v3.25.4
First Trust High Income Strategic Focus ETF Investment Risks - First Trust High Income Strategic Focus ETF
Oct. 31, 2025
Asset Backed Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] ASSET-BACKED SECURITIES RISK. The Fund may invest in Underlying ETFs that invest in asset-backed securities. Asset-backed securities are debt securities typically created by buying and pooling loans or other receivables other than mortgage loans and creating securities backed by those similar type assets. As with other debt securities, asset-backed securities are subject to credit risk, extension risk, interest rate risk, liquidity risk and valuation risk. These securities are generally not backed by the full faith and credit of the U.S. government and are subject to the risk of default on the underlying asset or loan, particularly during periods of economic downturn. The impairment of the value of collateral or other assets underlying an asset-backed security, such as a result of non-payment of loans or non-performance of underlying assets, may result in a reduction in the value of such asset-backed securities and losses to an Underlying ETF.
Authorized Participant Concentration Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] 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 (the difference between the market price of the Fund's shares and the Fund's net asset value) and possibly face delisting and the bid/ask spread (the difference between the price that someone is willing to pay for shares of the Fund at a specific point in time versus the price at which someone is willing to sell) on the Fund’s shares may widen.
Bank Loans Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] BANK LOANS RISK. The Fund may invest in Underlying ETFs that hold bank loans. Investments in bank loans are subject to the same risks as investments in other types of debt securities, including credit risk, interest rate risk, liquidity risk and valuation risk that may be heightened because of the limited public information available regarding bank loans and because loan borrowers may be leveraged and tend to be more adversely affected by changes in market or economic conditions. If an Underlying ETF holds a bank loan through another financial institution or relies on a financial institution to administer the loan, its receipt of principal and interest on the loan may be subject to the credit risk of that financial institution. It is possible that any collateral securing a loan may be insufficient or unavailable to the Underlying ETF, particularly for second lien loans or other junior or subordinated loans held by the Underlying ETF; provided, however, that some loans are not secured by any collateral. The Underlying ETF’s rights to collateral also may be limited by bankruptcy or insolvency laws. Additionally, there is no central clearinghouse for loan trades and the loan market has not established enforceable settlement standards or remedies for failure to settle. As such, the secondary market for bank loans may be subject to irregular trading activity, wide bid/ask spreads and extended trade settlement periods (in some cases longer than 7 days) which may cause the Underlying ETF to be unable to realize the full value of its investment. In addition, bank loans are generally not registered with the Securities and Exchange Commission under the Securities Act of 1933, as amended, and may not be considered “securities,” and an Underlying ETF may not be entitled to rely on the anti-fraud protections of the federal securities laws. Bank loans held by the Fund may be subject to amendments, waivers, or exchange offers that modify their terms. These transactions may be initiated by borrowers to address financial stress and may include exchanges of existing loans for new instruments with different priority, collateral, or economic characteristics. Participation in, or exclusion from, such transactions could result in an Underlying ETF holding debt that is structurally or contractually subordinated, less liquid, or of lower market value than prior to the transaction.
Call Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CALL RISK. The Fund invests in Underlying ETFs that hold debt securities. Some debt securities may be redeemed, or “called,” at the option of the issuer before their stated maturity date. In general, an issuer will call its debt securities if they can be refinanced by issuing new debt securities which bear a lower interest rate. It is possible that during periods of falling interest rates an issuer will call its high yielding debt securities. An Underlying ETF would then be forced to invest the proceeds at lower interest rates, likely resulting in a decline in its income.
Concentrated Investment Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CONCENTRATED INVESTMENT RISK. The Fund may invest a significant percentage of its assets in a small number of ETFs. In addition to subjecting the Fund to the risks of investing in such ETFs as described in this prospectus, this subjects the Fund to the risk that a decline in the value of one or more ETFs could have a significant negative impact on the Fund's net asset value and your investment. In addition, the overall performance of the Fund will be largely dependent on the performance of this small number of ETFs, and if any of those ETFs experiences negative performance or fails to achieve its investment objective, the Fund and your investment could be significantly negatively impacted. Additionally, if the Fund owns a significant percentage of the outstanding shares of an ETF, large purchases and sales of the ETF's shares by the Fund may create a number of risks for the ETF and its shareholders (including the Fund), including impacts to the ETF's size, market price, liquidity, bid/ask spreads, portfolio turnover and transaction costs, tax efficiency and ability to trade underlying securities advantageously. These risks may be exacerbated for newer ETFs.
Conflict Of Interest Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CONFLICT OF INTEREST RISK. The Fund invests in other ETFs that are also advised by, or are otherwise affiliated with, the Advisor. Because the Fund pays management fees in connection with its investments in other ETFs, the Advisor has a financial incentive to cause the Fund to invest in ETFs for which it also serves as investment advisor. The Advisor may invest in an affiliated ETF even in circumstances where an unaffiliated ETF may have lower fees or better performance over certain time periods.
