GMO Opportunistic Income Fund Investment Strategy - GMO Opportunistic Income Fund	Feb. 28, 2025
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Principal investment strategies</span>
Strategy Narrative [Text Block]	The Fund invests primarily in securitized credit securities. Securitized credit securities include, but are not limited to, commercial and residential (non-agency and agency) mortgage-backed securities, small balance commercial mortgages, collateralized loan obligations, collateralized debt obligations, and securities backed by pools of receivables in various industries. The interest rates for these securities may be fixed or variable. The Fund also may invest in other fixed-income instruments, including, without limitation, bonds and other similar instruments issued or guaranteed by the U.S. government and its agencies and instrumentalities, by non-U.S. governments and their agencies and instrumentalities and by private sector entities.The Fund also may invest in the following: interest-only, principal-only, or inverse floating rate debt; mortgage dollar rolls; securities on a when-issued, delayed delivery or forward commitment basis through the “to-be-announced” market; mortgage loans; securities of any maturity or duration with fixed, floating, or variable rates; equity and debt securities issued by real estate investment trusts; debt securities issued by business development companies; corporate debt securities of any quality and maturity, including high-yield securities (commonly referred to as “junk bonds”); and securities that are not rated by any rating agency.GMO utilizes both a top-down and bottom-up security selection approach. GMO allocates Fund assets among various asset classes within the structured fixed income market based on its views regarding the best value relative to what is currently available in the market. In managing the Fund’s portfolio, GMO typically analyzes a variety of factors including, among others, maturity, yield and ratings information, opportunities for price appreciation, collateral quality, credit support, structure, and market conditions. GMO attempts to diversify risks that arise from position sizes, sectors and geographies, ratings, duration, deal structure and collateral values and seeks to further limit risk of principal loss by causing the Fund to invest in securities or other instruments that it considers undervalued. To a lesser extent, GMO may use quantitative models to capitalize on price momentum across fixed income sectors. GMO does not manage the Fund to, or control the Fund’s risk relative to, any securities index or securities benchmark.From time to time, the Fund may have some direct or indirect exposure to equities. The Fund may invest in securities of companies of any market capitalization, as well as in securities of any maturity, duration, or credit quality.The Fund also may invest in exchange-traded funds (ETFs) and exchange-traded and over-the-counter (OTC) derivatives, including swap contracts (such as credit default swaps, swaps on securities and securities indices, total return swaps and interest rate swaps), futures contracts, forward currency contracts, currency and interest rate options, swaptions (including credit default swaptions), reverse repurchase agreements, and repurchase agreements. In addition, the Fund may lend its portfolio securities. The Fund is not limited in its use of derivatives or in the total notional value of its derivative positions. Leverage is not a principal component of the Fund’s investment strategy. However, because of its derivative positions, the Fund may at times have gross investment exposure in excess of its net assets (i.e., the Fund may be leveraged) and, therefore, may be subject to higher risk of loss during those times than if the Fund were not leveraged. The Fund’s performance can depend substantially on the performance of assets or indices underlying its derivatives even though it does not own those assets or indices.In seeking to achieve the Fund’s investment objective, GMO may invest a significant portion of the Fund’s net assets in cash and cash equivalents.The Fund also may invest in U.S. Treasury Fund, in money market funds unaffiliated with GMO, and directly in the types of investments typically held by money market funds. The Fund may, but is not required to, hedge part or all of its net foreign currency exposure into U.S. dollars.

GMO Opportunistic Income Fund Investment Strategy - GMO Opportunistic Income Fund

Feb. 28, 2025

<span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Principal investment strategies</span>

Strategy Narrative [Text Block]

The Fund invests primarily in securitized credit securities. Securitized credit securities include, but are not limited to, commercial and residential (non-agency and agency) mortgage-backed securities, small balance commercial mortgages, collateralized loan obligations, collateralized debt obligations, and securities backed by pools of receivables in various industries. The interest rates for these securities may be fixed or variable. The Fund also may invest in other fixed-income instruments, including, without limitation, bonds and other similar instruments issued or guaranteed by the U.S. government and its agencies and instrumentalities, by non-U.S. governments and their agencies and instrumentalities and by private sector entities.The Fund also may invest in the following: interest-only, principal-only, or inverse floating rate debt; mortgage dollar rolls; securities on a when-issued, delayed delivery or forward commitment basis through the “to-be-announced” market; mortgage loans; securities of any maturity or duration with fixed, floating, or variable rates; equity and debt securities issued by real estate investment trusts; debt securities issued by business development companies; corporate debt securities of any quality and maturity, including high-yield securities (commonly referred to as “junk bonds”); and securities that are not rated by any rating agency.GMO utilizes both a top-down and bottom-up security selection approach. GMO allocates Fund assets among various asset classes within the structured fixed income market based on its views regarding the best value relative to what is currently available in the market. In managing the Fund’s portfolio, GMO typically analyzes a variety of factors including, among others, maturity, yield and ratings information, opportunities for price appreciation, collateral quality, credit support, structure, and market conditions. GMO attempts to diversify risks that arise from position sizes, sectors and geographies, ratings, duration, deal structure and collateral values and seeks to further limit risk of principal loss by causing the Fund to invest in securities or other instruments that it considers undervalued. To a lesser extent, GMO may use quantitative models to capitalize on price momentum across fixed income sectors. GMO does not manage the Fund to, or control the Fund’s risk relative to, any securities index or securities benchmark.From time to time, the Fund may have some direct or indirect exposure to equities. The Fund may invest in securities of companies of any market capitalization, as well as in securities of any maturity, duration, or credit quality.The Fund also may invest in exchange-traded funds (ETFs) and exchange-traded and over-the-counter (OTC) derivatives, including swap contracts (such as credit default swaps, swaps on securities and securities indices, total return swaps and interest rate swaps), futures contracts, forward currency contracts, currency and interest rate options, swaptions (including credit default swaptions), reverse repurchase agreements, and repurchase agreements. In addition, the Fund may lend its portfolio securities. The Fund is not limited in its use of derivatives or in the total notional value of its derivative positions. Leverage is not a principal component of the Fund’s investment strategy. However, because of its derivative positions, the Fund may at times have gross investment exposure in excess of its net assets (i.e., the Fund may be leveraged) and, therefore, may be subject to higher risk of loss during those times than if the Fund were not leveraged. The Fund’s performance can depend substantially on the performance of assets or indices underlying its derivatives even though it does not own those assets or indices.In seeking to achieve the Fund’s investment objective, GMO may invest a significant portion of the Fund’s net assets in cash and cash equivalents.The Fund also may invest in U.S. Treasury Fund, in money market funds unaffiliated with GMO, and directly in the types of investments typically held by money market funds. The Fund may, but is not required to, hedge part or all of its net foreign currency exposure into U.S. dollars.