rr_RiskReturnHeading

SUMMARY INFORMATION

rr_ObjectivePrimaryTextBlock

The First Trust Consumer Discretionary AlphaDEX(R) 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 StrataQuant(R) Consumer Discretionary Index (the "Index").

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.

rr_OperatingExpensesCaption

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

Expense Example, No Redemption Narrative [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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 131% of the average value of its portfolio.

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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (including investment borrowings) in common stocks that comprise the Index. The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. 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.

The Index is in the "StrataQuant(R) Series," a family of custom enhanced indices developed, maintained and sponsored by NYSE Group, Inc. or its affiliates ("NYSE" or an "Index Provider"), and licensed to First Trust Portfolios L.P. by NYSE. Prior to the acquisition of the American Stock Exchange LLC (the "AMEX") by NYSE, the equity indices in the StrataQuant(R) Series were developed, maintained and sponsored by the AMEX. The Index is a modified equal-dollar weighted index designed by NYSE to objectively identify and select stocks from the Russell 1000(R) Index in the consumer discretionary sector that may generate positive alpha relative to traditional passive-style indices through the use of the AlphaDEX(R) selection methodology. Alpha is an indication of how much an investment outperforms or underperforms on a risk-adjusted basis relative to its benchmark. As of July 31, 2015, the Index was comprised of 130 stocks. The Index is rebalanced and reconstituted as of the last business day of each calendar quarter. Changes to the Index will be effective at the open of trading on the fourth business day of the following month.

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.

CONSUMER DISCRETIONARY COMPANIES RISK. Consumer discretionary companies are companies that provide non-essential goods and services, such as retailers, media companies and consumer services. These companies manufacture products and provide discretionary services directly to the consumer, and the success of these companies is tied closely to the performance of the overall domestic and international economy, interest rates, competition and consumer confidence. Success depends heavily on disposable household income and consumer spending. Changes in demographics and consumer tastes can also affect the demand for, and success of, consumer discretionary products in the marketplace.

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 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.

GROWTH STOCKS INVESTMENT RISK. Growth stocks tend to be more volatile than certain other types of stocks and their prices usually fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings.

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. Securities 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. Shares of the Fund could decline in value or 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.

PORTFOLIO TURNOVER RISK. The Fund's strategy may frequently involve buying and selling portfolio securities to rebalance the Fund's exposure to various market sectors. High portfolio turnover may result in the Fund paying higher levels of transaction costs and generating greater tax liabilities for shareholders. Portfolio turnover risk may cause the Fund's performance to be less than you expect.

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.

SMALLER COMPANIES RISK. Small and/or mid-capitalization 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 larger, more established companies.

VALUE STOCKS INVESTMENT RISK. The intrinsic value of a stock with value characteristics may not be fully recognized by the market for a long time or a stock judged to be undervalued may actually be appropriately priced at a low level.

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. 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, a broad-based market index and two specialized securities market indices. With respect to the Russell 1000(R) Consumer Discretionary Index (formerly the Russell 1000(R) Consumer Discretionary and Services Index), on or about September 18, 2008, Russell Investment Group ("Russell") began calculating its Russell U.S. Indices using an enhanced Russell sector scheme, the Russell Global Sectors (the "RGS"). The RGS and the former U.S. sector scheme ran in tandem until June 30, 2009, when Russell officially transitioned to the RGS and ceased calculating its indices using the U.S. sector scheme. Consequently, performance data is not available for the Russell 1000(R) Consumer Discretionary Index for the entire "Since Inception" period set forth in the table because performance data does not exist using solely the U.S. sector scheme or alternatively, using solely the RGS. 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.

rr_BarChartFootnotesTextBlock

[1]

The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -3.53%.

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2014

rr_RiskReturnAbstract

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_ManagementFeesOverAssets

0.50%

rr_Component1OtherExpensesOverAssets

none

^[2]

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

rr_ExpensesOverAssets

0.63%

rr_NetExpensesOverAssets

0.63%

rr_ExpenseExampleNoRedemptionYear03

253

rr_ExpenseExampleNoRedemptionYear10

$ 1,059

rr_AnnualReturn2009

57.06%

rr_AnnualReturn2011

0.98%

rr_AnnualReturn2013

42.99%

rr_AverageAnnualReturnYear01

11.63%

rr_AverageAnnualReturnSinceInception

8.63%

rr_AverageAnnualReturnYear01

11.36%

rr_AverageAnnualReturnSinceInception

8.36%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear05

15.99%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

20.65%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.64%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

21.38%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

21.10%

rr_RiskReturnHeading

SUMMARY INFORMATION

rr_ObjectivePrimaryTextBlock

The First Trust Consumer Staples AlphaDEX(R) 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 StrataQuant(R) Consumer Staples Index (the "Index").

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.

rr_OperatingExpensesCaption

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

Expense Example, No Redemption Narrative [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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 87% of the average value of its portfolio.

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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (including investment borrowings) in common stocks that comprise the Index. The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. 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.

