Total Annual Fund Operating Expenses:

rr_OtherExpensesOverAssets

none

^[1]

rr_NetExpensesOverAssets

0.79%

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, including commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund’s performance. Because the Fund had not yet commenced operations as of the date of this Prospectus, it does not have a portfolio turnover rate to provide.

rr_ExpenseExampleHeading

EXAMPLE

rr_ExpenseExampleYear01

$ 81

Bar Chart and Performance Table [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Lose Money [Text]

rr_RiskLoseMoney

An investor may lose money by investing in the Fund.

rr_BarChartAndPerformanceTableHeading

PERFORMANCE

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

When provided, the information will provide some indication of the risks of investing in the Fund by showing how the Fund's average annual returns compare with a broad measure of market performance.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.cambriafunds.com

Risk/Return [Heading]

rr_RiskReturnHeading

Cambria Shareholder Yield ETF

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks investment results that correspond (before fees and expenses) generally to the price and yield performance of its underlying index, the Cambria Shareholder Yield Index (the “Underlying Index”).

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy and hold Shares of the Fund. You may also pay brokerage commissions on the purchase and sale of Shares, which are not reflected in the table.

Management Fee:

rr_ManagementFeesOverAssets

0.59%

Portfolio Turnover [Heading]

rr_OtherExpensesOverAssets

none

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

16.00%

rr_ExpenseExampleHeading

EXAMPLE

rr_ExpenseExampleYear01

$ 60

Five Years

rr_ExpenseExampleYear05

329

Strategy Portfolio Concentration [Text]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

rr_StrategyPortfolioConcentration

To the extent that the Underlying Index concentrates (i.e., holds up to 25% of its total assets) in the securities of a particular sector, the Fund is expected to concentrate in that sector to approximately the same extent. As of July 31, 2018, the Fund and the Underlying Index were concentrated in the consumer discretionary and financial services sectors and had significant exposure to companies in the industrial sector.

Risk Not Insured Depository Institution [Text]

rr_RiskNarrativeTextBlock

An investment in the Fund involves risk, including those described below. There is no assurance that the Fund will achieve its investment objective. An investor may lose money by investing in the Fund.

Cyber Security Risk. The Fund, and its service providers, may be susceptible to operational and information security risks resulting from a breach in cyber security, including cyber-attacks. A breach in cyber security, intentional or unintentional, may adversely impact the Fund in many ways, including, but not limited to, disruption of the Fund’s operational capacity, loss of proprietary information, theft or corruption of data, denial-of-service attacks on websites or network resources, and the unauthorized release of confidential information. Cyber-attacks affecting the Fund’s third-party service providers, including Cambria, the custodian, and the transfer agent, market makers, Authorized Participants, or the issuers of securities in which the Fund invests may subject the Fund to many of the same risks associated with direct cyber security breaches.

Dividend Paying Security Risk. Securities that pay high dividends as a group can fall out of favor with the market, causing these companies to underperform companies that do not pay high dividends. Also, changes in the dividend policies of companies owned by the Fund and the capital resources available for these companies’ dividend payments may adversely affect the Fund.

Equity Investing Risk. The values of equity securities could decline generally or could underperform other investments due to factors affecting a specific issuer, market or securities markets generally.

Investment Risk. 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 government agency. When you sell your Shares, they could be worth less than what you paid for them.

Large Capitalization Company Risk. The Fund’s investments in large capitalization companies may underperform other segments of the market because they may be less responsive to competitive challenges and opportunities and unable to attain high growth rates during periods of economic expansion.

Market Events Risk. Turbulence in the financial markets and reduced liquidity may negatively affect issuers, which could have an adverse effect on the Fund. In addition, there is a risk that policy changes by the U.S. Government, Federal Reserve and/or other government actors, such as increasing interest rates, could cause increased volatility in financial markets and higher levels of Fund redemptions, which could have a negative impact on the Fund.

Passive Investment Risk. The Fund is managed with a passive investment strategy, attempting to track the performance of the Underlying Index. As a result, the Fund expects to hold components of the Underlying Index regardless of their current or projected performance. Maintaining investments regardless of market conditions or the performance of individual investments could cause the Fund’s return to be lower than if the Fund employed an active strategy.

Premium-Discount Risk. The Shares may trade above (premium) or below (discount) their net asset value (or “NAV”). The market prices of Shares will generally fluctuate in accordance with changes in NAV as well as the relative supply of, and demand for, Shares on the Exchange. This risk is heightened in times of market volatility or periods of steep market declines.

Quantitative Security Selection Risk. The Underlying Index uses quantitative techniques to determine whether securities should be included in the Underlying Index, and the Underlying Index may not perform as intended if it relies on erroneous or outdated data from one or more third parties. Errors in data used in the quantitative model may occur from time to time and may not be identified and/or corrected before having an adverse impact on the Fund and its shareholders.

Secondary Market Trading Risk. Investors buying or selling Shares in the secondary market may pay brokerage commissions, which may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of Shares. Although the Shares are listed on the Exchange, there can be no assurance that an active or liquid trading market for them will develop or be maintained. In addition, trading in Shares on the Exchange may be halted.