Contingent Convertible Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CONTINGENT CONVERTIBLE SECURITIES RISK. The Fund may invest in Underlying ETFs that invest in contingent convertible securities (“CoCos”). CoCos are hybrid securities most commonly issued by banking institutions that present risks similar to debt securities and convertible securities. CoCos are distinct in that they are intended to either convert into equity or have their principal written down upon the occurrence of certain “triggers.” When an issuer’s capital ratio falls below a specified trigger level, or in a regulator’s discretion depending on the regulator’s judgment about the issuer’s solvency prospects, a CoCo may be written down, written off or converted into an equity security. Due to the contingent write-down, write-off and conversion feature, CoCos may have substantially greater risk than other securities in times of financial stress. If the trigger level is breached, the issuer's decision to write down, write off or convert a CoCo may be outside its control, and an Underlying ETF may suffer a complete loss on an investment in CoCos with no chance of recovery even if the issuer remains in existence. The value of CoCos is unpredictable and may be influenced by many factors including, without limitation: the creditworthiness of the issuer and/or fluctuations in such issuer's applicable capital ratios; supply and demand for CoCos; general market conditions and available liquidity; and economic, financial and political events that affect the issuer, its particular market or the financial markets in general.
Convertible Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CONVERTIBLE SECURITIES RISK. The Fund may invest in Underlying ETFs that hold convertible securities. A convertible security has characteristics of both equity and debt securities and, as a result, is exposed to risks that are typically associated with both types of securities. The value of convertible securities may rise and fall with the market value of the underlying stock or, like a debt security, vary with changes in interest rates and the credit quality of the issuer. A convertible security tends to perform more like a stock when the underlying stock price is high relative to the conversion price and more like a debt security when the underlying stock price is low relative to the conversion price.
Counterparty Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] COUNTERPARTY RISK. The Fund may invest in Underlying ETFs that are subject to counterparty risk. Transactions involving a counterparty in which an Underlying ETF may engage are subject to the risk that the counterparty will not fulfill its obligation to the Underlying ETF. Counterparty risk may arise because of the counterparty’s financial condition (i.e., financial difficulties, bankruptcy, or insolvency), market activities and developments, or other reasons, whether foreseen or not. A counterparty’s inability to fulfill its obligation may result in significant financial loss to an Underlying ETF. An Underlying ETF may be unable to recover its investment from the counterparty or may obtain a limited recovery, and/or recovery may be delayed.
Covenant Lite Loans Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] COVENANT-LITE LOANS RISK. The Fund may invest in Underlying ETFs that hold covenant-lite loans. Covenant-lite loans contain fewer maintenance covenants than traditional loans, or no maintenance covenants at all, than traditional loans and may not include terms that allow the lender to monitor the financial performance of the borrower and declare a default if certain criteria are breached. This may hinder an Underlying ETF's ability to reprice credit risk associated with the borrower and reduce the Fund’s ability to restructure a problematic loan and mitigate potential loss. As a result, the Fund’s exposure to losses on such investments is increased, especially during a downturn in the credit cycle.
Credit Rating Agency Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CREDIT RATING AGENCY RISK. Credit ratings are determined by credit rating agencies such as S&P Global Ratings, Moody’s Investors Services, Inc. and Fitch Inc., and are only the opinions of such entities. Ratings assigned by a rating agency are not absolute standards of credit quality and do not evaluate market risk or the liquidity of securities. First Trust makes no warranty whatsoever regarding the ability of such ratings to accurately reflect the creditworthiness of an issuer. Any shortcomings, changes to or inefficiencies in credit rating agencies’ processes for determining credit ratings may adversely affect the credit ratings of securities held by the Fund or securities in which the Fund would otherwise invest and, as a result, may adversely affect those securities’ perceived or actual credit risk, as well as the Fund’s performance.
Credit Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CREDIT RISK. The Fund invests in Underlying ETFs that hold debt securities. An issuer or other obligated party of a debt security may be unable or unwilling to make dividend, interest and/or principal payments when due. In addition, the value of a debt security may decline because of concerns about the issuer’s ability or unwillingness to make such payments.
Credit Spread Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CREDIT SPREAD RISK. The Fund invests in Underlying ETFs that hold debt securities. From time to time, spreads (i.e., the difference in yield between debt securities that have different credit qualities or other differences) may increase, which may reduce the market value of some of the debt securities held by the Underlying ETFs in which the Fund may invest if the Proposal is implemented. While such Underlying ETFs may employ strategies to mitigate credit spread risk, these strategies may not be successful.
