XML 57 R10.htm IDEA: XBRL DOCUMENT v3.24.1.1.u2
Label Element Value
Risk Return Abstract rr_RiskReturnAbstract  
Registrant Name dei_EntityRegistrantName GMO TRUST
Prospectus Date rr_ProspectusDate Jun. 30, 2024
GMO International Equity Allocation Fund  
Risk Return Abstract rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading GMO INTERNATIONAL EQUITY ALLOCATION FUND
Objective [Heading] rr_ObjectiveHeading <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Investment objective</span>
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock Total return greater than that of its benchmark, the MSCI ACWI ex USA.
Expense [Heading] rr_ExpenseHeading <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Fees and expenses</span>
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The table below describes the fees and expenses that you may bear for each class of shares if you buy, hold, and sell shares of the Fund. 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.
Operating Expenses Caption [Text] rr_OperatingExpensesCaption <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Annual Fund operating expenses</span> <br/><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">(expenses that you bear each year as a percentage of the value of your investment)</span>
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination <span style="color:#000000;font-family:Times New Roman;font-size:8pt;font-style:italic;">June 30, 2025</span>
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Portfolio turnover</span>
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock The Fund pays transaction costs, such as commissions, when it buys and sells securities. A higher portfolio turnover rate may result in higher transaction costs and, for holders of Fund shares subject to U.S. taxes, higher income taxes. These transaction costs, which are not reflected in Annual Fund operating expenses or in the Example, affect the Fund’s performance. During its fiscal year ended February 29, 2024, the Fund’s portfolio turnover rate (excluding short-term investments) was 21% of the average value of its portfolio securities.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 21.00%
Expense Example [Heading] rr_ExpenseExampleHeading <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Example</span>
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, regardless of whether or not you redeem your shares at the end of such periods. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same as those shown in the table. The one year amounts shown reflect the expense reimbursement noted in the expense table. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Principal investment strategies</span>
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock The Fund is a fund of funds and invests primarily in equities traded in non-U.S. markets (including emerging markets) through its investment in Equity Funds and GMO-managed exchange-traded funds (collectively, the “underlying GMO Funds”) (see “Additional Information About the Funds’ Investment Strategies, Risks, and Expenses — Asset Allocation Funds”). The Fund also may invest directly in securities (including other underlying funds) and derivatives.GMO uses its quantitative multi-year forecasts of returns among asset classes, together with its assessment of the relative risks of asset classes, to determine the asset classes in which the Fund invests and how much the Fund invests in each asset class. An important component of those forecasts is GMO’s expectation that valuations ultimately revert to their fundamental fair (or intrinsic) value over a complete market cycle. GMO changes the Fund’s asset class exposures in response to changes in GMO’s investment outlook and its assessment of market valuations and may use redemptions or purchases of Fund shares to rebalance the Fund’s investments. The factors GMO considers and investment methods GMO uses can change over time.Under normal circumstances, the Fund invests (including through its investment in the underlying GMO Funds) at least 80% of its assets in equities (see “Name Policies”).The Fund may invest in securities of companies of any market capitalization. In addition, the Fund may lend its portfolio securities.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.