Sector Concentration Risk. To the extent that the Fund’s investments are concentrated in a particular sector, the Fund may be susceptible to loss due to adverse occurrences affecting that sector. As of July 31, 2018, the Fund and the Underlying Index were concentrated in the consumer discretionary and financial services sectors and had significant exposure to companies in the industrial sector.

Consumer Discretionary Sector Risk. The success of consumer product manufacturers and retailers is tied closely to the performance of the overall domestic and international economy, interest rates, competitive 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 products in the marketplace.

Financial Services Sector Risk. Performance of companies in the financial services sector may be adversely impacted by many factors, including, among others, government regulations, economic conditions, credit rating downgrades, changes in interest rates, and decreased liquidity in credit markets. This sector has experienced significant losses in the recent past, and the impact of more stringent capital requirements and of recent or future regulation on any individual financial company or on the sector as a whole cannot be predicted.

Industrial Sector Risk. Issuers in the industrial sector are affected by supply and demand, both for their specific product or service and for industrial sector products in general. The products of such issuers may face obsolescence due to rapid technological developments and frequent new product introduction. Government regulations, world events, economic conditions and exchange rates affect the performance of companies in the industrial sector. Issuers in the industrial sector may be adversely affected by liability for environmental damage, product liability claims and exchange rates. The industrial sector may also be adversely affected by changes or trends in commodity prices, which may be influenced by unpredictable factors.

Small and Medium Capitalization Company Risk. Investing in securities of small and medium capitalization companies involves greater risk than customarily is associated with investing in larger, more established companies. These companies’ securities may be more volatile and less liquid than those of more established companies, and they may be more sensitive to market conditions.

Tracking Error Risk. Although the Fund attempts to track the performance of the Underlying Index, the Fund may not be able to duplicate its exact composition or return due to, among other things, fees and expenses paid by the Fund that are not reflected in the Underlying Index. If the Fund is small, it may experience greater tracking error to its Underlying Index than it otherwise would at higher asset levels.

Value Investment Risk. The Fund’s shareholder yield strategy is a value investment strategy that should be expected to underperform in growth markets. Value investments are subject to the risk that their intrinsic value may never be realized by the market.

rr_RiskNotInsuredDepositoryInstitution

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 government agency.

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table indicate the risks of investing in the Fund by showing how the Fund’s average annual total returns compare with those of a broad measure of market performance. All returns include the reinvestment of dividends and distributions. As always, please note that the Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated performance information is available at www.cambriafunds.com.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.cambriafunds.com

Bar Chart [Heading]

rr_BarChartHeading

Total Annual Returns for Calendar Year Ended December 31

Annual Return 2015

rr_AnnualReturn2015

(1.25%)

Annual Return 2017

rr_AnnualReturn2017

19.74%

Year to Date Return, Label

rr_YearToDateReturnLabel

The Fund's year-to-date total return

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

15.84%

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2016

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst:

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(6.13%)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

Average annual total returns are shown on a before- and after-tax basis for the Fund. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold shares through tax-deferred arrangements, such as 401(k) plans or individual retirement plans.

rr_RiskReturnAbstract

rr_AverageAnnualReturnSinceInception

13.50%

rr_AverageAnnualReturnYear01

19.28%

rr_AverageAnnualReturnInceptionDate

May 13, 2013

rr_RiskReturnAbstract

rr_AverageAnnualReturnSinceInception

10.32%

rr_AverageAnnualReturnYear01

21.83%

rr_AverageAnnualReturnInceptionDate

May 13, 2013

rr_RiskReturnAbstract

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

rr_ExpenseHeading

FEES AND EXPENSES

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Total Annual Fund Operating Expenses:

rr_DistributionAndService12b1FeesOverAssets

none

rr_NetExpensesOverAssets

0.59%

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, including commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund’s performance. For the fiscal year ended April 30, 2018, the Fund’s portfolio turnover rate was 44% of the average value of its portfolio.

Expense Exchange Traded Fund Commissions [Text]

rr_ExpenseExchangeTradedFundCommissions

You may also pay brokerage commissions on the purchase and sale of Shares, which are not reflected in the table.

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example 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 redeem all of your Shares at the end of those periods. The example also assumes that the Fund provides a return of 5% a year and that the operating expenses remain the same. The example does not reflect any brokerage commissions that you may pay on purchases and sales of Shares. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Three Years

rr_ExpenseExampleYear03

189

Ten Years

rr_ExpenseExampleYear10

$ 738

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Under normal market conditions, the Fund will invest at least 80% of its total assets in the components of the Underlying Index and in depositary receipts representing components of the Underlying Index. The Underlying Index is comprised of equity securities of issuers in developed foreign markets. The Underlying Index considers an issuer to be in a developed foreign market if it is domiciled or listed and traded in any of the following countries: Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Hong Kong, Italy, Japan, Jersey, the Netherlands, New Zealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland, and the United Kingdom. The Underlying Index provider will update the list of developed foreign markets annually.

An issuer must have a high ranking across a composite of the following characteristics to be eligible for inclusion in the Underlying Index:

1.

Strong cash flows;

2.

Payment of dividends to shareholders;

3.