Currency Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CURRENCY RISK. The Fund may invest in Underlying ETFs that are subject to currency risk. Changes in currency exchange rates affect the value of investments denominated in a foreign currency, and therefore the value of such investments in an Underlying ETF’s portfolio. An Underlying ETF’s net asset value could decline if a currency to which an Underlying ETF has exposure depreciates against the U.S. dollar or if there are delays or limits on repatriation of such currency. Currency exchange rates can be very volatile and can change quickly and unpredictably. As a result, the value of an investment in such an Underlying ETF may change quickly and without warning.
Current Market Conditions Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CURRENT MARKET CONDITIONS RISK. Current market conditions risk is the risk that a particular investment, or shares of the Fund in general, may fall in value due to current market conditions. As a means to fight inflation, the Federal Reserve and certain foreign central banks have raised interest rates; however, the Federal Reserve has begun to lower interest rates and may continue to do so. U.S. regulators have proposed several changes to market and issuer regulations which would directly impact the Fund, and any regulatory changes could adversely impact the Fund’s ability to achieve its investment strategies or make certain investments. Potential future bank failures could result in disruption to the broader banking industry or markets generally and reduce confidence in financial institutions and the economy as a whole, which may also heighten market volatility and reduce liquidity. Additionally, challenges in commercial real estate markets, including high interest rates, declining valuations and elevated vacancies, could have a broader impact on financial markets. The ongoing adversarial political climate in the United States, as well as political and diplomatic events both domestic and abroad, have and may continue to have an adverse impact the U.S. regulatory landscape, markets and investor behavior, which could have a negative impact on the Fund’s investments and operations. The change in administration resulting from the 2024 United States national elections could result in significant impacts to international trade relations, tax and immigration policies, and other aspects of the national and international political and financial landscape, which could affect, among other things, inflation and the securities markets generally. Other unexpected political, regulatory and diplomatic events within the U.S. and abroad may affect investor and consumer confidence and may adversely impact financial markets and the broader economy. For example, ongoing armed conflicts between Russia and Ukraine in Europe and among Israel, Iran, Hamas and other militant groups in the Middle East, have caused and could continue to cause significant market disruptions and volatility within the markets in Russia, Europe, the Middle East and the United States. The hostilities and sanctions resulting from those hostilities have and could continue to have a significant impact on certain Fund investments as well as Fund performance and liquidity. The economies of the United States and its trading partners, as well as the financial markets generally, may be adversely impacted by trade disputes, including the imposition of tariffs, and other matters. For example, the United States has imposed trade barriers and restrictions on China. In addition, the Chinese government is engaged in a longstanding dispute with Taiwan, continually threatening an invasion. If the political climate between the United States and China does not improve or continues to deteriorate, if China were to attempt invading Taiwan, or if other geopolitical conflicts develop or worsen, economies, markets and individual securities may be adversely affected, and the value of the Fund’s assets may go down. A public health crisis and the ensuing policies enacted by governments and central banks may cause significant volatility and uncertainty in global financial markets, negatively impacting global growth prospects. As the COVID-19 global pandemic illustrated, such events may affect certain geographic regions, countries, sectors and industries more significantly than others. Advancements in technology may also adversely impact markets and the overall performance of the Fund. For instance, the economy may be significantly impacted by the advanced development and increased regulation of artificial intelligence. Additionally, cyber security breaches of both government and non-government entities could have negative impacts on infrastructure and the ability of such entities, including the Fund, to operate properly. These events, and any other future events, may adversely affect the prices and liquidity of the Fund’s portfolio investments and could result in disruptions in the trading markets.
Cyber Security Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] CYBER SECURITY RISK. The Fund is susceptible to operational, information security and related 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, any of which could result in a material adverse effect on the Fund or its shareholders. 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. Emerging threats like ransomware or zero-day exploits could also cause disruptions to Fund operations. 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, among many other third-party service providers, can also subject the Fund to many of the same risks associated with direct cyber security breaches. Further, errors, misconduct, or compromise of accounts of employees of the Fund or its third-party service providers can also create material cybersecurity risks. 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. Cyber security incidents may also trigger Fund obligations under data privacy laws, potentially increasing notification and compliance burdens. Cyber security incidents affecting issuers in whose securities the Fund invests may also have a negative impact on the value of the securities of such issuers, and in turn, the value of the Fund.
