485BPOS

    As filed with the Securities and Exchange Commission on December 3, 2015
================================================================================
                                            1933 Act Registration No. 333-140895
                                             1940 Act Registration No. 811-22019


                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933                     [ ]
Pre-Effective Amendment No. __                                              [ ]
Post-Effective Amendment No. 26                                             [X]
                                     and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940             [ ]
Amendment No. 29                                                            [X]


                  FIRST TRUST EXCHANGE-TRADED ALPHADEX(R) FUND
               (Exact name of registrant as specified in charter)

                       120 East Liberty Drive, Suite 400
                            Wheaton, Illinois 60187
              (Address of Principal Executive Offices) (Zip Code)


       REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE: (800) 621-1675

                       W. Scott Jardine, Esq., Secretary
                  First Trust Exchange-Traded AlphaDEX(R) Fund
                           First Trust Advisors L.P.
                       120 East Liberty Drive, Suite 400
                            Wheaton, Illinois 60187
                    (Name and Address of Agent for Service)

                                    Copy to:
                               Eric F. Fess, Esq.
                             Chapman and Cutler LLP
                             111 West Monroe Street
                            Chicago, Illinois 60603


It is proposed that this filing will become effective (check appropriate box):

[X] immediately upon filing pursuant to paragraph (b)
[ ] on _______________ pursuant to paragraph (b)
[ ] 60 days after filing pursuant to paragraph (a)(1)
[ ] on (date) pursuant to paragraph (a)(1)
[ ] 75 days after filing pursuant to paragraph (a)(2)
[ ] on (date) pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following box:

[ ] this post-effective amendment designates a new effective date for a
    previously filed post-effective amendment.





                       CONTENTS OF REGISTRATION STATEMENT

      This Registration Statement relates to the First Trust Consumer
Discretionary AlphaDEX(R) Fund, First Trust Consumer Staples AlphaDEX(R) Fund,
First Trust Energy AlphaDEX(R) Fund, First Trust Financials AlphaDEX(R) Fund,
First Trust Health Care AlphaDEX(R) Fund, First Trust Industrials/Producer
Durables AlphaDEX(R) Fund, First Trust Materials AlphaDEX(R) Fund, First Trust
Technology AlphaDEX(R) Fund, First Trust Utilities AlphaDEX(R) Fund, First Trust
Large Cap Core AlphaDEX(R) Fund, First Trust Mid Cap Core AlphaDEX(R) Fund,
First Trust Small Cap Core AlphaDEX(R) Fund, First Trust Large Cap Value
AlphaDEX(R) Fund, First Trust Large Cap Growth AlphaDEX(R) Fund, First Trust
Multi Cap Value AlphaDEX(R) Fund, First Trust Multi Cap Growth AlphaDEX(R) Fund,
First Trust Mid Cap Growth AlphaDEX(R) Fund, First Trust Mid Cap Value
AlphaDEX(R) Fund, First Trust Small Cap Growth AlphaDEX(R) Fund, First Trust
Small Cap Value AlphaDEX(R) Fund and First Trust Mega Cap AlphaDEX(R) Fund, each
a series of the Registrant.





                             SIGNATURES

      Pursuant to the requirements of the Securities Act of 1933 and the
Investment Company Act of 1940, the Registrant certifies that it meets all of
the requirements for effectiveness of this Registration Statement under Rule
485(b) under the Securities Act of 1933 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, duly authorized in the
City of Wheaton, and State of Illinois, on the 3rd day of December, 2015.



                                               FIRST TRUST EXCHANGE-TRADED
                                               ALPHADEX(R) FUND


                                                /s/ Mark R. Bradley
                                                -------------------------------
                                                Mark R. Bradley, President and
                                                Chief Executive Officer

      Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the date indicated:

SIGNATURE                      TITLE                        DATE
                               President and Chief          December 3, 2015
/s/ Mark R. Bradley            Executive Officer
---------------------------
    Mark R. Bradley
                               Treasurer, Chief
                               Financial Officer and        December 3, 2015
/s/ James M. Dykas             Chief Accounting Officer
---------------------------
    James M. Dykas

                                                )
James A. Bowen*                         Trustee )
                                                )
                                                )
Richard E. Erickson*                    Trustee )
                                                )
                                                )
Thomas R. Kadlec*                       Trustee )   BY: /s/ W. Scott Jardine
                                                )      ---------------------
                                                )           W. Scott Jardine
Robert F. Keith*                        Trustee )           Attorney-In-Fact
                                                )           December 3, 2015
                                                )
Niel B. Nielson *                       Trustee )
                                                )


*     Original powers of attorney authorizing James A. Bowen, W. Scott Jardine,
      and Eric F. Fess to execute Registrant's Registration Statement, and
      Amendments thereto, for each of the trustees of the Registrant on whose
      behalf this Registration Statement is filed, were previously executed,
      filed as an exhibit and are incorporated by reference herein.






                               INDEX TO EXHIBITS


      (101) Risk/return summary in interactive data format

XML

Label

Element

Value

Risk Return Abstract

rr_RiskReturnAbstract

Document Type

dei_DocumentType

485BPOS

Document Period End Date

dei_DocumentPeriodEndDate

Dec. 01, 2015

Registrant Name

dei_EntityRegistrantName

First Trust Exchange-Traded AlphaDEX Fund

Central Index Key

dei_EntityCentralIndexKey

0001383496

Amendment Flag

dei_AmendmentFlag

false

Document Creation Date

dei_DocumentCreationDate

Dec. 01, 2015

Document Effective Date

dei_DocumentEffectiveDate

Dec. 01, 2015

Prospectus Date

rr_ProspectusDate

Dec. 01, 2015

First Trust Consumer Discretionary AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST CONSUMER DISCRETIONARY ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
27.90% (September 30, 2009)	-28.37% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Consumer Discretionary AlphaDEX Fund | First Trust Consumer Discretionary AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.13%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.63%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.63%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 64

3 Years

rr_ExpenseExampleNoRedemptionYear03

253

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

461

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,059

Annual Return 2008

rr_AnnualReturn2008

(42.87%)

Annual Return 2009

rr_AnnualReturn2009

57.06%

Annual Return 2010

rr_AnnualReturn2010

31.98%

Annual Return 2011

rr_AnnualReturn2011

0.98%

Annual Return 2012

rr_AnnualReturn2012

15.82%

Annual Return 2013

rr_AnnualReturn2013

42.99%

Annual Return 2014

rr_AnnualReturn2014

11.63%

1 Year

rr_AverageAnnualReturnYear01

11.63%

5 Years

rr_AverageAnnualReturnYear05

19.76%

Since Inception

rr_AverageAnnualReturnSinceInception

8.63%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Consumer Discretionary AlphaDEX Fund | After Taxes on Distributions | First Trust Consumer Discretionary AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

11.36%

5 Years

rr_AverageAnnualReturnYear05

19.45%

Since Inception

rr_AverageAnnualReturnSinceInception

8.36%

First Trust Consumer Discretionary AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Consumer Discretionary AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.57%

5 Years

rr_AverageAnnualReturnYear05

15.99%

Since Inception

rr_AverageAnnualReturnSinceInception

6.80%

First Trust Consumer Discretionary AlphaDEX Fund | StrataQuant(R) Consumer Discretionary Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

12.42%

5 Years

rr_AverageAnnualReturnYear05

20.65%

Since Inception

rr_AverageAnnualReturnSinceInception

9.46%

First Trust Consumer Discretionary AlphaDEX Fund | Russell 1000(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.24%

5 Years

rr_AverageAnnualReturnYear05

15.64%

Since Inception

rr_AverageAnnualReturnSinceInception

6.62%

First Trust Consumer Discretionary AlphaDEX Fund | Standard and Poor's 500(R) Consumer Discretionary Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

9.68%

5 Years

rr_AverageAnnualReturnYear05

21.38%

Since Inception

rr_AverageAnnualReturnSinceInception

10.10%

First Trust Consumer Discretionary AlphaDEX Fund | Russell 1000(R) Consumer Discretionary Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

9.52%

5 Years

rr_AverageAnnualReturnYear05

21.10%

Since Inception

rr_AverageAnnualReturnSinceInception

First Trust Consumer Staples AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST CONSUMER STAPLES ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
20.65% (March 31, 2013)	-17.59% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Consumer Staples AlphaDEX Fund | First Trust Consumer Staples AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.12%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.62%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.62%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 63

3 Years

rr_ExpenseExampleNoRedemptionYear03

250

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

456

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,047

Annual Return 2008

rr_AnnualReturn2008

(24.67%)

Annual Return 2009

rr_AnnualReturn2009

27.13%

Annual Return 2010

rr_AnnualReturn2010

19.81%

Annual Return 2011

rr_AnnualReturn2011

13.15%

Annual Return 2012

rr_AnnualReturn2012

9.39%

Annual Return 2013

rr_AnnualReturn2013

41.94%

Annual Return 2014

rr_AnnualReturn2014

21.05%

1 Year

rr_AverageAnnualReturnYear01

21.05%

5 Years

rr_AverageAnnualReturnYear05

20.57%

Since Inception

rr_AverageAnnualReturnSinceInception

11.76%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Consumer Staples AlphaDEX Fund | After Taxes on Distributions | First Trust Consumer Staples AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

20.35%

5 Years

rr_AverageAnnualReturnYear05

20.01%

Since Inception

rr_AverageAnnualReturnSinceInception

11.25%

First Trust Consumer Staples AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Consumer Staples AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

11.88%

5 Years

rr_AverageAnnualReturnYear05

16.53%

Since Inception

rr_AverageAnnualReturnSinceInception

9.32%

First Trust Consumer Staples AlphaDEX Fund | StrataQuant(R) Consumer Staples Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

21.90%

5 Years

rr_AverageAnnualReturnYear05

21.56%

Since Inception

rr_AverageAnnualReturnSinceInception

12.64%

First Trust Consumer Staples AlphaDEX Fund | Russell 1000(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.24%

5 Years

rr_AverageAnnualReturnYear05

15.64%

Since Inception

rr_AverageAnnualReturnSinceInception

6.62%

First Trust Consumer Staples AlphaDEX Fund | Standard and Poor's 500(R) Consumer Staples Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

15.98%

5 Years

rr_AverageAnnualReturnYear05

16.08%

Since Inception

rr_AverageAnnualReturnSinceInception

11.00%

First Trust Consumer Staples AlphaDEX Fund | Russell 1000(R) Consumer Staples Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

17.02%

5 Years

rr_AverageAnnualReturnYear05

16.73%

Since Inception

rr_AverageAnnualReturnSinceInception

First Trust Energy AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST ENERGY ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
29.92% (June 30, 2008)	-38.75% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Energy AlphaDEX Fund | First Trust Energy AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.14%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.64%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.64%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 65

3 Years

rr_ExpenseExampleNoRedemptionYear03

257

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

466

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,071

Annual Return 2008

rr_AnnualReturn2008

(50.78%)

Annual Return 2009

rr_AnnualReturn2009

47.52%

Annual Return 2010

rr_AnnualReturn2010

27.77%

Annual Return 2011

rr_AnnualReturn2011

(8.16%)

Annual Return 2012

rr_AnnualReturn2012

3.67%

Annual Return 2013

rr_AnnualReturn2013

28.66%

Annual Return 2014

rr_AnnualReturn2014

(16.01%)

1 Year

rr_AverageAnnualReturnYear01

(16.01%)

