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Inverse NASDAQ-100 2x Strategy Fund Investment Risks - Class H [Member] - Inverse NASDAQ-100 2x Strategy Fund
Mar. 31, 2026
Compounding Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Compounding Risk—In addition to the correlation risks described under “Correlation Risk”, the Fund’s returns are subject to the effects of compounding, which generally will cause the Fund’s performance to not correlate to the performance of the benchmark over periods greater than a single day, before accounting for fees and fund expenses. Compounded returns are the result of reinvesting daily returns over periods greater than a single day. The Fund’s compounded returns for periods greater than a single day will be different than the performance of the benchmark over the same period. The effects of compounding on the performance of the Fund will be more pronounced when the underlying index experiences increased volatility, the greater the leverage employed in the Fund, and over longer holding periods. Compounding affects the performance of all investments over time, but has a more significant effect on a leveraged index fund because the magnified changes in performance produced by the use of leverage lead to greater increases and decreases in the fund’s daily returns which are then compounded over time. The effects of compounding, therefore, have a more significant effect on the Fund because it seeks to match a multiple of the inverse performance of the Fund’s underlying index on a daily basis. Fund performance for periods greater than one day can be estimated given any set of assumptions for the following factors: (a) underlying index performance; (b) underlying index volatility; (c) financing rates associated with leverage; (d) other Fund expenses; (e) dividends or interest paid by companies in the underlying index; and (f) period of time. The table below illustrates the impact of two principal factors – volatility and index performance – on Fund performance. The table shows estimated Fund returns for a number of combinations of performance and volatility over a one-year period. Performance shown in the table assumes: (a) no dividends paid by the companies included in the underlying index; (b) no Fund expenses; and (c) a cost of leverage of zero percent. If Fund expenses, including the cost of leverage, were included, the Fund’s performance would be lower than shown. The unshaded areas in the table below represent those scenarios where the Fund can be expected to return more than twice the inverse performance of the underlying index; conversely, the shaded areas in the table below represent those scenarios where the Fund can be expected to return the same or less than twice the inverse performance of the underlying index.Index PerformanceAnnualized Volatility1x-2x10%25%50%75%100%-60%120%506%404%199%13%-69%-50%100%286%229%91%-27%-82%-40%80%171%128%33%-49%-86%-30%60%99%70%-1%-62%-90%-20%40%52%31%-27%-70%-93%-10%20%20%3%-42%-77%-94%0%0%-3%-18%-52%-81%-96%10%-20%-19%-31%-61%-84%-96%20%-40%-32%-43%-67%-87%-97%30%-60%-42%-51%-72%-89%-97%40%-80%-50%-58%-75%-91%-97%50%-100%-57%-63%-79%-92%-98%60%-120%-62%-68%-82%-93%-98%The underlying index’s annualized historical volatility rate for the five-year period ended June 30, 2026 is 20.74%. The underlying index’s highest one-year volatility rate during the five-year period is 26.55%. The underlying index’s annualized performance for the five-year period ended June 30, 2026 is 16.68%. Historical underlying index volatility and performance are not indications of what the underlying index volatility and performance will be in the future. The table is intended to isolate the effects of the underlying index volatility and index performance on the return of the Fund, and underscore that the Fund is designed as a short-term trading vehicle for investors who intend to actively monitor and manage their portfolios.
Correlation Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Correlation Risk—A number of factors may affect the Fund’s ability to achieve a high degree of correlation with its benchmark, including instances in which the Fund does not hold or have exposure to each component security of the underlying index and the effect of compounding on the Fund’s returns, and there can be no guarantee that the Fund will achieve a high degree of correlation. Failure to achieve a high degree of correlation may prevent the Fund from achieving its investment objective. The Fund does not attempt to, and should not be expected to, provide returns which are an inverse multiple of the returns of the underlying index for periods other than a single day. The risk of the Fund not achieving its daily investment objective will be more acute when the underlying index has an extreme one-day movement approaching 50%. In addition, as a result of compounding, the Fund’s performance for periods greater than a single day is likely to be either greater than or less than the inverse of the performance of the underlying index times the stated multiple in the Fund’s investment objective, before accounting for Fund fees and expenses.