The Index is in the "StrataQuant(R) Series," a family of custom enhanced indices developed, maintained and sponsored by NYSE Group, Inc. or its affiliates ("NYSE" or an "Index Provider"), and licensed to First Trust Portfolios L.P. by NYSE. Prior to the acquisition of the American Stock Exchange LLC (the "AMEX") by NYSE, the equity indices in the StrataQuant(R) Series were developed, maintained and sponsored by the AMEX. The Index is a modified equal-dollar weighted index designed by NYSE to objectively identify and select stocks from the Russell 1000(R) Index in the consumer staples sector that may generate positive alpha relative to traditional passive-style indices through the use of the AlphaDEX(R) selection methodology. Alpha is an indication of how much an investment outperforms or underperforms on a risk-adjusted basis relative to its benchmark. As of July 31, 2015, the Index was comprised of 36 stocks. The Index is rebalanced and reconstituted as of the last business day of each calendar quarter. Changes to the Index will be effective at the open of trading on the fourth business day of the following month.

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.

CONSUMER STAPLES COMPANIES RISK. The Fund invests in the securities of consumer staples companies, which provide products directly to the consumer that are typically considered non-discretionary items based on consumer purchasing habits. The success of these companies is affected by a variety of factors, such as government regulations, which may affect the permissibility of using various food additives and the production methods of companies that manufacture food products.

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 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.

GROWTH STOCKS INVESTMENT RISK. Growth stocks tend to be more volatile than certain other types of stocks and their prices usually fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings.

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. Securities 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. Shares of the Fund could decline in value or 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.

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.

SMALLER COMPANIES RISK. Small and/or mid-capitalization 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 larger, more established companies.

VALUE STOCKS INVESTMENT RISK. The intrinsic value of a stock with value characteristics may not be fully recognized by the market for a long time or a stock judged to be undervalued may actually be appropriately priced at a low level.

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. 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, a broad-based market index and two specialized securities market indices. With respect to the Russell 1000(R) Consumer Staples Index, on or about September 18, 2008, Russell Investment Group ("Russell") began calculating its Russell U.S. Indices using an enhanced Russell sector scheme, the Russell Global Sectors (the "RGS"). The RGS and the former U.S. sector scheme ran in tandem until June 30, 2009, when Russell officially transitioned to the RGS and ceased calculating its indices using the U.S. sector scheme. Consequently, performance data is not available for the Russell 1000(R) Consumer Staples Index for the entire "Since Inception" period set forth in the table because performance data does not exist using solely the U.S. sector scheme or alternatively, using solely the RGS. 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.

rr_BarChartFootnotesTextBlock

[1]

The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -0.22%.

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2014

rr_RiskReturnAbstract

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_ManagementFeesOverAssets

0.50%

rr_Component1OtherExpensesOverAssets

none

^[2]

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

rr_ExpensesOverAssets

0.62%

rr_NetExpensesOverAssets

0.62%

rr_ExpenseExampleNoRedemptionYear03

250

rr_ExpenseExampleNoRedemptionYear10

$ 1,047

rr_AnnualReturn2009

27.13%

rr_AnnualReturn2011

13.15%

rr_AnnualReturn2013

41.94%

rr_AverageAnnualReturnYear01

21.05%

rr_AverageAnnualReturnSinceInception

11.76%

rr_AverageAnnualReturnYear01

20.35%

rr_AverageAnnualReturnSinceInception

11.25%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear05

16.53%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

21.56%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.64%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

16.08%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

16.73%

rr_RiskReturnHeading

SUMMARY INFORMATION

rr_ObjectivePrimaryTextBlock

The First Trust Energy AlphaDEX(R) 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 StrataQuant(R) Energy Index (the "Index").

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.

rr_OperatingExpensesCaption

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

Expense Example, No Redemption Narrative [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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 97% of the average value of its portfolio.

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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (including investment borrowings) in common stocks that comprise the Index. The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. 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.

The Index is in the "StrataQuant(R) Series," a family of custom enhanced indices developed, maintained and sponsored by NYSE Group, Inc. or its affiliates ("NYSE" or an "Index Provider"), and licensed to First Trust Portfolios L.P. by NYSE. Prior to the acquisition of the American Stock Exchange LLC (the "AMEX") by NYSE, the equity indices in the StrataQuant(R) Series were developed, maintained and sponsored by the AMEX. The Index is a modified equal-dollar weighted index designed by NYSE to objectively identify and select stocks from the Russell 1000(R) Index in the energy sector that may generate positive alpha relative to traditional passive-style indices through the use of the AlphaDEX(R) selection methodology. Alpha is an indication of how much an investment outperforms or underperforms on a risk-adjusted basis relative to its benchmark. As of July 31, 2015, the Index was comprised of 60 stocks. The Index is rebalanced and reconstituted as of the last business day of each calendar quarter. Changes to the Index will be effective at the open of trading on the fourth business day of the following month.

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.

ENERGY COMPANIES RISK. The Fund invests in the securities of energy companies, which include integrated oil companies that are involved in the exploration, production and refining process, gas distributors and pipeline-related companies and other energy companies involved with mining, producing and delivering energy-related services and drilling. General problems of energy companies include volatile fluctuations in price and supply of energy fuels, international politics, terrorist attacks, reduced demand, the success of exploration projects, clean-up and litigation costs relating to oil spills and environmental damage, and tax and other regulatory policies of various governments. Natural disasters such as hurricanes in the Gulf of Mexico also impact the petroleum industry. Oil production and refining companies are subject to extensive federal, state and local environmental laws and regulations regarding air emissions and the disposal of hazardous materials. In addition, oil prices are generally subject to extreme volatility.