5 Years

rr_AverageAnnualReturnYear05

5.62%

Since Inception

rr_AverageAnnualReturnSinceInception

1.30%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Energy AlphaDEX Fund | After Taxes on Distributions | First Trust Energy AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(16.54%)

5 Years

rr_AverageAnnualReturnYear05

5.25%

Since Inception

rr_AverageAnnualReturnSinceInception

1.03%

First Trust Energy AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Energy AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(9.00%)

5 Years

rr_AverageAnnualReturnYear05

4.24%

Since Inception

rr_AverageAnnualReturnSinceInception

0.89%

First Trust Energy AlphaDEX Fund | StrataQuant(R) Energy Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

(15.58%)

5 Years

rr_AverageAnnualReturnYear05

6.34%

Since Inception

rr_AverageAnnualReturnSinceInception

1.99%

First Trust Energy AlphaDEX Fund | Russell 1000(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.24%

5 Years

rr_AverageAnnualReturnYear05

15.64%

Since Inception

rr_AverageAnnualReturnSinceInception

6.62%

First Trust Energy AlphaDEX Fund | Standard and Poor's 500(R) Energy Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

(7.78%)

5 Years

rr_AverageAnnualReturnYear05

8.76%

Since Inception

rr_AverageAnnualReturnSinceInception

4.29%

First Trust Energy AlphaDEX Fund | Russell 1000(R) Energy Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

(8.62%)

5 Years

rr_AverageAnnualReturnYear05

8.38%

Since Inception

rr_AverageAnnualReturnSinceInception

First Trust Financials AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST FINANCIALS ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
30.65% (June 30, 2009)	-22.64% (March 31, 2009)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Financials AlphaDEX Fund | First Trust Financials AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.14%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.64%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.64%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 65

3 Years

rr_ExpenseExampleNoRedemptionYear03

257

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

466

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,071

Annual Return 2008

rr_AnnualReturn2008

(38.24%)

Annual Return 2009

rr_AnnualReturn2009

31.65%

Annual Return 2010

rr_AnnualReturn2010

19.11%

Annual Return 2011

rr_AnnualReturn2011

(7.35%)

Annual Return 2012

rr_AnnualReturn2012

21.24%

Annual Return 2013

rr_AnnualReturn2013

40.41%

Annual Return 2014

rr_AnnualReturn2014

8.71%

1 Year

rr_AverageAnnualReturnYear01

8.71%

5 Years

rr_AverageAnnualReturnYear05

15.35%

Since Inception

rr_AverageAnnualReturnSinceInception

3.76%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Financials AlphaDEX Fund | After Taxes on Distributions | First Trust Financials AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.96%

5 Years

rr_AverageAnnualReturnYear05

14.61%

Since Inception

rr_AverageAnnualReturnSinceInception

3.10%

First Trust Financials AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Financials AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.91%

5 Years

rr_AverageAnnualReturnYear05

12.00%

Since Inception

rr_AverageAnnualReturnSinceInception

2.59%

First Trust Financials AlphaDEX Fund | StrataQuant(R) Financials Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

9.45%

5 Years

rr_AverageAnnualReturnYear05

16.26%

Since Inception

rr_AverageAnnualReturnSinceInception

4.68%

First Trust Financials AlphaDEX Fund | Russell 1000(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.24%

5 Years

rr_AverageAnnualReturnYear05

15.64%

Since Inception

rr_AverageAnnualReturnSinceInception

6.62%

First Trust Financials AlphaDEX Fund | Standard and Poor's 500(R) Financials Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

15.20%

5 Years

rr_AverageAnnualReturnYear05

13.36%

Since Inception

rr_AverageAnnualReturnSinceInception

(3.28%)

First Trust Financials AlphaDEX Fund | Russell 1000(R) Financial Services Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

14.66%

5 Years

rr_AverageAnnualReturnYear05

13.84%

Since Inception

rr_AverageAnnualReturnSinceInception

First Trust Health Care AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST HEALTH CARE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
19.11% (September 30, 2009)	-19.65% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Health Care AlphaDEX Fund | First Trust Health Care AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.12%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.62%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.62%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 63

3 Years

rr_ExpenseExampleNoRedemptionYear03

250

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

456

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,047

Annual Return 2008

rr_AnnualReturn2008

(29.32%)

Annual Return 2009

rr_AnnualReturn2009

51.23%

Annual Return 2010

rr_AnnualReturn2010

19.04%

Annual Return 2011

rr_AnnualReturn2011

5.76%

Annual Return 2012

rr_AnnualReturn2012

20.81%

Annual Return 2013

rr_AnnualReturn2013

47.46%

Annual Return 2014

rr_AnnualReturn2014

25.40%

1 Year

rr_AverageAnnualReturnYear01

25.40%

5 Years

rr_AverageAnnualReturnYear05

22.98%

Since Inception

rr_AverageAnnualReturnSinceInception

15.62%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Health Care AlphaDEX Fund | After Taxes on Distributions | First Trust Health Care AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

25.40%

5 Years

rr_AverageAnnualReturnYear05

22.92%

Since Inception

rr_AverageAnnualReturnSinceInception

15.58%

First Trust Health Care AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Health Care AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

14.37%

5 Years

rr_AverageAnnualReturnYear05

18.91%

Since Inception

rr_AverageAnnualReturnSinceInception

13.00%

First Trust Health Care AlphaDEX Fund | StrataQuant(R) Health Care Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

26.17%

5 Years

rr_AverageAnnualReturnYear05

23.86%

Since Inception

rr_AverageAnnualReturnSinceInception

16.50%

First Trust Health Care AlphaDEX Fund | Russell 1000(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.24%

5 Years

rr_AverageAnnualReturnYear05

15.64%

Since Inception

rr_AverageAnnualReturnSinceInception

6.62%

First Trust Health Care AlphaDEX Fund | Standard and Poor's 500(R) Health Care Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

25.34%

5 Years

rr_AverageAnnualReturnYear05

19.38%

Since Inception

rr_AverageAnnualReturnSinceInception

10.74%

First Trust Health Care AlphaDEX Fund | Russell 1000(R) Health Care Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

25.95%

5 Years

rr_AverageAnnualReturnYear05

20.17%

Since Inception

rr_AverageAnnualReturnSinceInception

First Trust Industrials/Producer Durables AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST INDUSTRIALS/PRODUCER DURABLES ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
24.70% (September 30, 2009)	-28.74% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Industrials/Producer Durables AlphaDEX Fund | First Trust Industrials/Producer Durables AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.13%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.63%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.63%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 64

3 Years

rr_ExpenseExampleNoRedemptionYear03

253

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

461

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,059

Annual Return 2008

rr_AnnualReturn2008

(45.90%)

Annual Return 2009

rr_AnnualReturn2009

42.14%

Annual Return 2010

rr_AnnualReturn2010

25.62%

Annual Return 2011

rr_AnnualReturn2011

(5.95%)

Annual Return 2012

rr_AnnualReturn2012

15.44%

Annual Return 2013

rr_AnnualReturn2013

46.46%

Annual Return 2014

rr_AnnualReturn2014

8.13%

1 Year

rr_AverageAnnualReturnYear01

8.13%

5 Years

rr_AverageAnnualReturnYear05

16.65%

Since Inception

rr_AverageAnnualReturnSinceInception

6.48%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Industrials/Producer Durables AlphaDEX Fund | After Taxes on Distributions | First Trust Industrials/Producer Durables AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.62%

5 Years

rr_AverageAnnualReturnYear05

16.23%

Since Inception

rr_AverageAnnualReturnSinceInception

6.15%

First Trust Industrials/Producer Durables AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Industrials/Producer Durables AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.60%

5 Years

rr_AverageAnnualReturnYear05

13.27%

Since Inception

rr_AverageAnnualReturnSinceInception

4.98%

First Trust Industrials/Producer Durables AlphaDEX Fund | StrataQuant(R) Industrials Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

8.90%

5 Years

rr_AverageAnnualReturnYear05

17.55%

Since Inception

rr_AverageAnnualReturnSinceInception

7.29%

First Trust Industrials/Producer Durables AlphaDEX Fund | Russell 1000(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.24%

5 Years

rr_AverageAnnualReturnYear05

15.64%

Since Inception

rr_AverageAnnualReturnSinceInception

6.62%

First Trust Industrials/Producer Durables AlphaDEX Fund | Standard and Poor's 500(R) Industrials Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

9.83%

5 Years

rr_AverageAnnualReturnYear05

17.56%

Since Inception

rr_AverageAnnualReturnSinceInception

7.15%

First Trust Industrials/Producer Durables AlphaDEX Fund | Russell 1000(R) Producer Durables Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

9.85%

5 Years

rr_AverageAnnualReturnYear05

17.64%

Since Inception

rr_AverageAnnualReturnSinceInception

First Trust Materials AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST MATERIALS ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
32.74% (June 30, 2009)	-28.66% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Materials AlphaDEX Fund | First Trust Materials AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.14%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.64%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.64%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 65

3 Years

rr_ExpenseExampleNoRedemptionYear03

257

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

466

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,071

Annual Return 2008

rr_AnnualReturn2008

(44.61%)

Annual Return 2009

rr_AnnualReturn2009

59.95%

Annual Return 2010

rr_AnnualReturn2010

28.15%

Annual Return 2011

rr_AnnualReturn2011

(10.11%)

Annual Return 2012

rr_AnnualReturn2012

25.11%

Annual Return 2013

rr_AnnualReturn2013

26.73%

Annual Return 2014

rr_AnnualReturn2014

(0.98%)

1 Year

rr_AverageAnnualReturnYear01

(0.98%)

5 Years

rr_AverageAnnualReturnYear05

12.58%

Since Inception

rr_AverageAnnualReturnSinceInception

7.66%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Materials AlphaDEX Fund | After Taxes on Distributions | First Trust Materials AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.69%)

5 Years

rr_AverageAnnualReturnYear05

11.93%

Since Inception

rr_AverageAnnualReturnSinceInception

7.09%

First Trust Materials AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Materials AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(0.54%)

5 Years

rr_AverageAnnualReturnYear05

9.76%

Since Inception

rr_AverageAnnualReturnSinceInception

5.85%

First Trust Materials AlphaDEX Fund | StrataQuant(R) Materials Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

(0.37%)

5 Years

rr_AverageAnnualReturnYear05

13.46%

Since Inception

rr_AverageAnnualReturnSinceInception

8.48%

First Trust Materials AlphaDEX Fund | Russell 1000(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.24%

5 Years

rr_AverageAnnualReturnYear05

15.64%

Since Inception

rr_AverageAnnualReturnSinceInception

6.62%

First Trust Materials AlphaDEX Fund | Standard and Poor's 500(R) Materials Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

6.91%

5 Years

rr_AverageAnnualReturnYear05

11.23%

Since Inception

rr_AverageAnnualReturnSinceInception

5.16%

First Trust Materials AlphaDEX Fund | Russell 1000(R) Materials and Processing Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

5.48%

5 Years

rr_AverageAnnualReturnYear05

12.44%

Since Inception

rr_AverageAnnualReturnSinceInception

First Trust Technology AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST TECHNOLOGY ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
22.85% (June 30, 2009)	-28.69% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Technology AlphaDEX Fund | First Trust Technology AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.13%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.63%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.63%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 64

3 Years

rr_ExpenseExampleNoRedemptionYear03

253

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

461

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,059

Annual Return 2008

rr_AnnualReturn2008

(48.07%)