Debt Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] DEBT SECURITIES RISK. The Fund will invest in Underlying ETFs that hold debt securities. Investments in debt securities subject the holder to the credit risk of the issuer. Credit risk refers to the possibility that the issuer or other obligor of a security will not be able or willing to make payments of interest and principal when due. Generally, the value of debt securities will change inversely with changes in interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. During periods of falling interest rates, the income received by an Underlying ETF may decline. If the principal on a debt security is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. Debt securities generally do not trade on a securities exchange making them generally less liquid and more difficult to value than common stock. Debt securities held by the Fund may be subject to amendments, waivers, or exchange offers that modify their terms. These transactions may be initiated by borrowers to address financial stress and may include exchanges of existing debt securities for new instruments with different priority, collateral, or economic characteristics. Participation in, or exclusion from, such transactions could result in the Fund holding debt that is structurally or contractually subordinated, less liquid, or of lower market value than prior to the transaction.
Defaulted Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] DEFAULTED SECURITIES RISK. The Fund may invest in Underlying ETFs that hold defaulted securities. Defaulted securities pose a greater risk that principal will not be repaid than non-defaulted securities. The reorganization or liquidation of an issuer of a defaulted security may result in an Underlying ETF losing its entire investment or being required to accept cash or securities with a value less than its original investment. It may also be difficult to obtain complete and accurate information regarding the true financial condition of the issuer of a defaulted security. Defaulted securities and any securities received in an exchange for such securities may be subject to restrictions on resale.
Derivatives Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] DERIVATIVES RISK. The Fund may invest in Underlying ETFs that hold derivatives. The use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. These risks include or may include: (i) the risk that the value of the underlying assets may go up or down; (ii) the risk that the counterparty to a derivative transaction may not fulfill its contractual obligations; (iii) the risk of mispricing or improper valuation of a derivative; (iv) the risk that changes in the value of the derivative may not correlate perfectly with the underlying asset; (v) the risk that a derivative instrument cannot be sold, closed out or replaced quickly at or very close to its fundamental value; (vi) the risk of loss caused by the unenforceability of a party’s obligations under the derivative; and (vii) the risk that a disruption in the financial markets will cause difficulties for all market participants. Derivative prices are highly volatile and may fluctuate substantially during a short period of time. Such prices are influenced by numerous factors that affect the markets, including, but not limited to: changing supply and demand relationships; government programs and policies; national and international political and economic events, changes in interest rates, inflation and deflation and changes in supply and demand relationships. Trading derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities. Derivative contracts ordinarily have leverage inherent in their terms. The low margin deposits normally required in trading derivatives, including futures contracts, permit a high degree of leverage. Accordingly, a relatively small price movement may result in an immediate and substantial loss. The use of leverage may also cause an Underlying ETF to liquidate portfolio positions when it would not be advantageous to do so. The use of leveraged derivatives can magnify potential for gain or loss and, therefore, amplify the effects of market volatility on share price.
Emerging Markets Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] EMERGING MARKETS RISK. The Fund may invest in Underlying ETFs that hold securities of issuers located in emerging market countries. Investments in securities issued by governments and 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, auditing and reporting requirements, unsettled securities laws, unreliable securities valuation and greater risk associated with custody of securities. Financial and other reporting by companies and government entities also may be less reliable in emerging market countries. Shareholder claims that are available in the U.S., as well as regulatory oversight and authority that is common in the U.S., including for claims based on fraud, may be difficult or impossible for shareholders of securities in emerging market countries or for U.S. authorities to pursue. For funds that track an index or are managed based upon a benchmark, the index may not weight the securities in emerging market countries on the basis of investor protection limitations, financial reporting quality or available oversight mechanisms. 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.
ETF Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] ETF RISK. The Fund’s investment in shares of ETFs subjects it to the risks of owning the securities underlying the ETF, as well as the same structural risks faced by an investor purchasing shares of the Fund, including premium/discount risk and trading issues risk. As a shareholder in another ETF, the Fund bears its proportionate share of the ETF’s expenses, subjecting Fund shareholders to duplicative expenses.
Extension Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] EXTENSION RISK. The Fund invests in Underlying ETFs that hold debt securities. Extension risk is the risk that, when interest rates rise, certain obligations will be paid off by the issuer (or other obligated party) more slowly than anticipated, causing the value of these debt securities to fall. Rising interest rates tend to extend the duration of debt securities, making their market value more sensitive to changes in interest rates. The value of longer-term debt securities generally changes more in response to changes in interest rates than shorter-term debt securities. As a result, in a period of rising interest rates, securities may exhibit additional volatility and may lose value.
Floating Rate Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] FLOATING RATE SECURITIES RISK. The Fund may invest in Underlying ETFs that hold floating rate securities. Floating rate securities are structured so that the security’s coupon rate fluctuates based upon the level of a reference rate. As a result, the coupon on floating rate securities will generally decline in a falling interest rate environment, causing an investor to experience a reduction in the income it receives from the security. A floating rate security’s coupon rate resets periodically according to the terms of the security. Consequently, in a rising interest rate environment, floating rate securities with coupon rates that reset infrequently may lag behind the changes in market interest rates. Floating rate securities may also contain terms that impose a maximum coupon rate the issuer will pay, regardless of the level of the reference rate which would decrease the value of the security.