Net stock buybacks; and

4.

Net debt paydown.

Each of these characteristics will be measured on a one-month to 12-month basis by the Underlying Index methodology, and no single measurement will be dispositive. Pursuant to the methodology of the Underlying Index, the 100 issuers that have exhibited, in the aggregate, the strongest cash flows, the highest dividends paid to shareholders, and net stock buybacks and debt paydown will be included in the Underlying Index. Although securities in the Underlying Index may be denominated in either the U.S. dollar or other currencies and may include securities of companies in any industry and of any market capitalization, the Underlying Index is weighted based only on publicly available data and includes screens to limit its country and its sector and industry concentration to 30% and 25%, respectively, in order to seek to ensure its liquidity and investability. Other screens also will exclude as components any foreign issuers whose securities are highly restricted or illegal for U.S. persons to own, including due to the imposition of sanctions by the U.S. Government.

The Fund may invest up to 20% of its net assets in instruments not included in the Underlying Index, but which Cambria Investment Management, L.P. (“Cambria”), the Fund’s investment adviser, believes will help the Fund track the Underlying Index. For example, there may be instances in which Cambria may choose to purchase or sell securities not in the Underlying Index which Cambria believes are appropriate to substitute for one or more such securities.

The Fund employs a “passive management”--or indexing-- investment approach and seeks to track the performance of the Underlying Index. To track the performance of the Underlying Index, the Fund intends to employ a replication strategy, which means that the Fund will typically invest in substantially all of the components of the Underlying Index in approximately the same weights as they appear in the Underlying Index.

The Underlying Index was developed by Cambria Indices, LLC, an affiliate of Cambria, and is calculated by Solactive, AG, which is not affiliated with the Fund or Cambria. The Underlying Index is rebalanced and reconstituted quarterly. To the extent that the Underlying Index concentrates (i.e., holds 25% or more of its total assets) in the securities of a particular industry or group of industries, the Fund is expected to concentrate to approximately the same extent. As of July 31, 2018, neither the Fund nor the Underlying Index were concentrated in an industry or group of industries, but both had significant exposure to companies in the consumer discretionary, financial services, industrial, and materials sectors.

Risk [Heading]

rr_RiskHeading

PRINCIPAL RISKS

Risk Lose Money [Text]

rr_RiskLoseMoney

An investor may lose money by investing in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

PERFORMANCE

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table indicate the risks of investing in the Fund by showing how the Fund's average annual total returns compare with those of a broad measure of market performance.

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

As always, please note that the Fund's past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.

Annual Return 2014

rr_AnnualReturn2014

(7.69%)

Annual Return 2016

rr_AnnualReturn2016

6.52%

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

As of July 31, 2018, the Fund’s year-to-date total return was 7.72%.

Best and Worst Quarter Returns (for the period reflected in the bar chart above)

Best: 8.46%, for the quarter ended 9/30/2017

Worst: -10.44%, for the quarter ended 9/30/2015

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Jul. 31, 2018

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best:

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

8.46%

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2015

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for the period ending December 31, 2017

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns shown are not relevant to investors who hold shares through tax-deferred arrangements, such as 401(k) plans or individual retirement plans.

rr_AverageAnnualReturnYear01

28.46%

rr_AverageAnnualReturnInceptionDate

Dec. 02, 2013

rr_RiskReturnAbstract

rr_AverageAnnualReturnSinceInception

3.70%

rr_AverageAnnualReturnYear01

16.82%

rr_AverageAnnualReturnInceptionDate

Dec. 02, 2013

rr_RiskReturnAbstract

rr_AverageAnnualReturnSinceInception

4.69%

rr_AverageAnnualReturnYear01

25.62%

rr_AverageAnnualReturnInceptionDate

Dec. 02, 2013

rr_RiskReturnAbstract

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

rr_ExpenseHeading

FEES AND EXPENSES

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

rr_DistributionAndService12b1FeesOverAssets

none

Portfolio Turnover [Heading]

rr_OtherExpensesOverAssets

0.06%

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

26.00%

rr_ExpenseExampleHeading

EXAMPLE

rr_ExpenseExampleYear01

$ 66

Five Years

rr_ExpenseExampleYear05

362

Strategy Portfolio Concentration [Text]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

rr_StrategyPortfolioConcentration

To the extent that the Underlying Index concentrates (i.e., holds 25% or more of its total assets) in the securities of a particular industry or group of industries, the Fund is expected to concentrate to approximately the same extent. As of July 31, 2018, neither the Fund nor the Underlying Index were concentrated in an industry or group of industries, but both had significant exposure to companies in the energy, financial services, information technology, and materials sectors.

Risk Not Insured Depository Institution [Text]

rr_RiskNarrativeTextBlock

An investment in the Fund involves risk, including those described below. There is no assurance that the Fund will achieve its investment objective. An investor may lose money by investing in the Fund.

Cash Redemption Risk. The Fund’s investment strategy will require it to effect redemptions, in whole or in part, for cash. As a result, the Fund may pay out higher annual capital gain distributions and be less tax-efficient than if the in-kind redemption process was used exclusively. In addition, cash redemptions may incur higher brokerage costs than in-kind redemptions and these added costs may be borne by the Fund and negatively impact Fund performance.