Annual Return 2009

rr_AnnualReturn2009

66.95%

Annual Return 2010

rr_AnnualReturn2010

26.41%

Annual Return 2011

rr_AnnualReturn2011

(11.65%)

Annual Return 2012

rr_AnnualReturn2012

8.97%

Annual Return 2013

rr_AnnualReturn2013

37.73%

Annual Return 2014

rr_AnnualReturn2014

16.38%

1 Year

rr_AverageAnnualReturnYear01

16.38%

5 Years

rr_AverageAnnualReturnYear05

14.30%

Since Inception

rr_AverageAnnualReturnSinceInception

7.58%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Technology AlphaDEX Fund | After Taxes on Distributions | First Trust Technology AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

16.05%

5 Years

rr_AverageAnnualReturnYear05

14.17%

Since Inception

rr_AverageAnnualReturnSinceInception

7.50%

First Trust Technology AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Technology AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

9.26%

5 Years

rr_AverageAnnualReturnYear05

11.44%

Since Inception

rr_AverageAnnualReturnSinceInception

6.04%

First Trust Technology AlphaDEX Fund | StrataQuant(R) Technology Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

17.18%

5 Years

rr_AverageAnnualReturnYear05

15.19%

Since Inception

rr_AverageAnnualReturnSinceInception

8.49%

First Trust Technology AlphaDEX Fund | Russell 1000(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.24%

5 Years

rr_AverageAnnualReturnYear05

15.64%

Since Inception

rr_AverageAnnualReturnSinceInception

6.62%

First Trust Technology AlphaDEX Fund | Standard and Poor's 500(R) Information Technology Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

20.12%

5 Years

rr_AverageAnnualReturnYear05

14.86%

Since Inception

rr_AverageAnnualReturnSinceInception

9.45%

First Trust Technology AlphaDEX Fund | Russell 1000(R) Technology Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

20.32%

5 Years

rr_AverageAnnualReturnYear05

14.15%

Since Inception

rr_AverageAnnualReturnSinceInception

First Trust Utilities AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST UTILITIES ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
15.35% (June 30, 2009)	-14.04% (March 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Utilities AlphaDEX Fund | First Trust Utilities AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2],[3]

Other Expenses

rr_OtherExpensesOverAssets

0.16%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.66%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.66%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 67

3 Years

rr_ExpenseExampleNoRedemptionYear03

263

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

477

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,095

Annual Return 2008

rr_AnnualReturn2008

(27.43%)

Annual Return 2009

rr_AnnualReturn2009

22.54%

Annual Return 2010

rr_AnnualReturn2010

10.54%

Annual Return 2011

rr_AnnualReturn2011

10.33%

Annual Return 2012

rr_AnnualReturn2012

3.61%

Annual Return 2013

rr_AnnualReturn2013

17.51%

Annual Return 2014

rr_AnnualReturn2014

25.49%

1 Year

rr_AverageAnnualReturnYear01

25.49%

5 Years

rr_AverageAnnualReturnYear05

13.25%

Since Inception

rr_AverageAnnualReturnSinceInception

6.13%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Utilities AlphaDEX Fund | After Taxes on Distributions | First Trust Utilities AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

24.27%

5 Years

rr_AverageAnnualReturnYear05

12.01%

Since Inception

rr_AverageAnnualReturnSinceInception

4.92%

First Trust Utilities AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Utilities AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

14.38%

5 Years

rr_AverageAnnualReturnYear05

9.96%

Since Inception

rr_AverageAnnualReturnSinceInception

4.22%

First Trust Utilities AlphaDEX Fund | StrataQuant(R) Utilities Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

26.39%

5 Years

rr_AverageAnnualReturnYear05

14.26%

Since Inception

rr_AverageAnnualReturnSinceInception

7.08%

First Trust Utilities AlphaDEX Fund | Russell 1000(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.24%

5 Years

rr_AverageAnnualReturnYear05

15.64%

Since Inception

rr_AverageAnnualReturnSinceInception

6.62%

First Trust Utilities AlphaDEX Fund | Standard and Poor's 500(R) Utilities Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

28.98%

5 Years

rr_AverageAnnualReturnYear05

13.34%

Since Inception

rr_AverageAnnualReturnSinceInception

5.72%

First Trust Utilities AlphaDEX Fund | Russell 1000(R) Utilities Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

16.30%

5 Years

rr_AverageAnnualReturnYear05

12.59%

Since Inception

rr_AverageAnnualReturnSinceInception

First Trust Large Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST LARGE CAP CORE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -7.49%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
21.20% (June 30, 2009)	-23.68% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Large Cap Core AlphaDEX Fund | First Trust Large Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.11%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.61%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.61%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 62

3 Years

rr_ExpenseExampleNoRedemptionYear03

247

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

450

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,036

Annual Return 2008

rr_AnnualReturn2008

(38.35%)

Annual Return 2009

rr_AnnualReturn2009

36.11%

Annual Return 2010

rr_AnnualReturn2010

20.66%

Annual Return 2011

rr_AnnualReturn2011

(0.22%)

Annual Return 2012

rr_AnnualReturn2012

14.39%

Annual Return 2013

rr_AnnualReturn2013

35.77%

Annual Return 2014

rr_AnnualReturn2014

12.34%

1 Year

rr_AverageAnnualReturnYear01

12.34%

5 Years

rr_AverageAnnualReturnYear05

16.00%

Since Inception

rr_AverageAnnualReturnSinceInception

6.88%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Large Cap Core AlphaDEX Fund | After Taxes on Distributions | First Trust Large Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

11.69%

5 Years

rr_AverageAnnualReturnYear05

15.47%

Since Inception

rr_AverageAnnualReturnSinceInception

6.41%

First Trust Large Cap Core AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Large Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.97%

5 Years

rr_AverageAnnualReturnYear05

12.66%

Since Inception

rr_AverageAnnualReturnSinceInception

5.23%

First Trust Large Cap Core AlphaDEX Fund | Defined Large Cap Core Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.12%

5 Years

rr_AverageAnnualReturnYear05

16.85%

Since Inception

rr_AverageAnnualReturnSinceInception

7.68%

First Trust Large Cap Core AlphaDEX Fund | Standard and Poor's 500(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.69%

5 Years

rr_AverageAnnualReturnYear05

15.45%

Since Inception

rr_AverageAnnualReturnSinceInception

6.44%

First Trust Mid Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

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").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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 MidCap 400(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 300 stocks and the market capitalization range represented in the Index was $835 million to $14.634 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

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. 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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST MID CAP CORE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -8.28%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
24.50% (June 30, 2009)	-26.89% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Mid Cap Core AlphaDEX Fund | First Trust Mid Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.12%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.62%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.62%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 63

3 Years

rr_ExpenseExampleNoRedemptionYear03

250

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

456

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,047

Annual Return 2008

rr_AnnualReturn2008

(36.77%)

Annual Return 2009

rr_AnnualReturn2009

47.38%

Annual Return 2010

rr_AnnualReturn2010

27.03%

Annual Return 2011

rr_AnnualReturn2011

0.83%

Annual Return 2012

rr_AnnualReturn2012

14.23%

Annual Return 2013

rr_AnnualReturn2013

37.45%

Annual Return 2014

rr_AnnualReturn2014

5.56%

1 Year

rr_AverageAnnualReturnYear01

5.56%

5 Years

rr_AverageAnnualReturnYear05

16.25%

Since Inception

rr_AverageAnnualReturnSinceInception

8.43%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Mid Cap Core AlphaDEX Fund | After Taxes on Distributions | First Trust Mid Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.21%

5 Years

rr_AverageAnnualReturnYear05

15.94%

Since Inception

rr_AverageAnnualReturnSinceInception

8.14%

First Trust Mid Cap Core AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Mid Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.14%

5 Years

rr_AverageAnnualReturnYear05

13.00%

Since Inception

rr_AverageAnnualReturnSinceInception

6.63%

First Trust Mid Cap Core AlphaDEX Fund | Defined Mid Cap Core Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

6.28%

5 Years

rr_AverageAnnualReturnYear05

17.10%

Since Inception

rr_AverageAnnualReturnSinceInception

9.22%

First Trust Mid Cap Core AlphaDEX Fund | Standard and Poor's MidCap 400(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

9.77%

5 Years

rr_AverageAnnualReturnYear05

16.54%

Since Inception

rr_AverageAnnualReturnSinceInception

8.18%

First Trust Small Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust Small 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 Small Cap Core Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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 SmallCap 600(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 447 stocks and the market capitalization range represented in the Index was $60 million to $4.311 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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. Because the Fund invests in small capitalization companies, the Fund is more vulnerable to adverse general market or economic developments, may be less liquid, and may experience greater price volatility than larger, more established companies.

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-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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST SMALL CAP CORE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -10.22%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
29.60% (June 30, 2009)	-27.22% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Small Cap Core AlphaDEX Fund | First Trust Small Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.13%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.63%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.63%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 64

3 Years

rr_ExpenseExampleNoRedemptionYear03

253

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

461

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,059

Annual Return 2008

rr_AnnualReturn2008

(34.28%)

Annual Return 2009

rr_AnnualReturn2009

37.12%

Annual Return 2010

rr_AnnualReturn2010

26.92%

Annual Return 2011

rr_AnnualReturn2011

(0.10%)

Annual Return 2012

rr_AnnualReturn2012

15.39%

Annual Return 2013

rr_AnnualReturn2013

43.15%

Annual Return 2014

rr_AnnualReturn2014

1.31%

1 Year

rr_AverageAnnualReturnYear01

1.31%

5 Years

rr_AverageAnnualReturnYear05

16.24%

Since Inception

rr_AverageAnnualReturnSinceInception

7.14%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Small Cap Core AlphaDEX Fund | After Taxes on Distributions | First Trust Small Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

1.06%

5 Years

rr_AverageAnnualReturnYear05

15.99%

Since Inception

rr_AverageAnnualReturnSinceInception

6.94%

First Trust Small Cap Core AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Small Cap Core AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

0.74%

5 Years

rr_AverageAnnualReturnYear05

13.02%

Since Inception

rr_AverageAnnualReturnSinceInception

5.60%

First Trust Small Cap Core AlphaDEX Fund | Defined Small Cap Core Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

2.05%

5 Years

rr_AverageAnnualReturnYear05

17.11%

Since Inception

rr_AverageAnnualReturnSinceInception

8.00%

First Trust Small Cap Core AlphaDEX Fund | Standard and Poor's SmallCap 600(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

5.76%

5 Years

rr_AverageAnnualReturnYear05

17.27%

Since Inception

rr_AverageAnnualReturnSinceInception

7.75%

First Trust Large Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust Large Cap Value 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 Value Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 78% of the average value of its portfolio.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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) Value 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 204 stocks and the market capitalization range represented in the Index was $2.574 billion to $330.262 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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 a specialized securities market index. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

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

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

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST LARGE CAP VALUE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -12.41%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
31.01% (June 30, 2009)	-24.78% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Large Cap Value AlphaDEX Fund | First Trust Large Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.12%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.62%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.62%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 63

3 Years

rr_ExpenseExampleNoRedemptionYear03

250

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

456

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,047

Annual Return 2008

rr_AnnualReturn2008

(36.09%)