High Yield Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] HIGH YIELD SECURITIES RISK. The Fund may invest in Underlying ETFs that hold high yield securities. High yield securities, or “junk” bonds, are subject to greater market fluctuations, are less liquid and provide a greater risk of loss than investment grade securities, and therefore, are considered to be highly speculative. In general, high yield securities may have a greater risk of default than other types of securities and could cause income and principal losses for an Underlying ETF.
Hybrid Capital Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] HYBRID CAPITAL SECURITIES RISK. The Fund may invest in Underlying ETFs that hold hybrid capital securities. Hybrid capital securities are subject to the risks of equity securities and debt securities. The claims of holders of hybrid capital securities of an issuer are generally subordinated to those of holders of traditional debt securities in bankruptcy, and thus hybrid capital securities may be more volatile and subject to greater risk than traditional debt securities, and may in certain circumstances be even more volatile than traditional equity securities. At the same time, hybrid capital securities may not fully participate in gains of their issuer and thus potential returns of such securities are generally more limited than traditional equity securities, which would participate in such gains. The terms of hybrid capital securities may vary substantially and the risks of a particular hybrid capital security will depend upon the terms of the instrument, but may include the credit risk of the issuer, as well as liquidity risk, since they often are customized to meet the needs of an issuer or a particular investor, and therefore the number of investors that buy such instruments in the secondary market may be small.
Income Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] INCOME RISK. The Fund invests in Underlying ETFs that hold income-producing securities. The Fund's income may decline when interest rates fall or if there are defaults in the portfolio of an Underlying ETF. This decline can occur because an Underlying ETF may subsequently invest in lower-yielding securities as debt securities in its portfolio mature, are near maturity or are called, or an Underlying ETF otherwise needs to purchase additional debt securities.
Inflation Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] INFLATION RISK. The Fund invests in Underlying ETFs that hold securities that are subject to inflation risk. Inflation risk is the risk that the value of assets or income from investments will be less in the future as inflation decreases the value of money. As inflation increases, the present value of an Underlying ETF’s assets and distributions may decline.
Interest Rate Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] INTEREST RATE RISK. The Fund invests in Underlying ETFs that hold securities subject to interest rate risk. Interest rate risk is the risk that the value of the debt securities in an investor’s portfolio will decline because of rising market interest rates. Interest rate risk is generally lower for shorter term debt securities and higher for longer-term debt securities. An investor may be subject to a greater risk of rising interest rates than would normally be the case during periods of low interest rates. Duration is a reasonably accurate measure of a debt security’s price sensitivity to changes in interest rates and a common measure of interest rate risk. Duration measures a debt security’s expected life on a present value basis, taking into account the debt security’s yield, interest payments and final maturity. In general, duration represents the expected percentage change in the value of a security for an immediate 1% change in interest rates. For example, the price of a debt security with a three-year duration would be expected to drop by approximately 3% in response to a 1% increase in interest rates. Therefore, prices of debt securities with shorter durations tend to be less sensitive to interest rate changes than debt securities with longer durations. Higher sensitivity to interest rates is generally correlated with higher levels of volatility and, therefore, greater risk. As the value of a debt security changes over time, so will its duration.
Large Capitalization Companies Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] LARGE CAPITALIZATION COMPANIES RISK. Large capitalization companies may grow at a slower rate and be less able to adapt to changing market conditions than smaller capitalization companies. Thus, the return on investment in securities of large capitalization companies may be less than the return on investment in securities of small and/or mid capitalization companies. The performance of large capitalization companies also tends to trail the overall market during different market cycles.
Liquidity Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] LIQUIDITY RISK. The Fund may invest in Underlying ETFs that hold certain investments that may be subject to restrictions on resale, trade over-the-counter or in limited volume, or lack an active trading market. Accordingly, an Underlying ETF may not be able to sell or close out of such investments at favorable times or prices (or at all), or at the prices approximating those at which the Underlying ETF currently values them. Illiquid securities may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value.
Management Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] MANAGEMENT RISK. The Fund is subject to management risk because it is an actively managed portfolio. In managing the Fund’s investment portfolio, the portfolio managers will apply investment techniques and risk analyses that may not produce the desired result. There can be no guarantee that the Fund will meet its investment objectives.
