Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

First Trust Exchange-Traded Fund

Prospectus Date

rr_ProspectusDate

May 01, 2019

First Trust Chindia ETF

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

<p>Summary Information</p>

Objective [Heading]

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<p>Investment Objective</p>

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The First Trust Chindia ETF (the "Fund"), formerly First Trust ISE Chindia Index Fund, seeks investment results that correspond generally to the price and yield (before the Fund's fees and expenses) of an equity index called the ISE ChIndia™ Index (the "Index").

Expense [Heading]

rr_ExpenseHeading

<p>Fees and Expenses of the Fund</p>

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

<p> <b>Shareholder Fees</b> <br />(fees paid directly from your investment)</p>

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

<p></p><p> <b>Annual Fund Operating Expenses</b> <br />(expenses that you pay each year as a percentage of the value of your investment)</p>

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

April 30, 2020

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

<p>Portfolio Turnover</p>

Portfolio Turnover [Text Block]

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The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 22% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

22.00%

Expense Example [Heading]

rr_ExpenseExampleHeading

<p>Example</p>

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. The example assumes that the Fund's 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, acquired fund fees and expenses, taxes, and extraordinary expenses) from exceeding 0.60% of average daily net assets per year will be terminated following April 30, 2020. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

rr_StrategyHeading

<p>Principal Investment Strategies</p>

Strategy Narrative [Text Block]

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The Fund will normally invest at least 90% of its net assets (including investment borrowings) in the common stocks and depositary receipts 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 developed and owned by the International Securities Exchange, LLC (the "Index Provider"), and is calculated and maintained by Nasdaq.

The Index is a modified market capitalization-weighted index designed to track the performance of U.S.-listed securities issued by small, mid and large capitalization companies domiciled in China or India. To be eligible for inclusion in the Index, a security must be listed on a qualifying U.S. securities exchange and be issued by a company domiciled in China (excluding Taiwan) or India. In addition, a security must be issued by a company with a market capitalization of at least $250 million, have a three-month average daily trading volume of at least $1 million and a minimum free float of 20%. Qualifying securities are then sorted into two groups based upon their country of domicile (Chinese issuers and Indian issuers). Each group of securities is then ranked by market capitalization and three-month average daily trading volume. The two ranks for each security are added together to provide a composite score. Each group of securities is then ranked based upon this composite score. The 25 securities with the highest rank from China and the 25 securities from India with the highest rank are selected for inclusion in the Index. If there are less than 25 qualifying securities from either China or India, securities will be added from the other country until the Index is composed of 50 securities.

Securities chosen for inclusion in the Index are weighted according to a modified market capitalization weighting methodology based on the composite score described above.

• Each Chinese and Indian security ranked #1 through #3 is assigned a weight of 7.0%.

• Each Chinese and Indian security ranked #4 through #6 is assigned a weight of 4.0%.

• Each Chinese and Indian security ranked #7 through #9 is assigned a weight of 2.0%.

• The remaining Index weight is equally distributed among the remaining securities.

The Index may be significantly composed of American Depositary Receipts ("ADRs") and American Depositary Shares ("ADSs"). ADRs are certificates issued by a U.S. bank that represent a bank's holdings of a stated number of shares of a non U.S. company. ADSs are vehicles for non U.S. companies to list their equity shares on a U.S. exchange and are U.S. dollar denominated, and each share represents one or more underlying shares in a non U.S. company.

The Index is rebalanced and reconstituted semi-annually and the Fund will make corresponding changes to its portfolio shortly after the Index changes are made public. The Fund will be concentrated in an industry or a group of industries to the extent that the Index is so concentrated. As of March 31, 2019, the Index was composed of 50 securities and the Fund had significant investments in consumer discretionary companies, although this may change from time to time. To the extent the Fund invests a significant portion of its assets in a given jurisdiction or investment sector, the Fund may be exposed to the risks associated with that jurisdiction or investment sector.