Annual Return 2009

rr_AnnualReturn2009

41.18%

Annual Return 2010

rr_AnnualReturn2010

18.55%

Annual Return 2011

rr_AnnualReturn2011

1.32%

Annual Return 2012

rr_AnnualReturn2012

17.25%

Annual Return 2013

rr_AnnualReturn2013

33.92%

Annual Return 2014

rr_AnnualReturn2014

10.87%

1 Year

rr_AverageAnnualReturnYear01

10.87%

5 Years

rr_AverageAnnualReturnYear05

15.90%

Since Inception

rr_AverageAnnualReturnSinceInception

6.86%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Large Cap Value AlphaDEX Fund | After Taxes on Distributions | First Trust Large Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

10.00%

5 Years

rr_AverageAnnualReturnYear05

15.19%

Since Inception

rr_AverageAnnualReturnSinceInception

6.18%

First Trust Large Cap Value AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Large Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

6.14%

5 Years

rr_AverageAnnualReturnYear05

12.48%

Since Inception

rr_AverageAnnualReturnSinceInception

5.09%

First Trust Large Cap Value AlphaDEX Fund | Defined Large Cap Value Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

11.61%

5 Years

rr_AverageAnnualReturnYear05

16.76%

Since Inception

rr_AverageAnnualReturnSinceInception

7.69%

First Trust Large Cap Value AlphaDEX Fund | Standard and Poor's 500(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.69%

5 Years

rr_AverageAnnualReturnYear05

15.45%

Since Inception

rr_AverageAnnualReturnSinceInception

6.44%

First Trust Large Cap Value AlphaDEX Fund | Standard and Poor's 500(R) Value Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

12.36%

5 Years

rr_AverageAnnualReturnYear05

14.86%

Since Inception

rr_AverageAnnualReturnSinceInception

4.45%

First Trust Large Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust Large Cap Growth 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 Growth Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 143% of the average value of its portfolio.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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) Growth 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 173 stocks and the market capitalization range represented in the Index was $5.179 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

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 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.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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 a specialized securities market index. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

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

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

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST LARGE CAP GROWTH ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -1.40%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
18.05% (September 30, 2009)	-22.58% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Large Cap Growth AlphaDEX Fund | First Trust Large Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2]

Other Expenses

rr_OtherExpensesOverAssets

0.13%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.63%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.63%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 64

3 Years

rr_ExpenseExampleNoRedemptionYear03

253

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

461

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,059

Annual Return 2008

rr_AnnualReturn2008

(41.12%)

Annual Return 2009

rr_AnnualReturn2009

29.33%

Annual Return 2010

rr_AnnualReturn2010

23.67%

Annual Return 2011

rr_AnnualReturn2011

(2.65%)

Annual Return 2012

rr_AnnualReturn2012

9.92%

Annual Return 2013

rr_AnnualReturn2013

37.71%

Annual Return 2014

rr_AnnualReturn2014

14.47%

1 Year

rr_AverageAnnualReturnYear01

14.47%

5 Years

rr_AverageAnnualReturnYear05

15.84%

Since Inception

rr_AverageAnnualReturnSinceInception

6.59%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Large Cap Growth AlphaDEX Fund | After Taxes on Distributions | First Trust Large Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

14.07%

5 Years

rr_AverageAnnualReturnYear05

15.51%

Since Inception

rr_AverageAnnualReturnSinceInception

6.33%

First Trust Large Cap Growth AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Large Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.18%

5 Years

rr_AverageAnnualReturnYear05

12.63%

Since Inception

rr_AverageAnnualReturnSinceInception

5.11%

First Trust Large Cap Growth AlphaDEX Fund | Defined Large Cap Growth Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

15.26%

5 Years

rr_AverageAnnualReturnYear05

16.71%

Since Inception

rr_AverageAnnualReturnSinceInception

7.38%

First Trust Large Cap Growth AlphaDEX Fund | Standard and Poor's 500(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.69%

5 Years

rr_AverageAnnualReturnYear05

15.45%

Since Inception

rr_AverageAnnualReturnSinceInception

6.44%

First Trust Large Cap Growth AlphaDEX Fund | Standard and Poor's 500(R) Growth Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

14.89%

5 Years

rr_AverageAnnualReturnYear05

16.05%

Since Inception

rr_AverageAnnualReturnSinceInception

8.38%

First Trust Multi Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust Multi Cap Value 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 Multi Cap Value Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 82% of the average value of its portfolio.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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 Composite 1500(R) Value 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 642 stocks and the market capitalization range represented in the Index was $60 million to $330.262 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

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.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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 a specialized securities market index. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

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

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

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST MULTI CAP VALUE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -12.91%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
33.70% (June 30, 2009)	-26.85% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Multi Cap Value AlphaDEX Fund | First Trust Multi Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

^[2],[3]

Other Expenses

rr_OtherExpensesOverAssets

0.16%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.66%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[2]

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

rr_NetExpensesOverAssets

0.66%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 67

3 Years

rr_ExpenseExampleNoRedemptionYear03

263

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

477

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,095

Annual Return 2008

rr_AnnualReturn2008

(35.41%)

Annual Return 2009

rr_AnnualReturn2009

47.57%

Annual Return 2010

rr_AnnualReturn2010

22.13%

Annual Return 2011

rr_AnnualReturn2011

0.57%

Annual Return 2012

rr_AnnualReturn2012

17.17%

Annual Return 2013

rr_AnnualReturn2013

37.00%

Annual Return 2014

rr_AnnualReturn2014

7.86%

1 Year

rr_AverageAnnualReturnYear01

7.86%

5 Years

rr_AverageAnnualReturnYear05

16.29%

Since Inception

rr_AverageAnnualReturnSinceInception

7.59%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Multi Cap Value AlphaDEX Fund | After Taxes on Distributions | First Trust Multi Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

7.20%

5 Years

rr_AverageAnnualReturnYear05

15.71%

Since Inception

rr_AverageAnnualReturnSinceInception

7.04%

First Trust Multi Cap Value AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Multi Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.44%

5 Years

rr_AverageAnnualReturnYear05

12.88%

Since Inception

rr_AverageAnnualReturnSinceInception

5.78%

First Trust Multi Cap Value AlphaDEX Fund | Defined Multi Cap Value Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

8.70%

5 Years

rr_AverageAnnualReturnYear05

17.20%

Since Inception

rr_AverageAnnualReturnSinceInception

8.46%

First Trust Multi Cap Value AlphaDEX Fund | Standard and Poor's Composite 1500(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.08%

5 Years

rr_AverageAnnualReturnYear05

15.62%

Since Inception

rr_AverageAnnualReturnSinceInception

6.63%

First Trust Multi Cap Value AlphaDEX Fund | Standard and Poor's Composite 1500(R) Value Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

12.14%

5 Years

rr_AverageAnnualReturnYear05

15.06%

Since Inception

rr_AverageAnnualReturnSinceInception

4.78%

First Trust Multi Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust Multi Cap Growth 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 Multi Cap Growth Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 135% of the average value of its portfolio.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels until November 30, 2016. 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. The example assumes that the investment advisor's agreement to waive fees and/or pay the Fund's expenses to the extent necessary to prevent the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) from exceeding 0.70% of average daily net assets per year will be terminated following November 30, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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 Composite 1500(R) Growth 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 478 stocks and the market capitalization range represent in the Index was $189 million 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

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.

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 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.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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 a specialized securities market index. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

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

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

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST MULTI CAP GROWTH ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -2.47%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
19.09% (September 30, 2009)	-23.61% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Multi Cap Growth AlphaDEX Fund | First Trust Multi Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Fees Previously Waived or Expenses Reimbursed by First Trust

rr_Component1OtherExpensesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.22%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.72%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.02%)

^[2]

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

rr_NetExpensesOverAssets

0.70%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 72

3 Years

rr_ExpenseExampleNoRedemptionYear03

280

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

508

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,163

Annual Return 2008

rr_AnnualReturn2008

(38.98%)

Annual Return 2009

rr_AnnualReturn2009

29.69%

Annual Return 2010

rr_AnnualReturn2010

26.12%

Annual Return 2011

rr_AnnualReturn2011

(0.59%)

Annual Return 2012

rr_AnnualReturn2012

10.52%

Annual Return 2013

rr_AnnualReturn2013

38.40%

Annual Return 2014

rr_AnnualReturn2014

8.29%

1 Year

rr_AverageAnnualReturnYear01

8.29%

5 Years

rr_AverageAnnualReturnYear05

15.74%

Since Inception

rr_AverageAnnualReturnSinceInception

6.91%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Multi Cap Growth AlphaDEX Fund | After Taxes on Distributions | First Trust Multi Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.07%

5 Years

rr_AverageAnnualReturnYear05

15.54%

Since Inception

rr_AverageAnnualReturnSinceInception

6.77%

First Trust Multi Cap Growth AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Multi Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.69%

5 Years

rr_AverageAnnualReturnYear05

12.62%

Since Inception

rr_AverageAnnualReturnSinceInception

5.44%

First Trust Multi Cap Growth AlphaDEX Fund | Defined Multi Cap Growth Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

9.14%

5 Years

rr_AverageAnnualReturnYear05

16.65%

Since Inception

rr_AverageAnnualReturnSinceInception

7.74%

First Trust Multi Cap Growth AlphaDEX Fund | Standard and Poor's Composite 1500(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.08%

5 Years

rr_AverageAnnualReturnYear05

15.62%

Since Inception

rr_AverageAnnualReturnSinceInception

6.63%

First Trust Multi Cap Growth AlphaDEX Fund | Standard and Poor's Composite 1500(R) Growth Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

13.94%

5 Years

rr_AverageAnnualReturnYear05

16.19%

Since Inception

rr_AverageAnnualReturnSinceInception

8.46%

First Trust Mid Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust Mid Cap Value 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 Value Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 88% of the average value of its portfolio.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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 MidCap 400(R) Value 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 183 stocks and the market capitalization range represented in the Index was $835 million to $9.1 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

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.

SMALLER COMPANIES RISK. 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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year return 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST MID CAP VALUE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -11.60%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
14.59% (March 31, 2013)	-7.12% (September 30, 2014)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Mid Cap Value AlphaDEX Fund | First Trust Mid Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.70%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Other Expenses

rr_OtherExpensesOverAssets

none

^[4]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.70%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 72

3 Years

rr_ExpenseExampleNoRedemptionYear03

276

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

499

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,141

Annual Return 2012

rr_AnnualReturn2012

17.38%

Annual Return 2013

rr_AnnualReturn2013

37.85%

Annual Return 2014

rr_AnnualReturn2014

5.57%

1 Year

rr_AverageAnnualReturnYear01

5.57%

Since Inception

rr_AverageAnnualReturnSinceInception

13.47%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 19, 2011

First Trust Mid Cap Value AlphaDEX Fund | After Taxes on Distributions | First Trust Mid Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.07%

Since Inception

rr_AverageAnnualReturnSinceInception

13.04%

First Trust Mid Cap Value AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Mid Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.15%

Since Inception

rr_AverageAnnualReturnSinceInception

10.43%

First Trust Mid Cap Value AlphaDEX Fund | Defined Mid Cap Value Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

6.32%

Since Inception

rr_AverageAnnualReturnSinceInception

14.32%

First Trust Mid Cap Value AlphaDEX Fund | Standard and Poor's MidCap 400(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

12.10%

Since Inception

rr_AverageAnnualReturnSinceInception

14.12%

First Trust Mid Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust Mid Cap Growth 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 Growth Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 159% of the average value of its portfolio.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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 MidCap 400(R) Growth 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 115 stocks and the market capitalization range represented in the Index was $1.845 billion to $14.634 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

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 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.