Market Maker Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] 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 makers. 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 [Member]  
Prospectus [Line Items]  
Risk [Text Block] MARKET RISK. Market risk is the risk that a particular investment, or shares of the Fund in general, may fall in value. Securities are subject to market fluctuations caused by real or perceived adverse economic, political, and regulatory factors 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. In addition, local, regional or global events such as war, acts of terrorism, market manipulation, government defaults, government shutdowns, regulatory actions, political changes, diplomatic developments, the imposition of sanctions and other similar measures, spread of infectious diseases or other public health issues, recessions, natural disasters, or other events could have a significant negative impact on the Fund and its investments. Any of such circumstances could have a materially negative impact on the value of the Fund’s shares, the liquidity of an investment, and may result in increased market volatility. During any such events, the Fund’s shares may trade at increased premiums or discounts to their net asset value, the bid/ask spread on the Fund’s shares may widen and the returns on investment may fluctuate.
Mortgage Related Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] MORTGAGE-RELATED SECURITIES RISK. The Fund may invest in Underlying ETFs that hold mortgage-related securities. Mortgage-related securities are subject to the same risks as investments in other types of debt securities, including credit risk, interest rate risk, liquidity risk and valuation risk. However, these investments make an Underlying ETF more susceptible to adverse economic, political or regulatory events that affect the value of real estate. Mortgage-related securities are also significantly affected by the rate of prepayments and modifications of the mortgage loans underlying those securities, as well as by other factors such as borrower defaults, delinquencies, realized or liquidation losses and other shortfalls. The incidence of borrower defaults or delinquencies may rise significantly during financial downturns and could adversely affect the value of mortgage-related securities held by the Fund. Events such as war, acts of terrorism, spread of infectious diseases or other public health issues, recessions, or other events that result in broad and simultaneous financial hardships for individuals and businesses could have a significant negative impact on the value of mortgage-related securities. Mortgage-related securities are particularly sensitive to prepayment risk, given that the term to maturity for mortgage loans is generally substantially longer than the expected lives of those securities. As the timing and amount of prepayments cannot be accurately predicted, the timing of changes in the rate of prepayments of the mortgage loans may significantly affect a mortage-related security's actual yield to maturity. Along with prepayment risk, mortgage-related securities are significantly affected by interest rate risk.
Non Agency Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] NON-AGENCY SECURITIES RISK. The Fund may invest in Underlying ETFs that hold asset-backed and/or mortgage-backed securities offered by non-governmental issuers (known as "non-agency securities"). Investments in asset-backed or mortgage-backed securities offered by non-governmental issuers, such as commercial banks, savings and loans, private mortgage insurance companies, mortgage bankers and other secondary market issuers are subject to additional risks. There are no direct or indirect government or agency guarantees of payments in loan pools created by non-government issuers. Securities issued by private issuers are subject to the credit risks of the issuers. An unexpectedly high rate of defaults on the loan pool may adversely affect the value of a non-agency security and could result in losses to the Underlying ETFs. The risk of such defaults is generally higher in the case of pools that include subprime loans. Non-agency securities are typically traded “over-the-counter” rather than on a securities exchange and there may be a limited market for the securities, especially when there is a perceived weakness in the mortgage and real estate market sectors. Without an active trading market, the non-agency mortgage-related securities held by an Underlying ETF may be particularly difficult to value because of the complexities involved in assessing the value of the underlying loans and the value of these securities can change dramatically over time.
Non US Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] NON-U.S. SECURITIES RISK. The Fund may invest in Underlying ETFs that hold non-U.S. securities. Non-U.S. securities are subject to higher volatility than securities of domestic issuers due to possible adverse political, social or economic developments, restrictions on foreign investment or exchange of securities, capital controls, lack of liquidity, currency exchange rates, excessive taxation, government seizure of assets, the imposition of sanctions by foreign governments, different legal or accounting standards, and less government supervision and regulation of securities exchanges in foreign countries.
Operational Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] OPERATIONAL RISK. The Fund is subject to risks arising from various operational factors, including, but not limited to, human error, processing and communication errors, errors of the Fund’s service providers, counterparties or other third-parties, failed or inadequate processes and technology or systems failures. These errors or failures may adversely affect the Fund’s operations, including its ability to execute its investment process, calculate or disseminate its NAV or intraday indicative optimized portfolio value in a timely manner, and process creations or redemptions. The Fund relies on third-parties for a range of services, including custody, valuation, administration, transfer services, securities lending and accounting, among many others. Any delay or failure relating to engaging or maintaining such service providers may affect the Fund’s ability to meet its investment objectives. Although the Fund and the Fund's investment advisor seek to reduce these operational risks through controls and procedures, there is no way to completely protect against such risks.