Risk [Heading] rr_RiskHeading <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Principal risks of investing in the Fund</span>
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Performance</span>
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s annual total returns from year to year for the periods indicated and by comparing the Fund’s average annual total returns for different calendar periods with those of the Fund’s benchmark, a broad-based index. Share classes not shown would have substantially similar annual returns to those below because all share classes invest in the same portfolio of securities. Annual returns vary among share classes to the extent that they bear different expenses. Share classes that bear higher expenses than the share classes shown below would have lower returns. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.Actual after-tax returns depend on your tax situation and may differ from those shown. After-tax returns shown are not relevant if you are tax-exempt or if you hold your Fund shares through tax-advantaged arrangements (such as a 401(k) plan or individual retirement account). After-tax returns are shown for Class III shares only; after-tax returns for other classes will vary. Updated performance information for the Fund is available at www.gmo.com. Past performance (before and after taxes) is not an indication of future performance.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns <span style="color:#000000;font-family:Times New Roman;font-size:10pt;margin-left:3.76%;">The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">annual total returns from year to year for the periods indicated and by comparing the Fund’s average annual total returns for different calendar periods with those of the Fund’s benchmark, a broad-based index.</span>
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">www.gmo.com</span>
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">Past performance (before and after taxes) is not an indication of future performance.</span>
Bar Chart [Heading] rr_BarChartHeading <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Annual Total Returns/Class III Shares</span> <br/><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">Years Ending December 31</span>
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Quarter: 16.30% 2Q 2020
Lowest Quarter: -24.01% 1Q 2020
Year-to-Date: 4.88% As of 3/31/2024

Performance Table Heading rr_PerformanceTableHeading <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Average Annual Total Returns</span> <br/><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">Periods Ending December 31, 2023</span>
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">reflect the impact of state and local taxes.</span>
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">Actual after-tax returns depend on your tax situation and may differ from those shown. After-tax</span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;"> returns shown are not relevant if you are tax-exempt or if you hold your Fund shares through tax-advantaged arrangements (such as a 401(k) plan or individual retirement account). </span>
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">After-tax returns are shown for Class III shares only; after-tax returns for other classes </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">will vary.</span>
GMO International Equity Allocation Fund | Risk Lose Money [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Many factors can affect this value, and you may lose money by investing in the Fund.
GMO International Equity Allocation Fund | Market Risk Equities [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Market Risk – Equities – The market price of an equity in the Fund’s portfolio may decline due to factors affecting the issuer or its industry or the economy and equity markets generally. If the Fund purchases an equity for less than its fundamental fair (or intrinsic) value as assessed by GMO, the Fund runs the risk that the market price of the equity will not appreciate or will decline, (for example, if GMO’s assessment proves to be incorrect or the market fails to recognize the equity’s intrinsic value). The Fund also may purchase equities that typically trade at higher multiples of current earnings than other securities, and the market prices of these equities often are more sensitive to changes in future earnings expectations and interest rates than the market prices of equities trading at lower multiples. Declines in stock market prices generally are likely to reduce the net asset value of the Fund’s shares.
GMO International Equity Allocation Fund | Non-U.S. Investment Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Non-U.S. Investment Risk – The market prices of many non-U.S. securities fluctuate more than those of U.S. securities. Many non-U.S. securities markets are less stable, smaller, less liquid, and less regulated than U.S. securities markets, and the cost of trading in those markets often is higher than in U.S. securities markets. In addition, non-U.S. securities issuers often are not subject to as much regulation as U.S. issuers, and the reporting, recordkeeping, accounting, custody, and auditing standards to which those issuers are subject often are not as rigorous as U.S. standards. In addition, the Fund is subject to taxation by countries other than the United States, including potentially on a retroactive basis, on (i) capital gains it realizes or dividends, interest, or other amounts it realizes or accrues in respect of non-U.S. investments; (ii) transactions in those investments; and (iii) repatriation of proceeds generated from the sale or other disposition of those investments. Also, the Fund needs a license to invest directly in securities traded in many non-U.S. securities markets, and the Fund is subject to the risk that its license is terminated or suspended. In some non-U.S. securities markets, prevailing custody and trade settlement practices (e.g., the requirement to pay for securities prior to receipt) expose the Fund to credit and other risks. Further, adverse changes in investment regulations, capital requirements or exchange controls could adversely affect the value of the Fund’s investments. The risks above (such as substantial price fluctuations and market instability, illiquidity and lack of regulation) and other risks (e.g., nationalization, expropriation or other confiscation of assets of non-U.S. issuers, difficulties enforcing legal judgments or contractual rights and geopolitical risks) tend to be higher for investments in the securities of issuers tied economically to emerging countries. The economies of emerging countries often depend predominantly on only a few industries or commodities and often are more volatile than the economies of developed countries.
GMO International Equity Allocation Fund | Management and Operational Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Management and Operational Risk – The Fund runs the risk that GMO’s investment techniques will fail to produce intended results.GMO uses quantitative models as part of its investment process. GMO’s models may not accurately predict future market movements. In addition, GMO’s models rely on assumptions and data that are subject to limitations (e.g., inaccuracies, staleness) that could adversely affect their predictive value. The Fund also runs the risk that GMO’s assessment of an investment, including a security’s fundamental fair (or intrinsic) value, is wrong or that deficiencies in GMO’s or another service provider’s internal systems or controls will cause losses for the Fund or impair Fund operations.
