rr_ProspectusLineItems

rr_RiskReturnHeading

AAM S&P 500 HIGH DIVIDEND VALUE ETF

rr_ObjectiveHeading

Investment Objective

rr_ObjectivePrimaryTextBlock

The AAM S&P 500 High Dividend Value ETF (the “Fund”) seeks to track the total return performance, before fees and expenses, of the S&P 500 Dividend and Free Cash Flow Yield Index (the “Index”).

rr_ExpenseHeading

Fees and Expenses of the Fund

rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy, hold, and sell shares of the Fund (“Shares”). You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and Example below.

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

rr_PortfolioTurnoverHeading

Portfolio Turnover

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. For the fiscal year ended October 31, 2023, the Fund’s portfolio turnover rate was 63% of the average value of its portfolio.

rr_PortfolioTurnoverRate

63.00%

rr_ExpenseExampleHeading

Expense Example

rr_ExpenseExampleNarrativeTextBlock

This 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 continue to hold or redeem 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 the same.

rr_ExpenseExampleByYearCaption

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyHeading

Principal Investment Strategies

rr_StrategyNarrativeTextBlock

The Fund uses a “passive management” (or indexing) approach to track the total return performance, before fees and expenses, of the Index.

S&P 500 Dividend and Free Cash Flow Yield Index

The Index is a rules-based, equal-weighted index that is designed to provide exposure to the constituents of the S&P 500® Index that exhibit both high dividend yield and sustainable dividend distribution characteristics, while maintaining diversified sector exposure. The Index was developed in 2017 by S&P Dow Jones Indices, a division of S&P Global (the “Index Provider”). The S&P 500 Index consists of approximately 500 leading U.S.-listed companies representing approximately 80% of the U.S. equity market capitalization, and may include real estate investment trusts (“REITs”).

Construction of the Index begins with the universe of equity securities that are included in the S&P 500 Index. For each equity security in the S&P 500 Index, the security’s dividend yield and free-cash-flow yield (i.e., a company’s cash flow from operations less capital expenditures divided by its market capitalization) are adjusted to account for outliers. If a security’s dividend yield or free-cash-flow yield is in the top or bottom 2.5% of the S&P 500 Index, the dividend yield or free-cash-flow yield, as applicable, for such security is replaced with the dividend yield or free-cash-flow yield of the security nearest to such top or bottom 2.5% threshold. The universe is then screened to keep only equity securities with a positive indicated annual dividend yield (i.e., yield based on a company’s most recent dividend amount) and free-cash-flow yield. The remaining securities are referred to as the “Selection Pool”.

industrials, information technology, materials, real estate, communication services, and utilities. Fewer than five securities may be selected if there are fewer than five securities in the Selection Pool for a given sector.

The Fund’s Investment Strategy

The Fund will generally use a “replication” strategy to achieve its investment objective, meaning the Fund generally will invest in all of the component securities of the Index in approximately the same proportion as in the Index. However, the Fund may use a “representative sampling” strategy, meaning it may invest in a sample of the securities in the Index whose risk, return, and other characteristics closely resemble the risk, return, and other characteristics of the Index as a whole, when the Fund’s sub-adviser believes it is in the best interests of the Fund (e.g., when replicating the Index involves practical difficulties or substantial costs, an Index constituent becomes temporarily illiquid, unavailable, or less liquid, or as a result of legal restrictions or limitations that apply to the Fund but not to the Index).

The Fund may invest in securities or other investments not included in the Index, but which the Fund’s sub-adviser believes will help the Fund track the Index. For example, the Fund may invest in securities that are not components of the Index to reflect various corporate actions and other changes to the Index (such as reconstitutions, additions, and deletions).

Under normal circumstances, at least 80% of the Fund’s net assets, plus borrowings for investment purposes, will be invested in equity securities that (i) are included in the S&P 500 Index and (ii) have had a positive indicated annual dividend yield within the past year.

rr_StrategyPortfolioConcentration

To the extent the Index concentrates (i.e., holds more than 25% of its total assets) in the securities of a particular industry or group of related industries, the Fund will concentrate its investments to approximately the same extent as the Index. Under normal circumstances, at least 80% of the Fund’s net assets, plus borrowings for investment purposes, will be invested in equity securities that (i) are included in the S&P 500 Index and (ii) have had a positive indicated annual dividend yield within the past year.

rr_RiskHeading

Principal Investment Risks

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

The following performance information indicates some of the risks of investing in the Fund. The bar chart shows the Fund’s performance for calendar years ended December 31. The table illustrates how the Fund’s average annual returns for the 1-year, 5-year, and since inception periods compare with those of a broad measure of market performance and the Index. The Fund’s past performance, before and after taxes, does not necessarily indicate how it will perform in the future. Updated performance information is available on the Fund’s website at www.aamlive.com/ETF.

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following performance information indicates some of the risks of investing in the Fund.

rr_PerformanceAvailabilityWebSiteAddress

www.aamlive.com/ETF

rr_PerformancePastDoesNotIndicateFuture

The Fund’s past performance, before and after taxes, does not necessarily indicate how it will perform in the future.

rr_BarChartHeading

Calendar Year Total Returns

rr_BarChartClosingTextBlock

During the period of time shown in the bar chart, the Fund’s highest quarterly return was 18.53% for the quarter ended March 31, 2021 and the lowest quarterly return was -33.03% for the quarter ended March 31, 2020.

rr_HighestQuarterlyReturnLabel

highest quarterly return

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2021

rr_BarChartHighestQuarterlyReturn

18.53%

rr_LowestQuarterlyReturnLabel

lowest quarterly return

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_BarChartLowestQuarterlyReturn

(33.03%)

rr_PerformanceTableHeading

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

rr_PerformanceTableUsesHighestFederalRate

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns shown are not relevant to investors who hold their Shares through tax-deferred arrangements such as an individual retirement account (“IRA”) or other tax-advantaged accounts.

rr_PerformanceTableExplanationAfterTaxHigher

In certain cases, the figure representing “Return After Taxes on Distributions and Sale of Shares” may be higher than the other return figures for the same period. A higher after-tax return results when a capital loss occurs upon redemption and provides an assumed tax deduction that benefits the investor.

AAM S&P 500 High Dividend Value ETF | Risk Lose Money [Member]

rr_PerformanceTableClosingTextBlock

After-tax returns are calculated using the historical highest individual federal marginal income tax rates during the period covered by the table above 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 their Shares through tax-deferred arrangements such as an individual retirement account (“IRA”) or other tax-advantaged accounts. In certain cases, the figure representing “Return After Taxes on Distributions and Sale of Shares” may be higher than the other return figures for the same period. A higher after-tax return results when a capital loss occurs upon redemption and provides an assumed tax deduction that benefits the investor.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | Concentration Risk Member

rr_RiskTextBlock

As with any investment, there is a risk that you could lose all or a portion of your investment in the Fund.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | Equity Market Risk Member

rr_RiskTextBlock

Concentration Risk. The Fund’s investments will be concentrated in an industry or group of industries to the extent that the Index is so concentrated. In such event, the value of the Shares may rise and fall more than the value of shares of a fund that invests in securities of companies in a broader range of industries.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | ETF Risks Member

rr_RiskTextBlock

Equity Market Risk. The equity securities held in the Fund’s portfolio may experience sudden, unpredictable drops in value or long periods of decline in value. This may occur because of factors that affect securities markets generally or factors affecting specific issuers, industries, or sectors in which the Fund invests. Common stocks are generally exposed to greater risk than other types of securities, such as preferred stock and debt obligations, because common stockholders generally have inferior rights to receive payment from issuers. In addition, local, regional or global events such as war, including Russia’s invasion of Ukraine, acts of terrorism, spread of infectious diseases or other public health issues (such as the global pandemic caused by the COVID-19 virus), recessions, rising inflation, or other events could have a significant negative impact on the Fund and its investments. Such events may affect certain geographic regions, countries, sectors and industries more significantly than others. Such events could adversely affect the prices and liquidity of the Fund’s portfolio securities or other instruments and could result in disruptions in the trading markets.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | ETF Risks, Authorized Participants, Market Makers And Liquidity Providers Concentration Risk Member

rr_RiskTextBlock

ETF Risks. The Fund is an ETF, and, as a result of an ETF’s structure, it is exposed to the following risks:

◦Authorized Participants, Market Makers, and Liquidity Providers Concentration Risk. The Fund has a limited number of financial institutions that may act as Authorized Participants (“APs”). In addition, there may be a limited number of market makers and/or liquidity providers in the marketplace. To the extent either of the following events occur, Shares may trade at a material discount to NAV and possibly face delisting: (i) APs exit the business or otherwise become unable to process creation and/or redemption orders and no other APs step forward to perform these services, or (ii) market makers and/or liquidity providers exit the business or significantly reduce their business activities and no other entities step forward to perform their functions.

◦Costs of Buying or Selling Shares. Due to the costs of buying or selling Shares, including brokerage commissions imposed by brokers and bid-ask spreads, frequent trading of Shares may significantly reduce investment results and an investment in Shares may not be advisable for investors who anticipate regularly making small investments.

◦Shares May Trade at Prices Other Than NAV. As with all ETFs, Shares may be bought and sold in the secondary market at market prices. Although it is expected that the market price of Shares will approximate the Fund’s NAV, there may be times when the market price of Shares is more than the NAV intra-day (premium) or less than the NAV intra-day (discount) due to supply and demand of Shares or during periods of market volatility. This risk is heightened in times of market volatility, periods of steep market declines, and periods when there is limited trading activity for Shares in the secondary market, in which case such premiums or discounts may be significant.

◦Trading. Although Shares are listed for trading on NYSE Arca, Inc. (the “Exchange”) and may be traded on U.S. exchanges other than the Exchange, there can be no assurance that Shares will trade with any volume, or at all, on any stock exchange. In stressed market conditions, the liquidity of Shares may begin to mirror the liquidity of the Fund’s underlying portfolio holdings, which can be significantly less liquid than Shares, and this could lead to differences between the market price of the Shares and the underlying value of those Shares.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | ETF Risks, Costs Of Buying Or Selling Shares Risk Member

rr_RiskTextBlock

Authorized Participants, Market Makers, and Liquidity Providers Concentration Risk. The Fund has a limited number of financial institutions that may act as Authorized Participants (“APs”). In addition, there may be a limited number of market makers and/or liquidity providers in the marketplace. To the extent either of the following events occur, Shares may trade at a material discount to NAV and possibly face delisting: (i) APs exit the business or otherwise become unable to process creation and/or redemption orders and no other APs step forward to perform these services, or (ii) market makers and/or liquidity providers exit the business or significantly reduce their business activities and no other entities step forward to perform their functions.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | ETF Risks, Shares May Trade At Prices Other Than NAV Risk Member

rr_RiskTextBlock

Costs of Buying or Selling Shares. Due to the costs of buying or selling Shares, including brokerage commissions imposed by brokers and bid-ask spreads, frequent trading of Shares may significantly reduce investment results and an investment in Shares may not be advisable for investors who anticipate regularly making small investments.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | ETF Risks, Trading Risk Member

rr_RiskTextBlock

Shares May Trade at Prices Other Than NAV. As with all ETFs, Shares may be bought and sold in the secondary market at market prices. Although it is expected that the market price of Shares will approximate the Fund’s NAV, there may be times when the market price of Shares is more than the NAV intra-day (premium) or less than the NAV intra-day (discount) due to supply and demand of Shares or during periods of market volatility. This risk is heightened in times of market volatility, periods of steep market declines, and periods when there is limited trading activity for Shares in the secondary market, in which case such premiums or discounts may be significant.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | High Dividend Investing Risk Member

rr_RiskTextBlock

Trading. Although Shares are listed for trading on NYSE Arca, Inc. (the “Exchange”) and may be traded on U.S. exchanges other than the Exchange, there can be no assurance that Shares will trade with any volume, or at all, on any stock exchange. In stressed market conditions, the liquidity of Shares may begin to mirror the liquidity of the Fund’s underlying portfolio holdings, which can be significantly less liquid than Shares, and this could lead to differences between the market price of the Shares and the underlying value of those Shares.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | Index Provider Risk Member