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 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.

GROWTH STOCKS INVESTMENT RISK. Growth stocks tend to be more volatile than certain other types of stocks and their prices usually fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings.

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. Securities 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. Shares of the Fund could decline in value or 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.

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.

SMALLER COMPANIES RISK. Small and/or mid-capitalization 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 larger, more established companies.

VALUE STOCKS INVESTMENT RISK. The intrinsic value of a stock with value characteristics may not be fully recognized by the market for a long time or a stock judged to be undervalued may actually be appropriately priced at a low level.

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. 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, a broad-based market index and two specialized securities market indices. With respect to the Russell 1000(R) Energy Index, on or about September 18, 2008, Russell Investment Group ("Russell") began calculating its Russell U.S. Indices using an enhanced Russell sector scheme, the Russell Global Sectors (the "RGS"). The RGS and the former U.S. sector scheme ran in tandem until June 30, 2009, when Russell officially transitioned to the RGS and ceased calculating its indices using the U.S. sector scheme. In addition to the implementation of the RGS, Russell combined the Russell 1000(R) Integrated Oils Index and the Russell 1000(R) Other Energy Index into one index, the Russell 1000(R) Energy Index. Consequently, performance data is not available for the Russell 1000(R) Energy Index for the entire "Since Inception" period set forth in the table because performance data does not exist using solely the U.S. sector scheme or alternatively, using solely the RGS. 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.

rr_BarChartFootnotesTextBlock

[1]

The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -30.19%.

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2014

rr_RiskReturnAbstract

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_ManagementFeesOverAssets

0.50%

rr_Component1OtherExpensesOverAssets

none

^[2]

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

rr_ExpensesOverAssets

0.64%

rr_NetExpensesOverAssets

0.64%

rr_ExpenseExampleNoRedemptionYear03

257

rr_ExpenseExampleNoRedemptionYear10

$ 1,071

rr_AnnualReturn2009

47.52%

rr_AnnualReturn2011

(8.16%)

rr_AnnualReturn2013

28.66%

rr_AverageAnnualReturnYear01

(16.01%)

rr_AverageAnnualReturnSinceInception

1.30%

rr_AverageAnnualReturnYear01

(16.54%)

rr_AverageAnnualReturnSinceInception

1.03%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear05

4.24%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

6.34%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.64%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

8.76%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

8.38%

rr_RiskReturnHeading

SUMMARY INFORMATION

rr_ObjectivePrimaryTextBlock

The First Trust Financials AlphaDEX(R) 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 StrataQuant(R) Financials Index (the "Index").

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.

rr_OperatingExpensesCaption

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

Expense Example, No Redemption Narrative [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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 80% of the average value of its portfolio.

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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (including investment borrowings) in common stocks that comprise the Index. The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. 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.

The Index is in the "StrataQuant(R) Series," a family of custom enhanced indices developed, maintained and sponsored by NYSE Group, Inc. or its affiliates ("NYSE" or an "Index Provider"), and licensed to First Trust Portfolios L.P. by NYSE. Prior to the acquisition of the American Stock Exchange LLC (the "AMEX") by NYSE, the equity indices in the StrataQuant(R) Series were developed, maintained and sponsored by the AMEX. The Index is a modified equal-dollar weighted index designed by NYSE to objectively identify and select stocks from the Russell 1000(R) Index in the financial services sector that may generate positive alpha relative to traditional passive-style indices through the use of the AlphaDEX(R) selection methodology. Alpha is an indication of how much an investment outperforms or underperforms on a risk-adjusted basis relative to its benchmark. As of July 31, 2015, the Index was comprised of 171 stocks. The Index is rebalanced and reconstituted as of the last business day of each calendar quarter. Changes to the Index will be effective at the open of trading on the fourth business day of the following month.

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.

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 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.

FINANCIAL 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.

GROWTH STOCKS INVESTMENT RISK. Growth stocks tend to be more volatile than certain other types of stocks and their prices usually fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings.

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. Securities 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. Shares of the Fund could decline in value or 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.

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.

SMALLER COMPANIES RISK. Small and/or mid-capitalization 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 larger, more established companies.

VALUE STOCKS INVESTMENT RISK. The intrinsic value of a stock with value characteristics may not be fully recognized by the market for a long time or a stock judged to be undervalued may actually be appropriately priced at a low level.

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. 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, a broad-based market index and two specialized securities market indices. With respect to the Russell 1000(R) Financial Services Index, on or about September 18, 2008, Russell Investment Group ("Russell") began calculating its Russell U.S. Indices using an enhanced Russell sector scheme, the Russell Global Sectors (the "RGS"). The RGS and the former U.S. sector scheme ran in tandem until June 30, 2009, when Russell officially transitioned to the RGS and ceased calculating its indices using the U.S. sector scheme. Consequently, performance data is not available for the Russell 1000(R) Financial Services Index for the entire "Since Inception" period set forth in the table because performance data does not exist using solely the U.S. sector scheme or alternatively, using solely the RGS. 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.

rr_BarChartFootnotesTextBlock

[1]

The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -2.62%.

