GMO U.S. Small Cap Value Fund Investment Strategy - GMO U.S. Small Cap Value 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]	GMO seeks to achieve the Fund’s investment objective by investing the Fund’s assets primarily in equities of U.S. small-cap companies. GMO selects the securities the Fund buys and sells based on its evaluation of companies’ published financial information, securities’ prices, equity and other markets, the overall global economy, and governmental policies. In selecting securities for the Fund, GMO uses a combination of proprietary quantitative investment methods to identify U.S. equities GMO believes have positive return potential relative to other U.S. equities. Some of these methods evaluate individual companies or groups of companies based on the ratio of their security price to historical financial information and forecasted financial information, such as return on invested capital, profitability, cash flow and earnings, and a comparison of these ratios to current and historical averages. Other methods focus on patterns of information, such as price movement or volatility of an asset class, security, or market, and macroeconomic factors. In constructing the Fund’s portfolio, GMO also considers position size, sector and industry exposure, market capitalization, liquidity, and transaction costs. At times, the Fund may have substantial exposure to a single asset class, industry, sector and companies with similar market capitalizations. The Fund may invest in securities of companies of any market capitalization. GMO also may consider ESG (environmental, social and governance) criteria. For example, GMO generally avoids investing the Fund’s assets in companies engaged in the manufacture, supply, or distribution of cluster munitions, as well as companies primarily involved in the mining and production of thermal coal. The factors GMO considers and investment methods GMO uses can change over time.As an alternative to investing directly in equities, the Fund may invest in exchange-traded and over-the-counter (OTC) derivatives and exchange-traded funds (ETFs). The Fund also may invest in derivatives and ETFs in an attempt to obtain or adjust elements of its long or short investment exposure. Derivatives used may include futures, options, and swap contracts. In addition, the Fund may lend its portfolio securities.Under normal circumstances, the Fund invests directly and indirectly at least 80% of its assets in equities of small-cap companies (see “Name Policies”). The term “small-cap companies” means companies whose market capitalization at the time of investment is less than that of the companies in the bottom decile of market capitalization of the MSCI US IMI Index or that are included in the S&P SmallCap 600 Index. As of May 31, 2025, the market capitalization of companies comprising the bottom decile of the MSCI US IMI Index by market capitalization ranged from approximately $65.7 million to $14.0 billion. As of May 31, 2025, the market capitalization for the companies comprising the S&P SmallCap 600 Index ranged from approximately $185.1 million to $8.2 billion.Under normal circumstances, the Fund invests directly and indirectly (e.g., through underlying funds or derivatives) at least 80% of its assets in companies tied economically to the United States (see “Name Policies”).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.

GMO U.S. Small Cap Value Fund Investment Strategy - GMO U.S. Small Cap Value 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]

GMO seeks to achieve the Fund’s investment objective by investing the Fund’s assets primarily in equities of U.S. small-cap companies. GMO selects the securities the Fund buys and sells based on its evaluation of companies’ published financial information, securities’ prices, equity and other markets, the overall global economy, and governmental policies. In selecting securities for the Fund, GMO uses a combination of proprietary quantitative investment methods to identify U.S. equities GMO believes have positive return potential relative to other U.S. equities. Some of these methods evaluate individual companies or groups of companies based on the ratio of their security price to historical financial information and forecasted financial information, such as return on invested capital, profitability, cash flow and earnings, and a comparison of these ratios to current and historical averages. Other methods focus on patterns of information, such as price movement or volatility of an asset class, security, or market, and macroeconomic factors. In constructing the Fund’s portfolio, GMO also considers position size, sector and industry exposure, market capitalization, liquidity, and transaction costs. At times, the Fund may have substantial exposure to a single asset class, industry, sector and companies with similar market capitalizations. The Fund may invest in securities of companies of any market capitalization. GMO also may consider ESG (environmental, social and governance) criteria. For example, GMO generally avoids investing the Fund’s assets in companies engaged in the manufacture, supply, or distribution of cluster munitions, as well as companies primarily involved in the mining and production of thermal coal. The factors GMO considers and investment methods GMO uses can change over time.As an alternative to investing directly in equities, the Fund may invest in exchange-traded and over-the-counter (OTC) derivatives and exchange-traded funds (ETFs). The Fund also may invest in derivatives and ETFs in an attempt to obtain or adjust elements of its long or short investment exposure. Derivatives used may include futures, options, and swap contracts. In addition, the Fund may lend its portfolio securities.Under normal circumstances, the Fund invests directly and indirectly at least 80% of its assets in equities of small-cap companies (see “Name Policies”). The term “small-cap companies” means companies whose market capitalization at the time of investment is less than that of the companies in the bottom decile of market capitalization of the MSCI US IMI Index or that are included in the S&P SmallCap 600 Index. As of May 31, 2025, the market capitalization of companies comprising the bottom decile of the MSCI US IMI Index by market capitalization ranged from approximately $65.7 million to $14.0 billion. As of May 31, 2025, the market capitalization for the companies comprising the S&P SmallCap 600 Index ranged from approximately $185.1 million to $8.2 billion.Under normal circumstances, the Fund invests directly and indirectly (e.g., through underlying funds or derivatives) at least 80% of its assets in companies tied economically to the United States (see “Name Policies”).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.