Risk [Heading]

rr_RiskHeading

<p>Principal Risks</p>

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

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

ASIA RISK. The Fund is subject to certain risks specifically associated with investments in the securities of Asian issuers. Many Asian economies have experienced rapid growth and industrialization, and there is no assurance that this growth rate will be maintained. Some Asian economies are highly dependent on trade, and economic conditions in other countries within and outside Asia can impact these economies. Certain of these economies may be adversely affected by trade or policy disputes with its major trade partners. There is also a high concentration of market capitalization and trading volume in a small number of issuers representing a limited number of industries, as well as a high concentration of investors and financial intermediaries. Certain Asian countries have experienced and may in the future experience expropriation and nationalization of assets, confiscatory taxation, currency manipulation, political instability, armed conflict and social instability as a result of religious, ethnic, socio-economic and/or political unrest. In particular, escalated tensions involving North Korea and any outbreak of hostilities involving North Korea could have a severe adverse effect on Asian economies. Governments of certain Asian countries have exercised, and continue to exercise, substantial influence over many aspects of the private sector. In certain cases, the government owns or controls many companies, including the largest in the country. Accordingly, government actions could have a significant effect on the issuers of the Fund's securities or on economic conditions generally.

AUTHORIZED PARTICIPANT CONCENTRATION RISK. Only an authorized participant may engage in creation or redemption transactions directly with the Fund. A limited number of institutions act as authorized participants for the Fund. To the extent that these institutions exit the business or are unable to proceed with creation and/or redemption orders and no other authorized participant steps forward to create or redeem, the Fund's shares may trade at a premium or discount to the Fund's net asset value and possibly face delisting.

CHINA RISK. The Fund is subject to certain risks specifically associated with investments in the securities of Chinese issuers, including those issuers with securities listed on the Hong Kong Stock Exchange. China is an emerging market and demonstrates significantly higher volatility from time to time in comparison to developed markets. The central government has historically exercised substantial control over virtually every sector of the Chinese economy through administrative regulation and/or state ownership and actions of the Chinese central and local government authorities continue to have a substantial effect on economic conditions in China. Export growth continues to be a major driver of China's rapid economic growth. Reduction in spending on Chinese products and services, institution of tariffs or other trade barriers, or a downturn in any of the economies of China's key trading partners may have an adverse impact on the Chinese economy. Recent developments in relations between the U.S. and China have heightened concerns of increased tariffs and restrictions on trade between the two countries. An increase in tariffs or trade restrictions, or even the threat of such developments, could lead to a significant reduction in international trade, which could have a negative impact on China's export industry and a commensurately negative impact on the Fund.

CONCENTRATION RISK. To the extent that the Fund invests a large percentage of its assets in a single asset class or the securities of issuers within the same country, state, region, industry or sector, an adverse economic, business or political development may affect the value of the Fund's investments more than if the Fund were more broadly diversified. A concentration makes the Fund more susceptible to any single occurrence and may subject the Fund to greater market risk than a fund that is not so concentrated.

CONSUMER DISCRETIONARY COMPANIES RISK. Consumer discretionary companies, such as retailers, media companies and consumer services companies, provide non-essential goods and 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.

CYBER SECURITY RISK. The Fund is susceptible to operational risks through breaches in cyber security. A breach in cyber security refers to both intentional and unintentional events that may cause the Fund to lose proprietary information, suffer data corruption or lose operational capacity. Such events could cause the Fund to incur regulatory penalties, reputational damage, additional compliance costs associated with corrective measures and/or financial loss. Cyber security breaches may involve unauthorized access to the Fund's digital information systems through "hacking" or malicious software coding but may also result from outside attacks such as denial-of-service attacks through efforts to make network services unavailable to intended users. In addition, cyber security breaches of the issuers of securities in which the Fund invests or the Fund's third-party service providers, such as its administrator, transfer agent, custodian, or sub-advisor, as applicable, can also subject the Fund to many of the same risks associated with direct cyber security breaches. Although the Fund has established risk management systems designed to reduce the risks associated with cyber security, there is no guarantee that such efforts will succeed, especially because the Fund does not directly control the cyber security systems of issuers or third-party service providers.