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. 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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year return 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST MID CAP GROWTH ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -4.02%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
13.55% (March 31, 2013)	-6.22% (June 30, 2012)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Mid Cap Growth AlphaDEX Fund | First Trust Mid Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.70%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Other Expenses

rr_OtherExpensesOverAssets

none

^[4]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.70%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 72

3 Years

rr_ExpenseExampleNoRedemptionYear03

276

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

499

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,141

Annual Return 2012

rr_AnnualReturn2012

9.90%

Annual Return 2013

rr_AnnualReturn2013

36.64%

Annual Return 2014

rr_AnnualReturn2014

4.98%

1 Year

rr_AverageAnnualReturnYear01

4.98%

Since Inception

rr_AverageAnnualReturnSinceInception

11.01%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 19, 2011

First Trust Mid Cap Growth AlphaDEX Fund | After Taxes on Distributions | First Trust Mid Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

4.88%

Since Inception

rr_AverageAnnualReturnSinceInception

10.87%

First Trust Mid Cap Growth AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Mid Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.82%

Since Inception

rr_AverageAnnualReturnSinceInception

8.59%

First Trust Mid Cap Growth AlphaDEX Fund | Defined Mid Cap Growth Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

5.78%

Since Inception

rr_AverageAnnualReturnSinceInception

11.85%

First Trust Mid Cap Growth AlphaDEX Fund | Standard and Poor's MidCap 400(R) Growth Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

7.57%

Since Inception

rr_AverageAnnualReturnSinceInception

12.23%

First Trust Small Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust Small Cap Value 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 Small Cap Value Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 96% of the average value of its portfolio.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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 SmallCap 600(R) Value 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 255 stocks and the market capitalization range represented in the Index was $60 million to $3.268 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

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. Because the Fund invests in small capitalization companies, the Fund is more vulnerable to adverse general market or economic developments, may be less liquid, and may experience greater price volatility than larger, more established companies.

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-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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST SMALL CAP VALUE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -15.96%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
12.14% (March 31, 2012)	-9.38% (September 30, 2014)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Small Cap Value AlphaDEX Fund | First Trust Small Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.70%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Other Expenses

rr_OtherExpensesOverAssets

none

^[4]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.70%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 72

3 Years

rr_ExpenseExampleNoRedemptionYear03

276

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

499

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,141

Annual Return 2012

rr_AnnualReturn2012

16.63%

Annual Return 2013

rr_AnnualReturn2013

43.49%

Annual Return 2014

rr_AnnualReturn2014

3.76%

1 Year

rr_AverageAnnualReturnYear01

3.76%

Since Inception

rr_AverageAnnualReturnSinceInception

15.23%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 19, 2011

First Trust Small Cap Value AlphaDEX Fund | After Taxes on Distributions | First Trust Small Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

3.36%

Since Inception

rr_AverageAnnualReturnSinceInception

14.88%

First Trust Small Cap Value AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Small Cap Value AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

2.12%

Since Inception

rr_AverageAnnualReturnSinceInception

11.91%

First Trust Small Cap Value AlphaDEX Fund | Defined Small Cap Value Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

4.64%

Since Inception

rr_AverageAnnualReturnSinceInception

16.20%

First Trust Small Cap Value AlphaDEX Fund | Standard and Poor's SmallCap 600(R) Growth Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

7.54%

Since Inception

rr_AverageAnnualReturnSinceInception

15.50%

First Trust Small Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

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INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

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The First Trust Small Cap Growth 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 Small Cap Growth Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

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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.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 153% of the average value of its portfolio.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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 SmallCap 600(R) Growth 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 190 stocks and the market capitalization range represented in the Index was $189 million to $4.311 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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 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. Because the Fund invests in small capitalization companies, the Fund is more vulnerable to adverse general market or economic developments, may be less liquid, and may experience greater price volatility than larger, more established companies.

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-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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST SMALL CAP GROWTH ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -2.71%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
12.73% (September 30, 2013)	-8.17% (September 30, 2014)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Small Cap Growth AlphaDEX Fund | First Trust Small Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.70%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Other Expenses

rr_OtherExpensesOverAssets

none

^[4]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.70%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 72

3 Years

rr_ExpenseExampleNoRedemptionYear03

276

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

499

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,141

Annual Return 2012

rr_AnnualReturn2012

13.07%

Annual Return 2013

rr_AnnualReturn2013

42.93%

Annual Return 2014

rr_AnnualReturn2014

(1.65%)

1 Year

rr_AverageAnnualReturnYear01

(1.65%)

Since Inception

rr_AverageAnnualReturnSinceInception

11.61%

Inception Date

rr_AverageAnnualReturnInceptionDate

Apr. 19, 2011

First Trust Small Cap Growth AlphaDEX Fund | After Taxes on Distributions | First Trust Small Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.66%)

Since Inception

rr_AverageAnnualReturnSinceInception

11.56%

First Trust Small Cap Growth AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Small Cap Growth AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(0.93%)

Since Inception

rr_AverageAnnualReturnSinceInception

9.12%

First Trust Small Cap Growth AlphaDEX Fund | Defined Small Cap Growth Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

(0.77%)

Since Inception

rr_AverageAnnualReturnSinceInception

12.50%

First Trust Small Cap Growth AlphaDEX Fund | Standard and Poor's SmallCap 600(R) Growth Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

3.87%

Since Inception

rr_AverageAnnualReturnSinceInception

14.23%

First Trust Mega Cap AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

SUMMARY INFORMATION

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust Mega Cap 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 Mega Cap Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

FEES AND EXPENSES OF THE FUND

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the Fund. Investors purchasing and selling shares may be subject to costs (including customary brokerage commissions) charged by their broker, which are not reflected in the table below.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

SHAREHOLDER FEES (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 134% of the average value of its portfolio.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example, No Redemption Narrative [Text Block]

rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels. 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:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Strategy Narrative [Text Block]

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 BMI US 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. The securities of companies represented in the Index have market capitalizations that are consistent with the name of the Index. As of July 31, 2015, the Index was comprised of 50 stocks and the market capitalization range represented in the index was approximately $31.626 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.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. There can be no assurance that the Fund's investment objective will be achieved.

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.

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 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.

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.

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.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

ANNUAL TOTAL RETURN

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The bar chart and table below illustrate the annual calendar year return 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.

Bar Chart [Heading]

rr_BarChartHeading

FIRST TRUST MEGA CAP ALPHADEX(R) FUND--TOTAL RETURNS^[1]

Bar Chart Footnotes [Text Block]

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 -6.53%.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
10.74% (March 31, 2012)	-8.54% (June 30, 2012)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Performance Table Heading

rr_PerformanceTableHeading

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

First Trust Mega Cap AlphaDEX Fund | First Trust Mega Cap AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.70%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

^[1]

Other Expenses

rr_OtherExpensesOverAssets

none

^[4]

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.70%

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 72

3 Years

rr_ExpenseExampleNoRedemptionYear03

276

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

499

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,141

Annual Return 2012

rr_AnnualReturn2012

8.32%

Annual Return 2013

rr_AnnualReturn2013

31.92%

Annual Return 2014

rr_AnnualReturn2014

8.97%

1 Year

rr_AverageAnnualReturnYear01

8.97%

Since Inception

rr_AverageAnnualReturnSinceInception

10.19%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 11, 2011

First Trust Mega Cap AlphaDEX Fund | After Taxes on Distributions | First Trust Mega Cap AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

8.35%

Since Inception

rr_AverageAnnualReturnSinceInception

9.67%

First Trust Mega Cap AlphaDEX Fund | After Taxes on Distributions and Sales | First Trust Mega Cap AlphaDEX Fund

Risk Return Abstract

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

5.07%

Since Inception

rr_AverageAnnualReturnSinceInception

7.73%

First Trust Mega Cap AlphaDEX Fund | Defined Mega Cap Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

9.83%

Since Inception

rr_AverageAnnualReturnSinceInception

11.08%

First Trust Mega Cap AlphaDEX Fund | Standard and Poor's 100(R) Index

Risk Return Abstract

rr_RiskReturnAbstract

Label

rr_AverageAnnualReturnLabel

(reflects no deduction for fees, expenses or taxes)

1 Year

rr_AverageAnnualReturnYear01

12.74%

Since Inception

rr_AverageAnnualReturnSinceInception

14.88%

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[3] Expenses have been restated to reflect the current fiscal year.

[4] Pursuant to the Investment Management Agreement, First Trust will manage the investment of the Fund's assets and will be responsible for the Fund's expenses, including the cost of transfer agency, custody, fund administration, legal, audit, license and other services, but excluding fee payments under the Investment Management Agreement, interest, taxes, brokerage commissions and other expenses connected with the execution of portfolio transactions, distribution and service fees, pursuant to a 12b-1 plan, if any, and extraordinary expenses.

XML

First Trust Consumer Discretionary AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Consumer Discretionary AlphaDEX Fund First Trust Consumer Discretionary AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Consumer Discretionary AlphaDEX Fund First Trust Consumer Discretionary AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.13%
Total Annual Fund Operating Expenses	0.63%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.63%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Consumer Discretionary AlphaDEX Fund | First Trust Consumer Discretionary AlphaDEX Fund | USD ($)	64	253	461	1,059

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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.

PRINCIPAL RISKS

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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST CONSUMER DISCRETIONARY ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[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%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
27.90% (September 30, 2009)	-28.37% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Consumer Discretionary AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Consumer Discretionary AlphaDEX Fund

11.63%

19.76%

8.63%

May 08, 2007

First Trust Consumer Discretionary AlphaDEX Fund | After Taxes on Distributions

11.36%

19.45%

8.36%

First Trust Consumer Discretionary AlphaDEX Fund | After Taxes on Distributions and Sales

6.57%

15.99%

6.80%

StrataQuant(R) Consumer Discretionary Index

(reflects no deduction for fees, expenses or taxes)

12.42%

20.65%

9.46%

Russell 1000(R) Index

(reflects no deduction for fees, expenses or taxes)

13.24%

15.64%

6.62%

Standard and Poor's 500(R) Consumer Discretionary Index

(reflects no deduction for fees, expenses or taxes)

9.68%

21.38%

10.10%

Russell 1000(R) Consumer Discretionary Index

(reflects no deduction for fees, expenses or taxes)

9.52%

21.10%

First Trust Consumer Staples AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Consumer Staples AlphaDEX Fund First Trust Consumer Staples AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Consumer Staples AlphaDEX Fund First Trust Consumer Staples AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.12%
Total Annual Fund Operating Expenses	0.62%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.62%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Consumer Staples AlphaDEX Fund | First Trust Consumer Staples AlphaDEX Fund | USD ($)	63	250	456	1,047

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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.

PRINCIPAL RISKS

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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST CONSUMER STAPLES ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[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%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
20.65% (March 31, 2013)	-17.59% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Consumer Staples AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Consumer Staples AlphaDEX Fund

21.05%

20.57%

11.76%

May 08, 2007

First Trust Consumer Staples AlphaDEX Fund | After Taxes on Distributions

20.35%

20.01%

11.25%

First Trust Consumer Staples AlphaDEX Fund | After Taxes on Distributions and Sales

11.88%

16.53%

9.32%

StrataQuant(R) Consumer Staples Index

(reflects no deduction for fees, expenses or taxes)

21.90%

21.56%

12.64%

Russell 1000(R) Index

(reflects no deduction for fees, expenses or taxes)

13.24%

15.64%

6.62%

Standard and Poor's 500(R) Consumer Staples Index

(reflects no deduction for fees, expenses or taxes)

15.98%

16.08%

11.00%

Russell 1000(R) Consumer Staples Index

(reflects no deduction for fees, expenses or taxes)

17.02%

16.73%

First Trust Energy AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Energy AlphaDEX Fund First Trust Energy AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Energy AlphaDEX Fund First Trust Energy AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.14%
Total Annual Fund Operating Expenses	0.64%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.64%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Energy AlphaDEX Fund | First Trust Energy AlphaDEX Fund | USD ($)	65	257	466	1,071

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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.