Concentration Risk. To the extent the Underlying Index is concentrated in a particular industry or group of industries, the Fund is also expected to be concentrated in that industry or group of industries. As a result, the Fund may be susceptible to loss due to adverse occurrences affecting that industry or group of industries. As of July 31, 2018, neither the Fund nor the Underlying Index were concentrated in an industry or group of industries, but both had significant exposure to companies in the energy, financial services, information technology, and materials sectors.

Energy Sector Risk. The energy sector includes, for example, oil, gas, and consumable fuel companies. Energy companies can be substantially impacted by, among other things, the volatility of oil prices, worldwide supply and demand, worldwide economic growth, and political instability in oil or gas producing regions such as the Middle East and Eastern Europe.

Financial Services Sector Risk. Performance of companies in the financial services sector may be adversely impacted by many factors, including, among others, government regulations, economic conditions, credit rating downgrades, changes in interest rates, and decreased liquidity in credit markets. This sector has experienced significant losses in the recent past, and the impact of more stringent capital requirements and of recent or future regulation on any individual financial company or on the sector as a whole cannot be predicted.

Information Technology Sector Risk. Technology companies face intense competition, both domestically and internationally, which may have an adverse effect on profit margins. Technology companies may have limited product lines, markets, financial resources or personnel. The products of technology companies may face obsolescence due to rapid technological developments and frequent new product introduction, unpredictable changes in growth rates and competition for the services of qualified personnel. Companies in the technology sector are heavily dependent on patent and intellectual property rights. The loss or impairment of these rights may adversely affect the profitability of these companies.

Materials Sector Risk. Issuers in the materials sector may be adversely affected by commodity price volatility, exchange rates, import controls, increased competition, depletion of resources, technical progress, labor relations and government regulations, among other factors. Issuers in the materials sector may be liable for environmental damage and product liability claims. Production of materials may exceed demand as a result of market imbalances or economic downturns, leading to poor investment returns.

Cyber Security Risk. The Fund, and its service providers, may be susceptible to operational and information security risks resulting from a breach in cyber security, including cyber-attacks. A breach in cyber security, intentional or unintentional, may adversely impact the Fund in many ways, including, but not limited to, disruption of the Fund’s operational capacity, loss of proprietary information, theft or corruption of data, denial-of-service attacks on websites or network resources, and the unauthorized release of confidential information. Cyber-attacks affecting the Fund’s third-party service providers, including Cambria, the custodian, and the transfer agent, market makers, Authorized Participants, or the issuers of securities in which the Fund invests may subject the Fund to many of the same risks associated with direct cyber security breaches.

Depositary Receipts Risk. The risks of investments in depositary receipts are substantially similar to Foreign Investment Risks. In addition, depositary receipts may not track the price of the underlying foreign securities, and their value may change materially at times when the U.S. markets are not open for trading.

Dividend Paying Security Risk. Securities that pay high dividends as a group can fall out of favor with the market, causing these companies to underperform companies that do not pay high dividends. Also, changes in the dividend policies of companies owned by the Fund and the capital resources available for these companies’ dividend payments may adversely affect the Fund.

Emerging Markets Risk. Emerging market investments are subject to the same risks as foreign investments and to additional risks due to greater political and economic uncertainties as well as a relative lack of information about issuers in such markets. Securities of emerging market issuers may become illiquid and be subject to volatility and high transaction costs.

Equity Investing Risk. The values of equity securities could decline generally or could underperform other investments due to factors affecting a specific issuer, market or securities markets generally.

Foreign Investment Risk. Returns on investments in foreign securities could be more volatile than, or trail the returns on, investments in U.S. securities. Exposures to foreign securities entail special risks, including risks due to: (i) differences in information available about foreign issuers; (ii) differences in investor protection standards in other jurisdictions; (iii) capital controls risks, including the risk of a foreign jurisdiction imposing restrictions on the ability to repatriate or transfer currency or other assets; (iv) political, diplomatic and economic risks; (v) regulatory risks; and (vi) foreign market and trading risks, including the costs of trading and risks of settlement in foreign jurisdictions. In addition, the Fund’s investments in securities denominated in other currencies could decline due to changes in local currency relative to the value of the U.S. dollar, which may affect the Fund’s returns.

Geographic Investment Risk. To the extent the Fund invests a significant portion of its assets in the securities of companies of a single country or region, it is more likely to be impacted by events or conditions affecting that country or region. As of July 31, 2018, the Fund invested a significant portion of its assets in securities of companies in China, Taiwan, South Africa, and Russia.

Russia Risk. The Fund may invest a significant portion of its assets in Russian securities. As a result of recent events involving Ukraine and the Russian Federation, the United States and the European Union have imposed sanctions on certain Russian individuals and entities. Additional broader sanctions may be imposed in the future. These sanctions may result in the decline of the value and liquidity of Russian securities and could also result in the immediate freeze of Russian securities, impairing the ability of the Fund to buy, sell, receive or deliver those securities. The Fund may seek to suspend redemptions in the event that an emergency exists in which it is not reasonably practicable for the Fund to dispose of its securities or to determine the value of its net assets.