GMO International Equity Allocation Fund | Currency Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Currency Risk – Fluctuations in exchange rates can adversely affect the market value of the Fund’s foreign currency holdings and investments denominated in foreign currencies.
GMO International Equity Allocation Fund | Derivatives and Short Sales Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Derivatives and Short Sales Risk – The use of derivatives involves the risk that their value may not change as expected relative to changes in the value of the underlying assets, pools of assets, rates, currencies or indices. Derivatives also present other risks, including market risk, illiquidity risk, currency risk, credit risk, leveraging risk, commodities risk and counterparty risk. The market price of an option is affected by many factors, including changes in the market prices or dividend rates of underlying securities (or in the case of indices, the securities in such indices); the time remaining before expiration; changes in interest rates or exchange rates; and changes in the actual or perceived volatility of the relevant index or underlying securities. The Fund typically creates short investment exposure by selling securities short or by taking a derivative position in which the value of the derivative moves in the opposite direction from the price of an underlying asset, pool of assets, rate, currency or index. Specifically, the net asset value of the Fund’s shares will be adversely affected if the equities or other assets that are the subject of the Fund’s short exposures appreciate in value. The risk of loss associated with derivatives that provide short investment exposure and short sales of securities is theoretically unlimited.
GMO International Equity Allocation Fund | Fund of Funds Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Fund of Funds Risk – The Fund is indirectly exposed to all of the risks of an investment in the underlying funds in which it invests, including the risk that those underlying funds will not perform as expected. The fees and expenses associated with an investment in the Fund are less predictable than those associated with an investment in funds that charge a fixed management fee.
GMO International Equity Allocation Fund | Smaller Company Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Smaller Company Risk – Smaller companies may have limited product lines, markets, or financial resources, lack the competitive strength of larger companies, have less experienced managers or depend on a few key employees. The securities of companies with smaller market capitalizations often are less widely held and trade less frequently and in lesser quantities, and their market prices often fluctuate more, than the securities of companies with larger market capitalizations.
GMO International Equity Allocation Fund | Leveraging Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Leveraging Risk – The use of derivatives, short sales and securities lending can create leverage. Leverage increases the Fund’s losses when the value of its investments (including derivatives) declines. In addition, the Fund’s portfolio will be leveraged if it exercises its right to delay payment on a redemption and the value of the Fund’s assets declines between the time a redemption request is treated as being received by the Fund and the time the Fund liquidates assets to fund that redemption.
GMO International Equity Allocation Fund | Counterparty Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Counterparty Risk – The Fund runs the risk that the counterparty to a derivatives contract or a clearing member used by the Fund to hold a cleared derivatives contract is unable or unwilling to make timely settlement payments, return the Fund’s collateral or otherwise honor its obligations.
GMO International Equity Allocation Fund | Market Disruption and Geopolitical Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Market Disruption and Geopolitical Risk – Geopolitical and other events (e.g., wars, pandemics, sanctions, terrorism) often disrupt securities markets and adversely affect the general economy or particular economies and markets. Those events, as well as other changes in non-U.S. and U.S. economic and political conditions, could exacerbate other risks or otherwise reduce the value of the Fund’s investments.
GMO International Equity Allocation Fund | Focused Investment Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Focused Investment Risk – Investments in countries, regions, asset classes, sectors, industries, currencies, or issuers that are subject to the same or similar risk factors and investments whose market prices are closely correlated are subject to higher overall risk than investments that are more diversified or whose market prices are not as closely correlated.
GMO International Equity Allocation Fund | Large Shareholder Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Large Shareholder Risk – To the extent that a large number of shares of the Fund is held by a single shareholder (e.g., an institutional investor or another GMO Fund) or a group of shareholders with a common investment strategy (e.g., GMO asset allocation accounts), the Fund is subject to the risk that a redemption by that shareholder or group will require the Fund to sell investments at disadvantageous prices, disrupt the Fund’s operations, or force the Fund’s liquidation.
GMO International Equity Allocation Fund | Illiquidity Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Illiquidity Risk – Low trading volume, lack of a market maker, large position size, or legal restrictions increase the risk that the Fund or an underlying fund is limited or prevented from selling particular securities or closing derivative positions at desirable prices at a particular time or at all.
