condition of the relevant stock market, such as current market volatility, or when political or economic events affecting the issuers occur. In addition, common stock prices may be particularly sensitive to rising interest rates, as the cost of capital rises and borrowing costs increase.

INDEX CORRELATION 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.

INFORMATION TECHNOLOGY COMPANIES RISK. The Fund invests in the securities of information technology companies. Information technology companies are generally subject to the risks of rapidly changing technologies, short product life cycles, fierce competition, aggressive pricing and reduced profit margins, loss of patent, copyright and trademark protections, cyclical market patterns, evolving industry standards and frequent new product introductions. Information technology companies may be smaller and less experienced companies, with limited product lines, markets or financial resources and fewer experienced management or marketing personnel. Information technology company stocks, particularly those involved with the Internet, have experienced extreme price and volume fluctuations that often have been unrelated to their operating performance.

INTERNET COMPANIES RISK. The Fund invests in the securities of Internet companies. Internet companies are subject to rapid changes in technology, worldwide competition, rapid obsolescence of products and services, loss of patent protections, cyclical market patterns, evolving industry standards, frequent new product introductions and the considerable risk of owning small capitalization companies that have recently begun operations.

MARKET RISK. Market risk is the risk that a particular security owned by the Fund or shares of the Fund 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 securities prices. Overall Fund share values could decline generally or could underperform other investments.

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.

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. As a result, the Fund may be more susceptible to a single adverse economic or regulatory occurrence affecting one or more of these issuers, experience increased volatility and be highly concentrated in certain issuers.

NON-U.S. SECURITIES RISK. Non-U.S. 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.

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 if the Index is so concentrated. Therefore, the Fund will generally not sell a security because its issuer is in financial trouble, unless that security is removed or is anticipated to be removed from the Index.

SMALLER COMPANIES RISK. The Fund invests in small and/or mid capitalization companies. Such companies may be more vulnerable to adverse general market or economic developments, and their securities may be less liquid and may experience greater price volatility than larger, more established companies as a result of several factors, including limited trading volumes, products or financial resources, management inexperience and less publicly available information. Accordingly, such companies are generally subject to greater market risk than those of larger, more established companies.

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value for the past two years as well as the average annual Fund and Index returns for the one year and since inception periods ended December 31, 2013. The bar chart and table provide an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year-to-year and by showing how the Fund's average annual total returns based on net asset value compare to those of the Index and two broad-based securities market indices. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

Returns before taxes do not reflect the effects of any income or capital gains taxes. All after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of any state or local tax. Returns after taxes on distributions reflect the taxed return on the payment of dividends and capital gains. Returns after taxes on distributions and sale of shares assume you sold your shares at period end, and, therefore, are also adjusted for any capital gains or losses incurred. Returns for the market indices do not include expenses, which are deducted from Fund returns, or taxes.

Your own actual after-tax returns will depend on your specific tax situation and may differ from what is shown here. After-tax returns are not relevant to investors who hold Fund shares in tax-deferred accounts such as individual retirement accounts (IRAs) or employee-sponsored retirement plans.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the two-year period ended December 31, 2013, the Fund's highest and lowest calendar quarter returns were 24.11% and -12.45%, respectively, for the quarters ended March 31, 2012 and June 30, 2013. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.60%

3 Years

rr_ExpenseExampleNoRedemptionYear03

237

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

1,018

Annual Return 2013

rr_AnnualReturn2013

33.35%

Since Inception

rr_AverageAnnualReturnSinceInception

11.66%

1 Year

rr_AverageAnnualReturnYear01

33.35%

1 Year

rr_AverageAnnualReturnYear01

18.88%

1 Year

rr_AverageAnnualReturnYear01

34.18%

1 Year

rr_AverageAnnualReturnYear01

32.39%

1 Year

rr_AverageAnnualReturnYear01

28.99%

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust ISE Global Copper Index Fund (the "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 ISE Global Copper(TM) Index (the "Index").

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The 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, which are not reflected in the table below.

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The 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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 46% of the average value of its portfolio.