Counterparty Credit Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Counterparty Credit Risk—The Fund makes investments in financial instruments and OTC-traded derivatives involving counterparties to gain exposure to a particular group of securities, index, asset class or other reference asset without actually purchasing those securities or investments, to hedge a position, or for other investment purposes. Through these investments and related arrangements (e.g., prime brokerage or securities lending arrangements or derivatives transactions), the Fund is exposed to credit risks that the counterparty may be unwilling or unable to make timely payments or otherwise to meet its contractual obligations. If the counterparty becomes insolvent or defaults on (or otherwise becomes unable or unwilling to perform) its payment or other obligations to the Fund, the Fund may not receive the full amount that it is entitled to receive or may experience delays in recovering the collateral or other assets held by, or on behalf of, the counterparty. If this occurs, the value of your shares in the Fund will decrease. Counterparty credit risk also includes the related risk of having potentially significant exposure to such counterparty.
Depositary Receipt Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Depositary Receipt Risk—The Fund may hold the securities of non-U.S. companies in the form of depositary receipts. The underlying securities of the depositary receipts in the Fund’s portfolio are subject to fluctuations in foreign currency exchange rates that may affect the value of the Fund’s portfolio. In addition, the value of the securities underlying the depositary receipts may change materially when the U.S. markets are not open for trading. Investments in the underlying foreign securities also involve political and economic risks distinct from those associated with investing in the securities of U.S. issuers.
Derivatives Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Derivatives Risk—Derivatives and other instruments (collectively referred to in this paragraph as “derivatives”) pose risks in addition to and greater than those associated with investing directly in securities, currencies or other investments, including risks relating to leverage, market conditions and market risk, imperfect correlations with underlying investments or the Fund’s other portfolio holdings, high price volatility, lack of availability, counterparty credit, liquidity, valuation, operational and legal restrictions and risk. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with ordinary portfolio securities transactions. In addition, the use of derivatives may result in leverage, which may cause the Fund to be more volatile and riskier than if it had not been leveraged. Changes in the value of a derivative also may create sudden margin delivery or settlement payment obligations for the Fund, which can materially affect the performance of the Fund, its liquidity, and other aspects of the Fund’s risk profile. The Fund’s use of derivatives to obtain short exposure may result in greater volatility of the Fund's net asset value (“NAV”) per share. If the Advisor is incorrect about its expectations of market conditions, the use of derivatives also could result in a loss, which in some cases may be unlimited. Certain risks are specific to the particular type of derivative instrument in which the Fund may invest. For example, some of the derivatives in which the Fund invests may be traded (and privately negotiated) in the OTC market. OTC derivatives are subject to heightened counterparty, credit, legal, liquidity and valuation risks. Futures Contracts Risk—Futures contracts are exchange-traded contracts that call for the future delivery of an asset at a certain price and date, or cash settlement of the terms of the contract. Risks of futures contracts include imperfect correlation between the movements in the price of the instruments and the price of the underlying assets. In addition, there is a risk that the Fund may not be able to enter into a closing transaction because of an illiquid market. Exchanges can limit the number of futures positions that can be held or controlled by the Fund or the Advisor, thus limiting the ability to implement the Fund’s strategies. Futures markets are highly volatile and the use of futures may increase the volatility of the Fund’s NAV. Futures also are subject to leverage and liquidity risks. The Fund may invest in standard futures contracts, e-mini futures contracts, and micro e-mini futures contracts depending on the investment exposure needs of the Fund. E-mini futures contracts and micro e-mini futures contracts are similar to standard futures contracts, except that they are electronically traded and e-mini futures contracts generally are one-fifth the size of standard futures contracts and micro e-mini futures contracts generally are one-tenth the size of e-mini futures contracts. Options Risk—Options and options on futures contracts give the holder of the option the right, but not the obligation, to buy (or to sell) a position in