rr_RiskTextBlock

High Dividend Investing Risk. Companies with a high yield or payout ratio may reduce their dividend or stop paying dividends entirely while they are included in the Index. Such events could lower the price or yield of such company’s equity securities. Additionally, equity securities with a high yield or payout ratio may underperform other securities in certain market conditions.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | Market Risk Member

rr_RiskTextBlock

Index Provider Risk. There is no assurance that the Index Provider, or any agents that act on its behalf, will compile the Index accurately, or that the Index will be determined, maintained, constructed, reconstituted, rebalanced, composed, calculated or disseminated accurately. The Adviser relies upon the Index Provider and its agents to compile, determine, maintain, construct, reconstitute, rebalance, compose, calculate (or arrange for an agent to calculate), and disseminate the Index accurately. Any losses or costs associated with errors made by the Index Provider or its agents generally will be borne by the Fund and its shareholders.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | Passive Investment Risk Member

rr_RiskTextBlock

Market Risk. The trading prices of equity securities and other instruments fluctuate in response to a variety of factors. The Fund’s NAV and market price may fluctuate significantly in response to these and other factors. As a result, an investor could lose money over short or long periods of time.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | REIT Investment Risk Member

rr_RiskTextBlock

Passive Investment Risk. The Fund is not actively managed, and its sub-adviser would not sell shares of an equity security due to current or projected underperformance of a security, industry, or sector, unless that security is removed from the Index or the selling of shares of that security is otherwise required upon a reconstitution or rebalancing of the Index in accordance with the Index methodology.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | Tracking Error Risk Member

rr_RiskTextBlock

REIT Investment Risk. Investments in REITs involve unique risks. REITs may have limited financial resources, may trade less frequently and in limited volume, and may be more volatile than other securities. REITs may be affected by changes in the value of their underlying properties or mortgages or by defaults by their borrowers or tenants. Furthermore, these entities depend upon specialized management skills, have limited diversification and are, therefore, subject to risks inherent in financing a limited number of projects. In addition, the performance of a U.S. REIT may be affected by changes in the tax laws or by its failure to qualify for tax-free pass-through of income.

rr_ProspectusLineItems

AAM S&P 500 High Dividend Value ETF | S&P 500 Dividend and Free Cash Flow Yield Index (reflects no deduction for fees, expenses, or taxes)

rr_RiskTextBlock

Tracking Error Risk. As with all index funds, the performance of the Fund and the Index may differ from each other for a variety of reasons. For example, the Fund incurs operating expenses and portfolio transaction costs not incurred by the Index. In addition, the Fund may not be fully invested in the securities of the Index at all times or may hold securities not included in the Index.

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_ProspectusLineItems

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnLabel

S&P 500 Dividend and Free Cash Flow Yield Index (reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnYear01

5.86%

rr_AverageAnnualReturnYear05

8.95%

rr_AverageAnnualReturnSinceInception

7.00%

AAM S&P 500 High Dividend Value ETF | S&P 500® Index (reflects no deduction for fees, expenses or taxes)

rr_AverageAnnualReturnInceptionDate

Nov. 28, 2017

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_ProspectusLineItems

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnLabel

S&P 500® Index(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnYear01

26.29%

rr_AverageAnnualReturnYear05

15.69%

rr_AverageAnnualReturnSinceInception

12.24%

AAM S&P 500 High Dividend Value ETF | AAM S&P 500 High Dividend Value ETF

rr_AverageAnnualReturnInceptionDate

Nov. 28, 2017

rr_ProspectusLineItems

dei_TradingSymbol

SPDV

rr_ManagementFeesOverAssets

0.29%

rr_DistributionAndService12b1FeesOverAssets

none

rr_OtherExpensesOverAssets

none

rr_ExpensesOverAssets

0.29%

rr_ExpenseExampleYear01

$ 30

rr_ExpenseExampleYear03

rr_ExpenseExampleYear05

163

rr_ExpenseExampleYear10

$ 368

Annual Return 2018

rr_AnnualReturn2018

(6.13%)

Annual Return 2019

rr_AnnualReturn2019

20.52%

rr_AnnualReturn2020

(6.16%)

rr_AnnualReturn2021

29.41%

rr_AnnualReturn2022

(2.22%)

rr_AnnualReturn2023

5.48%

rr_AverageAnnualReturnLabel

Return Before Taxes

rr_AverageAnnualReturnYear01

5.48%

rr_AverageAnnualReturnYear05

8.58%

rr_AverageAnnualReturnSinceInception

6.65%

AAM S&P 500 High Dividend Value ETF | AAM S&P 500 High Dividend Value ETF | After Taxes on Distributions

rr_AverageAnnualReturnInceptionDate

Nov. 28, 2017

rr_ProspectusLineItems

rr_AverageAnnualReturnLabel

Return After Taxes on Distributions

rr_AverageAnnualReturnYear01

4.41%

rr_AverageAnnualReturnYear05

7.56%

AAM S&P 500 High Dividend Value ETF | AAM S&P 500 High Dividend Value ETF | After Taxes on Distributions and Sales

rr_AverageAnnualReturnSinceInception

5.67%

rr_ProspectusLineItems

rr_AverageAnnualReturnLabel

Return After Taxes on Distributions and Sale of Fund Shares

rr_AverageAnnualReturnYear01

3.85%

rr_AverageAnnualReturnYear05

6.60%

AAM S&P Emerging Markets High Dividend Value ETF

rr_AverageAnnualReturnSinceInception

5.06%

rr_ProspectusLineItems

rr_RiskReturnHeading

AAM S&P EMERGING MARKETS HIGH DIVIDEND VALUE ETF

rr_ObjectiveHeading

Investment Objective

rr_ObjectivePrimaryTextBlock

The AAM S&P Emerging Markets High Dividend Value ETF (the “Fund”) seeks to track the total return performance, before fees and expenses, of the S&P Emerging Markets Dividend and Free Cash Flow Yield Index (the “Index”).

rr_ExpenseHeading

Fees and Expenses of the Fund

rr_ExpenseNarrativeTextBlock

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

rr_PortfolioTurnoverHeading

Portfolio Turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

183.00%

rr_ExpenseExampleHeading

Expense Example

rr_ExpenseExampleNarrativeTextBlock

rr_ExpenseExampleByYearCaption

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyHeading

Principal Investment Strategies

rr_StrategyNarrativeTextBlock

The Fund uses a “passive management” (or indexing) approach to track the total return performance, before fees and expenses, of the Index.

S&P Emerging Markets Dividend and Free Cash Flow Yield Index

The Index is a rules-based, equal-weighted index that is designed to provide exposure to the constituents of the S&P Emerging Plus LargeMidCap Index that exhibit both high dividend yield and sustainable dividend distribution characteristics, while maintaining diversified sector exposure. The Index was developed in 2017 by S&P Dow Jones Indices, a division of S&P Global (the “Index Provider”). The S&P Emerging Plus LargeMidCap Index is designed to measure the performance of large- and mid-capitalization securities in emerging markets. The S&P Emerging Plus LargeMidCap Index is comprised of equity securities, including common stock and real estate investment trusts (“REITs”), that are listed in Brazil, Chile, China, Colombia, the Czech Republic, Egypt, Greece, Hungary, India, Indonesia, Kuwait, Malaysia, Mexico, Peru, the Philippines, Poland, Qatar, Saudi Arabia, South Africa, South Korea, Taiwan, Thailand, Turkey, and the United Arab Emirates (collectively, the “Emerging Markets”).

Construction of the Index begins with the universe of equity securities that are included in the S&P Emerging Plus LargeMidCap Index, have a minimum float-adjusted market capitalization of US$300 million, and have a median daily traded value of at least US$1 million. For each equity security in the S&P Emerging Plus LargeMidCap Index, the security’s dividend yield and free-cash-flow yield (i.e., a company’s cash flow from operations less capital expenditures divided by its market capitalization) are then adjusted to account for outliers. If a security’s dividend yield or free-cash-flow yield is in the top or bottom 2.5% of the S&P Emerging Plus LargeMidCap Index, the dividend yield or free-cash-flow yield, as applicable, for such security is replaced with the dividend yield or free-cash-flow yield of the security nearest to such top or bottom 2.5% threshold. The universe is then screened to keep only equity securities with a positive realized dividend yield (i.e., yield based on the total dividends paid for the most recent 12-month period) and free-cash-flow yield. The remaining securities are referred to as the “Selection Pool”.

yield score and free-cash-flow yield score from zero to one for each company. The equity securities in the Selection Pool are then ranked by the product of their dividend yield score and free-cash-flow yield score, and the top five scoring securities are selected from each sector (collectively, the “Index Constituents”). The Index uses Standard & Poor’s Global Industry Classification Standards to define companies within one of the following sectors: consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology, materials, real estate, communication services, and utilities. Fewer than five securities may be selected if there are fewer than five securities in the Selection Pool for a given sector.

The Index is reconstituted (i.e., Index Constituents are added or deleted and weights are reset to equal-weight) semi-annually after the close of the last business day in January and July. At the time of each reconstitution of the Index, Index Constituents are added or deleted based on company data as of the last business day of December and June, respectively, and the Index Constituents are equally-weighted based on closing prices as of five business days prior to the last business day of the reconstitution month. If an Index Constituent is removed from the S&P Emerging Plus LargeMidCap Index, such security will simultaneously be removed from the Index. Additions to the Index Constituents only take place during the semi-annual reconstitutions. If multiple share classes of a single company qualify for inclusion in the Index, only the share class with the highest liquidity, measured by median daily value traded, is selected. As of December 31, 2023, the Index included significant exposure to companies in China, India, Taiwan, and South Korea.

The Fund’s Investment Strategy

The Fund generally may invest in securities or other investments not included in the Index, but which the Fund’s sub-adviser believes will help the Fund track the Index. For example, the Fund may invest in securities that are not components of the Index to reflect various corporate actions and other changes to the Index (such as reconstitutions, additions, and deletions).

Under normal circumstances, at least 80% of the Fund’s net assets, plus borrowings for investment purposes, will be invested in equity securities that (i) are tied economically to Emerging Markets countries and (ii) have had a positive realized annual dividend yield within the past year.

rr_StrategyPortfolioConcentration

To the extent the Index concentrates (i.e., holds more than 25% of its total assets) in the securities of a particular industry or group of related industries, the Fund will concentrate its investments to approximately the same extent as the Index. Under normal circumstances, at least 80% of the Fund’s net assets, plus borrowings for investment purposes, will be invested in equity securities that (i) are tied economically to Emerging Markets countries and (ii) have had a positive realized annual dividend yield within the past year.

rr_RiskHeading

Principal Investment Risks

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following performance information indicates some of the risks of investing in the Fund.

rr_PerformanceAvailabilityWebSiteAddress

www.aamlive.com/ETF

rr_PerformancePastDoesNotIndicateFuture

The Fund’s past performance, before and after taxes, does not necessarily indicate how it will perform in the future.

rr_BarChartHeading

Calendar Year Total Returns

rr_BarChartClosingTextBlock

During the period of time shown in the bar chart, the Fund’s highest quarterly return was 25.51% for the quarter ended December 31, 2020 and the lowest quarterly return was -30.76% for the quarter ended March 31, 2020.

rr_HighestQuarterlyReturnLabel

highest quarterly return

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2020

rr_BarChartHighestQuarterlyReturn

25.51%

rr_LowestQuarterlyReturnLabel

lowest quarterly return

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_BarChartLowestQuarterlyReturn

(30.76%)

rr_PerformanceTableHeading

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

rr_PerformanceTableUsesHighestFederalRate

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns shown are not relevant to investors who hold their Shares through tax-deferred arrangements such as an individual retirement account (“IRA”) or other tax-advantaged accounts.