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

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.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels until February 28, 2015, and thereafter at 0.95% to represent the imposition of the 12b-1 fee of 0.25% per annum of the Fund's average daily net assets. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (plus the amount of any borrowings for investment purposes) in common stocks or in depositary receipts representing securities in the Index. First Trust Advisors L.P. ("First Trust" or the "Advisor") seeks to match the performance of the Index (before the Fund's fees and expenses).

The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. First Trust 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.

The Index is developed and owned by International Securities Exchange, LLC ("ISE" or the "Index Provider"). The Index is designed to provide a benchmark for investors interested in tracking public companies that are active in the copper mining business based on analysis of revenue derived from the sale of copper. Issuers of component securities must be actively engaged in some aspect of the copper mining business such as copper mining, refining or exploration. The Index has been created to provide investors with a product allowing them to quickly take advantage of both event-driven news and long-term trends as the need for copper continues to evolve.

ISE reviews the Index components quarterly in March, June, September and December of each year for eligibility and sets each component's weight in the Index according to the Index methodology. Changes are announced on ISE's publicly available website at www.ise.com at least five days prior to the effective date.

The Fund intends to invest entirely in securities included in the Index; however, there may also be instances in which the Fund may be underweighted or overweighted in certain securities in the Index, not invested in certain securities included in the Index, purchases securities not in the Index that are appropriate to substitute for certain securities in the Index or utilizes various combinations of the above techniques in seeking to track the Index.

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

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. There can be no assurance that the Fund's investment objective will be achieved.

CANADA RISK. Because the Fund invests a significant portion of its assets in companies that are domiciled in Canada, the Fund is particularly sensitive to political, economic and social conditions in that country. Canada is a major producer of metals and energy-related products. The Canadian economy is very dependent on the demand for, and supply and price of, natural resources, and the Canadian market is relatively concentrated in issuers involved in the production and distribution of natural resources. Any adverse events that affect Canada's major industries may have a negative impact on the overall Canadian economy and the shares of the Fund.

COPPER MINING COMPANY RISK. Securities in the Fund's portfolio may be significantly impacted by competitive pressures in the copper mining business and the price of copper. Because more than half of the world's copper production occurs in the United States, Chile, Canada, Russia and Zambia, the Fund's share price may be particularly sensitive to any adverse political or economic developments affecting these countries. The Fund's share price may experience volatility because the price of copper may fluctuate substantially over short periods of time. Moreover, the Index tracks companies involved in the copper mining business and not the price of copper. The securities of companies involved in the copper mining business may under- or over-perform the price of copper over the short term or the long term.

COPPER RISK. The Fund may be adversely affected by a decrease in the worldwide demand and price of copper. Various factors may lead to a decreased demand and price of copper. As an industrial metal, the demand for and price of copper may be negatively impacted by a decreased level of industrial activity using copper. Other factors include the availability of substitutes such as man-made or synthetic substitutes, disruptions in the supply chain, from mining to storage to smelting or refining, adjustments to inventory, variations in production costs, including storage, labor and energy costs, costs associated with regulatory compliance, including environmental regulations and changes in industrial, government and consumer demand, both in individual consuming nations and internationally.

CURRENCY RISK. The Fund may hold investments that are denominated in non-U.S. currencies, or in securities that provide exposure to such currencies, currency exchange rates or interest rates denominated in such currencies. Changes in currency exchange rates and the relative value of non-U.S. currencies will affect the value of the Fund's investment and the value of Fund shares. Currency exchange rates can be very volatile and can change quickly and unpredictably. As a result, the value of an investment in the Fund may change quickly and without warning and you may lose money.

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 shares into depositary receipts and vice versa. Such restrictions may cause shares of the underlying issuer to trade at a discount or premium to the market price of the depositary receipts.

EQUITY SECURITIES RISK. Because the Fund invests in equity securities, the value of the Fund's shares will fluctuate with changes in the value of these equity securities. Equity securities prices fluctuate for several reasons, including changes in investors' perceptions of the financial condition of an issuer or the general condition of the relevant stock market, such as current market volatility, or when political or economic events affecting the issuers occur. In addition, common stock prices may be particularly sensitive to rising interest rates, as the cost of capital rises and borrowing costs increase.