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2014

rr_RiskReturnAbstract

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_ManagementFeesOverAssets

0.50%

rr_Component1OtherExpensesOverAssets

none

^[2]

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

rr_ExpensesOverAssets

0.64%

rr_NetExpensesOverAssets

0.64%

rr_ExpenseExampleNoRedemptionYear03

257

rr_ExpenseExampleNoRedemptionYear10

$ 1,071

rr_AnnualReturn2009

31.65%

rr_AnnualReturn2011

(7.35%)

rr_AnnualReturn2013

40.41%

rr_AverageAnnualReturnYear01

8.71%

rr_AverageAnnualReturnSinceInception

3.76%

rr_AverageAnnualReturnYear01

7.96%

rr_AverageAnnualReturnSinceInception

3.10%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear05

12.00%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

16.26%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.64%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

13.36%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

13.84%

rr_RiskReturnHeading

SUMMARY INFORMATION

rr_ObjectivePrimaryTextBlock

The First Trust Health Care AlphaDEX(R) 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 StrataQuant(R) Health Care Index (the "Index").

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.

rr_OperatingExpensesCaption

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

Expense Example, No Redemption Narrative [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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 125% of the average value of its portfolio.

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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (including investment borrowings) in common stocks that comprise the Index. The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. 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.

The Index is in the "StrataQuant(R) Series," a family of custom enhanced indices developed, maintained and sponsored by NYSE Group, Inc. or its affiliates ("NYSE" or an "Index Provider"), and licensed to First Trust Portfolios L.P. by NYSE. Prior to the acquisition of the American Stock Exchange LLC (the "AMEX") by NYSE, the equity indices in the StrataQuant(R) Series were developed, maintained and sponsored by the AMEX. The Index is a modified equal-dollar weighted index designed by NYSE to objectively identify and select stocks from the Russell 1000(R) Index in the health care sector that may generate positive alpha relative to traditional passive-style indices through the use of the AlphaDEX(R) selection methodology. Alpha is an indication of how much an investment outperforms or underperforms on a risk-adjusted basis relative to its benchmark. As of July 31, 2015, the Index was comprised of 76 stocks. The Index is rebalanced and reconstituted as of the last business day of each calendar quarter. Changes to the Index will be effective at the open of trading on the fourth business day of the following month.

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.

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 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.

GROWTH STOCKS INVESTMENT RISK. Growth stocks tend to be more volatile than certain other types of stocks and their prices usually fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings.

HEALTH CARE COMPANIES RISK. Health care companies are companies involved in medical services or health care, including biotechnology research and production, drugs and pharmaceuticals and health care facilities and services. These companies are subject to extensive competition, generic drug sales or the loss of patent protection, product liability litigation and increased government regulation. Research and development costs of bringing new drugs to market are substantial, and there is no guarantee that the product will ever come to market. Health care facility operators may be affected by the demand for services, efforts by government or insurers to limit rates, restriction of government financial assistance and competition from other providers.

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. Securities 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. Shares of the Fund could decline in value or 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.

PORTFOLIO TURNOVER RISK. The Fund's strategy may frequently involve buying and selling portfolio securities to rebalance the Fund's exposure to various market sectors. High portfolio turnover may result in the Fund paying higher levels of transaction costs and generating greater tax liabilities for shareholders. Portfolio turnover risk may cause the Fund's performance to be less than you expect.

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.

SMALLER COMPANIES RISK. Small and/or mid-capitalization 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 larger, more established companies.

VALUE STOCKS INVESTMENT RISK. The intrinsic value of a stock with value characteristics may not be fully recognized by the market for a long time or a stock judged to be undervalued may actually be appropriately priced at a low level.

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. 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, a broad-based market index and two specialized securities market indices. With respect to the Russell 1000(R) Health Care Index, on or about September 18, 2008, Russell Investment Group ("Russell") began calculating its Russell U.S. Indices using an enhanced Russell sector scheme, the Russell Global Sectors (the "RGS"). The RGS and the former U.S. sector scheme ran in tandem until June 30, 2009, when Russell officially transitioned to the RGS and ceased calculating its indices using the U.S. sector scheme. Consequently, performance data is not available for the Russell 1000(R) Health Care Index for the entire "Since Inception" period set forth in the table because performance data does not exist using solely the U.S. sector scheme or alternatively, using solely the RGS. 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.

rr_BarChartFootnotesTextBlock

[1]

The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -3.42%.

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2014

rr_RiskReturnAbstract

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_ManagementFeesOverAssets

0.50%

rr_Component1OtherExpensesOverAssets

none

^[2]

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

rr_ExpensesOverAssets

0.62%

rr_NetExpensesOverAssets

0.62%

rr_ExpenseExampleNoRedemptionYear03

250

rr_ExpenseExampleNoRedemptionYear10

$ 1,047

rr_AnnualReturn2009

51.23%

rr_AnnualReturn2011

5.76%

rr_AnnualReturn2013

47.46%

rr_AverageAnnualReturnYear01

25.40%

rr_AverageAnnualReturnSinceInception

15.62%

rr_AverageAnnualReturnYear01

25.40%

rr_AverageAnnualReturnSinceInception

15.58%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear05

18.91%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

23.86%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.64%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

19.38%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

20.17%

rr_RiskReturnHeading

SUMMARY INFORMATION

rr_ObjectivePrimaryTextBlock

The First Trust Industrials/Producer Durables AlphaDEX(R) 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 StrataQuant(R) Industrials Index (the "Index").

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.

rr_OperatingExpensesCaption

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

Expense Example, No Redemption Narrative [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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 105% of the average value of its portfolio.