rr_PerformanceTableExplanationAfterTaxHigher

AAM S&P Emerging Markets High Dividend Value ETF | Risk Lose Money [Member]

rr_PerformanceTableClosingTextBlock

representing “Return After Taxes on Distributions and Sale of Shares” may be higher than the other return figures for the same period. A higher after-tax return results when a capital loss occurs upon redemption and provides an assumed tax deduction that benefits the investor.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Capital Controls And Sanctions Risk Member

rr_RiskTextBlock

As with any investment, there is a risk that you could lose all or a portion of your investment in the Fund.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Concentration Risk Member

rr_RiskTextBlock

Capital Controls and Sanctions Risk. Economic conditions, such as volatile currency exchange rates and interest rates, political events, military action and other conditions may, without prior warning, lead to foreign government intervention (including intervention by the U.S. government with respect to foreign governments, economic sectors, foreign companies and related securities and interests) and the imposition of capital controls and/or sanctions, which may also include retaliatory actions of one government against another government, such as seizure of assets. Capital controls and/or sanctions include the prohibition of, or restrictions on, the ability to transfer currency, securities or other assets. Capital controls and/or sanctions may also impact the ability of the Fund to buy, sell or otherwise transfer securities or currency, negatively impact the value and/or liquidity of such instruments, adversely affect the trading market and price for Shares, and cause the Fund to decline in value.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Currency Exchange Rate Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Emerging Markets Risk Member

rr_RiskTextBlock

Currency Exchange Rate Risk. The Fund invests primarily in investments denominated in non-U.S. currencies or in securities that provide exposure to such currencies. Changes in currency exchange rates and the relative value of non-U.S. currencies will affect the value of the Fund’s investment and the value of your Shares. Currency exchange rates can be very volatile and can change quickly and unpredictably. As a result, the value of an investment in the Fund may change quickly and without warning and you may lose money.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Equity Market Risk Member

rr_RiskTextBlock

Emerging Markets Risk. The Fund invests primarily in companies organized in emerging market nations. Investments in securities and instruments traded in developing or emerging markets, or that provide exposure to such securities or markets, can involve additional risks relating to political, economic, or regulatory conditions not associated with investments in U.S. securities and instruments or investments in more developed international markets. Such conditions may impact the ability of the Fund to buy, sell or otherwise transfer securities, adversely affect the trading market and price for Shares and cause the Fund to decline in value. Less information may be available about companies in emerging markets than in developed markets because such emerging markets companies may not be subject to accounting, auditing, and financial reporting standards or to other regulatory practices required by U.S. companies. Additionally, limitations on the availability of financial and business information about companies in emerging markets may affect the Index Provider’s ability to accurately determine the companies that meet the Index’s criteria.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | ETF Risks Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | ETF Risks, Authorized Participants, Market Makers And Liquidity Providers Concentration Risk Member

rr_RiskTextBlock

ETF Risks. The Fund is an ETF, and, as a result of an ETF’s structure, it is exposed to the following risks:

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | ETF Risks, Costs Of Buying Or Selling Shares Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | ETF Risks, Shares May Trade At Prices Other Than NAV Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | ETF Risks, Trading Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Foreign Markets Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Geographic Investment Risk Member

rr_RiskTextBlock

Foreign Markets Risk. Investments in non-U.S. securities involve certain risks that may not be present with investments in U.S. securities. For example, investments in non-U.S. securities may be subject to risk of loss due to foreign currency fluctuations or to political or economic instability. Investments in non-U.S. securities also may be subject to withholding or other taxes and may be subject to additional trading, settlement, custodial, and operational risks. These and other factors can make investments in the Fund more volatile and potentially less liquid than other types of investments.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Geographic Investment Risk, Risks Of Investing In China Risk Member

rr_RiskTextBlock

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.

◦Risks of Investing in China. Investments in Chinese issuers subject the Fund to risks specific to China. China may be subject to considerable degrees of economic, political and social instability. China is a developing market and demonstrates significantly higher volatility from time to time in comparison to developed markets. Over the past 25 years, the Chinese

government has undertaken reform of economic and market practices and is expanding the sphere of private ownership of property in China. However, Chinese markets generally continue to experience inefficiency, volatility and pricing anomalies resulting from governmental influence, a lack of publicly available information and/or political and social instability. Internal social unrest or confrontations with other neighboring countries, including military conflicts in response to such events, may also disrupt economic development in China and result in a greater risk of currency fluctuations, currency convertibility, interest rate fluctuations and higher rates of inflation. Export growth continues to be a major driver of China’s rapid economic growth. Reduction in spending on Chinese products and services, institution of tariffs or other trade barriers, or a downturn in any of the economies of China’s key trading partners may have an adverse impact on the Chinese economy. China is also vulnerable economically to the impact of a public health crisis, which could depress consumer demand, reduce economic output, and potentially lead to market closures, travel restrictions, and quarantines, all of which would negatively impact China’s economy and could affect the economies of its trading partners.

◦Risks of Investing in India. Investments in Indian issuers involve risks that are specific to India, including legal, regulatory, political and economic risks. Political and legal uncertainty, greater government control over the economy, currency fluctuations or blockage and the risk of nationalization or expropriation of assets may result in higher potential for losses. The securities markets in India are relatively underdeveloped and may subject the Fund to higher transaction costs or greater uncertainty than investments in more developed securities markets.

◦Risks of Investing in South Korea. Investments in South Korean issuers may subject the Fund to legal, regulatory, political, currency, security, and economic risks that are specific to South Korea. In addition, economic and political developments of South Korea’s neighbors may have an adverse effect on the South Korean economy.

◦Risks of Investing in Taiwan. Investments in Taiwanese issuers may subject the Fund to risks specific to Taiwan. Taiwan is a small island state with few raw material resources and limited land area and is reliant on imports for its commodity needs. Any fluctuations or shortages in the commodity markets could have a negative impact on the Taiwanese economy. Also, continued labor outsourcing may adversely affect the Taiwanese economy. Taiwan’s economy is intricately linked with economies of Asian countries that have experienced over-extensions of credit, frequent and pronounced currency fluctuations, currency devaluations, currency repatriation, rising unemployment and fluctuations in inflation. The Taiwanese economy is dependent on the economies of Japan and China, as well as the United States, and negative changes in their economies or a reduction in purchases by any of them of Taiwanese products and services would likely have an adverse impact on the Taiwanese economy. Taiwan’s geographic proximity to China and Taiwan’s history of political contention with China have resulted in ongoing tensions with China, including the risk of war with China. These tensions may materially affect the Taiwanese economy and securities markets.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Geographic Investment Risk, Risks Of Investing In India Risk Member

rr_RiskTextBlock

Risks of Investing in China. Investments in Chinese issuers subject the Fund to risks specific to China. China may be subject to considerable degrees of economic, political and social instability. China is a developing market and demonstrates significantly higher volatility from time to time in comparison to developed markets. Over the past 25 years, the Chinese government has undertaken reform of economic and market practices and is expanding the sphere of private ownership of property in China. However, Chinese markets generally continue to experience inefficiency, volatility and pricing anomalies resulting from governmental influence, a lack of publicly available information and/or political and social instability. Internal social unrest or confrontations with other neighboring countries, including military conflicts in response to such events, may also disrupt economic development in China and result in a greater risk of currency fluctuations, currency convertibility, interest rate fluctuations and higher rates of inflation. Export growth continues to be a major driver of China’s rapid economic growth. Reduction in spending on Chinese products and services, institution of tariffs or other trade barriers, or a downturn in any of the economies of China’s key trading partners may have an adverse impact on the Chinese economy. China is also vulnerable economically to the impact of a public health crisis, which could depress consumer demand, reduce economic output, and potentially lead to market closures, travel restrictions, and quarantines, all of which would negatively impact China’s economy and could affect the economies of its trading partners.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Geographic Investment Risk, Risks Of Investing In South Korea Risk Member

rr_RiskTextBlock

Risks of Investing in India. Investments in Indian issuers involve risks that are specific to India, including legal, regulatory, political and economic risks. Political and legal uncertainty, greater government control over the economy, currency fluctuations or blockage and the risk of nationalization or expropriation of assets may result in higher potential for losses. The securities markets in India are relatively underdeveloped and may subject the Fund to higher transaction costs or greater uncertainty than investments in more developed securities markets.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Geographic Investment Risk, Risks Of Investing In Taiwan Risk Member

rr_RiskTextBlock

Risks of Investing in South Korea. Investments in South Korean issuers may subject the Fund to legal, regulatory, political, currency, security, and economic risks that are specific to South Korea. In addition, economic and political developments of South Korea’s neighbors may have an adverse effect on the South Korean economy.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Geopolitical Risk Member

rr_RiskTextBlock

Risks of Investing in Taiwan. Investments in Taiwanese issuers may subject the Fund to risks specific to Taiwan. Taiwan is a small island state with few raw material resources and limited land area and is reliant on imports for its commodity needs. Any fluctuations or shortages in the commodity markets could have a negative impact on the Taiwanese economy. Also, continued labor outsourcing may adversely affect the Taiwanese economy. Taiwan’s economy is intricately linked with economies of Asian countries that have experienced over-extensions of credit, frequent and pronounced currency fluctuations, currency devaluations, currency repatriation, rising unemployment and fluctuations in inflation. The Taiwanese economy is dependent on the economies of Japan and China, as well as the United States, and negative changes in their economies or a reduction in purchases by any of them of Taiwanese products and services would likely have an adverse impact on the Taiwanese economy. Taiwan’s geographic proximity to China and Taiwan’s history of political contention with China have resulted in ongoing tensions with China, including the risk of war with China. These tensions may materially affect the Taiwanese economy and securities markets.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | High Dividend Investing Risk Member

rr_RiskTextBlock

Geopolitical Risk. Some countries and regions in which the Fund invests have experienced security concerns, war or threats of war and aggression, terrorism, economic uncertainty, natural and environmental disasters and/or systemic market dislocations that have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on the U.S. and world economies and markets generally, each of which may negatively impact the Fund’s investments.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Index Provider Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Market Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Passive Investment Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Portfolio Turnover Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | REIT Investment Risk Member

rr_RiskTextBlock

Portfolio Turnover Risk. The Fund may trade all or a significant portion of the securities in its portfolio in connection with each rebalance and reconstitution of its Index. A high portfolio turnover rate increases transaction costs, which may increase the Fund’s expenses. Frequent trading may also cause adverse tax consequences for investors in the Fund due to an increase in short-term capital gains.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Smaller Companies Risk Member

rr_RiskTextBlock

REIT Investment Risk. Investments in REITs involve unique risks. REITs may have limited financial resources, may trade less frequently and in limited volume, and may be more volatile than other securities. REITs may be affected by changes in the value of their underlying properties or mortgages or by defaults by their borrowers or tenants. Furthermore, these entities depend upon specialized management skills, have limited diversification and are, therefore, subject to risks inherent in financing a limited number of projects. In addition, the performance of a REIT may be affected by changes in the tax laws or by its failure to qualify for tax-free pass-through of income.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | Tracking Error Risk Member

rr_RiskTextBlock

Smaller Companies Risk. The equity securities of smaller companies have historically been subject to greater investment risk than securities of larger companies. The prices of equity securities of smaller companies tend to be more volatile and less liquid than the prices of equity securities of larger companies.

rr_ProspectusLineItems

AAM S&P Emerging Markets High Dividend Value ETF | S&P Emerging Markets Dividend and Free Cash Flow Yield Index (reflects no deduction for fees, expenses, or taxes)

rr_RiskTextBlock

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_ProspectusLineItems

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnLabel

S&P Emerging Markets Dividend and Free Cash Flow Yield Index(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnYear01

21.91%

rr_AverageAnnualReturnYear05

5.46%

rr_AverageAnnualReturnSinceInception

2.79%

AAM S&P Emerging Markets High Dividend Value ETF | S&P Emerging Plus LargeMidCap® Index (reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnInceptionDate

Nov. 28, 2017

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_ProspectusLineItems

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnLabel

S&P Emerging Plus LargeMidCap® Index(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnYear01

11.31%

rr_AverageAnnualReturnYear05

4.24%

rr_AverageAnnualReturnSinceInception

1.18%

AAM S&P Emerging Markets High Dividend Value ETF | AAM S&P Emerging Markets High Dividend Value ETF

rr_AverageAnnualReturnInceptionDate

Nov. 28, 2017

rr_ProspectusLineItems

dei_TradingSymbol

EEMD

rr_ManagementFeesOverAssets

0.49%

rr_DistributionAndService12b1FeesOverAssets

none

rr_OtherExpensesOverAssets

none

rr_ExpensesOverAssets

0.49%

rr_ExpenseExampleYear01

$ 50

rr_ExpenseExampleYear03

157

rr_ExpenseExampleYear05

274

rr_ExpenseExampleYear10

$ 616

Annual Return 2018

rr_AnnualReturn2018

(14.42%)