International Closed-Market Trading Risk. Because the Fund’s investments may be traded in markets that are closed when the Exchange is open, there are likely to be deviations between the current pricing of an underlying investment and stale investment pricing (i.e., the last quote from its closed foreign market), resulting in premiums or discounts to NAV that may be greater than those experienced by other ETFs.

Investment Risk. 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 government agency. When you sell your Shares, they could be worth less than what you paid for them.

Large Capitalization Company Risk. The Fund’s investments in large capitalization companies may underperform other segments of the market because they may be less responsive to competitive challenges and opportunities and unable to attain high growth rates during periods of economic expansion.

Market Events Risk. Turbulence in the financial markets and reduced liquidity may negatively affect issuers, which could have an adverse effect on the Fund. In addition, there is a risk that policy changes by the U.S. Government, Federal Reserve and/or other government actors, such as increasing interest rates, could cause increased volatility in financial markets and higher levels of Fund redemptions, which could have a negative impact on the Fund.

Passive Investment Risk. The Fund is managed with a passive investment strategy, attempting to track the performance of the Underlying Index. As a result, the Fund expects to hold components of the Underlying Index regardless of their current or projected performance. Maintaining investments regardless of market conditions or the performance of individual investments could cause the Fund’s return to be lower than if the Fund employed an active strategy.

Premium-Discount Risk. The Shares may trade above (premium) or below (discount) their net asset value (or “NAV”). The market prices of Shares will generally fluctuate in accordance with changes in NAV as well as the relative supply of, and demand for, Shares on the Exchange. This risk is heightened in times of market volatility or periods of steep market declines.

Quantitative Security Selection Risk. The Underlying Index uses quantitative techniques to determine whether securities should be included in the Underlying Index, and the Underlying Index may not perform as intended if it relies on erroneous or outdated data from one or more third parties. Errors in data used in the quantitative model may occur from time to time and may not be identified and/or corrected before having an adverse impact on the Fund and its shareholders.

Secondary Market Trading Risk. Investors buying or selling Shares in the secondary market may pay brokerage commissions, which may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of Shares. Although the Shares are listed on the Exchange, there can be no assurance that an active or liquid trading market for them will develop or be maintained. In addition, trading in Shares on the Exchange may be halted.

Small and Medium Capitalization Company Risk. Investing in securities of small and medium capitalization companies involves greater risk than customarily is associated with investing in larger, more established companies. These companies’ securities may be more volatile and less liquid than those of more established companies, and they may be more sensitive to market conditions.

Tracking Error Risk. Although the Fund attempts to track the performance of the Underlying Index, the Fund may not be able to duplicate its exact composition or return due to, among other things, fees and expenses paid by the Fund that are not reflected in the Underlying Index. If the Fund is small, it may experience greater tracking error to its Underlying Index than it otherwise would at higher asset levels.

Value Investment Risk. The Fund’s shareholder yield strategy is a value investment strategy that should be expected to underperform in growth markets. Value investments are subject to the risk that their intrinsic value may never be realized by the market.

rr_RiskNotInsuredDepositoryInstitution

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 government agency.

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The following bar chart and table indicate the risks of investing in the Fund by showing how the Fund’s average annual total returns compare with those of a broad measure of market performance. All returns include the reinvestment of dividends and distributions. As always, please note that the Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated performance information is available at www.cambriafunds.com.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.cambriafunds.com

Bar Chart [Heading]

rr_BarChartHeading

Total Annual Returns for Calendar Year Ended December 31

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

As of July 31, 2018, the Fund’s year-to-date total return was 8.25%.

Best and Worst Quarter Returns (for the period reflected in the bar chart above)

Best: 11.88% for the quarter ended 9/30/2017

Worst: 3.24% for the quarter ended 6/30/2017

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Jul. 31, 2018

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best:

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

11.88%

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Jun. 30, 2017

Performance Table Heading

rr_PerformanceTableHeading

Average Annual Total Returns for the period ending December 31, 2017

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns shown are not relevant to investors who hold shares through tax-deferred arrangements, such as 401(k) plans or individual retirement plans.

rr_AverageAnnualReturnYear01

38.25%

rr_AverageAnnualReturnInceptionDate

Jul. 13, 2016

rr_RiskReturnAbstract

rr_AverageAnnualReturnSinceInception

28.03%

rr_AverageAnnualReturnYear01

22.10%

rr_AverageAnnualReturnInceptionDate

Jul. 13, 2016

rr_RiskReturnAbstract

rr_AverageAnnualReturnSinceInception

29.67%

rr_AverageAnnualReturnYear01

37.75%

rr_AverageAnnualReturnInceptionDate

Jul. 13, 2016

rr_RiskReturnAbstract

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

rr_ExpenseHeading

FEES AND EXPENSES

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

Total Annual Fund Operating Expenses:

rr_DistributionAndService12b1FeesOverAssets

none

rr_NetExpensesOverAssets

0.59%

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund may pay transaction costs, including commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund’s performance. For the fiscal year ended April 30, 2018, the Fund’s portfolio turnover rate was 25% of the average value of its portfolio.