GMO International Equity Allocation Fund | Market Risk Fixed Income [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Market Risk – Fixed Income – The market price of a fixed income investment can decline due to market-related factors, including rising interest or inflation rates and widening credit spreads, or decreased liquidity due, for example, to market uncertainty about the value of a fixed income investment (or class of fixed income investments).
GMO International Equity Allocation Fund | Credit Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Credit Risk – The Fund runs the risk that the issuer or guarantor of a fixed income investment (including a sovereign or quasi-sovereign debt issuer) or the obligor of an obligation underlying an asset-backed security will be unable or unwilling to satisfy its obligation to pay principal and interest or otherwise to honor its obligations in a timely manner or at all. The market price of a fixed income investment will normally decline as a result of the failure of an issuer, guarantor, or obligor to meet its payment obligations or in anticipation of such a failure. Below investment grade investments have speculative characteristics, and negative changes in economic conditions or other circumstances are more likely to impair the ability of issuers of those investments to make principal and interest payments than issuers of investment grade investments.
GMO International Equity Allocation Fund | Class III  
Risk Return Abstract rr_RiskReturnAbstract  
Management fee rr_ManagementFeesOverAssets none [1]
Other expenses rr_OtherExpensesOverAssets 0.04%
Acquired fund fees and expenses (underlying fund expenses) rr_AcquiredFundFeesAndExpensesOverAssets 0.67%
Total annual fund operating expenses rr_ExpensesOverAssets 0.71%
Expense reimbursement/waiver rr_FeeWaiverOrReimbursementOverAssets (0.03%) [2]
Total annual fund operating expenses after expense reimbursement/waiver (Fund and underlying fund expenses) rr_NetExpensesOverAssets 0.68%
1 Year rr_ExpenseExampleYear01 $ 69
3 Years rr_ExpenseExampleYear03 224
5 Years rr_ExpenseExampleYear05 392
10 Years rr_ExpenseExampleYear10 $ 880
2014 rr_AnnualReturn2014 (6.22%)
2015 rr_AnnualReturn2015 (8.89%)
2016 rr_AnnualReturn2016 6.52%
2017 rr_AnnualReturn2017 27.80%
2018 rr_AnnualReturn2018 (17.81%)
2019 rr_AnnualReturn2019 23.81%
2020 rr_AnnualReturn2020 6.97%
2021 rr_AnnualReturn2021 7.96%
2022 rr_AnnualReturn2022 (18.90%)
2023 rr_AnnualReturn2023 20.23%
Year to Date Return, Label rr_YearToDateReturnLabel <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">Year-to-Date:</span>
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Mar. 31, 2024
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 4.88%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">Highest Quarter:</span>
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2020
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 16.30%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">Lowest Quarter:</span>
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Mar. 31, 2020
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (24.01%)
1 Year rr_AverageAnnualReturnYear01 20.23%
5 Years rr_AverageAnnualReturnYear05 6.87%
10 Years rr_AverageAnnualReturnYear10 2.91%
Incept. rr_AverageAnnualReturnSinceInception 6.28%
Inception Date rr_AverageAnnualReturnInceptionDate Oct. 11, 1996
GMO International Equity Allocation Fund | Class R6  
Risk Return Abstract rr_RiskReturnAbstract  
Management fee rr_ManagementFeesOverAssets none [1]
Other expenses rr_OtherExpensesOverAssets 0.04%
Acquired fund fees and expenses (underlying fund expenses) rr_AcquiredFundFeesAndExpensesOverAssets 0.67%
Total annual fund operating expenses rr_ExpensesOverAssets 0.71%
Expense reimbursement/waiver rr_FeeWaiverOrReimbursementOverAssets (0.03%) [2]
Total annual fund operating expenses after expense reimbursement/waiver (Fund and underlying fund expenses) rr_NetExpensesOverAssets 0.68%
1 Year rr_ExpenseExampleYear01 $ 69
3 Years rr_ExpenseExampleYear03 224
5 Years rr_ExpenseExampleYear05 392
10 Years rr_ExpenseExampleYear10 $ 880
1 Year rr_AverageAnnualReturnYear01 20.24%
5 Years rr_AverageAnnualReturnYear05
10 Years rr_AverageAnnualReturnYear10
Incept. rr_AverageAnnualReturnSinceInception 6.39%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 30, 2019