Annual Return 2019

rr_AnnualReturn2019

12.29%

rr_AnnualReturn2020

(0.06%)

rr_AnnualReturn2021

5.02%

rr_AnnualReturn2022

(11.54%)

rr_AnnualReturn2023

19.20%

rr_AverageAnnualReturnLabel

Return Before Taxes

rr_AverageAnnualReturnYear01

19.20%

rr_AverageAnnualReturnYear05

4.44%

rr_AverageAnnualReturnSinceInception

1.78%

AAM S&P Emerging Markets High Dividend Value ETF | AAM S&P Emerging Markets High Dividend Value ETF | After Taxes on Distributions

rr_AverageAnnualReturnInceptionDate

Nov. 28, 2017

rr_ProspectusLineItems

rr_AverageAnnualReturnLabel

Return After Taxes on Distributions

rr_AverageAnnualReturnYear01

16.72%

rr_AverageAnnualReturnYear05

3.04%

AAM S&P Emerging Markets High Dividend Value ETF | AAM S&P Emerging Markets High Dividend Value ETF | After Taxes on Distributions and Sales

rr_AverageAnnualReturnSinceInception

0.51%

rr_ProspectusLineItems

rr_AverageAnnualReturnLabel

Return After Taxes on Distributions and Sale of Fund Shares

rr_AverageAnnualReturnYear01

12.79%

rr_AverageAnnualReturnYear05

3.47%

AAM S&P Developed Markets High Dividend ETF

rr_AverageAnnualReturnSinceInception

1.41%

rr_ProspectusLineItems

rr_RiskReturnHeading

AAM S&P DEVELOPED MARKETS HIGH DIVIDEND VALUE ETF

rr_ObjectiveHeading

Investment Objective

rr_ObjectivePrimaryTextBlock

The AAM S&P Developed Markets High Dividend Value ETF (the “Fund”) seeks to track the total return performance, before fees and expenses, of the S&P Developed Ex-U.S. Dividend and Free Cash Flow Yield Index (the “Index”).

rr_ExpenseHeading

Fees and Expenses of the Fund

rr_ExpenseNarrativeTextBlock

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

rr_PortfolioTurnoverHeading

Portfolio Turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

93.00%

rr_ExpenseExampleHeading

Expense Example

rr_ExpenseExampleNarrativeTextBlock

rr_ExpenseExampleByYearCaption

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyHeading

Principal Investment Strategies

rr_StrategyNarrativeTextBlock

The Fund uses a “passive management” (or indexing) approach to track the total return performance, before fees and expenses, of the Index.

S&P Developed Ex-U.S. Dividend and Free Cash Flow Yield Index

The Index is a rules-based, equal-weighted index that is designed to provide exposure to the constituents of the S&P Developed BMI Ex-U.S. & Korea LargeMidCap Index (the “BMI Index”) that exhibit both high dividend yield and sustainable dividend distribution characteristics, while maintaining diversified sector exposure. The Index was developed in 2018 by S&P Dow Jones Indices, a division of S&P Global (the “Index Provider”). The BMI Index is a comprehensive benchmark including stocks from developed markets excluding the United States and Korea. The BMI Index is comprised of equity securities, including common stock and real estate investment trusts (“REITs”), that are listed in Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, Luxembourg, the Netherlands, New Zealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland, and the United Kingdom (collectively, the “Developed ex-U.S. & Korea Markets”).

Construction of the Index begins with the universe of equity securities that are included in the BMI Index, have a minimum float-adjusted market capitalization of US$1 billion, and have a median daily traded value of at least US$5 million. For each equity security in the BMI Index, the security’s dividend yield and free-cash-flow yield (i.e., a company’s cash flow from operations less capital expenditures divided by its market capitalization) are then adjusted to account for outliers. If a security’s dividend yield or free-cash-flow yield is in the top or bottom 2.5% of the BMI Index, the dividend yield or free-cash-flow yield, as applicable, for such security is replaced with the dividend yield or free-cash-flow yield of the security nearest to such top or bottom 2.5% threshold. The universe is then screened to keep only equity securities with a positive realized dividend yield (i.e., yield based on the total dividends paid for the most recent 12-month period) and free-cash-flow yield. These remaining securities are referred to as the “Selection Pool”.

For each security in the Selection Pool, the security’s dividend yield and free-cash-flow yield are then scored using a statistical normalization model (i.e., a tool to compare how close each yield is to the average yield for the Selection Pool) to assign a dividend yield score and free-cash-flow yield score from zero to one for each company. The equity securities in the Selection Pool are then ranked by the product of their dividend yield score and free-cash-flow yield score, and the top five scoring securities are selected from each of the eleven sectors for a total of 55 securities (collectively, the “Index Constituents”). The Index uses Standard & Poor’s Global Industry Classification Standards to define companies within one of the following sectors: communication services, consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology, materials, real estate, and utilities. Fewer than five securities may be selected if there are fewer than five securities in the Selection Pool for a given sector. At the time of each reconstitution of the Index, up to 25% of the Index’s weight (i.e., 13 stocks) may be from any individual country.

The Index is reconstituted (i.e., Index Constituents are added or deleted and weights are reset to equal-weight) semi-annually after the close of the third business day in January and July. At the time of each reconstitution of the Index, Index Constituents are added or deleted based on company data as of the last business day of December and June, respectively, and the Index Constituents are equally-weighted based on closing prices as of five business days prior to the last business day of the reconstitution month. If an Index Constituent is removed from the BMI Index, such security will simultaneously be removed from the Index. Additions to the Index Constituents only take place during the semi-annual reconstitutions. If multiple share classes of a single company qualify for inclusion in the Index, only the share class with the highest liquidity, measured by median daily value traded, is selected. As of December 31, 2023, the Index included significant exposure to companies in Japan, United Kingdom, and Canada.

The Fund’s Investment Strategy

The Fund will generally use a “replication” strategy to achieve its investment objective, meaning the Fund generally will invest in all of the component securities of the Index in approximately the same proportions as in the Index. However, the Fund may use a “representative sampling” strategy, meaning it may invest in a sample of the securities in the Index whose risk, return, and other characteristics closely resemble the risk, return, and other characteristics of the Index as a whole, when the Fund’s sub-adviser believes it is in the best interests of the Fund (e.g., when replicating the Index involves practical difficulties or substantial costs, an Index constituent becomes temporarily illiquid, unavailable, or less liquid, or as a result of legal restrictions or limitations that apply to the Fund but not to the Index).

Under normal circumstances, at least 80% of the Fund’s net assets, plus borrowings for investment purposes, will be invested in equity securities that (i) are traded principally on an exchange in a Developed ex-U.S. & Korea Markets country and (ii) have had a positive realized annual dividend yield within the past year.

rr_StrategyPortfolioConcentration

To the extent the Index concentrates (i.e., holds more than 25% of its total assets) in the securities of a particular industry or group of related industries, the Fund will concentrate its investments to approximately the same extent as the Index. Under normal circumstances, at least 80% of the Fund’s net assets, plus borrowings for investment purposes, will be invested in equity securities that (i) are traded principally on an exchange in a Developed ex-U.S. & Korea Markets country and (ii) have had a positive realized annual dividend yield within the past year.

rr_RiskHeading

Principal Investment Risks

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following performance information indicates some of the risks of investing in the Fund.

rr_PerformanceAvailabilityWebSiteAddress

www.aamlive.com/ETF

rr_PerformancePastDoesNotIndicateFuture

The Fund’s past performance, before and after taxes, does not necessarily indicate how it will perform in the future.

rr_BarChartHeading

Calendar Year Total Returns

rr_BarChartClosingTextBlock

During the period of time shown in the bar chart, the Fund’s highest quarterly return was 18.82% for the quarter ended December 31, 2022 and the lowest quarterly return was -33.11% for the quarter ended March 31, 2020.

rr_HighestQuarterlyReturnLabel

highest quarterly return

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2022

rr_BarChartHighestQuarterlyReturn

18.82%

rr_LowestQuarterlyReturnLabel

lowest quarterly return

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_BarChartLowestQuarterlyReturn

(33.11%)

rr_PerformanceTableHeading

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

rr_PerformanceTableUsesHighestFederalRate

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns shown are not relevant to investors who hold their Shares through tax-deferred arrangements such as an individual retirement account (“IRA”) or other tax-advantaged accounts.

rr_PerformanceTableExplanationAfterTaxHigher

AAM S&P Developed Markets High Dividend ETF | Risk Lose Money [Member]

rr_PerformanceTableClosingTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Concentration Risk Member

rr_RiskTextBlock

As with any investment, there is a risk that you could lose all or a portion of your investment in the Fund.

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Currency Exchange Rate Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Equity Market Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | ETF Risks Member

rr_RiskTextBlock

acts of terrorism, spread of infectious diseases or other public health issues (such as the global pandemic caused by the COVID-19 virus), recessions, rising inflation, or other events could have a significant negative impact on the Fund and its investments. Such events may affect certain geographic regions, countries, sectors and industries more significantly than others. Such events could adversely affect the prices and liquidity of the Fund’s portfolio securities or other instruments and could result in disruptions in the trading markets.

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | ETF Risks, Authorized Participants, Market Makers And Liquidity Providers Concentration Risk Member

rr_RiskTextBlock

ETF Risks. The Fund is an ETF, and, as a result of an ETF’s structure, it is exposed to the following risks:

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | ETF Risks, Costs Of Buying Or Selling Shares Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | ETF Risks, Shares May Trade At Prices Other Than NAV Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | ETF Risks, Trading Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Foreign Markets Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Geographic Investment Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Geographic Investment Risk, Risks Of Investing In Canada Risk Member

rr_RiskTextBlock

◦Risks of Investing in Canada. The Index may have significant exposure to companies in Canada, and, as a result, investment results could be dependent on the financial condition of the Canadian economy. The Canadian economy is reliant on the sale of natural resources and commodities, which can pose risks such as the fluctuation of prices and the variability of demand for exportation of such products. Changes in spending on Canadian products by the economies of other countries or changes in any of these economies may cause a significant impact on the Canadian economy.

◦Risks Related to Investing in Europe. The economies and markets of European countries are often closely connected and interdependent, and events in one country in Europe can have an adverse impact on other European countries. The Fund makes investments in securities of issuers that are domiciled in, or have significant operations in, member countries of the European Union (“EU”) that are subject to economic and monetary controls that can adversely affect the Fund’s investments. The European financial markets have experienced volatility and adverse trends in recent years and these events have adversely affected the exchange rate of the euro and may continue to significantly affect other European countries. Decreasing imports or exports, changes in governmental or EU regulations on trade, changes in the exchange rate of the euro, the default or threat of default by an EU member country on its sovereign debt, and/or an economic recession in an EU member country may have a significant adverse effect on the economies of EU member countries and their trading partners, including some or all of the European countries in which the Fund invests. Acts of war in Europe, including Russia’s large-scale military invasion of Ukraine, and the resulting sanctions by and against European nations could also have a severe adverse effect on both European and global economies, which in turn could affect the value of the Fund’s investments.

The United Kingdom (“UK”) formally exited from the EU on January 31, 2020 (known as “Brexit”), and effective December 31, 2020, the UK ended a transition period during which it continued to abide by the EU’s rules and the UK’s trade relationships with the EU were generally unchanged. Following this transition period, the impact on the UK and European economies and the broader global economy could be significant, resulting in negative impacts, such as increased volatility and illiquidity, and potentially lower economic growth of markets in the UK, Europe and globally, which may adversely affect the value of the Fund’s investments.