Preferred Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] PREFERRED SECURITIES RISK. The Fund may invest in Underlying ETFs that hold preferred securities. Preferred securities combine some of the characteristics of both common stocks and bonds. Preferred securities are typically subordinated to bonds and other debt securities in a company’s capital structure in terms of priority to corporate income, subjecting them to greater credit risk than those debt securities. Generally, holders of preferred securities have no voting rights with respect to the issuing company unless preferred dividends have been in arrears for a specified number of periods, at which time the preferred security holders may obtain limited rights. In certain circumstances, an issuer of preferred securities may defer payment on the securities and, in some cases, redeem the securities prior to a specified date. Preferred securities may also be substantially less liquid than other securities, including common stock.
Premium Discount Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] 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. During stressed market conditions, the market for the Fund’s shares may become less liquid in response to deteriorating liquidity in the market for the Fund’s underlying portfolio holdings, which could in turn lead to differences between the market price of the Fund’s shares and their net asset value and the bid/ask spread on the Fund’s shares may widen.
Prepayment Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] PREPAYMENT RISK. The Fund will invest in Underlying ETFs that hold debt securities. Prepayment risk is the risk that the issuer of a debt security will repay principal prior to the scheduled maturity date. Debt securities allowing prepayment may offer less potential for gains during a period of declining interest rates as an Underlying ETF may be required to reinvest the proceeds of any prepayment at lower interest rates. These factors may cause the value of an investment in the Fund to change.
Repurchase Agreement Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] REPURCHASE AGREEMENT RISK. The Fund may invest in Underlying ETFs that utilize repurchase agreements. Repurchase agreements are subject to the risk of failure. If an Underlying ETF’s counterparty defaults on its obligations and the Underlying ETF is delayed or prevented from recovering the collateral, or the value of the collateral is insufficient, the Underlying ETF may realize a loss.
Restricted Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] RESTRICTED SECURITIES RISK. The Fund may invest in Underlying ETFs that hold restricted securities. Restricted securities are securities that cannot be offered for public resale unless registered under the applicable securities laws or that have a contractual restriction that prohibits or limits their resale. An Underlying ETF may be unable to sell a restricted security on short notice or may be able to sell it only at a price below current value.
Senior Loan Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] SENIOR LOAN RISK. The Fund may invest in Underlying ETFs that hold senior loans. Senior loans represent debt obligations of sub-investment grade corporate borrowers, similar to high yield bonds; however, senior loans are different from traditional high yield bonds in that senior loans are typically senior to other obligations of the borrower and generally secured by a lien on all or some portion of the assets of the borrower. The senior loan market has seen a significant increase in loans with weaker lender protections including, but not limited to, limited financial maintenance covenants or, in some cases, no financial maintenance covenants (i.e., “covenant-lite loans”) that would typically be included in a traditional loan agreement and general weakening of other restrictive covenants applicable to the borrower such as limitations on incurrence of additional debt, restrictions on payments of junior debt or restrictions on dividends and distributions. Weaker lender protections such as the absence of financial maintenance covenants in a loan agreement and the inclusion of “borrower-favorable” terms may impact recovery values and/or trading levels of senior loans in the future. The absence of financial maintenance covenants in a loan agreement generally means that the lender may not be able to declare a default if financial performance deteriorates. This may hinder the ability of an Underlying ETF to reprice credit risk associated with a particular borrower and reduce the ability of an Underlying ETF to restructure a problematic loan and mitigate potential loss. As a result, the Fund’s exposure to losses on investments in senior loans may be increased, especially during a downturn in the credit cycle or changes in market or economic conditions. Senior loans are also subject to the same risks as investments in other types of debt securities, including credit risk, interest rate risk, liquidity risk and valuation risk that may be heightened because of the limited public information available regarding senior loans. If an Underlying ETF holds a senior loan through another financial institution or relies on a financial institution to administer the loan, its receipt of principal and interest on the loan may be subject to the credit risk of that financial institution. Although senior loans are generally secured by specific collateral, there can be no assurance that liquidation of such collateral would satisfy the borrower’s obligation in the event of non-payment of scheduled interest or principal or that such collateral could be readily liquidated. No active trading market may exist for certain senior loans, which may impair the ability of an Underlying ETF to realize full value in the event of the need to sell its position in a senior loan and which may make it difficult to accurately value senior loans. Lastly, senior loans may not be considered “securities,” and an Underlying ETF may not be entitled to rely on the anti-fraud protections of the federal securities laws.
Significant Exposure Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] SIGNIFICANT EXPOSURE RISK. To the extent that an Underlying ETF invests a significant 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 it were more broadly diversified. A significant exposure makes an Underlying ETF more susceptible to any single occurrence and may subject the Underlying ETF to greater market risk than a fund that is more broadly diversified.
Smaller Companies Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] 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, 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.