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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (including investment borrowings) in common stocks that comprise the Index. The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. 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.

The Index is in the "StrataQuant(R) Series," a family of custom enhanced indices developed, maintained and sponsored by NYSE Group, Inc. or its affiliates ("NYSE" or an "Index Provider"), and licensed to First Trust Portfolios L.P. by NYSE. Prior to the acquisition of the American Stock Exchange LLC (the "AMEX") by NYSE, the equity indices in the StrataQuant(R) Series were developed, maintained and sponsored by the AMEX. The Index is a modified equal-dollar weighted index designed by NYSE to objectively identify and select stocks from the Russell 1000(R) Index in the industrials and producer durables sectors that may generate positive alpha relative to traditional passive-style indices through the use of the AlphaDEX(R) selection methodology. Alpha is an indication of how much an investment outperforms or underperforms on a risk-adjusted basis relative to its benchmark. As of July 31, 2015, the Index was comprised of 100 stocks. The Index is rebalanced and reconstituted as of the last business day of each calendar quarter. Changes to the Index will be effective at the open of trading on the fourth business day of the following month.

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.

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 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.

GROWTH STOCKS INVESTMENT RISK. Growth stocks tend to be more volatile than certain other types of stocks and their prices usually fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings.

INDUSTRIALS COMPANIES RISK. The Fund invests in the securities of industrials companies, which convert unfinished goods into finished durables used to manufacture other goods or provide services. These companies produce electrical equipment and components, industrial products, manufactured housing and telecommunications equipment. General risks of these companies include the general state of the economy, intense competition, consolidation, domestic and international politics, excess capacity and consumer demand and spending trends. In addition, they may also be significantly affected by overall capital spending levels, economic cycles, technical obsolescence, delays in modernization, labor relations, government regulations and e-commerce initiatives.

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. Securities 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. Shares of the Fund could decline in value or 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.

PORTFOLIO TURNOVER RISK. The Fund's strategy may frequently involve buying and selling portfolio securities to rebalance the Fund's exposure to various market sectors. High portfolio turnover may result in the Fund paying higher levels of transaction costs and generating greater tax liabilities for shareholders. Portfolio turnover risk may cause the Fund's performance to be less than you expect.

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.

SMALLER COMPANIES RISK. Small and/or mid-capitalization 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 larger, more established companies.

VALUE STOCKS INVESTMENT RISK. The intrinsic value of a stock with value characteristics may not be fully recognized by the market for a long time or a stock judged to be undervalued may actually be appropriately priced at a low level.

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. 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, a broad-based market index and two specialized securities market indices. With respect to the Russell 1000(R) Producer Durables Index, on or about September 18, 2008, Russell Investment Group ("Russell") began calculating its Russell U.S. Indices using an enhanced Russell sector scheme, the Russell Global Sectors (the "RGS"). The RGS and the former U.S. sector scheme ran in tandem until June 30, 2009, when Russell officially transitioned to the RGS and ceased calculating its indices using the U.S. sector scheme. Consequently, performance data is not available for the Russell 1000(R) Producer Durables Index for the entire "Since Inception" period set forth in the table because performance data does not exist using solely the U.S. sector scheme or alternatively, using solely the RGS. 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.

rr_BarChartFootnotesTextBlock

[1]

The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -14.68%.

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2014

rr_RiskReturnAbstract

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_ManagementFeesOverAssets

0.50%

rr_Component1OtherExpensesOverAssets

none

^[2]

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

rr_ExpensesOverAssets

0.63%

rr_NetExpensesOverAssets

0.63%

rr_ExpenseExampleNoRedemptionYear03

253

rr_ExpenseExampleNoRedemptionYear10

$ 1,059

rr_AnnualReturn2009

42.14%

rr_AnnualReturn2011

(5.95%)

rr_AnnualReturn2013

46.46%

rr_AverageAnnualReturnYear01

8.13%

rr_AverageAnnualReturnSinceInception

6.48%

rr_AverageAnnualReturnYear01

7.62%

rr_AverageAnnualReturnSinceInception

6.15%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear05

13.27%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

17.55%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.64%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

17.56%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

17.64%

rr_RiskReturnHeading

SUMMARY INFORMATION

rr_ObjectivePrimaryTextBlock

The First Trust Materials AlphaDEX(R) 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 StrataQuant(R) Materials Index (the "Index").

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.

rr_OperatingExpensesCaption

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

Expense Example, No Redemption Narrative [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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 104% of the average value of its portfolio.

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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (including investment borrowings) in common stocks that comprise the Index. The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. 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.

The Index is in the "StrataQuant(R) Series," a family of custom enhanced indices developed, maintained and sponsored by NYSE Group, Inc. or its affiliates ("NYSE" or an "Index Provider"), and licensed to First Trust Portfolios L.P. by NYSE. Prior to the acquisition of the American Stock Exchange LLC (the "AMEX") by NYSE, the equity indices in the StrataQuant(R) Series were developed, maintained and sponsored by the AMEX. The Index is a modified equal-dollar weighted index designed by NYSE to objectively identify and select stocks from the Russell 1000(R) Index in the materials and processing sector that may generate positive alpha relative to traditional passive-style indices through the use of the AlphaDEX(R) selection methodology. Alpha is an indication of how much an investment outperforms or underperforms on a risk-adjusted basis relative to its benchmark. As of July 31, 2015, the Index was comprised of 53 stocks. The Index is rebalanced and reconstituted as of the last business day of each calendar quarter. Changes to the Index will be effective at the open of trading on the fourth business day of the following month.