DEPOSITARY RECEIPTS RISK. Depositary receipts may be less liquid than the underlying shares in their primary trading market. Any distributions paid to the holders of depositary receipts are usually subject to a fee charged by the depositary. Holders of depositary receipts may have limited voting rights, and investment restrictions in certain countries may adversely impact the value of depositary receipts because such restrictions may limit the ability to convert the equity shares into depositary receipts and vice versa. Such restrictions may cause the equity shares of the underlying issuer to trade at a discount or premium to the market price of the depositary receipts.

EMERGING MARKETS RISK. Investments in securities issued by companies operating in emerging market countries involve additional risks relating to political, economic, or regulatory conditions not associated with investments in securities and instruments issued by U.S. companies or by companies operating in other developed market countries. Investments in emerging markets securities are generally considered speculative in nature and are subject to the following heightened risks: smaller market capitalization of securities markets which may suffer periods of relative illiquidity; significant price volatility; restrictions on foreign investment; possible repatriation of investment income and capital; rapid inflation; and currency convertibility issues. Emerging market countries also often have less uniformity in accounting and reporting requirements, unsettled securities laws, unreliable securities valuation and greater risk associated with custody of securities. Furthermore, investors may be required to register the proceeds of sales and future economic or political crises could lead to price controls, forced mergers, expropriation or confiscatory taxation, seizure, nationalization or creation of government monopolies.

EQUITY SECURITIES RISK. The value of the Fund's shares will fluctuate with changes in the value of the equity securities in which it invests. 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 equity market, such as market volatility, or when political or economic events affecting an issuer occur. Common stock prices may be particularly sensitive to rising interest rates, as the cost of capital rises and borrowing costs increase. Equity securities may decline significantly in price over short or extended periods of time, and such declines may occur in the equity market as a whole, or they may occur in only a particular country, company, industry or sector of the market.

INDEX CONSTITUENT RISK. The Fund may be a constituent of one or more indices. As a result, the Fund may be included in one or more index-tracking exchange-traded funds or mutual funds. Being a component security of such a vehicle could greatly affect the trading activity involving the Fund's shares, the size of the Fund and the market volatility of the Fund. Inclusion in an index could increase demand for the Fund and removal from an index could result in outsized selling activity in a relatively short period of time. As a result, the Fund's net asset value could be negatively impacted and the Fund's market price may be below the Fund's net asset value during certain periods. In addition, index rebalances may potentially result in increased trading activity in the Fund's shares.

INDEX PROVIDER RISK. There is no assurance that the Index Provider will compile the Index accurately, or that the Index will be determined, maintained, constructed, reconstituted, rebalanced, composed, calculated or disseminated accurately. To correct any such error, the Index Provider may carry out an unscheduled rebalance or other modification of the Index constituents or weightings, which may increase the Fund's costs. The Index Provider does not provide any representation or warranty in relation to the quality, accuracy or completeness of data in the Index, and it does not guarantee that the Index will be calculated in accordance with its stated methodology. Losses or costs associated with any Index Provider errors generally will be borne by the Fund and its shareholders.

INDIA RISK. The Fund is subject to certain risks specifically associated with investments in the securities of Indian issuers. Investment in Indian securities involves risks in addition to those associated with investments in securities of issuers in more developed countries, which may adversely affect the value of the Fund's assets. Such heightened risks include, among others, political and legal uncertainty, greater government control over the economy, currency fluctuations or blockage and the risk of nationalization or expropriation of assets. In addition, religious and border disputes persist in India. Moreover, India has experienced civil unrest and hostilities with neighboring countries, including Pakistan, and the Indian government has confronted separatist movements in several Indian states. The securities market of India is considered an emerging market that is characterized by a small number of listed companies that have significantly smaller market capitalizations, greater price volatility, greater delays and possibility of disruptions in settlement transactions, greater political uncertainties and greater dependence on international trade or development assistance and substantially less liquidity than companies in more developed markets. These factors, coupled with restrictions on foreign investment and other factors, limit the supply of securities available for investment by the Fund. This will affect the rate at which the Fund is able to invest in the securities of Indian companies, the purchase and sale prices for such securities and the timing of purchases and sales. Certain restrictions on foreign investments may decrease the liquidity of the Fund's portfolio, subject the Fund to higher transaction costs, or inhibit the Fund's ability to track the Index. Investments in Indian securities may also may be limited or prevented, at times, due to the limits on foreign ownership imposed by the Reserve Bank of India ("RBI"). In addition, a natural or other disaster could occur in India that could affect the Indian economy or operations of the Fund, causing an adverse impact on the Fund.