PRINCIPAL RISKS

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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST ENERGY ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[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%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
29.92% (June 30, 2008)	-38.75% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Energy AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Energy AlphaDEX Fund

(16.01%)

5.62%

1.30%

May 08, 2007

First Trust Energy AlphaDEX Fund | After Taxes on Distributions

(16.54%)

5.25%

1.03%

First Trust Energy AlphaDEX Fund | After Taxes on Distributions and Sales

(9.00%)

4.24%

0.89%

StrataQuant(R) Energy Index

(reflects no deduction for fees, expenses or taxes)

(15.58%)

6.34%

1.99%

Russell 1000(R) Index

(reflects no deduction for fees, expenses or taxes)

13.24%

15.64%

6.62%

Standard and Poor's 500(R) Energy Index

(reflects no deduction for fees, expenses or taxes)

(7.78%)

8.76%

4.29%

Russell 1000(R) Energy Index

(reflects no deduction for fees, expenses or taxes)

(8.62%)

8.38%

First Trust Financials AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Financials AlphaDEX Fund First Trust Financials AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Financials AlphaDEX Fund First Trust Financials AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.14%
Total Annual Fund Operating Expenses	0.64%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.64%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Financials AlphaDEX Fund | First Trust Financials AlphaDEX Fund | USD ($)	65	257	466	1,071

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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.

PRINCIPAL RISKS

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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST FINANCIALS ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[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%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
30.65% (June 30, 2009)	-22.64% (March 31, 2009)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Financials AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Financials AlphaDEX Fund

8.71%

15.35%

3.76%

May 08, 2007

First Trust Financials AlphaDEX Fund | After Taxes on Distributions

7.96%

14.61%

3.10%

First Trust Financials AlphaDEX Fund | After Taxes on Distributions and Sales

4.91%

12.00%

2.59%

StrataQuant(R) Financials Index

(reflects no deduction for fees, expenses or taxes)

9.45%

16.26%

4.68%

Russell 1000(R) Index

(reflects no deduction for fees, expenses or taxes)

13.24%

15.64%

6.62%

Standard and Poor's 500(R) Financials Index

(reflects no deduction for fees, expenses or taxes)

15.20%

13.36%

(3.28%)

Russell 1000(R) Financial Services Index

(reflects no deduction for fees, expenses or taxes)

14.66%

13.84%

First Trust Health Care AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Health Care AlphaDEX Fund First Trust Health Care AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Health Care AlphaDEX Fund First Trust Health Care AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.12%
Total Annual Fund Operating Expenses	0.62%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.62%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Health Care AlphaDEX Fund | First Trust Health Care AlphaDEX Fund | USD ($)	63	250	456	1,047

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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.

PRINCIPAL RISKS

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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST HEALTH CARE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[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%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
19.11% (September 30, 2009)	-19.65% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Health Care AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Health Care AlphaDEX Fund

25.40%

22.98%

15.62%

May 08, 2007

First Trust Health Care AlphaDEX Fund | After Taxes on Distributions

25.40%

22.92%

15.58%

First Trust Health Care AlphaDEX Fund | After Taxes on Distributions and Sales

14.37%

18.91%

13.00%

StrataQuant(R) Health Care Index

(reflects no deduction for fees, expenses or taxes)

26.17%

23.86%

16.50%

Russell 1000(R) Index

(reflects no deduction for fees, expenses or taxes)

13.24%

15.64%

6.62%

Standard and Poor's 500(R) Health Care Index

(reflects no deduction for fees, expenses or taxes)

25.34%

19.38%

10.74%

Russell 1000(R) Health Care Index

(reflects no deduction for fees, expenses or taxes)

25.95%

20.17%

First Trust Industrials/Producer Durables AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Industrials/Producer Durables AlphaDEX Fund First Trust Industrials/Producer Durables AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Industrials/Producer Durables AlphaDEX Fund First Trust Industrials/Producer Durables AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.13%
Total Annual Fund Operating Expenses	0.63%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.63%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Industrials/Producer Durables AlphaDEX Fund | First Trust Industrials/Producer Durables AlphaDEX Fund | USD ($)	64	253	461	1,059

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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.

PRINCIPAL RISKS

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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST INDUSTRIALS/PRODUCER DURABLES ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[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%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
24.70% (September 30, 2009)	-28.74% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Industrials/Producer Durables AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Industrials/Producer Durables AlphaDEX Fund

8.13%

16.65%

6.48%

May 08, 2007

First Trust Industrials/Producer Durables AlphaDEX Fund | After Taxes on Distributions

7.62%

16.23%

6.15%

First Trust Industrials/Producer Durables AlphaDEX Fund | After Taxes on Distributions and Sales

4.60%

13.27%

4.98%

StrataQuant(R) Industrials Index

(reflects no deduction for fees, expenses or taxes)

8.90%

17.55%

7.29%

Russell 1000(R) Index

(reflects no deduction for fees, expenses or taxes)

13.24%

15.64%

6.62%

Standard and Poor's 500(R) Industrials Index

(reflects no deduction for fees, expenses or taxes)

9.83%

17.56%

7.15%

Russell 1000(R) Producer Durables Index

(reflects no deduction for fees, expenses or taxes)

9.85%

17.64%

First Trust Materials AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Materials AlphaDEX Fund First Trust Materials AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Materials AlphaDEX Fund First Trust Materials AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.14%
Total Annual Fund Operating Expenses	0.64%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.64%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Materials AlphaDEX Fund | First Trust Materials AlphaDEX Fund | USD ($)	65	257	466	1,071

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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.

PRINCIPAL RISKS

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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST MATERIALS ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[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%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
32.74% (June 30, 2009)	-28.66% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Materials AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Materials AlphaDEX Fund

(0.98%)

12.58%

7.66%

May 08, 2007

First Trust Materials AlphaDEX Fund | After Taxes on Distributions

(1.69%)

11.93%

7.09%

First Trust Materials AlphaDEX Fund | After Taxes on Distributions and Sales

(0.54%)

9.76%

5.85%

StrataQuant(R) Materials Index

(reflects no deduction for fees, expenses or taxes)

(0.37%)

13.46%

8.48%

Russell 1000(R) Index

(reflects no deduction for fees, expenses or taxes)

13.24%

15.64%

6.62%

Standard and Poor's 500(R) Materials Index

(reflects no deduction for fees, expenses or taxes)

6.91%

11.23%

5.16%

Russell 1000(R) Materials and Processing Index

(reflects no deduction for fees, expenses or taxes)

5.48%

12.44%

First Trust Technology AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Technology AlphaDEX Fund First Trust Technology AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Technology AlphaDEX Fund First Trust Technology AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.13%
Total Annual Fund Operating Expenses	0.63%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.63%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Technology AlphaDEX Fund | First Trust Technology AlphaDEX Fund | USD ($)	64	253	461	1,059

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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.

PRINCIPAL RISKS

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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST TECHNOLOGY ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[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%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
22.85% (June 30, 2009)	-28.69% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Technology AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Technology AlphaDEX Fund

16.38%

14.30%

7.58%

May 08, 2007

First Trust Technology AlphaDEX Fund | After Taxes on Distributions

16.05%

14.17%

7.50%

First Trust Technology AlphaDEX Fund | After Taxes on Distributions and Sales

9.26%

11.44%

6.04%

StrataQuant(R) Technology Index

(reflects no deduction for fees, expenses or taxes)

17.18%

15.19%

8.49%

Russell 1000(R) Index

(reflects no deduction for fees, expenses or taxes)

13.24%

15.64%

6.62%

Standard and Poor's 500(R) Information Technology Index

(reflects no deduction for fees, expenses or taxes)

20.12%

14.86%

9.45%

Russell 1000(R) Technology Index

(reflects no deduction for fees, expenses or taxes)

20.32%

14.15%

First Trust Utilities AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Utilities AlphaDEX Fund First Trust Utilities AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Utilities AlphaDEX Fund First Trust Utilities AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2],[3]
Other Expenses	0.16%
Total Annual Fund Operating Expenses	0.66%
Fee Waiver and Expense Reimbursement	none	[3]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.66%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Utilities AlphaDEX Fund | First Trust Utilities AlphaDEX Fund | USD ($)	67	263	477	1,095

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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.

PRINCIPAL RISKS

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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST UTILITIES ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[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%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
15.35% (June 30, 2009)	-14.04% (March 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Utilities AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Utilities AlphaDEX Fund

25.49%

13.25%

6.13%

May 08, 2007

First Trust Utilities AlphaDEX Fund | After Taxes on Distributions

24.27%

12.01%

4.92%

First Trust Utilities AlphaDEX Fund | After Taxes on Distributions and Sales

14.38%

9.96%

4.22%

StrataQuant(R) Utilities Index

(reflects no deduction for fees, expenses or taxes)

26.39%

14.26%

7.08%

Russell 1000(R) Index

(reflects no deduction for fees, expenses or taxes)

13.24%

15.64%

6.62%

Standard and Poor's 500(R) Utilities Index

(reflects no deduction for fees, expenses or taxes)

28.98%

13.34%

5.72%

Russell 1000(R) Utilities Index

(reflects no deduction for fees, expenses or taxes)

16.30%

12.59%

First Trust Large Cap Core AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Large Cap Core AlphaDEX Fund First Trust Large Cap Core AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Large Cap Core AlphaDEX Fund First Trust Large Cap Core AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.11%
Total Annual Fund Operating Expenses	0.61%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.61%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Large Cap Core AlphaDEX Fund | First Trust Large Cap Core AlphaDEX Fund | USD ($)	62	247	450	1,036

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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.

PRINCIPAL RISKS

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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST LARGE CAP CORE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[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%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
21.20% (June 30, 2009)	-23.68% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Large Cap Core AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Large Cap Core AlphaDEX Fund

12.34%

16.00%

6.88%

May 08, 2007

First Trust Large Cap Core AlphaDEX Fund | After Taxes on Distributions

11.69%

15.47%

6.41%

First Trust Large Cap Core AlphaDEX Fund | After Taxes on Distributions and Sales

6.97%

12.66%

5.23%

Defined Large Cap Core Index

(reflects no deduction for fees, expenses or taxes)

13.12%

16.85%

7.68%

Standard and Poor's 500(R) Index

(reflects no deduction for fees, expenses or taxes)

13.69%

15.45%

6.44%

First Trust Mid Cap Core AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

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").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Mid Cap Core AlphaDEX Fund First Trust Mid Cap Core AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Mid Cap Core AlphaDEX Fund First Trust Mid Cap Core AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.12%
Total Annual Fund Operating Expenses	0.62%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.62%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Mid Cap Core AlphaDEX Fund | First Trust Mid Cap Core AlphaDEX Fund | USD ($)	63	250	456	1,047

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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 MidCap 400(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 300 stocks and the market capitalization range represented in the Index was $835 million to $14.634 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.

PRINCIPAL RISKS

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 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.