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.

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 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.

GROWTH STOCKS INVESTMENT RISK. Growth stocks tend to be more volatile than certain other types of stocks and their prices usually fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings.

INDUSTRIALS COMPANIES RISK. The Fund invests in the securities of industrials companies, which convert unfinished goods into finished durables used to manufacture other goods or provide services. These companies produce electrical equipment and components, industrial products, manufactured housing and telecommunications equipment. General risks of these companies include the general state of the economy, intense competition, consolidation, domestic and international politics, excess capacity and consumer demand and spending trends. In addition, they may also be significantly affected by overall capital spending levels, economic cycles, technical obsolescence, delays in modernization, labor relations, government regulations and e-commerce initiatives.

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. Securities 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. Shares of the Fund could decline in value or underperform other investments.

MATERIALS AND PROCESSING COMPANIES RISK. The Fund invests in the securities of materials and processing companies, which are involved in the extracting or processing of raw materials. General risks of these companies include the general state of the economy, consolidation, domestic and international politics and excess capacity. In addition, 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.

PORTFOLIO TURNOVER RISK. The Fund's strategy may frequently involve buying and selling portfolio securities to rebalance the Fund's exposure to various market sectors. High portfolio turnover may result in the Fund paying higher levels of transaction costs and generating greater tax liabilities for shareholders. Portfolio turnover risk may cause the Fund's performance to be less than you expect.

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.

SMALLER COMPANIES RISK. Small and/or mid-capitalization 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 larger, more established companies.

VALUE STOCKS INVESTMENT RISK. The intrinsic value of a stock with value characteristics may not be fully recognized by the market for a long time or a stock judged to be undervalued may actually be appropriately priced at a low level.

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. 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, a broad-based market index and two specialized securities market indices. With respect to the Russell 1000(R) Materials and Processing Index, on or about September 18, 2008, Russell Investment Group ("Russell") began calculating its Russell U.S. Indices using an enhanced Russell sector scheme, the Russell Global Sectors (the "RGS"). The RGS and the former U.S. sector scheme ran in tandem until June 30, 2009, when Russell officially transitioned to the RGS and ceased calculating its indices using the U.S. sector scheme. Consequently, performance data is not available for the Russell 1000(R) Materials and Processing Index for the entire "Since Inception" period set forth in the table because performance data does not exist using solely the U.S. sector scheme or alternatively, using solely the RGS. 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.

rr_BarChartFootnotesTextBlock

[1]

The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -13.88%.

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2014

rr_RiskReturnAbstract

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_ManagementFeesOverAssets

0.50%

rr_Component1OtherExpensesOverAssets

none

^[2]

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

rr_ExpensesOverAssets

0.64%

rr_NetExpensesOverAssets

0.64%

rr_ExpenseExampleNoRedemptionYear03

257

rr_ExpenseExampleNoRedemptionYear10

$ 1,071

rr_AnnualReturn2009

59.95%

rr_AnnualReturn2011

(10.11%)

rr_AnnualReturn2013

26.73%

rr_AverageAnnualReturnYear01

(0.98%)

rr_AverageAnnualReturnSinceInception

7.66%

rr_AverageAnnualReturnYear01

(1.69%)

rr_AverageAnnualReturnSinceInception

7.09%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear05

9.76%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

13.46%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.64%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

11.23%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

12.44%

rr_RiskReturnHeading

SUMMARY INFORMATION

rr_ObjectivePrimaryTextBlock

The First Trust Technology AlphaDEX(R) 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 StrataQuant(R) Technology Index (the "Index").

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.

rr_OperatingExpensesCaption

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

Expense Example, No Redemption Narrative [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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 91% of the average value of its portfolio.

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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (including investment borrowings) in common stocks that comprise the Index. The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. 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.

The Index is in the "StrataQuant(R) Series," a family of custom enhanced indices developed, maintained and sponsored by NYSE Group, Inc. or its affiliates ("NYSE" or an "Index Provider"), and licensed to First Trust Portfolios L.P. by NYSE. Prior to the acquisition of the American Stock Exchange LLC (the "AMEX") by NYSE, the equity indices in the StrataQuant(R) Series were developed, maintained and sponsored by the AMEX. The Index is a modified equal-dollar weighted index designed by NYSE to objectively identify and select stocks from the Russell 1000(R) Index in the technology sector that may generate positive alpha relative to traditional passive-style indices through the use of the AlphaDEX(R) selection methodology. Alpha is an indication of how much an investment outperforms or underperforms on a risk-adjusted basis relative to its benchmark. As of July 31, 2015, the Index was comprised of 85 stocks. The Index is rebalanced and reconstituted as of the last business day of each calendar quarter. Changes to the Index will be effective at the open of trading on the fourth business day of the following month.

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.

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 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.

GROWTH STOCKS INVESTMENT RISK. Growth stocks tend to be more volatile than certain other types of stocks and their prices usually fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings.

INFORMATION TECHNOLOGY COMPANIES RISK. 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.

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. Securities 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. Shares of the Fund could decline in value or 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.