MARKET MAKER RISK. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares due to a limited number of market markers. Decisions by market makers or authorized participants to reduce their role or step away from these activities in times of market stress could inhibit the effectiveness of the arbitrage process in maintaining the relationship between the underlying values of the Fund's portfolio securities and the Fund's market price. The Fund may rely on a small number of third-party market makers to provide a market for the purchase and sale of shares. Any trading halt or other problem relating to the trading activity of these market makers could result in a dramatic change in the spread between the Fund's net asset value and the price at which the Fund's shares are trading on the Exchange, which could result in a decrease in value of the Fund's shares. This reduced effectiveness could result in Fund shares trading at a discount to net asset value and also in greater than normal intraday bid-ask spreads for Fund shares.

MARKET RISK. Market risk is the risk that a particular security, 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. The Fund incurs operating expenses not applicable to the Index, and may incur costs in buying and selling securities, especially when rebalancing the Fund's portfolio holdings to reflect changes in the composition of the Index. In addition, the Fund's portfolio holdings may not exactly replicate the securities included in the Index or the ratios between the securities included in the Index.

NON-DIVERSIFICATION RISK. The Fund is classified as "non-diversified" under the Investment Company Act of 1940, as amended (the "1940 Act"). As a result, the Fund is only limited as to the percentage of its assets which may be invested in the securities of any one issuer by the diversification requirements imposed by the Internal Revenue Code of 1986, as amended. The Fund may invest a relatively high percentage of its assets in a limited number of issuers. As a result, the Fund may be more susceptible to a single adverse economic or regulatory occurrence affecting one or more of these issuers, experience increased volatility and be highly invested in certain issuers.

PASSIVE INVESTMENT RISK. The Fund is not actively managed. The Fund invests in securities included in or representative of the Index regardless of investment merit. The Fund generally will not attempt to take defensive positions in declining markets. In the event that the Index is no longer calculated, the Index license is terminated or the identity or character of the Index is materially changed, the Fund will seek to engage a replacement index.

PREMIUM/DISCOUNT RISK. The market price of the Fund's shares will generally fluctuate in accordance with changes in the Fund's net asset value as well as the relative supply of and demand for shares on the Exchange. The Fund's investment advisor cannot predict whether shares will trade below, at or above their net asset value because the shares trade on the Exchange at market prices and not at net asset value. Price differences may be due, in large part, to the fact that supply and demand forces at work in the secondary trading market for shares will be closely related, but not identical, to the same forces influencing the prices of the holdings of the Fund trading individually or in the aggregate at any point in time. However, given that shares can only be purchased and redeemed in Creation Units, and only to and from broker-dealers and large institutional investors that have entered into participation agreements (unlike shares of closed-end funds, which frequently trade at appreciable discounts from, and sometimes at premiums to, their net asset value), the Fund's investment advisor believes that large discounts or premiums to the net asset value of shares should not be sustained.

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, fewer 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.

TRADING ISSUES RISK. Although the shares of the Fund are listed for trading on the Exchange, there can be no assurance that an active trading market for such shares will develop or be maintained. Further, secondary markets may be subject to irregular trading activity and wide bid-ask spreads (which may be especially pronounced for smaller funds). Trading in shares on the Exchange may be halted due to market conditions or for reasons that, in the view of the Exchange, make trading in shares inadvisable. In addition, trading in shares on the Exchange is subject to trading halts caused by extraordinary market volatility pursuant to the Exchange's "circuit breaker" rules. Market makers are under no obligation to make a market in the Fund's shares, and authorized participants are not obligated to submit purchase or redemption orders for Creation Units. In the event market makers cease making a market in the Fund's shares or authorized participants stop submitting purchase or redemption orders for Creation Units, Fund shares may trade at a larger premium or discount to their net asset value. There can be no assurance that the requirements of the Exchange necessary to maintain the listing of the Fund will continue to be met or will remain unchanged. The Fund may have difficulty maintaining its listing on the Exchange in the event the Fund's assets are small or the Fund does not have enough shareholders.