Expense Exchange Traded Fund Commissions [Text]

rr_ExpenseExchangeTradedFundCommissions

You may also pay brokerage commissions on the purchase and sale of Shares, which are not reflected in the table.

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following example 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 redeem all of your Shares at the end of those periods. The example also assumes that the Fund provides a return of 5% a year and that the operating expenses remain the same. The example does not reflect any brokerage commissions that you may pay on purchases and sales of Shares. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Three Years

rr_ExpenseExampleYear03

189

Ten Years

rr_ExpenseExampleYear10

$ 738

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Under normal market conditions, at least 80% of the value of the Fund’s net assets (plus borrowings for investment purposes) will be invested in sovereign and quasi-sovereign bonds. For the purposes of this policy, sovereign and quasi-sovereign bonds include such securities and instruments that provide exposure to securities that invest in or have exposure to such bonds, including exchange-traded products (“ETPs”) such as exchange-traded funds (“ETFs”) and exchange-traded notes (“ETNs”). The Fund will invest in emerging and developed countries, including countries located in the G-20 and other countries. Potential issuer countries include, but are not limited to, Argentina, Australia, Brazil, Canada, Chile, China, Colombia, members of the European Union, including Greece, Hungary, Poland, and Romania, Hong Kong, India, Israel, Indonesia, Japan, Malaysia, Mexico, New Zealand, Norway, Peru, the Philippines, Russia, Saudi Arabia, Singapore, South Africa, South Korea, Sweden, Switzerland, Taiwan, Thailand, Turkey, the United Kingdom and the United States.

Sovereign bonds include debt securities issued by a national government, instrument or political sub-division. Quasi-sovereign bonds include debt securities issued by a supra-national government or a state-owned enterprise or agency. The sovereign and quasi-sovereign bonds that the Fund invests in may be denominated in local and foreign currencies. The Fund may invest in securities of any duration or maturity.

The Fund may invest up to 20% of its net assets in ETPs, including ETFs and ETNs, that invest in or provide exposure to sovereign and quasi-sovereign bonds, money market instruments or other high quality debt securities, cash or cash equivalents.

Cambria Investment Management, L.P., the Fund’s investment adviser (“Cambria”), utilizes a quantitative model to select sovereign and quasi-sovereign bond exposures for the Fund. The model reviews various characteristics of potential investments, with yield as the largest determinant. Accordingly, the Fund may invest in high yield bonds rated below investment grade by Moody’s Investors Service, Standard & Poor’s or Fitch Ratings (commonly referred to as “junk bonds”), or unrated bonds that are determined by Cambria to be of such credit quality. By considering together the various characteristics of potential investments, the model identifies potential allocations for the Fund, as well as opportune times to make such allocations. A screen excludes foreign issuers whose securities are highly restricted or illegal for U.S. persons to own, including due to the imposition of sanctions by the U.S. Government.

Cambria has discretion on a daily basis to actively manage the Fund’s portfolio in accordance with the Fund’s investment objective. The Fund may sell a security when Cambria believes that the security is overvalued or better investment opportunities are available, to invest in cash and cash equivalents, or to meet redemptions. Cambria expects to rebalance to target allocations at least quarterly. As a result, the Fund may experience high portfolio turnover.

The Fund is non-diversified.

Risk Nondiversified Status [Text]

rr_RiskNarrativeTextBlock

An investment in the Fund involves risk, including those described below. There is no assurance that the Fund will achieve its investment objective. An investor may lose money by investing in the Fund.

Cash Redemption Risk. The Fund’s investment strategy will require it to effect redemptions, in whole or in part, for cash. As a result, the Fund may pay out higher annual capital gain distributions and be less tax-efficient than if the in-kind redemption process was used exclusively. In addition, cash redemptions may incur higher brokerage costs than in-kind redemptions and these added costs may be borne by the Fund and negatively impact Fund performance.

Cyber Security Risk. The Fund, and its service providers, may be susceptible to operational and information security risks resulting from a breach in cyber security, including cyber-attacks. A breach in cyber security, intentional or unintentional, may adversely impact the Fund in many ways, including, but not limited to, disruption of the Fund’s operational capacity, loss of proprietary information, theft or corruption of data, denial-of-service attacks on websites or network resources, and the unauthorized release of confidential information. Cyber-attacks affecting the Fund’s third-party service providers, including Cambria, the custodian, and the transfer agent, market makers, Authorized Participants, or the issuers of securities in which the Fund invests may subject the Fund to many of the same risks associated with direct cyber security breaches.

Emerging Markets Risk. Emerging market investments are subject to the same risks as foreign investments and to additional risks due to greater political and economic uncertainties as well as a relative lack of information about issuers in such markets. Securities of emerging market issuers may become illiquid and be subject to volatility and high transaction costs.

Exchange-Traded Funds and Exchange-Traded Products and Investment Companies Risk. The risks of investing in securities of ETFs, ETPs and investment companies typically reflect the risks of the types of instruments in which the underlying ETF, ETP or investment company invests. In addition, with such investments, the Fund bears its proportionate share of the fees and expenses of the underlying entity. As a result, the Fund’s operating expenses may be higher and performance may be lower.