a security or in a contract to the writer of the option, at a certain price. Options are subject to correlation risk because there may be an imperfect correlation between the options and the markets for underlying instruments that could cause a given transaction to fail to achieve its objectives. The successful use of options depends on the Advisor’s ability to predict correctly future price fluctuations and the degree of correlation between the markets for options and the underlying instruments. Exchanges can limit the number of options positions that can be held or controlled by the Fund or the Advisor, thus limiting the ability to implement the Fund’s strategies. Options also are particularly subject to leverage risk and can be subject to liquidity risk. Swap Agreements Risk—Swap agreements are contracts among the Fund and a counterparty to exchange the return of the pre-determined underlying investment (such as the rate of return of the underlying index). Swap agreements may be negotiated bilaterally and traded OTC between two parties or, for certain standardized swaps, must be traded on a designated contract market or swap execution facility. Risks associated with the use of swap agreements are different from those associated with ordinary portfolio securities transactions, due in part to the fact they could be considered illiquid and many swaps trade on the OTC market. Swaps are particularly subject to counterparty credit, correlation, valuation, liquidity and leveraging risks. While exchange trading and central clearing are intended to reduce counterparty credit risk and increase liquidity, they do not make swap transactions risk-free. Additionally, applicable regulators have adopted rules imposing certain margin requirements, including minimums, on OTC swaps, which may result in the Fund and its counterparties posting higher margin amounts for OTC swaps, which could increase the cost of swap transactions to the Fund and impose added operational complexity.
Early Closing Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Early Closing Risk—The Fund is subject to the risk that unanticipated early closings of securities exchanges and other financial markets may result in the Fund’s inability to buy or sell securities or other financial instruments on that day and may cause the Fund to incur substantial trading losses.
Equity Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Equity Securities Risk—Equity securities include common stocks and other equity and equity-related securities (and securities convertible into stocks). The Fund is exposed to the risks of equity securities primarily through its investments in equity-related derivatives and other investments. The prices of equity securities generally fluctuate more than those of fixed-income investments, may rise or fall rapidly or unpredictably, and may reflect real or perceived changes in the issuing company’s financial condition and changes in the overall market or economy. Common stocks generally represent the riskiest investment in a company and dividend payments (if declared) to preferred stockholders generally rank junior to payments due to a company’s debtholders. An increase in the value of equity securities to which the Fund has exposure will adversely affect the value of your investment in the Fund.
Foreign Issuer Exposure Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Foreign Issuer Exposure Risk—The Fund may invest in securities of foreign companies directly or in financial instruments that are indirectly linked to the performance of foreign issuers, such as ADRs. The Fund’s exposure to foreign issuers and investments in foreign securities, if any, carry unique, additional and heightened risks when compared to U.S. securities, including, but not limited to: currency fluctuations; adverse political (including geopolitical), social and economic developments; trade restrictions (including tariffs) or other government restrictions by the U.S. or other governments; unreliable, untimely or less publicly available information; less government supervision; reporting, accounting, and auditing standards that are not comparable to those in the United States; less liquidity and more volatility; limited legal recourse; and higher transactional costs.
Industry Concentration Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Industry Concentration Risk—The Fund may concentrate its investments in a limited number of issuers conducting business in the same industry or group of related industries. To the extent the Fund does so, the Fund is more vulnerable to adverse market, economic, regulatory, political or other developments affecting that industry or group of related industries than a fund that invests its assets more broadly. As of June 30, 2026, the underlying index components, and thus the Fund's investments, are concentrated in securities issued by companies in the industries described below.  The industries in which the underlying index components, and thus the Fund's assets, may be concentrated will vary as the composition of the underlying index changes over time. 