Bar Chart and Performance Table [Heading]

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<p>Annual Total Return</p>

Performance Narrative [Text Block]

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The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. The bar chart and table provide an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year-to-year and by showing how the Fund's average annual total returns based on net asset value compared to those of the Index, a broad-based market index and a 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.

Bar Chart [Heading]

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<p>First Trust Chindia ETF<br />Calendar Year Total Returns as of 12/31 </p>

Bar Chart Closing [Text Block]

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During the periods shown in the chart above:

Best Quarter		Worst Quarter
47.58%	June 30, 2009	-26.46%	September 30, 2011

Performance Table Heading

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<p>Average Annual Total Returns for the Periods Ended December 31, 2018</p>

Performance Table Narrative

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

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 Chindia ETF | First Trust Chindia ETF

Risk/Return:

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.40%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.19%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.59%

Fee Waiver and Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

none

^[1]

Total Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement

rr_NetExpensesOverAssets

0.59%

1 Year

rr_ExpenseExampleNoRedemptionYear01

$ 60

3 Years

rr_ExpenseExampleNoRedemptionYear03

189

5 Years

rr_ExpenseExampleNoRedemptionYear05

329

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 738

2009

rr_AnnualReturn2009

81.58%

2010

rr_AnnualReturn2010

18.46%

2011

rr_AnnualReturn2011

(26.02%)

2012

rr_AnnualReturn2012

17.11%

2013

rr_AnnualReturn2013

35.81%

2014

rr_AnnualReturn2014

2.37%

2015

rr_AnnualReturn2015

(0.32%)

2016

rr_AnnualReturn2016

(2.15%)

2017

rr_AnnualReturn2017

47.36%

2018

rr_AnnualReturn2018

(20.68%)

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best Quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

47.58%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst Quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(26.46%)

1 Year

rr_AverageAnnualReturnYear01

(20.68%)

5 Years

rr_AverageAnnualReturnYear05

3.14%

10 Years

rr_AverageAnnualReturnYear10

11.44%

Since Inception

rr_AverageAnnualReturnSinceInception

4.99%

Inception Date

rr_AverageAnnualReturnInceptionDate

May 08, 2007

First Trust Chindia ETF | After tax on distributions | First Trust Chindia ETF

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(21.15%)

5 Years

rr_AverageAnnualReturnYear05

2.59%

10 Years

rr_AverageAnnualReturnYear10

10.92%

Since Inception

rr_AverageAnnualReturnSinceInception

4.52%

First Trust Chindia ETF | After tax on distributions and sale of fund shares | First Trust Chindia ETF

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(12.21%)

5 Years

rr_AverageAnnualReturnYear05

2.18%

10 Years

rr_AverageAnnualReturnYear10

9.27%

Since Inception

rr_AverageAnnualReturnSinceInception

3.77%

First Trust Chindia ETF | ISE ChIndia(TM) Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(20.27%)

5 Years

rr_AverageAnnualReturnYear05

3.64%

10 Years

rr_AverageAnnualReturnYear10

12.00%

Since Inception

rr_AverageAnnualReturnSinceInception

5.53%

First Trust Chindia ETF | Russell 3000® Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(5.24%)

5 Years

rr_AverageAnnualReturnYear05

7.91%

10 Years

rr_AverageAnnualReturnYear10

13.18%

Since Inception

rr_AverageAnnualReturnSinceInception

6.66%

First Trust Chindia ETF | MSCI Emerging Markets Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(14.58%)

5 Years

rr_AverageAnnualReturnYear05

1.65%

10 Years

rr_AverageAnnualReturnYear10

8.02%

Since Inception

rr_AverageAnnualReturnSinceInception

2.17%

[1] 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, acquired fund fees and expenses, taxes and extraordinary expenses) exceed 0.60% of its average daily net assets per year (the "Expense Cap") at least through April 30, 2020. 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 (i) the applicable expense limitation in place for the most recent fiscal year for which such expense limitation was in place, (ii) the applicable expense limitation in place at the time the fees were waived, or (iii) the current expense limitation. 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 April 30, 2020 upon 60 days' written notice.