The example below is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds.The example assumes that you invest $10,000 in the Fund for the time periods indicated and then hold or sell all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain at current levels. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The Fund will normally invest at least 90% of its net assets (plus any borrowings for investment purposes) in the securities that comprise the Index. The Fund, using an indexing investment approach, attempts to fully replicate, before fees and expenses, the performance of the Index. The Index is owned and is developed, maintained and sponsored by VettaFi LLC (the “Index Provider”). The Index Provider retains the right at any time, upon prior written notice, to modify the Index methodology.According to the Index Provider, the Index seeks to provide exposure to companies with securities listed on major global recognized exchanges that are engaged in the global e-commerce industry. According to the Index Provider, to be eligible for inclusion in the Index, a security must be issued by a company principally engaged in (deriving greater than or equal to 50% of their revenue from) one or a combination of the four following business segments comprising the global e-commerce industry: (1) content navigation; (2) online retail; (3) online marketplace; and (4) e-commerce infrastructure.1.Content Navigation — revenue from advertisers paying to use the search results, social media feeds, email systems, banner ad slots, etc., as vehicles for their ads, and/or paying for the activity/profile data on consumers to efficiently target their ads. These websites primarily organize/help to navigate content produced by others (whether users or advertisers) rather than producing their own content.2.Online Retail — similar to a brick-and-mortar retail store, but online; apart from drop-shipping models, inventories are either created by the retailer (i.e., store-brand goods/services) or bought from brands at wholesale prices so profits are captured by the online retailer, and the online retailer is the one deciding the final price quoted to the consumer.3.Online Marketplace — offer brands/sellers a digital location or platform to list their products and services. These marketplaces offer a lower cost of entry to sellers seeking to engage in the e-commerce space through the platform’s offerings, especially technical and customer support, in exchange for a cut of the profits.4.E-Commerce Infrastructure — logistics and fulfillment for online orders; financial and other technology, services and/or infrastructure required for e-commerce business activities.The Fund will invest at least 80% of its net assets (plus any borrowings for investment purposes) in companies that derive at least 50% of their revenues from at least one of the four e-commerce business segments described above. The Fund may invest up to 20% of its net assets (plus any borrowings for investment purposes) in companies that are engaged in one or more of the four business segments outlined above but do not derive at least 50% of their revenues from at least one of the four business segments.In addition to being principally engaged in one or a combination of the four business segments comprising the e-commerce industry, in order to be eligible for inclusion in the Index a company’s stock must be listed on a major recognized stock exchange, be a constituent of the S-Network Global 5500 Index and meet the size, float and liquidity standards of the Index. Each eligible security is assigned to the business segment where the highest percentage of revenues are derived. The Index then selects the15 stocks with the largest market capitalization from each of the four business segments and assigns an equal weight to each. These weights will deviate based upon market movements in between Index rebalances. The Fund may invest in depositary receipts, emerging market companies, securities denominated in non-U.S. currencies and companies with various market capitalizations, including small capitalization companies.The Index is rebalanced and reconstituted quarterly and the Fund will make corresponding changes to its portfolio shortly after the Index changes are made public. The Index’s quarterly rebalance and reconstitution schedule may cause the Fund to experience a higher rate of portfolio turnover. The Fund will be concentrated (i.e., invests more than 25% of Fund assets) in an industry or a group of industries to the extent that the Index is so concentrated. As of June 28, 2024, the Fund had significant investments in consumer discretionary companies and communication services companies, although this may change from time to time. The Fund's investments will change as the Index changes and, as a result, the Fund may have significant investments in jurisdictions or investment sectors that it may not have had as of June 28, 2024. To the extent the Fund invests a significant portion of its assets in a given jurisdiction or investment sector, the Fund may be exposed to the risks associated with that jurisdiction or investment sector. In order to gain exposure to certain Chinese companies that are included in the Index but are unavailable to direct investment by foreign investors, the Fund invests significantly in non-Chinese shell companies that have created structures known as variable interest entities (“VIEs”) in order to gain exposure to such Chinese companies.The Fund is classified as “non-diversified” under the Investment Company Act of 1940, as amended (the “1940 Act”).