INDEX CORRELATION 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.

MARKET RISK. Market risk is the risk that a particular security owned by the Fund or shares of the Fund 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 securities prices. Overall Fund share values could decline generally or could underperform other investments.

MATERIALS COMPANIES RISK. The Fund invests significantly in materials companies. General risks of the materials sector include the general state of the economy, consolidation, domestic and international politics and excess capacity. In addition, basic materials companies may also be significantly affected by volatility of commodity prices, import controls, worldwide competition, liability for environmental damage, depletion of resources and mandated expenditures for safety and pollution control devices.

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.

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. As a result, the Fund may be more susceptible to a single adverse economic or regulatory occurrence affecting one or more of these issuers, experience increased volatility and be highly concentrated in certain issuers.

NON-U.S. SECURITIES AND EMERGING MARKETS RISK. Non-U.S. 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.

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 if the Index is so concentrated. Therefore, the Fund will generally not sell a security because its issuer is in financial trouble, unless that security is removed or is anticipated to be removed from the Index.

SMALLER COMPANIES RISK. The Fund invests in small and/or mid capitalization companies. Such companies may be more vulnerable to adverse general market or economic developments, and their securities may be less liquid and may experience greater price volatility than larger, more established companies as a result of several factors, including limited trading volumes, products or financial resources, management inexperience and less publicly available information. Accordingly, such companies are generally subject to greater market risk than those of larger, more established companies.

UNITED KINGDOM RISK. Because the Fund invests a significant portion of its assets in companies that are domiciled in the United Kingdom, the Fund is particularly sensitive to political, economic and social conditions in that country. The Fund may be affected unfavorably by political developments, social instability, changes in government policies and other political and economic developments in the United Kingdom.

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value for the past three years as well as the average annual Fund and Index returns for the one year and since inception periods ended December 31, 2013. The bar chart and table provide an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year-to-year and by showing how the Fund's average annual total returns based on net asset value compare to those of the Index and two broad-based securities market indices. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

Returns before taxes do not reflect the effects of any income or capital gains taxes. All after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of any state or local tax. Returns after taxes on distributions reflect the taxed return on the payment of dividends and capital gains. Returns after taxes on distributions and sale of shares assume you sold your shares at period end, and, therefore, are also adjusted for any capital gains or losses incurred. Returns for the market indices do not include expenses, which are deducted from Fund returns, or taxes.

Your own actual after-tax returns will depend on your specific tax situation and may differ from what is shown here. After-tax returns are not relevant to investors who hold Fund shares in tax-deferred accounts such as individual retirement accounts (IRAs) or employee-sponsored retirement plans.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the three-year period ended December 31, 2013, the Fund's highest and lowest calendar quarter returns were 15.51% and -37.68%, respectively, for the quarters ended December 31, 2011 and September 30, 2011. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.70%

3 Years

rr_ExpenseExampleNoRedemptionYear03

269

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

1,135

Annual Return 2012

rr_AnnualReturn2012

5.61%

1 Year

rr_AverageAnnualReturnYear01

(24.92%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Mar. 11, 2010

[RiskReturnAbstract]

rr_RiskReturnAbstract

Since Inception

rr_AverageAnnualReturnSinceInception

(6.04%)

[RiskReturnAbstract]

rr_RiskReturnAbstract

Since Inception

rr_AverageAnnualReturnSinceInception

(4.08%)

[RiskReturnAbstract]

rr_RiskReturnAbstract

Since Inception

rr_AverageAnnualReturnSinceInception

10.61%

[RiskReturnAbstract]

rr_RiskReturnAbstract

Since Inception

rr_AverageAnnualReturnSinceInception

(4.06%)

[RiskReturnAbstract]

rr_RiskReturnAbstract

Since Inception

rr_AverageAnnualReturnSinceInception

1.31%

[RiskReturnAbstract]

rr_RiskReturnAbstract

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST ISE GLOBAL ENGINEERING AND CONSTRUCTION INDEX FUND--TOTAL RETURNS

Performance Table Heading

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2013

[RiskReturnAbstract]

rr_RiskReturnAbstract

Management Fees

rr_ManagementFeesOverAssets

0.40%

Other Expenses

rr_Component1OtherExpensesOverAssets

0.49%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.19%)

^[4]

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

72

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

570

Annual Return 2009

rr_AnnualReturn2009

25.44%

Annual Return 2011

rr_AnnualReturn2011

(17.44%)

Annual Return 2013

rr_AnnualReturn2013

23.10%

5 Years

rr_AverageAnnualReturnYear05

12.43%

Inception Date

rr_AverageAnnualReturnInceptionDate

Oct. 13, 2008

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

11.75%

1 Year

rr_AverageAnnualReturnYear01

12.98%

Since Inception

rr_AverageAnnualReturnSinceInception

9.71%

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

13.93%

1 Year

rr_AverageAnnualReturnYear01

33.55%

Since Inception

rr_AverageAnnualReturnSinceInception

15.57%

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

17.07%

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust ISE Global Platinum Index Fund (the "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 ISE Global Platinum(TM) Index (the "Index").

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The 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, which are not reflected in the table below.

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The 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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 46% of the average value of its portfolio.

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

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.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels until February 28, 2015, and thereafter at 0.95% to represent the imposition of the 12b-1 fee of 0.25% per annum of the Fund's average daily net assets. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (plus the amount of any borrowings for investment purposes) in securities or in depositary receipts representing securities in the Index. First Trust Advisors L.P. ("First Trust" or the "Advisor") seeks to match the performance of the Index (before the Fund's fees and expenses).

The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. First Trust 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.

The Index is developed and owned by International Securities Exchange, LLC ("ISE" or the "Index Provider"). The Index is designed to provide a benchmark for investors interested in tracking public companies that are active in platinum group metals ("PGM") mining based on revenue analysis of those companies. PGMs collectively refer to six elements, platinum, palladium, osmium, iridium, ruthenium and rhodium, which have similar physical and chemical properties and tend to occur together in the same mineral deposits. Issuers of component securities must be actively engaged in some aspect of PGM mining such as mining, refining or exploration. The Index has been created to provide investors with a product allowing them to quickly take advantage of both event-driven news and long-term trends as the need for PGMs continues to evolve.

ISE reviews the Index components quarterly in March, June, September and December of each year for eligibility and sets each component's weight in the Index according to the Index methodology. Changes are announced on ISE's publicly available website at www.ise.com at least five days prior to the effective date.

The Fund intends to invest entirely in securities included in the Index; however, there may also be instances in which the Fund may be underweighted or overweighted in certain securities in the Index, not invested in certain securities included in the Index, purchases securities not in the Index that are appropriate to substitute for certain securities in the Index or utilizes various combinations of the above techniques in seeking to track the Index.

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

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. There can be no assurance that the Fund's investment objective will be achieved.

CURRENCY RISK. The Fund may hold investments that are denominated in non-U.S. currencies, or in securities that provide exposure to such currencies, currency exchange rates or interest rates denominated in such currencies. Changes in currency exchange rates and the relative value of non-U.S. currencies will affect the value of the Fund's investment and the value of Fund shares. Currency exchange rates can be very volatile and can change quickly and unpredictably. As a result, the value of an investment in the Fund may change quickly and without warning and you may lose money.

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 shares into depositary receipts and vice versa. Such restrictions may cause shares of the underlying issuer to trade at a discount or premium to the market price of the depositary receipts.

EQUITY SECURITIES RISK. Because the Fund invests in equity securities, the value of the Fund's shares will fluctuate with changes in the value of these equity securities. Equity securities prices fluctuate for several reasons, including changes in investors' perceptions of the financial condition of an issuer or the general condition of the relevant stock market, such as current market volatility, or when political or economic events affecting the issuers occur. In addition, common stock prices may be particularly sensitive to rising interest rates, as the cost of capital rises and borrowing costs increase.

INDEX CORRELATION 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.

LIQUIDITY RISK. Whether or not the equity securities in the Fund are listed on a securities exchange, the principal trading market for certain of the equity securities in the Fund may be in the over-the-counter market. As a result, the existence of a liquid trading market for the equity securities may depend on whether dealers will make a market in the equity securities. There can be no assurance that a market will be made for any of the equity securities, that any market for the equity securities will be maintained or that there will be sufficient liquidity of the equity securities in any markets made. The price at which the equity securities are held in the Fund will be adversely affected if trading markets for the equity securities are limited or absent.

MARKET RISK. Market risk is the risk that a particular security owned by the Fund or shares of the Fund 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 securities prices. Overall Fund share values could decline generally or could underperform other investments.

MATERIALS COMPANIES RISK. The Fund invests significantly in materials companies. General risks of the materials sector include the general state of the economy, consolidation, domestic and international politics and excess capacity. In addition, basic materials companies may also be significantly affected by volatility of commodity prices, import controls, worldwide competition, liability for environmental damage, depletion of resources and mandated expenditures for safety and pollution control devices.

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.

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. As a result, the Fund may be more susceptible to a single adverse economic or regulatory occurrence affecting one or more of these issuers, experience increased volatility and be highly concentrated in certain issuers.

NON-U.S. SECURITIES AND EMERGING MARKETS RISK. Non-U.S. 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.

PGM MINING COMPANY RISK. Securities in the Fund's portfolio may be significantly impacted by competitive pressures in the PGM mining business and the price of PGMs. Because a vast majority of the world's PGM production occurs in Russia and South Africa, the Fund's share price may be particularly sensitive to any adverse political or economic developments affecting these countries. The Fund's share price may experience volatility because the price of PGMs may fluctuate substantially over short periods of time. Moreover, the Index tracks companies involved in the PGM mining business and not the price of PGMs. The securities of companies involved in the PGM mining business may under- or over-perform the price of PGMs over the short term or the long term.

PGM RISK. The Fund may be adversely affected by a decrease in the worldwide demand and price of PGMs. Various factors may lead to a decreased demand and price of PGMs. An increase in the level of hedge activity of PGM-producing companies could cause a decline in world PGM prices. A significant negative change in the attitude of speculators and investors towards PGMs could cause a decline in world PGM prices. A widening of interest rate differentials between the cost of money and the cost of PGMs could also negatively affect the price of PGMs which, in turn, could negatively affect the price of the shares. In addition, automobile components that use PGMs account for a significant percentage of the global demand for PGMs. Because of the decline in demand and reduction in sales experienced by the global automotive industry the price of PGMs may be negatively affected. PGM companies are also subject to risks associated with the exploration, development and production of PGMs, including competition for land, difficulties in obtaining required governmental approval to mine land, inability to raise adequate capital, increases in production costs and political unrest in nations where sources of PGMs are located, particularly Russia and South Africa.

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 if the Index is so concentrated. Therefore, the Fund will generally not sell a security because its issuer is in financial trouble, unless that security is removed or is anticipated to be removed from the Index.

SMALLER COMPANIES RISK. The Fund invests in small and/or mid capitalization companies. Such companies may be more vulnerable to adverse general market or economic developments, and their securities may be less liquid and may experience greater price volatility than larger, more established companies as a result of several factors, including limited trading volumes, products or financial resources, management inexperience and less publicly available information. Accordingly, such companies are generally subject to greater market risk than those of larger, more established companies.

SOUTH AFRICA RISK. Because a significant percentage of the world's PGM mining takes place in South Africa, the Fund is particularly sensitive to political and economic conditions in that country. South Africa has historically experienced acts of terrorism and strained international relations related to border disputes, historical animosities, racial tensions and other domestic concerns. These situations may cause uncertainty in the South African market and may adversely affect the performance of the South African economy.