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. 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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST MID CAP CORE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -8.28%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
24.50% (June 30, 2009)	-26.89% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Mid Cap Core AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Mid Cap Core AlphaDEX Fund

5.56%

16.25%

8.43%

May 08, 2007

First Trust Mid Cap Core AlphaDEX Fund | After Taxes on Distributions

5.21%

15.94%

8.14%

First Trust Mid Cap Core AlphaDEX Fund | After Taxes on Distributions and Sales

3.14%

13.00%

6.63%

Defined Mid Cap Core Index

(reflects no deduction for fees, expenses or taxes)

6.28%

17.10%

9.22%

Standard and Poor's MidCap 400(R) Index

(reflects no deduction for fees, expenses or taxes)

9.77%

16.54%

8.18%

First Trust Small Cap Core AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

The First Trust Small 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 Small Cap Core Index (the "Index").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Small Cap Core AlphaDEX Fund First Trust Small Cap Core AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Small Cap Core AlphaDEX Fund First Trust Small Cap Core AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.13%
Total Annual Fund Operating Expenses	0.63%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.63%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Small Cap Core AlphaDEX Fund | First Trust Small Cap Core AlphaDEX Fund | USD ($)	64	253	461	1,059

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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.

PRINCIPAL INVESTMENT STRATEGIES

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 SmallCap 600(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 447 stocks and the market capitalization range represented in the Index was $60 million to $4.311 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.

PRINCIPAL RISKS

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 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. Because the Fund invests in small capitalization companies, the Fund is more vulnerable to adverse general market or economic developments, may be less liquid, and may experience greater price volatility than larger, more established companies.

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-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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST SMALL CAP CORE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -10.22%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
29.60% (June 30, 2009)	-27.22% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Small Cap Core AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Small Cap Core AlphaDEX Fund

1.31%

16.24%

7.14%

May 08, 2007

First Trust Small Cap Core AlphaDEX Fund | After Taxes on Distributions

1.06%

15.99%

6.94%

First Trust Small Cap Core AlphaDEX Fund | After Taxes on Distributions and Sales

0.74%

13.02%

5.60%

Defined Small Cap Core Index

(reflects no deduction for fees, expenses or taxes)

2.05%

17.11%

8.00%

Standard and Poor's SmallCap 600(R) Index

(reflects no deduction for fees, expenses or taxes)

5.76%

17.27%

7.75%

First Trust Large Cap Value AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

The First Trust Large Cap Value 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 Value Index (the "Index").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Large Cap Value AlphaDEX Fund First Trust Large Cap Value AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Large Cap Value AlphaDEX Fund First Trust Large Cap Value AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.12%
Total Annual Fund Operating Expenses	0.62%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.62%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Large Cap Value AlphaDEX Fund | First Trust Large Cap Value AlphaDEX Fund | USD ($)	63	250	456	1,047

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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 78% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

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) Value 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 204 stocks and the market capitalization range represented in the Index was $2.574 billion to $330.262 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.

PRINCIPAL RISKS

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.

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.

ANNUAL TOTAL RETURN

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 a specialized securities market index. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

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

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

FIRST TRUST LARGE CAP VALUE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -12.41%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
31.01% (June 30, 2009)	-24.78% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Large Cap Value AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Large Cap Value AlphaDEX Fund

10.87%

15.90%

6.86%

May 08, 2007

First Trust Large Cap Value AlphaDEX Fund | After Taxes on Distributions

10.00%

15.19%

6.18%

First Trust Large Cap Value AlphaDEX Fund | After Taxes on Distributions and Sales

6.14%

12.48%

5.09%

Defined Large Cap Value Index

(reflects no deduction for fees, expenses or taxes)

11.61%

16.76%

7.69%

Standard and Poor's 500(R) Index

(reflects no deduction for fees, expenses or taxes)

13.69%

15.45%

6.44%

Standard and Poor's 500(R) Value Index

(reflects no deduction for fees, expenses or taxes)

12.36%

14.86%

4.45%

First Trust Large Cap Growth AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

The First Trust Large Cap Growth 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 Growth Index (the "Index").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Large Cap Growth AlphaDEX Fund First Trust Large Cap Growth AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Large Cap Growth AlphaDEX Fund First Trust Large Cap Growth AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2]
Other Expenses	0.13%
Total Annual Fund Operating Expenses	0.63%
Fee Waiver and Expense Reimbursement	none	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.63%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Large Cap Growth AlphaDEX Fund | First Trust Large Cap Growth AlphaDEX Fund | USD ($)	64	253	461	1,059

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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 143% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

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) Growth 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 173 stocks and the market capitalization range represented in the Index was $5.179 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.

PRINCIPAL RISKS

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.

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 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.

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.

ANNUAL TOTAL RETURN

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 a specialized securities market index. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

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

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

FIRST TRUST LARGE CAP GROWTH ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -1.40%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
18.05% (September 30, 2009)	-22.58% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Large Cap Growth AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Large Cap Growth AlphaDEX Fund

14.47%

15.84%

6.59%

May 08, 2007

First Trust Large Cap Growth AlphaDEX Fund | After Taxes on Distributions

14.07%

15.51%

6.33%

First Trust Large Cap Growth AlphaDEX Fund | After Taxes on Distributions and Sales

8.18%

12.63%

5.11%

Defined Large Cap Growth Index

(reflects no deduction for fees, expenses or taxes)

15.26%

16.71%

7.38%

Standard and Poor's 500(R) Index

(reflects no deduction for fees, expenses or taxes)

13.69%

15.45%

6.44%

Standard and Poor's 500(R) Growth Index

(reflects no deduction for fees, expenses or taxes)

14.89%

16.05%

8.38%

First Trust Multi Cap Value AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

The First Trust Multi Cap Value 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 Multi Cap Value Index (the "Index").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Multi Cap Value AlphaDEX Fund First Trust Multi Cap Value AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Multi Cap Value AlphaDEX Fund First Trust Multi Cap Value AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none	[2],[3]
Other Expenses	0.16%
Total Annual Fund Operating Expenses	0.66%
Fee Waiver and Expense Reimbursement	none	[3]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.66%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Multi Cap Value AlphaDEX Fund | First Trust Multi Cap Value AlphaDEX Fund | USD ($)	67	263	477	1,095

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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 82% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

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 Composite 1500(R) Value 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 642 stocks and the market capitalization range represented in the Index was $60 million to $330.262 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.

PRINCIPAL RISKS

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.

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.

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.

ANNUAL TOTAL RETURN

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 a specialized securities market index. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

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

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

FIRST TRUST MULTI CAP VALUE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -12.91%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
33.70% (June 30, 2009)	-26.85% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Multi Cap Value AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Multi Cap Value AlphaDEX Fund

7.86%

16.29%

7.59%

May 08, 2007

First Trust Multi Cap Value AlphaDEX Fund | After Taxes on Distributions

7.20%

15.71%

7.04%

First Trust Multi Cap Value AlphaDEX Fund | After Taxes on Distributions and Sales

4.44%

12.88%

5.78%

Defined Multi Cap Value Index

(reflects no deduction for fees, expenses or taxes)

8.70%

17.20%

8.46%

Standard and Poor's Composite 1500(R) Index

(reflects no deduction for fees, expenses or taxes)

13.08%

15.62%

6.63%

Standard and Poor's Composite 1500(R) Value Index

(reflects no deduction for fees, expenses or taxes)

12.14%

15.06%

4.78%

First Trust Multi Cap Growth AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

The First Trust Multi Cap Growth 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 Multi Cap Growth Index (the "Index").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Multi Cap Growth AlphaDEX Fund First Trust Multi Cap Growth AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Multi Cap Growth AlphaDEX Fund First Trust Multi Cap Growth AlphaDEX Fund
Management Fees	0.50%
Distribution and Service (12b-1) Fees	none	[1]
Fees Previously Waived or Expenses Reimbursed by First Trust	none
Other Expenses	0.22%
Total Annual Fund Operating Expenses	0.72%
Fee Waiver and Expense Reimbursement	0.02%	[2]
Total Net Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	0.70%

EXAMPLE

The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. This example does not take into account customary brokerage commissions that you pay when purchasing or selling shares of the Fund in the secondary market.

The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain at current levels until November 30, 2016. 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. The example assumes that the investment advisor's agreement to waive fees and/or pay the Fund's expenses to the extent necessary to prevent the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) from exceeding 0.70% of average daily net assets per year will be terminated following November 30, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Multi Cap Growth AlphaDEX Fund | First Trust Multi Cap Growth AlphaDEX Fund | USD ($)	72	280	508	1,163

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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 135% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

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 Composite 1500(R) Growth 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 478 stocks and the market capitalization range represent in the Index was $189 million 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.

PRINCIPAL RISKS

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.

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.

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 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.

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.

ANNUAL TOTAL RETURN

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 a specialized securities market index. See "Total Return Information" for additional performance information regarding the Fund. The Fund's performance information is accessible on the Fund's website at www.ftportfolios.com.

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

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

FIRST TRUST MULTI CAP GROWTH ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -2.47%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
19.09% (September 30, 2009)	-23.61% (December 31, 2008)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Multi Cap Growth AlphaDEX Fund

Label

1 Year

5 Years

Since Inception

Inception Date

First Trust Multi Cap Growth AlphaDEX Fund

8.29%

15.74%

6.91%

May 08, 2007

First Trust Multi Cap Growth AlphaDEX Fund | After Taxes on Distributions

8.07%

15.54%

6.77%

First Trust Multi Cap Growth AlphaDEX Fund | After Taxes on Distributions and Sales

4.69%

12.62%

5.44%

Defined Multi Cap Growth Index

(reflects no deduction for fees, expenses or taxes)

9.14%

16.65%

7.74%

Standard and Poor's Composite 1500(R) Index

(reflects no deduction for fees, expenses or taxes)

13.08%

15.62%

6.63%

Standard and Poor's Composite 1500(R) Growth Index

(reflects no deduction for fees, expenses or taxes)

13.94%

16.19%

8.46%

First Trust Mid Cap Value AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

The First Trust Mid Cap Value 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 Value Index (the "Index").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Mid Cap Value AlphaDEX Fund First Trust Mid Cap Value AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Mid Cap Value AlphaDEX Fund First Trust Mid Cap Value AlphaDEX Fund
Management Fees	0.70%
Distribution and Service (12b-1) Fees	none	[1]
Other Expenses	none	[2]
Total Annual Fund Operating Expenses	0.70%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Mid Cap Value AlphaDEX Fund | First Trust Mid Cap Value AlphaDEX Fund | USD ($)	72	276	499	1,141

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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 88% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

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 MidCap 400(R) Value 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 183 stocks and the market capitalization range represented in the Index was $835 million to $9.1 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.

PRINCIPAL RISKS

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.

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.

SMALLER COMPANIES RISK. 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.

ANNUAL TOTAL RETURN

The bar chart and table below illustrate the annual calendar year return 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.