Exchange-Traded Notes Risk. Because ETNs are unsecured, unsubordinated debt securities, an investment in an ETN exposes the Fund to the risk that an ETN’s issuer may be unable to pay. In addition, as with investments in other ETPs, the Fund will bear its proportionate share of the fees and expenses of the ETN, which may cause the Fund’s operating expenses to be higher and its performance to be lower.

Fixed Income Risk. A decline in an issuer’s credit rating may cause a decrease in the value of its fixed income securities and an increase in their investment risk and volatility. During periods of falling interest rates, an issuer of a callable bond held by the Fund may “call” (or repay) the security before its stated maturity, and the Fund may have to reinvest the proceeds at lower interest rates, resulting in a decline in the Fund’s income. The market value of fixed income securities generally changes in response to changes in interest rates.

Foreign Investment Risk. Returns on investments in foreign securities could be more volatile than, or trail the returns on, investments in U.S. securities. Exposures to foreign securities entail special risks, including risks due to: (i) differences in information available about foreign issuers; (ii) differences in investor protection standards in other jurisdictions; (iii) capital controls risks, including the risk of a foreign jurisdiction imposing restrictions on the ability to repatriate or transfer currency or other assets; (iv) political, diplomatic and economic risks; (v) regulatory risks; and (vi) foreign market and trading risks, including the costs of trading and risks of settlement in foreign jurisdictions. In addition, the Fund’s investments in securities denominated in other currencies could decline due to changes in local currency relative to the value of the U.S. dollar, which may affect the Fund’s returns.

Geographic Investment Risk. To the extent the Fund invests a significant portion of its assets in the securities of companies of a single country or region, it is more likely to be impacted by events or conditions affecting that country or region. As of July 31, 2018, the Fund invested a significant portion of its assets in securities of companies in Asia, South America, and Europe, including Greece and Russia.

Greece Risk. The Fund may invest in the securities of Greek issuers. Recent geopolitical events in the European Union, and specifically in Greece, have destabilized Greece. The duration and outcome of the current situation cannot be predicted, and it is possible that Greece may exit the European Monetary Union, which would likely result in the redenomination and devaluation of the Greek currency and increase the potential for Greece to default on its other outstanding debts.

Events in Greece may adversely affect the value and liquidity of the Fund’s investments in Greek issuers. For example, capital controls may restrict the Fund’s ability to sell Greek securities and reinvest the proceeds. If the Athens Stock Exchange closes, current market quotations for the securities of Greek issuers normally traded there will not be available and the Fund will fair value any such securities in its portfolio. As a result, the market price of the Fund’s shares may significantly deviate from the Fund’s NAV. In addition, the unavailability of current market quotations from the Athens Stock Exchange may affect: the calculation of the value of the Underlying Index and the calculation of the Fund’s Intraday Indicative Value. As a result, the Fund’s NAV may experience increased tracking error with respect to the Underlying Index.

Russia Risk. The Fund may invest in Russian securities. As a result of recent events involving Ukraine and the Russian Federation, the United States and the European Union have imposed sanctions on certain Russian individuals and entities. Additional broader sanctions may be imposed in the future. These sanctions may result in the decline of the value and liquidity of Russian securities and could also result in the immediate freeze of Russian securities, impairing the ability of the Fund to buy, sell, receive or deliver those securities. The Fund may seek to suspend redemptions in the event that an emergency exists in which it is not reasonably practicable for the Fund to dispose of its securities or to determine the value of its net assets.

High Yield Securities Risk. High yield securities and unrated securities of comparable credit quality are subject to the increased risk of an issuer’s inability to meet principal and interest payment obligations. High yield securities are subject to a greater risk of default and investments in them are inherently speculative. The secondary markets in which high yield securities are traded may be less liquid and more volatile than the market for higher grade securities.

Interest Rate Risk. The market value of fixed income securities generally changes in response to changes in interest rates. As interest rates rise, the value of certain fixed income securities is likely to decrease. Similarly, if interest rates decline, the value of fixed income securities is likely to increase. Interest rate risk is generally lower for shorter-term investments and higher for longer-term investments. As of the date of this Prospectus, interest rates are near historic lows, but risks associated with rising interest rates are heightened given the Federal Reserve’s recent interest rate hikes, which could signal an end to the historically low interest rate environment. To the extent that rates increase substantially and/or rapidly, the Fund may be subject to significant losses.

International Closed-Market Trading Risk. Because the Fund’s investments may be traded in markets that are closed when the Exchange is open, there are likely to be deviations between the current pricing of an underlying investment and stale investment pricing (i.e., the last quote from its closed foreign market), resulting in premiums or discounts to NAV that may be greater than those experienced by other ETFs.

Investment Risk. 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 government agency. When you sell your Shares they could be worth less than what you paid for them.

Liquidity Risk. Liquidity risk exists when a particular investment is difficult to purchase or sell. A significant, rapid rise in interest rates may result in a period of volatility and increased redemptions if Fund securities become illiquid and are forced to sell the illiquid securities at disadvantageous times or prices. This could have a negative effect on the Fund’s ability to achieve its investment objective and may result in losses to Fund shareholders.