◦Risks Related to Investing in Japan. The Japanese economy may be subject to considerable degrees of economic, political and social instability, which could have a negative impact on Japanese securities. While the Japanese economy has recently emerged from a prolonged economic downturn, Japan’s economic growth rate may remain relatively low in the future. In addition, Japan is subject to the risk of natural disasters, such as earthquakes, volcanoes, typhoons and tsunamis. Additionally, decreasing U.S. imports, new trade regulations, changes in the U.S. dollar exchange rates, a recession in the United States or continued increases in foreclosure rates may have an adverse impact on the economy of Japan. Japan also has few natural resources, and any fluctuation or shortage in the commodity markets could have a negative impact on Japanese securities.

◦Risks Related to Investing in the United Kingdom. The Fund is subject to certain risks specifically associated with investments in the securities of United Kingdom issuers. Investments in issuers located in the United Kingdom may subject the Fund to regulatory, political, currency, security and economic risk specific to the United Kingdom. The United Kingdom has one of the largest economies in Europe and is heavily dependent on trade with the European Union (“EU”), and to a lesser extent the United States and China. As a result, the economy of the United Kingdom may be impacted by changes to the economic health of EU member countries, the United States and China. In 2016, the United Kingdom voted via referendum to leave the EU (“Brexit”). After years of negotiations between the United Kingdom and the EU, a withdrawal agreement was reached whereby the United Kingdom formally left the EU. The precise impact on the United Kingdom’s economy as a result of its departure from the EU depends to a large degree on its ability to conclude favorable trade deals with the EU and other countries, including the United States, China, India and Japan. While new trade deals may boost economic growth, such growth may not be able to offset the increased costs of trade with the EU resulting from the United Kingdom’s loss of its membership in the EU single market. Certain sectors within the United Kingdom’s economy may be particularly affected by Brexit, including the automotive, chemicals, financial services and professional services.

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Geographic Investment Risk, Risks Related To Investing In Europe Risk Member

rr_RiskTextBlock

Risks of Investing in Canada. The Index may have significant exposure to companies in Canada, and, as a result, investment results could be dependent on the financial condition of the Canadian economy. The Canadian economy is reliant on the sale of natural resources and commodities, which can pose risks such as the fluctuation of prices and the variability of demand for exportation of such products. Changes in spending on Canadian products by the economies of other countries or changes in any of these economies may cause a significant impact on the Canadian economy.

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Geographic Investment Risk, Risks Related To Investing In Japan Risk Member

rr_RiskTextBlock

Risks Related to Investing in Europe. The economies and markets of European countries are often closely connected and interdependent, and events in one country in Europe can have an adverse impact on other European countries. The Fund makes investments in securities of issuers that are domiciled in, or have significant operations in, member countries of the European Union (“EU”) that are subject to economic and monetary controls that can adversely affect the Fund’s investments. The European financial markets have experienced volatility and adverse trends in recent years and these events have adversely affected the exchange rate of the euro and may continue to significantly affect other European countries. Decreasing imports or exports, changes in governmental or EU regulations on trade, changes in the exchange rate of the euro, the default or threat of default by an EU member country on its sovereign debt, and/or an economic recession in an EU member country may have a significant adverse effect on the economies of EU member countries and their trading partners, including some or all of the European countries in which the Fund invests. Acts of war in Europe, including Russia’s large-scale military invasion of Ukraine, and the resulting sanctions by and against European nations could also have a severe adverse effect on both European and global economies, which in turn could affect the value of the Fund’s investments. The United Kingdom (“UK”) formally exited from the EU on January 31, 2020 (known as “Brexit”), and effective December 31, 2020, the UK ended a transition period during which it continued to abide by the EU’s rules and the UK’s trade relationships with the EU were generally unchanged. Following this transition period, the impact on the UK and European economies and the broader global economy could be significant, resulting in negative impacts, such as increased volatility and illiquidity, and potentially lower economic growth of markets in the UK, Europe and globally, which may adversely affect the value of the Fund’s investments.

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Geographic Investment Risk, Risks Related To Investing In The United Kingdom Risk Member

rr_RiskTextBlock

Risks Related to Investing in Japan. The Japanese economy may be subject to considerable degrees of economic, political and social instability, which could have a negative impact on Japanese securities. While the Japanese economy has recently emerged from a prolonged economic downturn, Japan’s economic growth rate may remain relatively low in the future. In addition, Japan is subject to the risk of natural disasters, such as earthquakes, volcanoes, typhoons and tsunamis. Additionally, decreasing U.S. imports, new trade regulations, changes in the U.S. dollar exchange rates, a recession in the United States or continued increases in foreclosure rates may have an adverse impact on the economy of Japan. Japan also has few natural resources, and any fluctuation or shortage in the commodity markets could have a negative impact on Japanese securities.

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | High Dividend Investing Risk Member

rr_RiskTextBlock

Risks Related to Investing in the United Kingdom. The Fund is subject to certain risks specifically associated with investments in the securities of United Kingdom issuers. Investments in issuers located in the United Kingdom may subject the Fund to regulatory, political, currency, security and economic risk specific to the United Kingdom. The United Kingdom has one of the largest economies in Europe and is heavily dependent on trade with the European Union (“EU”), and to a lesser extent the United States and China. As a result, the economy of the United Kingdom may be impacted by changes to the economic health of EU member countries, the United States and China. In 2016, the United Kingdom voted via referendum to leave the EU (“Brexit”). After years of negotiations between the United Kingdom and the EU, a withdrawal agreement was reached whereby the United Kingdom formally left the EU. The precise impact on the United Kingdom’s economy as a result of its departure from the EU depends to a large degree on its ability to conclude favorable trade deals with the EU and other countries, including the United States, China, India and Japan. While new trade deals may boost economic growth, such growth may not be able to offset the increased costs of trade with the EU resulting from the United Kingdom’s loss of its membership in the EU single market. Certain sectors within the United Kingdom’s economy may be particularly affected by Brexit, including the automotive, chemicals, financial services and professional services.

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Index Provider Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Market Capitalization Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Market Risk Member

rr_RiskTextBlock

Market Capitalization Risk. The securities of large-capitalization companies may be relatively mature compared to smaller companies and therefore subject to slower growth during times of economic expansion. The securities of mid-capitalization companies may be more vulnerable to adverse issuer, market, political, or economic developments than securities of large-capitalization companies. The securities of mid-capitalization companies generally trade in lower volumes and are subject to greater and more unpredictable price changes than large capitalization stocks or the stock market as a whole.

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Passive Investment Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | REIT Investment Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | Tracking Error Risk Member

rr_RiskTextBlock

REIT Investment Risk. Investments in REITs involve unique risks. REITs may have limited financial resources, may trade less frequently and in limited volume, and may be more volatile than other securities. REITs may be affected by changes in the value of their underlying properties or mortgages or by defaults by their borrowers or tenants. Furthermore, these entities depend upon specialized management skills, have limited diversification and are, therefore, subject to risks inherent in financing a limited number of projects. In addition, the performance of a REIT may be affected by changes in the tax laws or by its failure to qualify for tax-free pass-through of income.

rr_ProspectusLineItems

AAM S&P Developed Markets High Dividend ETF | S&P Developed Ex-U.S. Dividend and Free Cash Flow Yield Index (reflects no deduction for fees, expenses, or taxes)

rr_RiskTextBlock

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_ProspectusLineItems

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnLabel

S&P Developed Ex-U.S. Dividend and Free Cash Flow Yield Index(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnYear01

19.98%

rr_AverageAnnualReturnYear05

5.16%

rr_AverageAnnualReturnSinceInception

4.08%

AAM S&P Developed Markets High Dividend ETF | S&P Developed BMI Ex-U.S. & Korea LargeMidcap Index (reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnInceptionDate

Nov. 27, 2018

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_ProspectusLineItems

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnLabel

S&P Developed BMI Ex-U.S. & Korea LargeMidcap Index(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnYear01

17.80%

rr_AverageAnnualReturnYear05

8.35%

rr_AverageAnnualReturnSinceInception

7.22%

AAM S&P Developed Markets High Dividend ETF | AAM S&P Developed Markets High Dividend ETF

rr_AverageAnnualReturnInceptionDate

Nov. 27, 2018

rr_ProspectusLineItems

dei_TradingSymbol

DMDV

rr_ManagementFeesOverAssets

0.39%

rr_DistributionAndService12b1FeesOverAssets

none

rr_OtherExpensesOverAssets

none

rr_ExpensesOverAssets

0.39%

rr_ExpenseExampleYear01

$ 40

rr_ExpenseExampleYear03

125

rr_ExpenseExampleYear05

219

rr_ExpenseExampleYear10

$ 493

Annual Return 2019

rr_AnnualReturn2019

17.33%

rr_AnnualReturn2020

(11.55%)

rr_AnnualReturn2021

10.54%

rr_AnnualReturn2022

(8.00%)

rr_AnnualReturn2023

19.19%

rr_AverageAnnualReturnLabel

Return Before Taxes

rr_AverageAnnualReturnYear01

19.19%

rr_AverageAnnualReturnYear05

4.70%

rr_AverageAnnualReturnSinceInception

3.64%

AAM S&P Developed Markets High Dividend ETF | AAM S&P Developed Markets High Dividend ETF | After Taxes on Distributions

rr_AverageAnnualReturnInceptionDate

Nov. 27, 2018

rr_ProspectusLineItems

rr_AverageAnnualReturnLabel

Return After Taxes on Distributions

rr_AverageAnnualReturnYear01

17.88%

rr_AverageAnnualReturnYear05

3.83%

AAM S&P Developed Markets High Dividend ETF | AAM S&P Developed Markets High Dividend ETF | After Taxes on Distributions and Sales

rr_AverageAnnualReturnSinceInception

2.79%

rr_ProspectusLineItems

rr_AverageAnnualReturnLabel

Return After Taxes on Distributions and Sale of Fund Shares

rr_AverageAnnualReturnYear01

13.33%

rr_AverageAnnualReturnYear05

3.97%

AAM Low Duration Preferred and Income Securities ETF

rr_AverageAnnualReturnSinceInception

3.13%

rr_ProspectusLineItems

rr_RiskReturnHeading

AAM LOW DURATION PREFERRED AND INCOME SECURITIES ETF

rr_ObjectiveHeading

Investment Objective

rr_ObjectivePrimaryTextBlock

The AAM Low Duration Preferred and Income Securities ETF (the “Fund”) seeks to track the total return performance, before fees and expenses, of the ICE 0-5 Year Duration Exchange-Listed Preferred & Hybrid Securities Index (the “Index”).

rr_ExpenseHeading

Fees and Expenses of the Fund

rr_ExpenseNarrativeTextBlock

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

rr_PortfolioTurnoverHeading

Portfolio Turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

100.00%

rr_ExpenseExampleHeading

Expense Example

rr_ExpenseExampleNarrativeTextBlock

rr_ExpenseExampleByYearCaption

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyHeading

Principal Investment Strategies

rr_StrategyNarrativeTextBlock

The Fund uses a “passive management” (or indexing) approach to track the total return performance, before fees and expenses, of the Index.

ICE 0-5 Year Duration Exchange-Listed Preferred & Hybrid Securities Index

The Index measures the performance of exchange-listed, U.S. dollar-denominated preferred securities and hybrid securities listed on the New York Stock Exchange (“NYSE”) or NASDAQ Capital Market (“NASDAQ”) with an option-adjusted duration of less than five years. The Index was developed by ICE Data Indices, LLC (“IDI”), the Fund’s index provider (the “Index Provider”) and an affiliate of the NYSE.

Duration is a measure of a security’s price sensitivity to changes in yields or interest rates and a lower duration indicates less sensitivity to interest rates. For example, the price of a security with a three-year duration would be expected to drop by approximately 3% in response to a 1% increase in interest rates. A security’s “option-adjusted duration” is a measure of its sensitivity to changes in interest rates, while factoring in the call features associated with such security.

Preferred stock generally refers to a unit of ownership in a company (like common stock) that has preference over common stock in the payment of dividends and in the event of a company’s liquidation. Unlike common stocks, preferred stocks are generally not entitled to vote on corporate matters. Preferred stock in the Index includes U.S.-listed preferred stock and American Depositary Receipts (“ADRs”) representing preferred stock issued by non-U.S. companies.