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.

SMALLER COMPANIES RISK. Small and/or mid-capitalization 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 larger, more established companies.

VALUE STOCKS INVESTMENT RISK. The intrinsic value of a stock with value characteristics may not be fully recognized by the market for a long time or a stock judged to be undervalued may actually be appropriately priced at a low level.

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. 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, a broad-based market index and two specialized securities market indices. With respect to the Russell 1000(R) Technology Index, on or about September 18, 2008, Russell Investment Group ("Russell") began calculating its Russell U.S. Indices using an enhanced Russell sector scheme, the Russell Global Sectors (the "RGS"). The RGS and the former U.S. sector scheme ran in tandem until June 30, 2009, when Russell officially transitioned to the RGS and ceased calculating its indices using the U.S. sector scheme. Consequently, performance data is not available for the Russell 1000(R) Technology Index for the entire "Since Inception" period set forth in the table because performance data does not exist using solely the U.S. sector scheme or alternatively, using solely the RGS. 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.

rr_BarChartFootnotesTextBlock

[1]

The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -8.05%.

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2014

rr_RiskReturnAbstract

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_ManagementFeesOverAssets

0.50%

rr_Component1OtherExpensesOverAssets

none

^[2]

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

rr_ExpensesOverAssets

0.63%

rr_NetExpensesOverAssets

0.63%

rr_ExpenseExampleNoRedemptionYear03

253

rr_ExpenseExampleNoRedemptionYear10

$ 1,059

rr_AnnualReturn2009

66.95%

rr_AnnualReturn2011

(11.65%)

rr_AnnualReturn2013

37.73%

rr_AverageAnnualReturnYear01

16.38%

rr_AverageAnnualReturnSinceInception

7.58%

rr_AverageAnnualReturnYear01

16.05%

rr_AverageAnnualReturnSinceInception

7.50%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear05

11.44%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.19%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.64%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

14.86%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

14.15%

rr_RiskReturnHeading

SUMMARY INFORMATION

rr_ObjectivePrimaryTextBlock

The First Trust Utilities AlphaDEX(R) 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 StrataQuant(R) Utilities Index (the "Index").

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.

rr_OperatingExpensesCaption

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

Expense Example, No Redemption Narrative [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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 94% of the average value of its portfolio.

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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (including investment borrowings) in common stocks that comprise the Index. The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. 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.

The Index is in the "StrataQuant(R) Series," a family of custom enhanced indices developed, maintained and sponsored by NYSE Group, Inc. or its affiliates ("NYSE" or an "Index Provider"), and licensed to First Trust Portfolios L.P. by NYSE. Prior to the acquisition of the American Stock Exchange LLC (the "AMEX") by NYSE, the equity indices in the StrataQuant(R) Series were developed, maintained and sponsored by the AMEX. The Index is a modified equal-dollar weighted index designed by NYSE to objectively identify and select stocks from the Russell 1000(R) Index in the utilities sector that may generate positive alpha relative to traditional passive-style indices through the use of the AlphaDEX(R) selection methodology. Alpha is an indication of how much an investment outperforms or underperforms on a risk-adjusted basis relative to its benchmark. As of July 31, 2015, the Index was comprised of 40 stocks. The Index is rebalanced and reconstituted as of the last business day of each calendar quarter. Changes to the Index will be effective at the open of trading on the fourth business day of the following month.

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.

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 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.

GROWTH STOCKS INVESTMENT RISK. Growth stocks tend to be more volatile than certain other types of stocks and their prices usually fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings.

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. Securities 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. Shares of the Fund could decline in value or 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.

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.

SMALLER COMPANIES RISK. Small and/or mid-capitalization 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 larger, more established companies.

TELECOMMUNICATIONS COMPANIES RISK. The Fund invests in the securities of telecommunications companies. Telecommunications companies are subject to risks, which include increased competition and regulation by various regulatory authorities, the need to commit substantial capital and technological obsolescence.

UTILITIES COMPANIES RISK. The Fund invests in the securities of utilities companies. General problems of utilities companies include the imposition of rate caps, increased competition due to deregulation, the difficulty in obtaining an adequate return on invested capital or in financing large construction projects, the limitations on operations and increased costs and delays attributable to environmental considerations and the capital market's ability to absorb utility debt. In addition, taxes, government regulation, international politics, price and supply fluctuations, volatile interest rates and energy conservation may cause difficulties for utilities. All of such issuers have been experiencing certain of these problems in varying degrees.

VALUE STOCKS INVESTMENT RISK. The intrinsic value of a stock with value characteristics may not be fully recognized by the market for a long time or a stock judged to be undervalued may actually be appropriately priced at a low level.