Management Risk. The Fund is actively managed using proprietary investment strategies and processes. There can be no guarantee that these strategies and processes will be successful or that the Fund will achieve its investment objective.

Market Events Risk. Turbulence in the financial markets and reduced liquidity may negatively affect issuers, which could have an adverse effect on the Fund. In addition, there is a risk that policy changes by the U.S. Government, Federal Reserve and/or other government actors, such as increasing interest rates, could cause increased volatility in financial markets and higher levels of Fund redemptions, which could have a negative impact on the Fund.

Non-Diversification Risk. The Fund is non-diversified. Investment by the Fund in securities of a limited number of issuers may expose it to greater market risk and potential monetary losses than if its assets were diversified among the securities of a greater number of issuers.

Portfolio Turnover Risk. The Fund’s strategy may result in high portfolio turnover rates, which may increase the Fund’s brokerage commission costs and negatively impact the Fund’s performance. Such portfolio turnover also may generate net short-term capital gains.

Premium-Discount Risk. The Shares may trade above (premium) or below (discount) their net asset value (or “NAV”). The market prices of Shares will generally fluctuate in accordance with changes in NAV as well as the relative supply of, and demand for, Shares on the Exchange. This risk is heightened in times of market volatility or periods of steep market declines.

Quantitative Security Selection Risk. Cambria uses quantitative techniques to generate investment decisions and its processes and stock selection, and the Fund may not perform as intended if it relies on erroneous or outdated data from one or more third parties. Errors in data used in the quantitative model may occur from time to time and may not be identified and/or corrected before having an adverse impact on the Fund and its shareholders.

Secondary Market Trading Risk. Investors buying or selling Shares in the secondary market may pay brokerage commissions or other charges, which may be a significant proportional cost for investors seeking to buy or sell relatively small amounts of Shares. Although the Shares are listed on the Exchange, there can be no assurance that an active or liquid trading market for them will develop or be maintained. In addition, trading in Shares on the Exchange may be halted.

Sovereign Debt Securities Risk. Investments in sovereign and quasi-sovereign debt obligations involve special risks not present in corporate debt obligations. The issuer of the sovereign debt or the authorities that control the repayment of the debt may be unable or unwilling to repay principal or interest when due, and the Fund may have limited recourse in the event of a default. During periods of economic uncertainty, the market prices of sovereign debt, and the Fund’s net asset value, may be more volatile than prices of U.S. debt obligations. In the past, certain non-U.S. markets have encountered difficulties in servicing their debt obligations, withheld payments of principal and interest and declared moratoria on the payment of principal and interest on their sovereign debts. These risks increase for lower-rated and high yield debt securities, as discussed in this Prospectus.

rr_RiskNondiversifiedStatus

The Fund is non-diversified. Investment by the Fund in securities of a limited number of issuers may expose it to greater market risk and potential monetary losses than if its assets were diversified among the securities of a greater number of issuers.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

PERFORMANCE

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following bar chart and table indicate the risks of investing in the Fund by showing how the Fund's average annual total returns compare with those of a broad measure of market performance.

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

As always, please note that the Fund's past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.

Annual Return 2017

rr_AnnualReturn2017

13.76%

Year to Date Return, Label

rr_YearToDateReturnLabel

The Fund's year-to-date total return

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

(3.70%)

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2017

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst:

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

1.04%

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Closing [Text Block]

rr_PerformanceTableClosingTextBlock

Average annual total returns are shown on a before- and after-tax basis for the Fund. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold shares through tax-deferred arrangements, such as 401(k) plans or individual retirement plans.

rr_RiskReturnAbstract

rr_AverageAnnualReturnSinceInception

10.93%

rr_AverageAnnualReturnYear01

11.01%

rr_AverageAnnualReturnInceptionDate

Feb. 22, 2016

rr_RiskReturnAbstract

rr_AverageAnnualReturnSinceInception

7.33%

rr_AverageAnnualReturnYear01

7.49%

rr_AverageAnnualReturnInceptionDate

Feb. 22, 2016

rr_RiskReturnAbstract

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

rr_ExpenseHeading

FEES AND EXPENSES

rr_OperatingExpensesCaption

ANNUAL FUND OPERATING EXPENSES (EXPENSES THAT YOU PAY EACH YEAR AS A PERCENTAGE OF THE VALUE OF YOUR INVESTMENT)

rr_DistributionAndService12b1FeesOverAssets

none

Portfolio Turnover [Heading]

rr_OtherExpensesOverAssets

0.09%

rr_PortfolioTurnoverHeading

PORTFOLIO TURNOVER

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

14.00%

rr_ExpenseExampleHeading

EXAMPLE

rr_ExpenseExampleYear01

$ 69

Five Years

rr_ExpenseExampleYear05

379

Strategy Portfolio Concentration [Text]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGIES

rr_StrategyPortfolioConcentration

To the extent that the Underlying Index concentrates (i.e., holds 25% or more of its total assets) in the securities of a particular industry or group of industries, the Fund is expected to concentrate to approximately the same extent. As of July 31, 2018, the Fund and the Underlying Index were concentrated in the financial services sectors and had significant exposure to companies in the energy and materials sectors.