“Hybrid” securities are those that have characteristics of both equity and fixed income securities. Hybrid securities typically have preference over an issuer’s common stock with respect to the payment of dividends and in the event of a company’s liquidation and are issued and traded in a similar manner to traditional preferred stock. Holders of hybrid securities may be eligible to receive fixed, periodic payments from the issuer of a hybrid security, although the issuer may have the right to defer such payments or extend the

hybrid security’s maturity date. Preferred stocks and hybrid securities generally are issued with a fixed par value and pay dividends based on a percentage of that par value at a fixed or variable rate.

Additionally, preferred stocks and hybrid securities often have a liquidation value that generally equals the original purchase price of such security at the date of issuance. The Index may include many different categories of preferred stock and hybrid securities, such as floating and fixed rate preferreds, fixed-to-floating rate securities, callable preferreds, convertible preferreds, cumulative and non-cumulative preferreds, certain capital securities, preferred real estate investment trusts (“REITs”) or hybrid REITs, trust preferreds or various other preferred stock and hybrid securities. The Index may include preferred and hybrid securities of any quality, including high-yield securities (also known as junk bonds), and securities that are not rated by any rating agencies. The Index uses a market capitalization weighted methodology subject to certain constraints and is rebalanced monthly.

At the time of each monthly rebalance and reconstitution of the Index, the Index includes issuances of preferred stocks and notes with at least $100 million face amount outstanding and hybrid securities with at least $250 million face amount outstanding that meet minimum price, liquidity, trading volume, maturity, and other requirements, as applicable, as determined by the Index methodology. To be eligible for inclusion in the Index, corporate hybrid debt must have at least 18 months to final maturity at the time of issuance. Additionally, to qualify for inclusion in the Index a security must be priced at no more than 105% of its face value. Once included in the Index, a security remains eligible for inclusion so long as its option-adjusted duration is less than six years.

The Index may include large-, mid- or small-capitalization companies and includes preferred stocks of non-U.S. issuers. As of December 31, 2023, a significant portion of the Index was represented by securities of companies in the real estate and financials service sectors. Also as of December 31, 2023, the Index was comprised of 189 components and had an effective duration of 1.53 years.

The Index uses a market capitalization weighted methodology subject to certain constraints, including a maximum allocation of 4.75% to any individual issuer. The Index is rebalanced on the last calendar day of each month, based on closing prices as of three business days prior to the last business day of the month.

The Fund’s Investment Strategy

The Fund will generally use a “replication” strategy to achieve its investment objective, meaning the Fund generally will invest in all of the component securities of the Index in approximately the same proportion as in the Index. However, the Fund may use a “representative sampling” strategy, meaning it may invest in a sample of the securities in the Index whose risk, return and other characteristics closely resemble the risk, return and other characteristics of the Index as a whole, when the Fund’s sub-adviser believes it is in the best interests of the Fund (e.g., when replicating the Index involves practical difficulties or substantial costs, an Index constituent becomes temporarily illiquid, unavailable or less liquid, or as a result of legal restrictions or limitations that apply to the Fund but not to the Index).

Under normal circumstances, at least 80% of the Fund’s net assets, plus borrowings for investment purposes, will be invested in preferred and income securities.

rr_StrategyPortfolioConcentration

To the extent the Index concentrates (i.e., holds more than 25% of its total assets) in the securities of a particular industry or group of related industries, the Fund will concentrate its investments to approximately the same extent as the Index.Under normal circumstances, at least 80% of the Fund’s net assets, plus borrowings for investment purposes, will be invested in preferred and income securities.

rr_RiskHeading

Principal Investment Risks

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

The following performance information indicates some of the risks of investing in the Fund. The bar chart shows the Fund’s performance for the most recent calendar year ended December 31. The table illustrates how the Fund’s average annual returns for the 1-year and since inception periods compare with those of a broad measure of market performance and the Index. The Fund’s past performance, before and after taxes, does not necessarily indicate how it will perform in the future. Updated performance information is available on the Fund’s website at www.aamlive.com/ETF.

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following performance information indicates some of the risks of investing in the Fund.

rr_PerformanceAvailabilityWebSiteAddress

www.aamlive.com/ETF

rr_PerformancePastDoesNotIndicateFuture

The Fund’s past performance, before and after taxes, does not necessarily indicate how it will perform in the future.

rr_BarChartHeading

Calendar Year Total Returns

rr_BarChartClosingTextBlock

During the period of time shown in the bar chart, the Fund’s highest quarterly return was 10.75% for the quarter ended June 30, 2020 and the lowest quarterly return was -14.62% for the quarter ended March 31, 2020.

rr_HighestQuarterlyReturnLabel

highest quarterly return

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

rr_BarChartHighestQuarterlyReturn

10.75%

rr_LowestQuarterlyReturnLabel

lowest quarterly return

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_BarChartLowestQuarterlyReturn

(14.62%)

rr_PerformanceTableHeading

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

rr_PerformanceTableUsesHighestFederalRate

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns shown are not relevant to investors who hold their Shares through tax-deferred arrangements such as an individual retirement account (“IRA”) or other tax-advantaged accounts.

rr_PerformanceTableExplanationAfterTaxHigher

AAM Low Duration Preferred and Income Securities ETF | Risk Lose Money [Member]

rr_PerformanceTableClosingTextBlock

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Call Risk Member

rr_RiskTextBlock

As with any investment, there is a risk that you could lose all or a portion of your investment in the Fund.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Cash Redemption Risk Member

rr_RiskTextBlock

Call Risk. During periods of falling interest rates, an issuer of a callable security 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.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Concentration Risk Member

rr_RiskTextBlock

Cash Redemption Risk. The Fund’s investment strategy may require it to redeem shares for cash or to otherwise include cash as part of its redemption proceeds. The Fund may be required to sell or unwind portfolio investments to obtain the cash needed to distribute redemption proceeds. This may cause the Fund to recognize a capital gain that it might not have recognized if it had made a redemption in-kind. As a result, the Fund may pay out higher annual capital gain distributions than if the in-kind redemption process was used.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Credit Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Depositary Receipt Risk Member

rr_RiskTextBlock

Credit Risk. Debt issuers and other counterparties may not honor their obligations or may have their debt downgraded by ratings agencies. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also adversely affect the value of the Fund’s investment in that issuer.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Dividend-Paying Securities Risk Member

rr_RiskTextBlock

Depositary Receipt Risk. Depositary Receipts involve risks similar to those associated with investments in foreign securities, such as changes in political or economic conditions of other countries and changes in the exchange rates of foreign currencies. Depositary Receipts listed on U.S. exchanges are issued by banks or trust companies, and entitle the holder to all dividends and capital gains that are paid out on the underlying foreign shares (“Underlying Shares”). When the Fund invests in Depositary Receipts as a substitute for an investment directly in the Underlying Shares, the Fund is exposed to the risk that the Depositary Receipts may not provide a return that corresponds precisely with that of the Underlying Shares.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Equity Market Risk Member

rr_RiskTextBlock

Dividend-Paying Securities Risk. There is no guarantee that issuers of the securities held by the Fund will declare dividends in the future or that, if declared, they will either remain at current levels or increase over time.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Extension Risk Member

rr_RiskTextBlock

Equity Market Risk. Equity securities, including preferred stocks, and hybrid securities that have equity characteristics may experience sudden, unpredictable drops in value or long periods of decline in value. This may occur because of factors that affect securities markets generally or factors affecting specific issuers, industries, sectors or companies in which the Fund invests. Preferred stocks and hybrid securities generally are subject to more risks than debt securities because stockholders’ claims are subordinated to those of holders of debt securities upon the bankruptcy of the issuer. In addition, local, regional or global events such as war, including Russia’s invasion of Ukraine, acts of terrorism, spread of infectious diseases or other public health issues (such as the global pandemic caused by the COVID-19 virus), recessions, or other events could have a significant negative impact on the Fund and its investments. Such events may affect certain geographic regions, countries, sectors and industries more significantly than others. Such events could adversely affect the prices and liquidity of the Fund’s portfolio securities or other instruments and could result in disruptions in the trading markets.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | ETF Risks Member

rr_RiskTextBlock

Extension Risk. During periods of rising interest rates, certain debt obligations will be paid off substantially more slowly than originally anticipated and the value of those securities may fall sharply, resulting in a decline in the Fund’s income and potentially in the value of the Fund’s investments.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | ETF Risks, Authorized Participants, Market Makers And Liquidity Providers Concentration Risk Member

rr_RiskTextBlock

ETF Risks. The Fund is an ETF, and, as a result of an ETF’s structure, it is exposed to the following risks:

◦Trading. Although Shares are listed for trading on the NYSE Arca, Inc. (the “Exchange”) and may be traded on U.S. exchanges other than the Exchange, there can be no assurance that Shares will trade with any volume, or at all, on any stock exchange. In stressed market conditions, the liquidity of Shares may begin to mirror the liquidity of the Fund’s underlying portfolio holdings, which can be significantly less liquid than Shares, and this could lead to differences between the market price of the Shares and the underlying value of those Shares.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | ETF Risks, Costs Of Buying Or Selling Shares Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | ETF Risks, Shares May Trade At Prices Other Than NAV Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | ETF Risks, Trading Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Foreign Markets Risk Member

rr_RiskTextBlock

Trading. Although Shares are listed for trading on the NYSE Arca, Inc. (the “Exchange”) and may be traded on U.S. exchanges other than the Exchange, there can be no assurance that Shares will trade with any volume, or at all, on any stock exchange. In stressed market conditions, the liquidity of Shares may begin to mirror the liquidity of the Fund’s underlying portfolio holdings, which can be significantly less liquid than Shares, and this could lead to differences between the market price of the Shares and the underlying value of those Shares.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | High-Yield Securities Risk Member

rr_RiskTextBlock

other taxes and may be indirectly subject to additional trading, settlement, custodial, and operational risks. These and other factors can make investments in the Fund more volatile and potentially less liquid than other types of investments.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Hybrid Securities Risk Member

rr_RiskTextBlock

High-Yield Securities Risk. High-yield securities (also known as “junk bonds”) carry a greater degree of risk and are considered speculative by the major credit rating agencies. High-yield securities may be issued by companies that are restructuring, are smaller and less creditworthy, or are more highly indebted than other companies. This means that they may have more difficulty making scheduled payments of principal and interest. Changes in the value of high-yield securities are influenced more by changes in the financial and business position of the issuing company than by changes in interest rates when compared to investment grade securities. High-yield securities have greater volatility because there is less certainty that principal and interest payments will be made as scheduled. The Fund’s investments in high-yield securities expose it to a substantial degree of credit risk. These investments are considered speculative under traditional investment standards. Prices of high-yield securities will rise and fall primarily in response to actual or perceived changes in the issuer's financial health, although changes in market interest rates also will affect prices. High-yield securities may experience reduced liquidity and sudden and substantial decreases in price.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Index Provider Risk Member

rr_RiskTextBlock

Hybrid Securities Risk. Hybrid securities are subject to the risks of equity securities and debt securities. The claims of holders of hybrid securities of an issuer are generally subordinated to those of holders of traditional debt securities in bankruptcy, and thus hybrid securities may be more volatile and subject to greater risk than traditional debt securities, and may in certain circumstances even be more volatile than traditional equity securities. At the same time, hybrid securities may not fully participate in gains of their issuer and thus potential returns of such securities are generally more limited than traditional equity securities, which would participate in such gains.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Interest Rate Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Issuer-Specific Risk Member

rr_RiskTextBlock

Interest Rate Risk. Generally, the value of fixed income securities, as well as hybrid securities with fixed income characteristics, will change inversely with changes in interest rates. An increase in interest rates may cause the value of fixed income securities and such hybrid securities to decline. Conversely, as interest rates fall, the market value of fixed income securities and such hybrid securities tend to increase. This risk will be greater for long-term securities than for short-term securities.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Market Capitalization Risk Member

rr_RiskTextBlock

Issuer-Specific Risk. Issuer-specific events, including changes in the financial condition of an issuer, can have a negative impact on the value of the Fund.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Market Risk Member

rr_RiskTextBlock

Market Capitalization Risk. The securities of large-capitalization companies may be relatively mature compared to smaller companies and therefore subject to slower growth during times of economic expansion. The securities of mid-capitalization companies may be more vulnerable to adverse issuer, market, political, or economic developments than securities of large-capitalization companies. The securities of small-capitalization companies generally trade in lower volumes and are subject to greater and more unpredictable price changes than larger capitalization stocks or the stock market as a whole.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Passive Investment Risk Member