Semiconductors And Semiconductor Equipment Industry [Member]  
Prospectus [Line Items]  
Risk [Text Block] Semiconductors & Semiconductor Equipment Industry. As a result of the Fund's concentration in the Semiconductors & Semiconductor Equipment Industry, the Fund is subject to the risks associated with that Industry. The Semiconductors & Semiconductor Equipment Industry includes manufacturers of semiconductor equipment, including equipment used in the solar power industry (e.g., raw wafers, gases, liquids and related packaging and material delivery systems), and semiconductors and related products, including manufacturers of solar modules, cells, integrated circuit devices, diodes and light-emitting diodes (LEDs), microprocessors and chips. Companies in the Semiconductors & Semiconductor Equipment Industry rely heavily on technology. The prices of the securities of companies in the Semiconductors & Semiconductor Equipment Industry may fluctuate widely due to competitive pressures, increased sensitivity to short product cycles and aggressive pricing, heavy expenses incurred for research and development of products or services that prove unsuccessful, problems related to bringing products to market, and rapid obsolescence of products. Legislative or regulatory changes and increased government supervision also may affect companies in the Semiconductors & Semiconductor Equipment Industry. The Semiconductors & Semiconductor Equipment Industry is a separate industry within the Information Technology Sector.
Software Industry [Member]  
Prospectus [Line Items]  
Risk [Text Block] Software Industry. As a result of the Fund's concentration in the Software Industry, the Fund is subject to the risks associated with that Industry. The Software Industry includes companies engaged in developing and producing software designed for specialized applications for the business and consumer markets, including enterprise and technical software, cloud-based software and companies engaged in bitcoin mining, and in developing and producing software for operating systems and platforms, database management software and firewalls. The prices of the securities of issuers in the Software Industry may fluctuate widely due to competitive pressures, increased sensitivity to short product cycles and aggressive pricing, heavy expenses incurred for research and development of products or services that prove unsuccessful, challenges related to bringing products to market, and rapid obsolescence of products. In addition, many software companies rely on a combination of patents, copyrights, trademarks and trade secret laws to establish and protect their proprietary rights in their products and technologies. There can be no assurance that the steps taken by software companies to protect their proprietary rights will be adequate to prevent misappropriation of their technology or that competitors will not independently develop technologies that are substantially equivalent or superior to such companies' technology. Legislative or regulatory changes and increased government supervision also may affect companies in the Software Industry. The Software Industry is a separate industry within the Information Technology Sector.
Interest Rate Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Interest Rate Risk—Fixed income and other debt instruments are subject to the possibility that interest rates could change (or are expected to change). Changes in interest rates (or the expectation of such changes) can be difficult to forecast and may adversely affect the Fund’s investments in these instruments, such as the value or liquidity of, and income generated by, the investments. Interest rates may change as a result of a variety of factors, and the change may be sudden and significant, with unpredictable impacts on the financial markets and the Fund’s investments. Fixed income and other debt instruments with longer durations are more sensitive to changes in interest rates and, thus, subject to more volatility than similar instruments with shorter durations. Generally, when interest rates increase, the values of previously issued fixed income and other debt instruments decline and when interest rates decrease, the values of fixed income and other debt instruments rise. During periods of rising interest rates, changes in interest rates on adjustable rate securities may lag behind changes in market rates, which may cause the value of such securities to decline until their interest rates reset to market rates. During periods of declining interest rates, because the interest rates on adjustable rate securities generally reset downward, their market value is unlikely to rise to the same extent as the value of comparable fixed rate securities. The Fund’s yield, returns, and performance may be adversely affected by changing interest rates and the Fund’s NAV per share may be more volatile during changing interest rate environments. Changes in fiscal, economic, monetary and other policies or measures have in the past, and may in the future, cause or exacerbate the risks associated with changing interest rates. Changes in interest rates may also lead to an increase in Fund redemptions, which may result in high portfolio turnover costs and lower valuations, thereby adversely affecting the Fund’s performance.
Large Capitalization Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Large-Capitalization Securities Risk—The Fund is subject to the risk that large-capitalization securities may outperform other segments of the equity market or the equity market as a whole. Larger, more established companies may be unable to respond quickly to new competitive challenges such as changes in technology and may not be able to attain the high growth rate of smaller companies, especially during extended periods of economic expansion.
Leveraging Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Leveraging Risk—The Fund achieves leveraged exposure to the underlying index through the use of derivative instruments. The more the Fund invests in leveraged instruments, the more this leverage will magnify any losses on those investments. The Fund’s investment in these instruments generally requires a small investment relative to the amount of investment exposure assumed. As a result, such investments may give rise to losses that exceed the amount invested in those instruments. Since the Fund’s investment strategy involves consistently applied leverage, the value of the Fund’s shares will tend to increase or decrease more than the value of any increase or decrease in the underlying index. Leverage will have the effect of magnifying tracking error and also may increase the Fund’s sensitivity to various risks and interest rate environments.