FIRST TRUST MID CAP VALUE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -11.60%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
14.59% (March 31, 2013)	-7.12% (September 30, 2014)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Mid Cap Value AlphaDEX Fund

Label

1 Year

Since Inception

Inception Date

First Trust Mid Cap Value AlphaDEX Fund

5.57%

13.47%

Apr. 19, 2011

First Trust Mid Cap Value AlphaDEX Fund | After Taxes on Distributions

5.07%

13.04%

First Trust Mid Cap Value AlphaDEX Fund | After Taxes on Distributions and Sales

3.15%

10.43%

Defined Mid Cap Value Index

(reflects no deduction for fees, expenses or taxes)

6.32%

14.32%

Standard and Poor's MidCap 400(R) Index

(reflects no deduction for fees, expenses or taxes)

12.10%

14.12%

First Trust Mid Cap Growth AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

The First Trust Mid Cap Growth 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 Growth Index (the "Index").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Mid Cap Growth AlphaDEX Fund First Trust Mid Cap Growth AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Mid Cap Growth AlphaDEX Fund First Trust Mid Cap Growth AlphaDEX Fund
Management Fees	0.70%
Distribution and Service (12b-1) Fees	none	[1]
Other Expenses	none	[2]
Total Annual Fund Operating Expenses	0.70%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Mid Cap Growth AlphaDEX Fund | First Trust Mid Cap Growth AlphaDEX Fund | USD ($)	72	276	499	1,141

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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 159% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

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 MidCap 400(R) Growth 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 115 stocks and the market capitalization range represented in the Index was $1.845 billion to $14.634 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.

PRINCIPAL RISKS

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.

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 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.

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. 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.

ANNUAL TOTAL RETURN

The bar chart and table below illustrate the annual calendar year return 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.

FIRST TRUST MID CAP GROWTH ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -4.02%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
13.55% (March 31, 2013)	-6.22% (June 30, 2012)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Mid Cap Growth AlphaDEX Fund

Label

1 Year

Since Inception

Inception Date

First Trust Mid Cap Growth AlphaDEX Fund

4.98%

11.01%

Apr. 19, 2011

First Trust Mid Cap Growth AlphaDEX Fund | After Taxes on Distributions

4.88%

10.87%

First Trust Mid Cap Growth AlphaDEX Fund | After Taxes on Distributions and Sales

2.82%

8.59%

Defined Mid Cap Growth Index

(reflects no deduction for fees, expenses or taxes)

5.78%

11.85%

Standard and Poor's MidCap 400(R) Growth Index

(reflects no deduction for fees, expenses or taxes)

7.57%

12.23%

First Trust Small Cap Value AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

The First Trust Small Cap Value 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 Small Cap Value Index (the "Index").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Small Cap Value AlphaDEX Fund First Trust Small Cap Value AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Small Cap Value AlphaDEX Fund First Trust Small Cap Value AlphaDEX Fund
Management Fees	0.70%
Distribution and Service (12b-1) Fees	none	[1]
Other Expenses	none	[2]
Total Annual Fund Operating Expenses	0.70%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Small Cap Value AlphaDEX Fund | First Trust Small Cap Value AlphaDEX Fund | USD ($)	72	276	499	1,141

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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 96% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

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 SmallCap 600(R) Value 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 255 stocks and the market capitalization range represented in the Index was $60 million to $3.268 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.

PRINCIPAL RISKS

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.

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. Because the Fund invests in small capitalization companies, the Fund is more vulnerable to adverse general market or economic developments, may be less liquid, and may experience greater price volatility than larger, more established companies.

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-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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST SMALL CAP VALUE ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -15.96%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
12.14% (March 31, 2012)	-9.38% (September 30, 2014)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Small Cap Value AlphaDEX Fund

Label

1 Year

Since Inception

Inception Date

First Trust Small Cap Value AlphaDEX Fund

3.76%

15.23%

Apr. 19, 2011

First Trust Small Cap Value AlphaDEX Fund | After Taxes on Distributions

3.36%

14.88%

First Trust Small Cap Value AlphaDEX Fund | After Taxes on Distributions and Sales

2.12%

11.91%

Defined Small Cap Value Index

(reflects no deduction for fees, expenses or taxes)

4.64%

16.20%

Standard and Poor's SmallCap 600(R) Growth Index

(reflects no deduction for fees, expenses or taxes)

7.54%

15.50%

First Trust Small Cap Growth AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

The First Trust Small Cap Growth 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 Small Cap Growth Index (the "Index").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Small Cap Growth AlphaDEX Fund First Trust Small Cap Growth AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Small Cap Growth AlphaDEX Fund First Trust Small Cap Growth AlphaDEX Fund
Management Fees	0.70%
Distribution and Service (12b-1) Fees	none	[1]
Other Expenses	none	[2]
Total Annual Fund Operating Expenses	0.70%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Small Cap Growth AlphaDEX Fund | First Trust Small Cap Growth AlphaDEX Fund | USD ($)	72	276	499	1,141

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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 153% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

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 SmallCap 600(R) Growth 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 190 stocks and the market capitalization range represented in the Index was $189 million to $4.311 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.

PRINCIPAL RISKS

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 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. Because the Fund invests in small capitalization companies, the Fund is more vulnerable to adverse general market or economic developments, may be less liquid, and may experience greater price volatility than larger, more established companies.

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-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.

ANNUAL TOTAL RETURN

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.

FIRST TRUST SMALL CAP GROWTH ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -2.71%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
12.73% (September 30, 2013)	-8.17% (September 30, 2014)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Small Cap Growth AlphaDEX Fund

Label

1 Year

Since Inception

Inception Date

First Trust Small Cap Growth AlphaDEX Fund

(1.65%)

11.61%

Apr. 19, 2011

First Trust Small Cap Growth AlphaDEX Fund | After Taxes on Distributions

(1.66%)

11.56%

First Trust Small Cap Growth AlphaDEX Fund | After Taxes on Distributions and Sales

(0.93%)

9.12%

Defined Small Cap Growth Index

(reflects no deduction for fees, expenses or taxes)

(0.77%)

12.50%

Standard and Poor's SmallCap 600(R) Growth Index

(reflects no deduction for fees, expenses or taxes)

3.87%

14.23%

First Trust Mega Cap AlphaDEX Fund

SUMMARY INFORMATION

INVESTMENT OBJECTIVE

The First Trust Mega Cap 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 Mega Cap Index (the "Index").

FEES AND EXPENSES OF THE FUND

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.

SHAREHOLDER FEES (fees paid directly from your investment)

Shareholder Fees	First Trust Mega Cap AlphaDEX Fund First Trust Mega Cap AlphaDEX Fund
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none

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

Annual Fund Operating Expenses	First Trust Mega Cap AlphaDEX Fund First Trust Mega Cap AlphaDEX Fund
Management Fees	0.70%
Distribution and Service (12b-1) Fees	none	[1]
Other Expenses	none	[2]
Total Annual Fund Operating Expenses	0.70%

EXAMPLE

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:

Expense Example, No Redemption	1 Year	3 Years	5 Years	10 Years
First Trust Mega Cap AlphaDEX Fund | First Trust Mega Cap AlphaDEX Fund | USD ($)	72	276	499	1,141

PORTFOLIO TURNOVER

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover 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 134% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

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 BMI US 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. The securities of companies represented in the Index have market capitalizations that are consistent with the name of the Index. As of July 31, 2015, the Index was comprised of 50 stocks and the market capitalization range represented in the index was approximately $31.626 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.

PRINCIPAL RISKS

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.

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 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.

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.

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.

ANNUAL TOTAL RETURN

The bar chart and table below illustrate the annual calendar year return 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.

FIRST TRUST MEGA CAP ALPHADEX(R) FUND--TOTAL RETURNS^[1]

[1] The Fund's year-to-date return based on net asset value for the period 12/31/2014 to 9/30/2015 was -6.53%.

During the period shown in the chart above:

BEST QUARTER	WORST QUARTER
10.74% (March 31, 2012)	-8.54% (June 30, 2012)

The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

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

Average Annual Total Returns - First Trust Mega Cap AlphaDEX Fund

Label

1 Year

Since Inception

Inception Date

First Trust Mega Cap AlphaDEX Fund

8.97%

10.19%

May 11, 2011

First Trust Mega Cap AlphaDEX Fund | After Taxes on Distributions

8.35%

9.67%

First Trust Mega Cap AlphaDEX Fund | After Taxes on Distributions and Sales

5.07%

7.73%

Defined Mega Cap Index

(reflects no deduction for fees, expenses or taxes)

9.83%

11.08%

Standard and Poor's 100(R) Index

(reflects no deduction for fees, expenses or taxes)

12.74%

14.88%

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] Expenses have been restated to reflect the current fiscal year.

[3] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] Expenses have been restated to reflect the current fiscal year.

[3] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] First Trust Advisors L.P., the Fund's investment advisor, has agreed to waive fees and/or reimburse Fund expenses to the extent that the operating expenses of the Fund (excluding interest expense, brokerage commissions and other trading expenses, taxes and extraordinary expenses) exceed 0.70% of its average daily net assets per year (the "Expense Cap") at least through November 30, 2016. Expenses reimbursed and fees waived under such agreement are subject to recovery by the Fund's investment advisor for up to three years from the date the fee was waived or expense was incurred, but no reimbursement payment will be made by the Fund if it results in the Fund exceeding an expense ratio equal to the Expense Cap in place at the time the expenses were reimbursed or fees waived by the Fund's investment advisor. The agreement may be terminated by the Trust on behalf of the Fund at any time and by the Fund's investment advisor only after November 30, 2016 upon 60 days' written notice.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] Pursuant to the Investment Management Agreement, First Trust will manage the investment of the Fund's assets and will be responsible for the Fund's expenses, including the cost of transfer agency, custody, fund administration, legal, audit, license and other services, but excluding fee payments under the Investment Management Agreement, interest, taxes, brokerage commissions and other expenses connected with the execution of portfolio transactions, distribution and service fees, pursuant to a 12b-1 plan, if any, and extraordinary expenses.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] Pursuant to the Investment Management Agreement, First Trust will manage the investment of the Fund's assets and will be responsible for the Fund's expenses, including the cost of transfer agency, custody, fund administration, legal, audit, license and other services, but excluding fee payments under the Investment Management Agreement, interest, taxes, brokerage commissions and other expenses connected with the execution of portfolio transactions, distribution and service fees, pursuant to a 12b-1 plan, if any, and extraordinary expenses.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] Pursuant to the Investment Management Agreement, First Trust will manage the investment of the Fund's assets and will be responsible for the Fund's expenses, including the cost of transfer agency, custody, fund administration, legal, audit, license and other services, but excluding fee payments under the Investment Management Agreement, interest, taxes, brokerage commissions and other expenses connected with the execution of portfolio transactions, distribution and service fees, pursuant to a 12b-1 plan, if any, and extraordinary expenses.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] Pursuant to the Investment Management Agreement, First Trust will manage the investment of the Fund's assets and will be responsible for the Fund's expenses, including the cost of transfer agency, custody, fund administration, legal, audit, license and other services, but excluding fee payments under the Investment Management Agreement, interest, taxes, brokerage commissions and other expenses connected with the execution of portfolio transactions, distribution and service fees, pursuant to a 12b-1 plan, if any, and extraordinary expenses.

[1] Although the Fund has adopted a 12b-1 plan that permits it to pay up to 0.25% per annum, it will not pay 12b-1 fees any time before December 31, 2016.

[2] Pursuant to the Investment Management Agreement, First Trust will manage the investment of the Fund's assets and will be responsible for the Fund's expenses, including the cost of transfer agency, custody, fund administration, legal, audit, license and other services, but excluding fee payments under the Investment Management Agreement, interest, taxes, brokerage commissions and other expenses connected with the execution of portfolio transactions, distribution and service fees, pursuant to a 12b-1 plan, if any, and extraordinary expenses.