rr_RiskTextBlock

Market Risk. The trading prices of preferred stocks and hybrid securities and other instruments fluctuate in response to a variety of factors. The Fund’s NAV and market price may fluctuate significantly in response to these and other factors. As a result, an investor could lose money over short or long periods of time.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Portfolio Turnover Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Preferred Securities Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Prepayment Risk Member

rr_RiskTextBlock

Preferred Securities Risk. Preferred stocks are subject to the risks of equity securities generally and also risks associated with fixed income securities, such as interest rate risk. A company’s preferred stock generally pays dividends only after the company makes required payments to creditors. As a result, the value of a company’s preferred stock will react more strongly than bonds and other debt to actual or perceived changes in the company’s financial condition or prospects. Preferred stock may be less liquid than many other types of securities, such as common stock, and generally has limited or no voting rights. In addition, preferred stock is subject to the risks that a company may defer or not pay dividends, and, in certain situations, may call or redeem its preferred stock or convert it to common stock.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | REIT Investment Risk Member

rr_RiskTextBlock

Prepayment Risk. This is the risk that a borrower will prepay some or the entire principal owed to the Fund. If that happens, the Fund may have to replace the security by investing the proceeds in a security with a lower yield. This could reduce the share price and income distributions of the Fund.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Sector Risk Member

rr_RiskTextBlock

REIT Investment Risk. Investments in REITs involve unique risks. REITs may have limited financial resources, may trade less frequently and in limited volume, and may be more volatile than other securities. REITs may be affected by changes in the value of their underlying properties or mortgages or by defaults by their borrowers or tenants. Furthermore, these entities depend upon specialized management skills, have limited diversification and are, therefore, subject to risks inherent in financing a limited number of projects. In addition, the performance of a REIT may be affected by changes in the tax laws or by its failure to qualify for tax-free pass-through of income.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Sector Risk, Financial Sector Risk Member

rr_RiskTextBlock

Sector Risk. To the extent the Fund invests more heavily in particular sectors of the economy, its performance will be especially sensitive to developments that significantly affect those sectors. ◦Financial Sector Risk. Companies in the financial sector may be significantly affected by changes in interest rates, government regulation, the rate of defaults on corporate, consumer and government debt, the availability and cost of capital, and fallout from the housing and sub-prime mortgage crisis. 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. In recent years, cyber attacks and technology malfunctions and failures have become increasingly frequent in this sector and have caused significant losses.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | Tracking Error Risk Member

rr_RiskTextBlock

Financial Sector Risk. Companies in the financial sector may be significantly affected by changes in interest rates, government regulation, the rate of defaults on corporate, consumer and government debt, the availability and cost of capital, and fallout from the housing and sub-prime mortgage crisis. 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. In recent years, cyber attacks and technology malfunctions and failures have become increasingly frequent in this sector and have caused significant losses.

rr_ProspectusLineItems

AAM Low Duration Preferred and Income Securities ETF | ICE 0-5 Year Duration Exchange-Listed Preferred & Hybrid Securities Index (reflects no deduction for fees, expenses, or taxes)

rr_RiskTextBlock

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_ProspectusLineItems

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnLabel

ICE 0-5 Year Duration Exchange-Listed Preferred & Hybrid Securities Index (reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnYear01

8.61%

rr_AverageAnnualReturnSinceInception

1.44%

AAM Low Duration Preferred and Income Securities ETF | ICE Exchange-Listed Preferred & Hybrid Securities Index (reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnInceptionDate

Nov. 19, 2019

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_ProspectusLineItems

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnLabel

ICE Exchange-Listed Preferred & Hybrid Securities Index(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnYear01

9.84%

rr_AverageAnnualReturnSinceInception

1.67%

AAM Low Duration Preferred and Income Securities ETF | AAM Low Duration Preferred and Income Securities ETF

rr_AverageAnnualReturnInceptionDate

Nov. 19, 2019

rr_ProspectusLineItems

dei_TradingSymbol

PFLD

rr_ManagementFeesOverAssets

0.45%

rr_DistributionAndService12b1FeesOverAssets

none

rr_OtherExpensesOverAssets

0.01%

rr_ExpensesOverAssets

0.46%

rr_ExpenseExampleYear01

$ 47

rr_ExpenseExampleYear03

145

rr_ExpenseExampleYear05

253

rr_ExpenseExampleYear10

$ 568

rr_AnnualReturn2020

5.24%

rr_AnnualReturn2021

4.59%

rr_AnnualReturn2022

(13.24%)

rr_AnnualReturn2023

8.21%

rr_AverageAnnualReturnLabel

Return Before Taxes

rr_AverageAnnualReturnYear01

8.21%

rr_AverageAnnualReturnSinceInception

1.06%

AAM Low Duration Preferred and Income Securities ETF | AAM Low Duration Preferred and Income Securities ETF | After Taxes on Distributions

rr_AverageAnnualReturnInceptionDate

Nov. 19, 2019

rr_ProspectusLineItems

rr_AverageAnnualReturnLabel

Return After Taxes on Distributions

rr_AverageAnnualReturnYear01

6.10%

AAM Low Duration Preferred and Income Securities ETF | AAM Low Duration Preferred and Income Securities ETF | After Taxes on Distributions and Sales

rr_AverageAnnualReturnSinceInception

(0.57%)

rr_ProspectusLineItems

rr_AverageAnnualReturnLabel

Return After Taxes on Distributions and Sale of Fund Shares

rr_AverageAnnualReturnYear01

5.77%

rr_AverageAnnualReturnSinceInception

0.49%

AAM Transformers ETF

rr_ProspectusLineItems

rr_RiskReturnHeading

AAM TRANSFORMERS ETF

rr_ObjectiveHeading

Investment Objective

rr_ObjectivePrimaryTextBlock

The AAM Transformers ETF (the “Fund”) seeks to track the total return performance, before fees and expenses, of the Pence Transformers Index (the “Index”).

rr_ExpenseHeading

Fees and Expenses of the Fund

rr_ExpenseNarrativeTextBlock

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

rr_PortfolioTurnoverHeading

Portfolio Turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

82.00%

rr_ExpenseExampleHeading

Expense Example

rr_ExpenseExampleNarrativeTextBlock

rr_ExpenseExampleByYearCaption

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

rr_StrategyHeading

Principal Investment Strategy

rr_StrategyNarrativeTextBlock

The Fund uses a “passive management” (or indexing) approach to track the total return performance, before fees and expenses, of the Index.

Pence Transformers Index

The Index is a rules-based index that measures the performance of U.S.-listed common equity securities, including American Depositary Receipts (“ADRs”) for foreign securities, of companies poised to benefit from a significant disruption and/or transformation of consumer behavior and technological innovation. Examples of significant disruptions and/or transformation of consumer behavior and technological innovation include, but are not limited to, (i) advancements in autonomous driving capabilities and electric vehicle technology disrupting the automobile manufacturers and trucking sub-industries; (ii) changes in consumer behavior shifting retail sales from brick and mortar businesses to digital channels transforming the internet and digital marketing retail sub-industry; (iii) recent developments in cellular data speeds and improvements in mobile technologies disrupting the interactive media and services sub-industry; and (iv) new technologies that provide carbon offsets for existing business models or the development of greener alternatives to existing energy production transforming the renewable electricity producers sub-industry.

Securities eligible for inclusion in the Index must be classified in one of the following sub-industries of the Global Industry Classification Standard (“GICS”):


Sub-Industries
Aerospace & Defense	Electronic Components	IT Consulting & Other Services
Alternative Carriers	Electronic Equipment & Instruments	Oil & Gas Refining & Marketing
Application Software	Heavy Electrical Equipment	Renewable Electricity Producers
Automobile Manufacturers	Hotels, Resorts & Cruise Lines	Semiconductor Equipment
Communications Equipment	Industrial Machinery	Semiconductors
Consumer Electronics	Interactive Home Entertainment	Specialty Chemicals
Copper	Interactive Media & Services	Systems Software
Data Processing & Outsourced Services	Internet & Direct Marketing Retail	Technology Hardware, Storage & Peripherals
Electrical Components & Equipment	Internet Services & Infrastructure	Trucking

Companies are screened from the universe of eligible securities based on descriptions of a company in regulatory filings (e.g., financial statements, annual reports), investor presentations, analyst reports, and industry-specific publications. In seeking companies that are expected to have market dominance, the Index analyzes the following quantitative factors that, in the opinion of Pence Capital Management, LLC (the “Index Provider”), provide an indication of a significant disruption and/or transformation of consumer behavior and technological innovation: research and development (“R&D”) spending as a percentage of sales, projected sales, and projected sales growth. The screening of the Index is performed by the Index Provider, and the Index was developed in 2021 by the Index Provider.

To be included in the Index, a company must have (i) a minimum float-adjusted market capitalization of $2 billion, (ii) a minimum liquidity threshold of an average daily traded value of $2 million over a three-month period, and (iii) a consensus analyst rating above 3.0. Broker-dealers issue ratings based on an analyst’s measure of a stock’s expected performance in a given time period, where a rating of 5.0 is the strongest ranking (e.g., buy) and 1.0 is the weakest ranking (e.g., sell). A consensus rating is the average of all brokers’ recommendations which have updated their recommendation in a given time period. To be eligible for inclusion in the Index, there must be at least five analysts making a recommendation for the company (except for ADRs and newly-listed securities). An ADR may be included in the Index with fewer than five analysts’ ratings, if the underlying security for which the ADR is based on has at least five analysts making a recommendation for the company. Newly-listed securities may also be included in the Index with fewer than five analysts’ ratings (i.e., a company that is post-IPO but may not have wide analyst coverage due to IPO lock-up periods) if a company is in one of the specified industries, has a minimum market capitalization over $2 billion, and has projected revenue over $200 million.

The Index is reconstituted (i.e., Index constituents are added or deleted and weightings within each category are reset to equal-weight) after the close of business on the third Friday of March, June, September, and December. At the time of each reconstitution of the Index, Index constituents are added or deleted based on company data as of the last business day of February, May, August, and November, respectively, and the Index constituents are equally weighted within the following categories based on closing prices as of ten business days prior to the reconstitution date.


Category 1 (20% weight)			U.S.-based companies with over $100 billion market capitalization
Category 2 (30% weight)			U.S.-based companies with $20 billion to $100 billion market capitalization
Category 3 (25% weight)			U.S.-based companies with $2 billion to $20 billion market capitalization
Category 4 (15% weight)			international companies with over $30 billion market capitalization
Category 5 (10% weight)			international companies with $2 billion to $30 billion market capitalization

The aggregate weight of U.S.-based companies (companies in Categories 1, 2, and 3) is capped at 75%. If the Index does not identify any companies in one or more of those categories, the excess weight will be equally distributed to the remaining category or categories (e.g., if there are no Category 2 companies identified, then Category 1 would be weighted at 35% and Category 3 would be weighted at 40%). If the Index does not identify any U.S.-based companies, then Category 4 would be weighted at 60% and Category 5 would be weighted at 40%.

The remaining 25% of the Index is made up of international companies (Categories 4 and 5). If the Index does not identify any companies in either category, the excess weight will be distributed to the other category (e.g., if there are no Category 4 companies identified, then Category 5 would be weighted 25%). If the Index does not identify any international companies, the excess weight will be equally distributed among Categories 1, 2 and 3 (e.g., Category 1 would be weighted 28.3%, Category 2 would be weighted 38.3%, and Category 3 would be weighted 33.4%).

As of December 31, 2023, there were 190 companies in the Index, with a market capitalization ranging from $2.0 billion to $3.04 trillion. The Index consists only of mid- and large-capitalization companies greater than $2 billion at the time of each reconstruction.