GMO International Equity Allocation Fund | Class I  
Risk Return Abstract rr_RiskReturnAbstract  
Management fee rr_ManagementFeesOverAssets none [1]
Other expenses rr_OtherExpensesOverAssets 0.14% [3]
Acquired fund fees and expenses (underlying fund expenses) rr_AcquiredFundFeesAndExpensesOverAssets 0.67%
Total annual fund operating expenses rr_ExpensesOverAssets 0.81%
Expense reimbursement/waiver rr_FeeWaiverOrReimbursementOverAssets (0.03%) [2],[3]
Total annual fund operating expenses after expense reimbursement/waiver (Fund and underlying fund expenses) rr_NetExpensesOverAssets 0.78%
1 Year rr_ExpenseExampleYear01 $ 80
3 Years rr_ExpenseExampleYear03 256
5 Years rr_ExpenseExampleYear05 447
10 Years rr_ExpenseExampleYear10 $ 999
GMO International Equity Allocation Fund | Return After Taxes on Distributions | Class III  
Risk Return Abstract rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 18.08%
5 Years rr_AverageAnnualReturnYear05 5.54%
10 Years rr_AverageAnnualReturnYear10 1.84%
Incept. rr_AverageAnnualReturnSinceInception 4.83%
GMO International Equity Allocation Fund | Return After Taxes on Distributions and Sale of Shares | Class III  
Risk Return Abstract rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 13.12%
5 Years rr_AverageAnnualReturnYear05 5.28%
10 Years rr_AverageAnnualReturnYear10 2.24%
Incept. rr_AverageAnnualReturnSinceInception 4.99%
GMO International Equity Allocation Fund | MSCI ACWI ex USA (Fund benchmark) (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) | Class III  
Risk Return Abstract rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 15.62% [4]
5 Years rr_AverageAnnualReturnYear05 7.08% [4]
10 Years rr_AverageAnnualReturnYear10 3.83% [4]
Incept. rr_AverageAnnualReturnSinceInception 5.07% [4]
GMO International Equity Allocation Fund | MSCI ACWI ex USA (Fund benchmark) (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) | Class R6  
Risk Return Abstract rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 15.62% [4]
5 Years rr_AverageAnnualReturnYear05 [4]
10 Years rr_AverageAnnualReturnYear10 [4]
Incept. rr_AverageAnnualReturnSinceInception 6.14% [4]
[1] Includes both management fee and class-specific shareholder service fee, if any, for each class of shares. For additional information about the shareholder service fee applicable to each class of shares of the Fund, please see the table included in the section of the Prospectus entitled “Multiple Classes and Eligibility.”
[2] GMO has contractually agreed to reimburse the Fund for the following expenses: audit expenses, fund accounting expenses, pricing service expenses, expenses of non-investment related tax services, transfer agency expenses (excluding, in the case of Class I shares, any amounts paid for sub-transfer agency, recordkeeping and other administrative services provided by financial intermediaries for the benefit of Class I shareholders), expenses of non-investment related legal services provided to the Fund by or at the direction of GMO, federal securities law filing expenses, printing expenses, state and federal registration fees and custody expenses. This reimbursement will continue through at least June 30, 2025 and may not be terminated prior to this date without the action or consent of the Trust’s Board of Trustees.
[3] Includes estimate of payments for sub-transfer agency, recordkeeping and other administrative services for Class I's initial fiscal year. Grantham, Mayo, Van Otterloo & Co. LLC ("GMO") has contractually agreed to waive its fees with respect to and/or reimburse Class I shares to the extent that amounts paid by the Fund out of the net assets attributable to Class I shares for sub-transfer agency, recordkeeping and other administrative services provided by financial intermediaries for the benefit of Class I shareholders exceed 0.15% of the average daily net assets attributable to Class I shares. This reimbursement will continue through at least June 30, 2025 and may not be terminated prior to this date without the action or consent of the Trust’s Board of Trustees.
[4] MSCI data may not be reproduced or used for any other purpose. MSCI provides no warranties, has not prepared or approved this report, and has no liability hereunder.