Liquidity and Valuation Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Liquidity and Valuation Risk—It may be difficult for the Fund to purchase and sell particular investments to meet redemption requests or otherwise within a reasonable time at a fair price, or the price at which it has been valued by the Advisor for purposes of the Fund’s NAV, causing the Fund to be less liquid and unable to realize what the Advisor believes should be the price of the investment. Valuation of portfolio investments may be difficult, such as during periods of market turmoil or reduced liquidity, and for investments that may, for example, trade infrequently or irregularly. In these and other circumstances, an investment may be valued using fair value methodologies, which are inherently subjective, reflect good faith judgments based on available information and may not accurately estimate the price at which the Fund could sell the investment at that time. Liquidity and valuation risks are heightened in a changing interest rate or volatile environment particularly for fixed-income and other debt instruments.
Market Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Market Risk—The value of, or income generated by, the investments held by the Fund may fluctuate rapidly and unpredictably. These fluctuations may be frequent and significant. In addition, the Fund may incur losses as a result of various market and economic factors, such as those affecting (or perceived to affect) individual companies or issuers or particular industries, or from broader influences, such as general market conditions. In addition, responses to government actions or interventions (including, but not limited, to the threat or imposition of tariffs, trade restrictions, currency restrictions or similar actions) as well as developments related to economic, political (including geopolitical), social, public health, market, extreme weather, natural or man-made disasters or other conditions or events may cause volatility in financial markets and reduced liquidity in equity, credit and/or debt markets, which could adversely impact the Fund and its investments and their value and performance. Under such conditions, the Fund (or an underlying fund) may experience significant redemption activity by shareholders and could be forced to sell portfolio securities or other assets at unfavorable prices in an effort to generate sufficient cash to pay redeeming shareholders. Certain securities may be difficult to value under such conditions. The Fund’s investments may perform poorly or underperform the general securities markets or other types of securities.
OTC Trading Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] OTC Trading Risk—Certain of the derivatives in which the Fund may invest may be traded (and privately negotiated) in the OTC market. While the OTC derivatives market is the primary trading venue for many derivatives, it is largely unregulated and provides for less transparency than a national securities or commodities exchange. As a result and similar to other privately negotiated contracts, the Fund is subject to counterparty credit risk with respect to such derivatives contracts.
Passive Investment Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Passive Investment Risk—The Fund is not actively managed and the Advisor does not attempt to take defensive positions in rising markets. Therefore, the Fund may be subject to greater losses in a rising market than a fund that is actively managed.
Portfolio Turnover Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Portfolio Turnover Risk—Periodic rebalancing of the Fund's holdings  pursuant to its daily investment objective may lead to a greater number of portfolio transactions in the Fund than experienced by other mutual funds. Such frequent and active trading may lead to significantly higher transaction costs because of increased broker commissions associated with such transactions.
Regulatory and Legal Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Regulatory and Legal Risk—U.S. and non-U.S. governmental agencies and other regulators regularly implement additional regulations (or amend regulations) and legislators pass new laws that affect the investments held by the Fund, the strategies used by the Fund and/or the level of regulation or taxation applicable to the Fund, its investments or service providers. These developments impact the investment strategies, performance, costs and operations of the Fund or taxation of shareholders.
Repurchase Agreement Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Repurchase Agreement Risk—The Fund’s investment in repurchase agreements may be subject to market and credit risk with respect to the collateral securing the repurchase agreements. Investments in repurchase agreements also may be subject to the risk that the market value of the underlying obligations may decline prior to the expiration of the repurchase agreement term.
Sector Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Sector Risk—To the extent the components of the Fund’s underlying index, and therefore, the Fund’s holdings, have significant exposure to one or more market sectors, the Fund may be especially sensitive to the developments affecting and risks of such market sectors. The sectors to which the underlying index components, and thus the Fund’s assets, may have significant exposure will vary as the composition of the underlying index changes over time. As of June 30, 2026, the Fund is subject to the Sector Risks described below.