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value for the past three years as well as the average annual Fund and Index returns for the one year and since inception periods ended December 31, 2013. The bar chart and table provide an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year-to-year and by showing how the Fund's average annual total returns based on net asset value compare to those of the Index and two broad-based securities market indices. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

Returns before taxes do not reflect the effects of any income or capital gains taxes. All after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of any state or local tax. Returns after taxes on distributions reflect the taxed return on the payment of dividends and capital gains. Returns after taxes on distributions and sale of shares assume you sold your shares at period end, and, therefore, are also adjusted for any capital gains or losses incurred. Returns for the market indices do not include expenses, which are deducted from Fund returns, or taxes.

Your own actual after-tax returns will depend on your specific tax situation and may differ from what is shown here. After-tax returns are not relevant to investors who hold Fund shares in tax-deferred accounts such as individual retirement accounts (IRAs) or employee-sponsored retirement plans.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the three-year period ended December 31, 2013, the Fund's highest and lowest calendar quarter returns were 17.11% and -32.85%, respectively, for the quarters ended September 30, 2013 and September 30, 2011. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.70%

3 Years

rr_ExpenseExampleNoRedemptionYear03

269

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

1,135

Annual Return 2012

rr_AnnualReturn2012

(17.50%)

1 Year

rr_AverageAnnualReturnYear01

(13.89%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Mar. 11, 2010

[RiskReturnAbstract]

rr_RiskReturnAbstract

Since Inception

rr_AverageAnnualReturnSinceInception

(19.96%)

[RiskReturnAbstract]

rr_RiskReturnAbstract

Since Inception

rr_AverageAnnualReturnSinceInception

(13.82%)

[RiskReturnAbstract]

rr_RiskReturnAbstract

Since Inception

rr_AverageAnnualReturnSinceInception

10.61%

[RiskReturnAbstract]

rr_RiskReturnAbstract

Since Inception

rr_AverageAnnualReturnSinceInception

1.31%

[RiskReturnAbstract]

rr_RiskReturnAbstract

Since Inception

rr_AverageAnnualReturnSinceInception

(18.86%)

[RiskReturnAbstract]

rr_RiskReturnAbstract

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST ISE GLOBAL WIND ENERGY INDEX FUND--TOTAL RETURNS

Performance Table Heading

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2013

[RiskReturnAbstract]

rr_RiskReturnAbstract

Management Fees

rr_ManagementFeesOverAssets

0.40%

Other Expenses

rr_Component1OtherExpensesOverAssets

0.44%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.24%)

^[3]

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

61

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

536

Annual Return 2009

rr_AnnualReturn2009

26.01%

Annual Return 2011

rr_AnnualReturn2011

(21.59%)

Annual Return 2013

rr_AnnualReturn2013

64.51%

5 Years

rr_AverageAnnualReturnYear05

(0.42%)

Inception Date

rr_AverageAnnualReturnInceptionDate

Jun. 16, 2008

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

(0.86%)

1 Year

rr_AverageAnnualReturnYear01

36.45%

Since Inception

rr_AverageAnnualReturnSinceInception

(10.52%)

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

15.02%

1 Year

rr_AverageAnnualReturnYear01

33.55%

Since Inception

rr_AverageAnnualReturnSinceInception

8.38%

[RiskReturnAbstract]

rr_RiskReturnAbstract

5 Years

rr_AverageAnnualReturnYear05

0.79%

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust NASDAQ CEA Smartphone Index Fund (the "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").

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The 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, which are not reflected in the table below.

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The 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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 23% of the average value of its portfolio.

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

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.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels until February 28, 2015, and thereafter at 0.95% to represent the imposition of the 12b-1 fee of 0.25% per annum of the Fund's average daily net assets. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (plus the amount of any borrowings for investment purposes) in common stocks or in depositary receipts representing securities in the Index. First Trust Advisors L.P. ("First Trust" or the "Advisor") seeks to match the performance of the Index (before the Fund's fees and expenses).

The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. First Trust 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.

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.

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 December 31, 2013, there were 61 securities that comprised the Index.