Sovereign And Quasi Sovereign Debt Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] SOVEREIGN AND QUASI-SOVEREIGN DEBT SECURITIES RISK. The Fund may invest in Underlying ETFs that hold sovereign and/or quasi-sovereign debt securities. Sovereign and quasi-sovereign debt securities that are issued or guaranteed by foreign governmental entities. Investments in such securities are subject to the risk that the relevant sovereign government or governmental entity may delay or refuse to pay interest or repay principal on its debt. Such delays or refusals may be due to cash flow problems, insufficient foreign currency reserves, political considerations, the size of its debt relative to the economy or the failure to put in place economic reforms required by the International Monetary Fund or other multilateral agencies. There is no legal process for collecting sovereign debt that is not repaid, nor are there bankruptcy proceedings through which all or part of the unpaid sovereign debt may be collected.
Trading Issues Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] TRADING ISSUES RISK. Trading in Fund 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 Fund shares on the Exchange is subject to trading halts caused by extraordinary market volatility pursuant to the Exchange’s “circuit breaker” rules. 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, the Fund does not have enough shareholders, or if the Fund is unable to proceed with creation and/or redemption orders.
US Government Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] U.S. GOVERNMENT SECURITIES RISK. The Fund invests in Underlying ETFs that invest in U.S. government securities. U.S. government securities are subject to interest rate risk but generally do not involve the credit risks associated with investments in other types of debt securities. As a result, the yields available from U.S. government securities are generally lower than the yields available from other debt securities. U.S. government securities are guaranteed only as to the timely payment of interest and the payment of principal when held to maturity. While securities issued or guaranteed by U.S. federal government agencies (such as Ginnie Mae) are backed by the full faith and credit of the U.S. Department of the Treasury, securities issued by government sponsored entities (such as Fannie Mae and Freddie Mac) are solely the obligation of the issuer and generally do not carry any guarantee from the U.S. government.
Valuation Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] VALUATION RISK. The Fund will invest in Underlying ETFs that hold debt securities. The sale price the Underlying ETF could receive for a security may differ from the Underlying ETF’s valuation of the security, particularly for securities that trade in low volume or volatile markets or that are valued using a fair value methodology. Unlike publicly traded securities that trade on national securities exchanges, there is no central place or exchange for trading most debt securities. Debt securities generally trade on an “over-the-counter” market. Due to the lack of centralized information and trading, and variations in lot sizes of certain debt securities, the valuation of debt securities may carry more uncertainty and risk than that of publicly traded securities. Debt securities are commonly valued by third-party pricing services that utilize a range of market-based inputs and assumptions, including readily available market quotations obtained from broker-dealers making markets in such securities, cash flows and transactions for comparable instruments. However, because the available information is less reliable and more subjective, elements of judgment may play a greater role in valuation of debt securities than for other types of securities. Different pricing services may incorporate different assumptions and inputs into their valuation methodologies, potentially resulting in different values for the same securities. As a result, if the Advisor were to change its valuation policies, or if the Underlying ETF were to change pricing services, or if a pricing service were to change its valuation methodology, there could be a material impact, either positive or negative, on the Underlying ETF’s net asset value. Additionally, pricing services generally price debt securities assuming orderly transactions of an institutional “round lot” size, but some trades may occur in smaller, “odd lot” sizes, often at lower prices than institutional round lot trades. There is no assurance that the Underlying ETF will be able to sell a portfolio security at the price established by the pricing service, which could result in a loss to the Underlying ETF and, in turn, the Fund. In addition, the value of the debt securities in the Underlying ETF's portfolio may change on days or during time periods when shareholders will not be able to purchase or sell the Fund's shares. Net asset value calculation may also be impacted by operational risks arising from factors such as failures in systems and technology.
When Issued TBA And Delayed Delivery Transactions Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] WHEN-ISSUED, TBA AND DELAYED DELIVERY TRANSACTIONS RISK. The Fund may invest in Underlying ETFs that purchase securities on a when-issued, TBA, delayed delivery or forward commitment basis In such a transaction, the purchase price of the securities is typically fixed at the time of the commitment, but delivery and payment can take place a month or more after the date of the commitment. At the time of delivery of the securities, the value may be more or less than the purchase or sale price. Purchasing securities on a when-issued, TBA, delayed delivery or forward commitment basis may give rise to investment leverage and may increase the Underlying ETF’s volatility. Default by, or bankruptcy of, a counterparty to a when-issued, TBA, delayed delivery or forward commitment transaction would expose the Underlying ETF to possible losses because of an adverse market action, expenses or delays in connection with the purchase or sale of the pools specified in such transaction.
Risk Lose Money [Member]  
Prospectus [Line Items]  
Risk [Text Block] You could lose money by investing in the Fund.
Risk Not Insured Depository Institution [Member]  
Prospectus [Line Items]  
Risk [Text Block] 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.