Communication Services Sector Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Communication Services Sector Risk. The Fund's investments are exposed to issuers conducting business in the Communication Services Sector. The Communication Services Sector includes companies that facilitate communication and offer related content and information through various mediums. It includes telecom and media & entertainment companies, including producers of interactive gaming products and companies engaged in content and information creation or distribution through proprietary platforms. The Fund is subject to the risk that the securities of such issuers will underperform the market as a whole due to legislative or regulatory changes, adverse market conditions and/or increased competition affecting the Communication Services Sector. The performance of companies operating in the Communication Services Sector has historically been closely tied to the performance of the overall economy and also is affected by economic growth, consumer confidence, attitudes and spending. Increased sensitivity to short product cycles and aggressive pricing, challenges in bringing products to market and changes in demographics and consumer tastes also can affect the demand for, and success of, communication services products and services in the marketplace.
Consumer Discretionary Sector Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Consumer Discretionary Sector Risk. The Fund’s investments are exposed to issuers conducting business in the Consumer Discretionary Sector. The manufacturing segment of the Consumer Discretionary Sector includes automobiles and components, household durable goods, leisure products, and textiles and apparel. The services segment includes hotels, restaurants and other leisure facilities, and distributors and retailers of consumer discretionary products. The Fund is subject to the risk that the securities of such issuers will underperform the market as a whole due to legislative or regulatory changes, adverse market conditions and/or increased competition affecting the Consumer Discretionary Sector. The performance of companies operating in the Consumer Discretionary Sector has historically been closely tied to the performance of the overall economy, and also is affected by economic growth, consumer confidence, attitudes and spending. Changes in demographics and consumer tastes also can affect the demand for, and success of, consumer products and services in the marketplace. Moreover, the Consumer Discretionary Sector encompasses those businesses that tend to be the most sensitive to economic cycles.
Consumer Staples Sector Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Consumer Staples Sector Risk. The Fund’s investments are exposed to issuers conducting business in the Consumer Staples Sector. The Consumer Staples Sector includes manufacturers and distributors of food, beverages and tobacco and producers of non-durable household goods and personal products. The Consumer Staples Sector also includes distributors and retailers of other consumer staples products, including food and drug retailing companies. The Fund is subject to the risk that the securities of such issuers will underperform the market as a whole due to legislative or regulatory changes, adverse market conditions and/or increased competition affecting the Consumer Staples Sector. The performance of companies operating in the Consumer Staples Sector has historically been closely tied to the performance of the overall economy, and also is affected by consumer confidence, demands and preferences, and spending. In addition, companies in the Consumer Staples Sector may be subject to risks pertaining to the supply of, demand for, and prices of raw materials.
Health Care Sector Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Health Care Sector Risk. The Fund's investments are exposed to issuers conducting business in the Health Care Sector. The Health Care Sector includes health care providers and services, companies that manufacture and distribute health care equipment and supplies, and health care technology companies. It also includes companies involved in the research, development, production and marketing of pharmaceuticals and biotechnology products. The Fund is subject to the risk that the securities of such issuers will underperform the market as a whole due to legislative or regulatory changes, adverse market conditions and/or increased competition affecting the Health Care Sector. The performance of companies operating in the Health Care Sector is closely tied to government regulation and policies (such as health care reform measures) and may be affected by government approval of products and services, competitive pricing pressures, rising costs of medical products and services, product obsolescence, and product liability and other similar litigation. In addition, companies operating in the Health Care Sector are heavily dependent on patent and other intellectual property rights, and a company’s ability to obtain and protect its patents (or the failure to do so) may affect profitability.