The Fund’s Investment Strategy

The Fund will generally use a “replication” strategy to achieve its investment objective, meaning the Fund will generally invest in all of the component securities of the Index in the same approximate proportions as in the Index. However, the Fund may use a “representative sampling” strategy, meaning it may invest in a sample of the securities in the Index whose risk, return, and other characteristics closely resemble the risk, return, and other characteristics of the Index as a whole, when the Fund’s sub-adviser believes it is in the best interests of the Fund (e.g., when replicating the Index involves practical difficulties or substantial costs, an Index constituent becomes temporarily illiquid, unavailable, or less liquid, or as a result of legal restrictions or limitations that apply to the Fund but not to the Index).

To the extent the Index concentrates (i.e., holds more than 25% of its total assets) in the securities of a particular industry or group of related industries, the Fund will concentrate its investments to approximately the same extent as the Index. As of December 31, 2023, the Index was concentrated in the software industry and had significant exposure to the Semiconductors & Semiconductor Equipment industry, as well as the Information Technology sector, more generally.

rr_StrategyPortfolioConcentration

To the extent the Index concentrates (i.e., holds more than 25% of its total assets) in the securities of a particular industry or group of related industries, the Fund will concentrate its investments to approximately the same extent as the Index. As of December 31, 2023, the Index was concentrated in the software industry and had significant exposure to the Semiconductors & Semiconductor Equipment industry, as well as the Information Technology sector, more generally.

rr_RiskHeading

Principal Investment Risks

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

rr_PerformanceInformationIllustratesVariabilityOfReturns

The following performance information indicates some of the risks of investing in the Fund.

rr_PerformanceAvailabilityWebSiteAddress

www.aamlive.com/ETF

rr_PerformancePastDoesNotIndicateFuture

The Fund’s past performance, before and after taxes, does not necessarily indicate how it will perform in the future.

rr_BarChartHeading

Calendar Year Total Return

rr_BarChartClosingTextBlock

During the period of time shown in the bar chart, the Fund’s highest quarterly return was 19.95% for the quarter ended March 31, 2023, and the lowest quarterly return was -5.76% for the quarter ended September 30, 2023.

rr_HighestQuarterlyReturnLabel

highest quarterly return

rr_BarChartHighestQuarterlyReturnDate

Mar. 31, 2023

rr_BarChartHighestQuarterlyReturn

19.95%

rr_LowestQuarterlyReturnLabel

lowest quarterly return

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2023

rr_BarChartLowestQuarterlyReturn

(5.76%)

rr_PerformanceTableHeading

Average Annual Total Returns For the Period Ended December 31, 2023

rr_PerformanceTableUsesHighestFederalRate

rr_PerformanceTableNotRelevantToTaxDeferred

After-tax returns shown are not relevant to investors who hold their Shares through tax-deferred arrangements such as an individual retirement account (“IRA”) or other tax-advantaged accounts.

rr_PerformanceTableExplanationAfterTaxHigher

AAM Transformers ETF | Risk Lose Money [Member]

rr_PerformanceTableClosingTextBlock

rr_ProspectusLineItems

AAM Transformers ETF | Concentration Risk Member

rr_RiskTextBlock

As with any investment, there is a risk that you could lose all or a portion of your investment in the Fund.

rr_ProspectusLineItems

AAM Transformers ETF | Concentration Risk, Software Companies Risk Member

rr_RiskTextBlock

◦Software Companies Risk. The software industry can be significantly affected by intense competition, aggressive pricing, technological innovations, and product obsolescence. Companies in the software industry are subject to significant competitive pressures, such as aggressive pricing, new market entrants, competition for market share, short product cycles due to an accelerated rate of technological developments and the potential for limited earnings and/or falling profit margins. These companies also face the risks that new services, equipment or technologies will not be accepted by consumers and businesses or will become obsolete rapidly.

◦Semiconductor Companies Risk. Semiconductor companies are subject to the cyclical nature of the semiconductor and semiconductor equipment industry, and, as a result, their securities’ prices may fluctuate significantly and rapidly. In addition, the companies in the semiconductor and semiconductor equipment industry are subject to the risks of rapid obsolescence of products; substantial capital equipment expenditures; improper functioning of internal processes and information technology systems; changes in industry standards or regulations; inability to meet customer demand; unreliability of manufacturers and subcontractors to manufacture, assemble, and test companies’ products; and disruptions in companies’ activities such as acquisitions, divestitures, strategic investments and partnerships. The research and development efforts of these companies are focused on a limited number of new technologies and products. Any delay in the development or discontinuation of these technologies or products by companies in the industry, or their failure to achieve market acceptance, may compromise the competitive position of companies. These companies depend on intellectual property rights and may be adversely affected by loss or impairment of these rights.

rr_ProspectusLineItems

AAM Transformers ETF | Concentration Risk, Semiconductor Companies Risk Member

rr_RiskTextBlock

Software Companies Risk. The software industry can be significantly affected by intense competition, aggressive pricing, technological innovations, and product obsolescence. Companies in the software industry are subject to significant competitive pressures, such as aggressive pricing, new market entrants, competition for market share, short product cycles due to an accelerated rate of technological developments and the potential for limited earnings and/or falling profit margins. These companies also face the risks that new services, equipment or technologies will not be accepted by consumers and businesses or will become obsolete rapidly.

rr_ProspectusLineItems

AAM Transformers ETF | Depositary Receipt Risk Member

rr_RiskTextBlock

Semiconductor Companies Risk. Semiconductor companies are subject to the cyclical nature of the semiconductor and semiconductor equipment industry, and, as a result, their securities’ prices may fluctuate significantly and rapidly. In addition, the companies in the semiconductor and semiconductor equipment industry are subject to the risks of rapid obsolescence of products; substantial capital equipment expenditures; improper functioning of internal processes and information technology systems; changes in industry standards or regulations; inability to meet customer demand; unreliability of manufacturers and subcontractors to manufacture, assemble, and test companies’ products; and disruptions in companies’ activities such as acquisitions, divestitures, strategic investments and partnerships. The research and development efforts of these companies are focused on a limited number of new technologies and products. Any delay in the development or discontinuation of these technologies or products by companies in the industry, or their failure to achieve market acceptance, may compromise the competitive position of companies. These companies depend on intellectual property rights and may be adversely affected by loss or impairment of these rights.

rr_ProspectusLineItems

AAM Transformers ETF | Equity Market Risk Member

rr_RiskTextBlock

Depositary Receipt Risk. Depositary Receipts involve risks similar to those associated with investments in foreign securities, such as changes in political or economic conditions of other countries and changes in the exchange rates of foreign currencies. Depositary Receipts listed on U.S. exchanges are issued by banks or trust companies and entitle the holder to all dividends and capital gains that are paid out on the underlying foreign shares (“Underlying Shares”). When the Fund invests in Depositary Receipts as a substitute for an investment directly in the Underlying Shares, the Fund is exposed to the risk that the Depositary Receipts may not provide a return that corresponds precisely with that of the Underlying Shares.

rr_ProspectusLineItems

AAM Transformers ETF | ETF Risks Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Transformers ETF | ETF Risks, Authorized Participants, Market Makers And Liquidity Providers Concentration Risk Member

rr_RiskTextBlock

ETF Risks. The Fund is an ETF, and, as a result of an ETF’s structure, it is exposed to the following risks:

rr_ProspectusLineItems

AAM Transformers ETF | ETF Risks, Costs Of Buying Or Selling Shares Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Transformers ETF | ETF Risks, Shares May Trade At Prices Other Than NAV Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Transformers ETF | ETF Risks, Trading Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Transformers ETF | Foreign Markets Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Transformers ETF | Index Provider Risk Member

rr_RiskTextBlock

Foreign Markets Risk. Investments in ADRs that provide exposure to non-U.S. securities involve certain risks that may not be present with investments in U.S. securities. For example, the value of non-U.S. securities may be subject to risk of decline due to foreign currency fluctuations or to political or economic instability. Investments in ADRs also may be subject to withholding or other taxes and may be indirectly subject to additional trading, settlement, custodial, and operational risks. These and other factors can make investments in the Fund more volatile and potentially less liquid than other types of investments.

rr_ProspectusLineItems

AAM Transformers ETF | Market Capitalization Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Transformers ETF | Market Capitalization Risk, Large-Capitalization Investing Risk Member

rr_RiskTextBlock

Market Capitalization Risk.

◦Large-Capitalization Investing. The securities of large-capitalization companies may be relatively mature compared to smaller companies and therefore subject to slower growth during times of economic expansion. Large-capitalization companies may also be unable to respond quickly to new competitive challenges, such as changes in technology and consumer tastes.

◦Mid-Capitalization Investing. The securities of mid-capitalization companies may be more vulnerable to adverse issuer, market, political, or economic developments than securities of large-capitalization companies. The securities of mid-capitalization companies generally trade in lower volumes and are subject to greater and more unpredictable price changes than large capitalization stocks or the stock market as a whole.

rr_ProspectusLineItems

AAM Transformers ETF | Market Capitalization Risk, Mid-Capitalization Investing Member

rr_RiskTextBlock

Large-Capitalization Investing. The securities of large-capitalization companies may be relatively mature compared to smaller companies and therefore subject to slower growth during times of economic expansion. Large-capitalization companies may also be unable to respond quickly to new competitive challenges, such as changes in technology and consumer tastes.

rr_ProspectusLineItems

AAM Transformers ETF | Models And Data Risk Member

rr_RiskTextBlock

Mid-Capitalization Investing. The securities of mid-capitalization companies may be more vulnerable to adverse issuer, market, political, or economic developments than securities of large-capitalization companies. The securities of mid-capitalization companies generally trade in lower volumes and are subject to greater and more unpredictable price changes than large capitalization stocks or the stock market as a whole.

rr_ProspectusLineItems

AAM Transformers ETF | Passive Investment Risk Member

rr_RiskTextBlock

Models and Data Risk. The composition of the Index is heavily dependent on proprietary quantitative models as well as information and data supplied by third parties (“Models and Data”). When Models and Data prove to be incorrect or incomplete, any decisions made in reliance thereon may lead to securities being included in or excluded from the Index that would have been excluded or included had the Models and Data been correct and complete. If the composition of the Index reflects such errors, the Fund’s portfolio can be expected to reflect the errors, too.

rr_ProspectusLineItems

AAM Transformers ETF | Sector Risk Member

rr_RiskTextBlock

rr_ProspectusLineItems

AAM Transformers ETF | Sector Risk, Information Technology Sector Risk Member

rr_RiskTextBlock

Sector Risk. To the extent the Fund invests more heavily in particular sectors of the economy, its performance will be especially sensitive to developments that significantly affect those sectors. ◦Information Technology Sector Risk. Market or economic factors impacting information technology companies and companies that rely heavily on technological advances could have a significant effect on the value of the Fund’s investments. The value of stocks of information technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of information technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Information technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability.

rr_ProspectusLineItems

AAM Transformers ETF | Tracking Error Risk Member

rr_RiskTextBlock

Information Technology Sector Risk. Market or economic factors impacting information technology companies and companies that rely heavily on technological advances could have a significant effect on the value of the Fund’s investments. The value of stocks of information technology companies and companies that rely heavily on technology is particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition, both domestically and internationally, including competition from foreign competitors with lower production costs. Stocks of information technology companies and companies that rely heavily on technology, especially those of smaller, less-seasoned companies, tend to be more volatile than the overall market. Information technology companies are heavily dependent on patent and intellectual property rights, the loss or impairment of which may adversely affect profitability.

rr_ProspectusLineItems

AAM Transformers ETF | S&P 500® Index (reflects no deduction for fees, expenses or taxes)

rr_RiskTextBlock

Tracking Error Risk. As with all index funds, the performance of the Fund and the Index may vary somewhat for a variety of reasons. For example, the Fund incurs operating expenses and portfolio transaction costs not incurred by the Index. In addition, the Fund may not be fully invested in the securities of the Index at all times or may hold securities not included in the Index. The Fund may use a representative sampling strategy to achieve its investment objective, if the Fund’s Sub-Adviser believes it is in the best interest of the Fund, which generally can be expected to produce a greater non-correlation risk.

Index No Deduction for Fees, Expenses, Taxes [Text]

rr_ProspectusLineItems

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects no deduction for fees, expenses, or taxes)

rr_AverageAnnualReturnLabel

S&P 500® Index(reflects no deduction for fees, expenses, or taxes)