v3.25.2
Investment Risks - AMG GW&K Muni Income ETF
Sep. 24, 2025
Debt Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Debt Securities Risk—the value of a debt security changes in response to various factors, including, for example, market-related factors, such as changes in interest rates or changes in the actual or perceived ability of an issuer to meet its obligations. Investments in debt securities are subject to, among other risks, credit risk, interest rate risk, extension risk, prepayment risk and liquidity risk.
Municipal Market Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Municipal Market Risk—factors unique to the municipal bond market may negatively affect the value of municipal bonds. These factors include political or legislative changes, and uncertainties related to the tax status of the securities and the rights of investors in the securities. The Fund may invest in a group of municipal obligations that are related in such a way that an economic, business, or political development affecting one would also affect the others.
Interest Rate Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Interest Rate Risk—fixed coupon payments (cash flows) of bonds and debt securities may become less competitive with the market in periods of rising interest rates and cause bond prices to decline. During periods of increasing interest rates, the Fund may experience high levels of volatility and shareholder redemptions, and may have to sell securities at times when it would otherwise not do so, and at unfavorable prices, which could reduce the returns of the Fund.
Credit Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Credit Risk—the issuer of bonds or other debt securities may be unable or unwilling, or may be perceived as unable or unwilling, to make timely interest or principal payments or otherwise honor its obligations. Changes in an issuer’s financial strength, credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer.
Liquidity Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Liquidity Risk—the Fund may not be able to dispose of particular investments, such as illiquid securities, readily at favorable times or prices or the Fund may have to sell them at a loss.
Changing Distribution Level Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Changing Distribution Level Risk—the Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amount paid by the Fund will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.
Extension Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Extension Risk—during periods of rising interest rates, a debtor may pay back a bond or other fixed income security slower than expected or required, and the value of such security may fall.
High Yield Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
High Yield Risk—below investment grade debt securities and unrated securities of similar credit quality (commonly known as “junk bonds” or “high yield securities”) may be subject to greater levels of interest rate, credit, liquidity, and market risk than higher-rated securities. These securities are considered predominately speculative with respect to the issuer’s continuing ability to make principal and interest payments.
Inflation Deflation Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Inflation/Deflation Risk—inflation risk is the risk that the value of assets or income from investments will be worth less in the future. Inflation rates may change frequently and drastically as a result of various factors and the Fund’s investments may not keep pace with inflation, which may result in losses to Fund investors or adversely affect the real value of shareholders’ investments in the Fund. As inflation rates increase, fixed income securities markets may experience heightened levels of interest rate volatility and liquidity risk. Deflation risk is the risk that the prices throughout the economy decline over time – the opposite of inflation. Deflation may have an adverse effect on the creditworthiness of issuers and may make issuer default more likely, which may result in a decline in the value of the Fund’s portfolio.
Management Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Management Risk—because the Fund is an actively managed investment portfolio, security selection or focus on securities in a particular style, market sector or group of companies may cause the Fund to incur losses or underperform relative to its benchmarks or other funds with a similar investment objective. There can be no guarantee that the Subadviser’s investment techniques and risk analysis will produce the desired result.
Market Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Market Risk— market prices of investments held by the Fund may fall rapidly or unpredictably due to a variety of factors, including economic, political, or market conditions, or other factors including terrorism, war, natural disasters and the spread of infectious illness or other public health issues, including epidemics or pandemics, or in response to events that affect particular industries or companies.
New Fund Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
New Fund Risk—the Fund is a new fund, which may result in additional risk. There can be no assurance that the Fund will grow to an economically viable size, in which case the Fund may cease operations. In such an event, investors may be required to
liquidate or transfer their investments at an inopportune time. In addition, until the Fund achieves sufficient scale, a Fund shareholder may experience proportionally higher Fund expenses than would be experienced by shareholders of a fund with a larger asset base.
Prepayment Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Prepayment Risk—a debtor may exercise its right to pay back a bond or other debt security earlier than expected or required during periods of decreasing interest rates.
Reinvestment Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Reinvestment Risk—the Fund may have difficulty reinvesting payments from debtors and may receive lower rates than from its original investments.
Sector Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Sector Risk— issuers and companies that are in similar industry sectors may be similarly affected by particular economic or market events; to the extent the Fund has substantial holdings within a particular sector, the risks associated with that sector increase. A portion of the Fund's assets may be invested in fixed income securities that would tend to respond similarly to particular economic or political developments or the interest on which is based on revenues or otherwise related to similar types of projects.  An example would be securities of issuers whose revenues are paid from similar types of projects, such as utilities or transportation.
ETF Structure Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
ETF Structure Risks— the Fund is structured as an ETF and is subject to special risks, including:
Not Individually Redeemable. Shares are not individually redeemable by retail investors and may be redeemed from the Fund only by Authorized Participants at NAV in large blocks known as “Creation Units.” An Authorized Participant may incur brokerage costs purchasing enough shares to constitute a Creation Unit.
Trading Issues. An active trading market for the Fund’s shares may not be developed or maintained. Trading in shares on the NYSE may be halted due to market conditions or for reasons that, in the view of the NYSE, make trading in shares inadvisable, such as extraordinary market volatility. There can be no assurance that shares will continue to meet the listing requirements of the NYSE. If the Fund’s shares are traded outside a collateralized settlement system, the number of financial institutions that can act as Authorized Participants that can post collateral on an agency basis is limited, which may limit the market for the Fund’s shares. In addition, there may be a limited number of market makers and/or liquidity providers in the marketplace. To the extent the foregoing or either of the following events occur, shares may trade at a material discount to NAV and possibly face delisting: (i) Authorized Participants exit the business or otherwise become unable to process creation and/or redemption orders and no other Authorized Participants 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.
Market Price Variance Risk. The market price of the Fund’s shares will fluctuate in response to changes in NAV and supply and demand for shares and will include a “bid-ask spread” charged by the exchange specialists, market makers or other participants that trade the particular security. There may be times when the market price and the NAV vary significantly. This means that shares may trade at a discount or premium to NAV.
Market Trading Risk. The Fund faces numerous market trading risks, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruptions in the creation/redemption process. Any of these factors, among others, may lead to the Fund’s shares trading at a premium or discount to NAV.
Fluctuation of Net Asset Value Risk. The NAV of the Fund’s shares will generally fluctuate with changes in the market value of the Fund’s holdings. The market prices of the Fund’s shares
will generally fluctuate in accordance with changes in NAV as well as the relative supply of and demand for the Fund’s shares on the NYSE. The Investment Manager cannot predict whether the shares will trade below, at or above their NAV. Price differences may be due, because of, among other factors, the fact that supply and demand forces at work in the secondary trading market for the Fund’s shares. It is expected that these forces generally will be closely related to, but not identical to, the same forces influencing the prices of the Fund’s holdings trading individually or in the aggregate at any point in time.
Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund, and no Authorized Participant is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants, none of which are or will be obligated to engage in creation or redemption transactions. To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the Fund and no other Authorized Participant is able to step forward to create or redeem Creation Units, Fund shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.
Risk Lose Money [Member]  
Prospectus [Line Items]  
Risk [Text Block] There is the risk that you may lose money on your investment.
Risk Not Insured Depository Institution [Member]  
Prospectus [Line Items]  
Risk [Text Block] Aninvestment in the Fund is not a deposit or obligation of any bank,is not endorsed or guaranteed by any bank, and is not insured bythe Federal Deposit Insurance Corporation (“FDIC”) or any othergovernment agency.