Information Technology Sector Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Information Technology Sector Risk. The Fund's investments are exposed to issuers conducting business in the Information Technology Sector. The Information Technology Sector includes companies that offer software and information technology services, manufacturers and distributors of technology hardware and equipment (such as communications equipment, cellular phones, computers and peripherals), electronic equipment and related equipment and materials, and semiconductors and related equipment and materials. The Fund is subject to the risk that the securities of such issuers will underperform the market as a whole due to legislative or regulatory changes, adverse market conditions and/or increased competition affecting the Information Technology Sector. Companies in the Information Technology Sector may be affected by limited product lines, market competition (both domestically and internationally), financial resources and/or personnel. The prices of the securities of companies operating in the Information Technology Sector are closely tied to increased sensitivity to short product cycles and product obsolescence, aggressive pricing, and problems with bringing products to market. Failure to introduce new products, develop and maintain a loyal customer base, or achieve general market acceptance for products could have a material adverse effect on a company’s business. In addition, companies in the Information Technology Sector are heavily dependent on intellectual property and the loss of patent, copyright and trademark protections may adversely affect the profitability of these companies.
Shareholder Trading Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Shareholder Trading Risk—The Fund may be used as a tool for certain investors that employ trading strategies involving frequent trading. Such trading strategies may lead to increased portfolio turnover in the Fund, higher transaction costs, and the possibility of increased short-term capital gains (which will be taxable to shareholders as ordinary income when distributed to them) and/or long-term capital gains.  Large movements of assets into and out of the Fund due to active or frequent trading also may adversely affect the Fund's ability to achieve its investment objective.
Short Sale and Short Exposure Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Short Sale and Short Exposure Risk—Short selling a security involves selling a borrowed security with the expectation that the value of that security will decline, so that the security may be purchased at a lower price when returning the borrowed security. A short exposure through a derivative exposes the Fund to counterparty credit and leverage risks. The loss on a short sale or other short exposure, which, in some cases, may be theoretically unlimited, may be greater than a direct investment in the security itself because the price of the borrowed security may rise, thereby increasing the price at which the security must be purchased. Government actions also may affect the Fund’s ability to engage in short selling.
Tracking Error Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Tracking Error Risk—The Advisor may not be able to cause the Fund’s performance to match that of the Fund’s benchmark, either on a daily or aggregate basis. Factors such as Fund expenses, imperfect correlation between the Fund’s investments and those of the underlying index, rounding of share prices, changes to the composition of the underlying index, regulatory policies, high portfolio turnover rate, and the use of leverage all contribute to tracking error. Tracking error may cause the Fund’s performance to be less than you expect.
Trading Halt Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Trading Halt Risk—The Fund typically will hold futures contracts and short-term options. The major exchanges on which these contracts are traded, such as the Chicago Mercantile Exchange, have established limits on how much the trading price of a futures contract or option may decline over various time periods within a day, and may halt trading in a contract that exceeds such limits. If a trading halt occurs, the Fund may temporarily be unable to purchase or sell certain securities, futures contracts or options. Such a trading halt near the time the Fund prices its shares may limit the Fund’s ability to use leverage and fully invest its assets, which could increase tracking error and adversely affect performance, and may prevent the Fund from achieving its investment objective.
U.S. Government Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] U.S. Government Securities Risk—U.S. government securities may or may not be backed by the full faith and credit of the U.S. government. U.S. government securities are subject to the risks associated with fixed income and debt securities, particularly interest rate risk and credit risk. In addition, U.S. government securities not backed by the full faith and credit of the U.S. government involve credit risk that is greater than other types of U.S. government securities.
Risk Lose Money [Member]  
Prospectus [Line Items]  
Risk [Text Block] The value of an investment in the Fund will fluctuate and is subject to investment risks, which means investors could lose money, including all or part of their investment in the Fund.
Risk Not Insured Depository Institution [Member]  
Prospectus [Line Items]  
Risk [Text Block] An investment in the Fund is not a bank deposit and is not insured or guaranteed by the FDIC or any governmental agency.
Risk Nondiversified Status [Member]  
Prospectus [Line Items]  
Risk [Text Block] Non-Diversification Risk—The Fund is considered non-diversified and can invest a greater portion of its assets in securities of individual issuers than a diversified fund. As a result, changes in the market value of a single issuer's securities could cause greater fluctuations in the value of Fund shares than would occur in a diversified fund. The Fund may become diversified for periods of time solely as a result of changes in the composition of the underlying index (e.g., changes in the relative market capitalization or weights of one or more index component stocks).