Risk [Heading]

rr_RiskHeading

Principal Risks

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Annual Total Return

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart and table below illustrate the annual calendar year returns of the Fund based on net asset value as well as the average annual Fund and Index returns. The bar chart and table below provide an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year-to-year and by showing how the Fund’s average annual total returns based on net asset value compared to those of the Index and a broad-based market index. The Nasdaq US Benchmark Retail Index is an index designed to provide exposure to U.S. companies comprising the retail sector.

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

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

Bar Chart Footnotes [Text Block]

rr_BarChartFootnotesTextBlock

(1)The Fund's calendar year-to-date total return based on net asset value for the period 12/31/23 to 06/30/24 was 4.65%.

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for the Periods Ended December 31, 2023

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

All after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of any state or local tax.

Performance Table Explanation after Tax Higher

rr_PerformanceTableExplanationAfterTaxHigher

Returns after taxes on distributions reflect the taxed return on the payment of dividends and capital gains. Returns after taxes on distributions and sale of shares assume you sold your shares at period end, and, therefore, are also adjusted for any capital gains or losses incurred. Returns for the market indices do not include expenses, which are deducted from Fund returns, or taxes.

Risk [Text Block]

rr_RiskTextBlock

You could lose money by investing in the Fund.

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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.

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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, which remains at elevated levels, the Federal Reserve and certain foreign central banks have raised interest rates, and the Federal Reserve has begun the process to reverse previously implemented quantitative easing. 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. Recent and 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. 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. 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, 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 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. The COVID-19 global pandemic, or any future public health crisis, and the ensuing policies enacted by governments and central banks have caused and may continue to cause significant volatility and uncertainty in global financial markets, negatively impacting global growth prospects. While vaccines have been developed, there is no guarantee that vaccines will be effective against emerging future variants of the disease. As this 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. 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.

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

INTERNET COMPANIES RISK. Internet companies are subject to rapid changes in technology, hacking or other cyber security events, worldwide competition, rapid obsolescence of products and services, loss of patent protections, cyclical market patterns, evolving industry standards, frequent new product introductions and the considerable risk of owning small capitalization companies that have recently begun operations. Many Internet companies have incurred large losses since their inception and may continue to incur large losses in the hope of capturing market share and generating future revenues. Accordingly, many such companies expect to incur significant operating losses for the foreseeable future, and may never be profitable. The markets in which many Internet companies compete face rapidly evolving industry standards, frequent new service and product announcements, introductions and enhancements and changing customer demands. The failure of an Internet company to adapt to such changes could have a material adverse effect on the company's business. In addition, the widespread adoption of new Internet, networking, telecommunications technologies, or other technological changes could require substantial expenditures by an Internet company to modify or adapt its services or infrastructure, which could have a material adverse effect on an Internet company's business.

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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.

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

ONLINE RETAIL RISK. Companies that operate in the online marketplace, retail and travel segments are subject to fluctuating consumer demand. Unlike traditional brick and mortar retailers, online marketplaces and retailers must assume shipping costs or pass such costs to consumers. Consumer access to price information for the same or similar products may cause companies that operate in the online marketplace, retail and travel segments to reduce profit margins in order to compete. Profit margins in the travel industry are particularly sensitive to seasonal demand, fuel costs and consumer perception of various risks associated with travel to various destinations. Due to the nature of their business models, companies that operate in the online marketplace, retail and travel segments may also be subject to heightened cybersecurity risk, including the risk of theft or damage to vital hardware, software and information systems. The loss or public dissemination of sensitive customer information or other proprietary data may negatively affect the financial performance of such companies to a greater extent than traditional brick and mortar retailers. As a result of such companies being web-based and the fact that they process, store, and transmit large amounts of data, including personal information, for their customers, failure to prevent or mitigate data loss or other security breaches, including breaches of vendors’ technology and systems, could expose companies that operate in the online marketplace, retail and travel segments or their customers to a risk of loss or misuse of such information, adversely affect their operating results, result in litigation or potential liability, and otherwise harm their businesses.

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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.

Risk Return Abstract

rr_RiskReturnAbstract

Risk [Text Block]

rr_RiskTextBlock

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.

Risk Return Abstract

rr_RiskReturnAbstract