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. 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, a broad-based market index and two specialized securities market indices. With respect to the Russell 1000(R) Utilities Index, on or about September 18, 2008, Russell Investment Group ("Russell") began calculating its Russell U.S. Indices using an enhanced Russell sector scheme, the Russell Global Sectors (the "RGS"). The RGS and the former U.S. sector scheme ran in tandem until June 30, 2009, when Russell officially transitioned to the RGS and ceased calculating its indices using the U.S. sector scheme. Consequently, performance data is not available for the Russell 1000(R) Utilities Index for the entire "Since Inception" period set forth in the table because performance data does not exist using solely the U.S. sector scheme or alternatively, using solely the RGS. 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.

rr_BarChartFootnotesTextBlock

[1]

The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -6.52%.

rr_PerformanceTableHeading

AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2014

rr_RiskReturnAbstract

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_ManagementFeesOverAssets

0.50%

rr_Component1OtherExpensesOverAssets

none

^[2],[3]

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

rr_ExpensesOverAssets

0.66%

rr_NetExpensesOverAssets

0.66%

rr_ExpenseExampleNoRedemptionYear03

263

rr_ExpenseExampleNoRedemptionYear10

$ 1,095

rr_AnnualReturn2009

22.54%

rr_AnnualReturn2011

10.33%

rr_AnnualReturn2013

17.51%

rr_AverageAnnualReturnYear01

25.49%

rr_AverageAnnualReturnSinceInception

6.13%

rr_AverageAnnualReturnYear01

24.27%

rr_AverageAnnualReturnSinceInception

4.92%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear05

9.96%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

14.26%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.64%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

13.34%

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

12.59%

rr_RiskReturnHeading

SUMMARY INFORMATION

rr_ObjectivePrimaryTextBlock

The First Trust Large Cap Core AlphaDEX(R) 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 Defined Large Cap Core Index (the "Index").

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.

rr_OperatingExpensesCaption

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

Expense Example, No Redemption Narrative [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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 91% of the average value of its portfolio.

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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (including investment borrowings) in common stocks that comprise the Index. The Fund, using an "indexing" investment approach, attempts to replicate, before fees and expenses, the performance of the Index. 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.

The Index is in the "Defined Index Series," a family of custom enhanced indices developed, maintained and sponsored by S&P Dow Jones Indices LLC ("S&P" or an "Index Provider"). The Index is a modified equal-dollar weighted index designed by S&P to objectively identify and select stocks from the S&P 500(R) Index that may generate positive alpha relative to traditional passive-style indices through the use of the AlphaDEX(R) selection methodology. Alpha is an indication of how much an investment outperforms or underperforms on a risk-adjusted basis relative to its benchmark. As of July 31, 2015, the Index was comprised of 376 stocks and the market capitalization range represented in the Index was $2.574 billion to $692.065 billion. The Index is rebalanced and reconstituted as of the last business day of each calendar quarter. Changes to the Index will be effective at the open of trading on the sixth business day of the following month.

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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.

CONSUMER DISCRETIONARY COMPANIES RISK. Consumer discretionary companies are companies that provide non-essential goods and services, such as retailers, media companies and consumer services. These companies manufacture products and provide discretionary services directly to the consumer, and the success of these companies is tied closely to the performance of the overall domestic and international economy, interest rates, competition and consumer confidence. Success depends heavily on disposable household income and consumer spending. Changes in demographics and consumer tastes can also affect the demand for, and success of, consumer discretionary products in the marketplace.

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 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.

GROWTH STOCKS INVESTMENT RISK. Growth stocks tend to be more volatile than certain other types of stocks and their prices usually fluctuate more dramatically than the overall stock market. A stock with growth characteristics can have sharp price declines due to decreases in current or expected earnings.

MARKET CAPITALIZATION RISK. The Fund normally invests at least 90% of its assets in common stocks that comprise the Index. The securities of companies represented in the Index generally have market capitalizations that are consistent with the name of the Index. To determine the market capitalization range of such securities, the Fund uses the current range of the Index. However, the Fund will not sell a security because the security has exceeded or fallen below the current market capitalization range of the Index. Because of market movement, there can be no assurance that the securities in the Fund will stay within a given market capitalization range. As a result, the Fund may be exposed to additional risk or may not give investors the opportunity to invest fully in a given market capitalization range.

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. Securities 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. Shares of the Fund could decline in value or 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.

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.

VALUE STOCKS INVESTMENT RISK. The intrinsic value of a stock with value characteristics may not be fully recognized by the market for a long time or a stock judged to be undervalued may actually be appropriately priced at a low level.

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The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. 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 a broad-based 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 index 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.

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[1]

The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -7.49%.

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AVERAGE ANNUAL TOTAL RETURNS FOR THE PERIODS ENDED DECEMBER 31, 2014

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Fees Previously Waived or Expenses Reimbursed by First Trust

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0.50%

rr_Component1OtherExpensesOverAssets

none

^[2]

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

rr_ExpensesOverAssets

0.61%

rr_NetExpensesOverAssets

0.61%

rr_ExpenseExampleNoRedemptionYear03

247

rr_ExpenseExampleNoRedemptionYear10

$ 1,036

rr_AnnualReturn2009

36.11%

rr_AnnualReturn2011

(0.22%)

rr_AnnualReturn2013

35.77%

rr_AverageAnnualReturnYear01

12.34%

rr_AverageAnnualReturnSinceInception

6.88%

rr_AverageAnnualReturnYear01

11.69%

rr_AverageAnnualReturnSinceInception

6.41%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear05

12.66%

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(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

16.85%

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(reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnYear05

15.45%

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SUMMARY INFORMATION

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The First Trust Mid Cap Core AlphaDEX(R) 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 Defined Mid Cap Core Index (the "Index").

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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.

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

Expense Example, No Redemption Narrative [Text Block]

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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 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. During the most recent fiscal year, the Fund's portfolio turnover rate was 102% of the average value of its portfolio.

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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. 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 December 31, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be: