Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	GMO TRUST
Prospectus Date	rr_ProspectusDate	Jun. 30, 2016
GMO Emerging Domestic Opportunities Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	GMO EMERGING DOMESTIC OPPORTUNITIES FUND
Objective [Heading]	rr_ObjectiveHeading	Investment objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	Total return.
Expense [Heading]	rr_ExpenseHeading	Fees and expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The tables below describe the fees and expenses that you may bear for each class of shares if you buy and hold shares of the Fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder fees (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund operating expenses (expenses that you bear each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	June 30, 2017
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio turnover
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, when Fund shares are held in a taxable account, higher 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, 2016, the Fund’s portfolio turnover rate (excluding short-term investments) was 250% of the average value of its portfolio. That portfolio turnover rate includes investments in U.S. Treasury Fund, which the Fund uses as a short-term investment vehicle for cash management. The Fund’s portfolio turnover rate during its fiscal year ended February 29, 2016, excluding transactions in U.S. Treasury Fund, was 189% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	250.00%
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
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. 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 and waiver noted in the expense table. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example by, Year, Caption [Text]	rr_ExpenseExampleByYearCaption	If you sell your shares
Expense Example, No Redemption, By Year, Caption [Text]	rr_ExpenseExampleNoRedemptionByYearCaption	If you do not sell your shares
Strategy [Heading]	rr_StrategyHeading	Principal investment strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund typically invests directly and indirectly (e.g., through underlying funds or derivatives) in equities, and, to a lesser extent, fixed income securities, of companies whose prospects are linked to the internal ("domestic") development and growth of the world's non-developed markets ("emerging markets"), including companies that provide goods and services to emerging market consumers. "Emerging markets" include all markets that are not treated as "developed markets" in the MSCI World Index or MSCI EAFE Index. The term "equities" refers to direct and indirect investments in common and preferred stocks and other stock-related securities, such as convertible securities, depositary receipts, and equity real estate investment trusts (REITs) and income trusts. Under normal circumstances, the Fund invests directly and indirectly at least 80% of its assets in investments related to emerging markets (see "Name Policies"). The Fund's investments are not limited to investments in companies located in any particular country or geographic region, and often include investments in companies located in developed markets (e.g., the United States) that are related to, or whose prospects are linked to, emerging markets. GMO does not manage the Fund to, or control the Fund's risk relative to, any securities index or securities benchmark. GMO primarily uses fundamental analysis to evaluate and select countries, sectors, and companies that it believes are likely to benefit from domestic growth in emerging markets. The process begins with country and sector allocation and then focuses on the selection of individual companies. In evaluating and selecting investments, GMO may consider many factors, including, among others, GMO's assessment of a country's and/or sector's fundamentals or growth prospects as well as a company's positioning relative to its competitors. In constructing the Fund's portfolio, GMO weighs a number of factors, including the trade-off among forecasted returns, risk, transaction costs, and liquidity. The factors GMO considers and investment methods GMO uses can change over time. As an alternative to investing directly in equities and fixed income securities, 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, and as a substitute for securities lending. Derivatives used may include options, futures, warrants, swap contracts, and reverse repurchase agreements. The Fund's foreign currency exposure may differ from the currency exposure represented by its equity investments. In addition, the Fund may lend its portfolio securities. The Fund may invest in securities of companies of any market capitalization. The Fund also may invest in securities of any credit quality (including below investment grade securities (commonly referred to as "junk bonds")). The Fund also may invest in U.S. Treasury Fund, in money market funds unaffiliated with GMO, or directly in the types of investments typically held by money market funds.
Risk [Heading]	rr_RiskHeading	Principal risks of investing in the Fund
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The value of the Fund’s shares changes with the value of the Fund’s investments. Many factors can affect this value, and you may lose money by investing in the Fund. The Fund is a non-diversified investment company under the Investment Company Act of 1940, as amended, and therefore a decline in the market price of a particular security held by the Fund may affect the Fund’s performance more than if the Fund were a diversified investment company. The principal risks of investing in the Fund are summarized below. For a more complete discussion of these risks, see “Description of Principal Risks.” Market Risk – Equities – The market price of an equity may decline due to factors affecting the issuer, 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 determined by GMO, the Fund runs the risk that the market price of the equity will not appreciate or will decline due to GMO's incorrect assessment of the equity's fundamental fair (or 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 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. 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. Transactions in non-U.S. securities generally involve higher commission rates, transfer taxes, and custodial costs than similar transactions in U.S. securities. In addition, the Fund may be subject to non-U.S. taxes, 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 many non-U.S. securities markets, and the Fund is subject to the risk that it could not invest if its license were 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. These and other risks (e.g., nationalization, expropriation or other confiscation of assets of non-U.S. issuers) tend to be greater for investments in companies tied economically to emerging countries, the economies of which may be predominantly based on only a few industries or dependent on revenues from particular commodities and which often are more volatile than the economies of developed countries. 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. Management and Operational Risk – The Fund runs the risk that GMO's investment techniques will fail to produce desired results. GMO often uses quantitative models as part of its investment process. GMO's models are not necessarily predictive of future market events and use simplifying assumptions that can limit their effectiveness. In addition, the data on which the models are based is subject to limitations (e.g., inaccuracies, staleness) that could adversely affect the Fund's performance. The Fund also runs the risk that GMO's assessment of an investment (including a company's fundamental fair (or intrinsic) value) may be 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. Illiquidity Risk – Low trading volume, lack of a market maker, large position size, or legal restrictions may limit or prevent the Fund from selling particular securities or closing derivative positions at desirable prices. 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, rates, or indices. Derivatives also present other risks, including market risk, illiquidity risk, currency risk, credit 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 stock market and underlying securities. The Fund may create short investment exposure by taking a derivative position in which the value of the derivative moves in the opposite direction from the price of an underlying investment, pool of investments, index or currency. The risks of loss associated with derivatives that provide short investment exposure and short sales of securities are theoretically unlimited. Market Disruption and Geopolitical Risk – Geopolitical and other events may disrupt securities markets and adversely affect global economies and markets. Those events, as well as other changes in non-U.S. and U.S. economic and political conditions, could adversely affect the value of the Fund’s investments. Small Company Risk – Smaller companies may have limited product lines, markets, or financial resources, may lack the competitive strength of larger companies, may have inexperienced managers or may 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. Market Risk – Fixed Income Investments – The market price of a fixed income investment can decline due to market-related factors, including rising interest rates and widening credit spreads, or decreased liquidity stemming from the market's uncertainty about the value of a fixed income investment (or class of fixed income investments). Credit Risk – The Fund runs the risk that the issuer or guarantor of a fixed income investment 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. The market price of a fixed income investment will normally decline as a result of the issuer's, guarantor's, or obligor's failure to meet its payment obligations, or in anticipation of such failure. Below investment grade securities have speculative characteristics, and changes in economic conditions or other circumstances are more likely to impair the ability of issuers of those securities to make principal and interest payments than is the case with issuers of investment grade securities. Counterparty Risk – The Fund runs the risk that the counterparty to a derivatives contract, a clearing member used by the Fund to hold a cleared derivatives contract, or a borrower of the Fund's securities will be unable or unwilling to make timely settlement payments, return the Fund's margin or otherwise honor its obligations. Focused Investment Risk – The Fund's investments in companies whose prospects are linked to the internal development and growth of a particular emerging markets country create additional risk because the performance of those companies is likely to be highly correlated. 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 ETFs), including the risk that those underlying funds will not perform as expected. Leveraging Risk – The use of reverse repurchase agreements and other derivatives and securities lending creates leverage. Leverage increases the Fund's losses when the value of its investments (including derivatives) declines. 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 those shareholders of all or a large portion of their Fund shares will require the Fund to sell securities at disadvantageous prices or otherwise disrupt the Fund's operations.
Risk Lose Money [Text]	rr_RiskLoseMoney	Many factors can affect this value, and you may lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	The Fund is a non-diversified investment company under the Investment Company Act of 1940, as amended, and therefore a decline in the market price of a particular security held by the Fund may affect the Fund's performance more than if the Fund were a diversified investment company.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance
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 a broad-based index. Purchase premiums and redemption fees are not reflected in the bar chart, but are reflected in the table; as a result, the returns in the table are lower than the returns in the bar chart. Returns in the table reflect current purchase premiums and redemption fees. 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 II 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	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 a broad-based index.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.gmo.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	Past performance (before and after taxes) is not an indication of future performance.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns/Class II Shares Years Ending December 31
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	Purchase premiums and redemption fees are not reflected in the bar chart, but are reflected in the table; as a result, the returns in the table are lower than the returns in the bar chart.
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest Quarter: 12.66% (1Q2012) Lowest Quarter: – 10.52% (3Q2015) Year-to-Date (as of 3/31/16): 1.49%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns Periods Ending December 31, 2015
Performance Table Does Reflect Sales Loads	rr_PerformanceTableDoesReflectSalesLoads	Returns in the table reflect current purchase premiums and redemption fees.
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	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.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	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).
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown for Class II shares only; after-tax returns for other classes will vary.
GMO Emerging Domestic Opportunities Fund | Class II
Risk/Return:	rr_RiskReturnAbstract
Purchase premium (as a percentage of amount invested)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	0.80%
Redemption fee (as a percentage of amount redeemed)	rr_RedemptionFeeOverRedemption	0.80%
Management fee	rr_ManagementFeesOverAssets	0.75%	[1]
Shareholder service fee	rr_DistributionOrSimilarNon12b1FeesOverAssets	0.22%	[1]
Other expenses	rr_OtherExpensesOverAssets	0.14%
Acquired fund fees and expenses (underlying fund expenses)	rr_AcquiredFundFeesAndExpensesOverAssets	0.11%	[2]
Total annual fund operating expenses	rr_ExpensesOverAssets	1.22%
Expense reimbursement/waiver	rr_FeeWaiverOrReimbursementOverAssets	(0.04%)	[1]
Total annual fund operating expenses	rr_NetExpensesOverAssets	1.18%	[3]
1 Year	rr_ExpenseExampleYear01	$ 282
3 Years	rr_ExpenseExampleYear03	549
5 Years	rr_ExpenseExampleYear05	837
10 Years	rr_ExpenseExampleYear10	1,657
1 Year	rr_ExpenseExampleNoRedemptionYear01	199
3 Years	rr_ExpenseExampleNoRedemptionYear03	460
5 Years	rr_ExpenseExampleNoRedemptionYear05	741
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 1,542
2012	rr_AnnualReturn2012	25.08%
2013	rr_AnnualReturn2013	3.40%
2014	rr_AnnualReturn2014	(0.69%)
2015	rr_AnnualReturn2015	(8.30%)
Year to Date Return, Label	rr_YearToDateReturnLabel	Year-to-Date
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Mar. 31, 2016
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	1.49%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest Quarter:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Mar. 31, 2012
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	12.66%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest Quarter:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2015
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(10.52%)
1 Year	rr_AverageAnnualReturnYear01	(9.76%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	1.60%
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 24, 2011
GMO Emerging Domestic Opportunities Fund | Class III
Risk/Return:	rr_RiskReturnAbstract
Purchase premium (as a percentage of amount invested)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	0.80%
Redemption fee (as a percentage of amount redeemed)	rr_RedemptionFeeOverRedemption	0.80%
Management fee	rr_ManagementFeesOverAssets	0.75%	[1]
Shareholder service fee	rr_DistributionOrSimilarNon12b1FeesOverAssets	0.15%	[1]
Other expenses	rr_OtherExpensesOverAssets	0.14%
Acquired fund fees and expenses (underlying fund expenses)	rr_AcquiredFundFeesAndExpensesOverAssets	0.11%	[2]
Total annual fund operating expenses	rr_ExpensesOverAssets	1.15%
Expense reimbursement/waiver	rr_FeeWaiverOrReimbursementOverAssets	(0.04%)	[1]
Total annual fund operating expenses	rr_NetExpensesOverAssets	1.11%	[3]
1 Year	rr_ExpenseExampleYear01	$ 275
3 Years	rr_ExpenseExampleYear03	527
5 Years	rr_ExpenseExampleYear05	800
10 Years	rr_ExpenseExampleYear10	1,579
1 Year	rr_ExpenseExampleNoRedemptionYear01	192
3 Years	rr_ExpenseExampleNoRedemptionYear03	439
5 Years	rr_ExpenseExampleNoRedemptionYear05	704
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 1,463
1 Year	rr_AverageAnnualReturnYear01	(9.73%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	1.94%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jun. 29, 2012
GMO Emerging Domestic Opportunities Fund | Class IV
Risk/Return:	rr_RiskReturnAbstract
Purchase premium (as a percentage of amount invested)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	0.80%
Redemption fee (as a percentage of amount redeemed)	rr_RedemptionFeeOverRedemption	0.80%
Management fee	rr_ManagementFeesOverAssets	0.75%	[1]
Shareholder service fee	rr_DistributionOrSimilarNon12b1FeesOverAssets	0.105%	[1]
Other expenses	rr_OtherExpensesOverAssets	0.14%
Acquired fund fees and expenses (underlying fund expenses)	rr_AcquiredFundFeesAndExpensesOverAssets	0.11%	[2]
Total annual fund operating expenses	rr_ExpensesOverAssets	1.11%
Expense reimbursement/waiver	rr_FeeWaiverOrReimbursementOverAssets	(0.04%)	[1]
Total annual fund operating expenses	rr_NetExpensesOverAssets	1.07%	[3]
1 Year	rr_ExpenseExampleYear01	$ 271
3 Years	rr_ExpenseExampleYear03	515
5 Years	rr_ExpenseExampleYear05	779
10 Years	rr_ExpenseExampleYear10	1,534
1 Year	rr_ExpenseExampleNoRedemptionYear01	188
3 Years	rr_ExpenseExampleNoRedemptionYear03	426
5 Years	rr_ExpenseExampleNoRedemptionYear05	683
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 1,417
1 Year	rr_AverageAnnualReturnYear01	(9.69%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	0.64%
Inception Date	rr_AverageAnnualReturnInceptionDate	May 02, 2012
GMO Emerging Domestic Opportunities Fund | Class V
Risk/Return:	rr_RiskReturnAbstract
Purchase premium (as a percentage of amount invested)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	0.80%
Redemption fee (as a percentage of amount redeemed)	rr_RedemptionFeeOverRedemption	0.80%
Management fee	rr_ManagementFeesOverAssets	0.75%	[1]
Shareholder service fee	rr_DistributionOrSimilarNon12b1FeesOverAssets	0.085%	[1]
Other expenses	rr_OtherExpensesOverAssets	0.14%
Acquired fund fees and expenses (underlying fund expenses)	rr_AcquiredFundFeesAndExpensesOverAssets	0.11%	[2]
Total annual fund operating expenses	rr_ExpensesOverAssets	1.09%
Expense reimbursement/waiver	rr_FeeWaiverOrReimbursementOverAssets	(0.04%)	[1]
Total annual fund operating expenses	rr_NetExpensesOverAssets	1.05%	[3]
1 Year	rr_ExpenseExampleYear01	$ 269
3 Years	rr_ExpenseExampleYear03	509
5 Years	rr_ExpenseExampleYear05	768
10 Years	rr_ExpenseExampleYear10	1,511
1 Year	rr_ExpenseExampleNoRedemptionYear01	186
3 Years	rr_ExpenseExampleNoRedemptionYear03	420
5 Years	rr_ExpenseExampleNoRedemptionYear05	672
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 1,395
1 Year	rr_AverageAnnualReturnYear01	(9.62%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	(5.23%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Nov. 29, 2013
GMO Emerging Domestic Opportunities Fund | Class VI
Risk/Return:	rr_RiskReturnAbstract
Purchase premium (as a percentage of amount invested)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	0.80%
Redemption fee (as a percentage of amount redeemed)	rr_RedemptionFeeOverRedemption	0.80%
Management fee	rr_ManagementFeesOverAssets	0.75%	[1]
Shareholder service fee	rr_DistributionOrSimilarNon12b1FeesOverAssets	0.055%	[1]
Other expenses	rr_OtherExpensesOverAssets	0.14%
Acquired fund fees and expenses (underlying fund expenses)	rr_AcquiredFundFeesAndExpensesOverAssets	0.11%	[2]
Total annual fund operating expenses	rr_ExpensesOverAssets	1.06%
Expense reimbursement/waiver	rr_FeeWaiverOrReimbursementOverAssets	(0.04%)	[1]
Total annual fund operating expenses	rr_NetExpensesOverAssets	1.02%	[3]
1 Year	rr_ExpenseExampleYear01	$ 266
3 Years	rr_ExpenseExampleYear03	500
5 Years	rr_ExpenseExampleYear05	753
10 Years	rr_ExpenseExampleYear10	1,477
1 Year	rr_ExpenseExampleNoRedemptionYear01	183
3 Years	rr_ExpenseExampleNoRedemptionYear03	411
5 Years	rr_ExpenseExampleNoRedemptionYear05	656
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 1,360
1 Year	rr_AverageAnnualReturnYear01	(9.63%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	2.61%
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 19, 2011
GMO Emerging Domestic Opportunities Fund | Return After Taxes on Distributions | Class II
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(9.81%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	1.24%
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 24, 2011
GMO Emerging Domestic Opportunities Fund | Return After Taxes on Distributions and Sale of Fund Shares | Class II
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(4.88%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	1.39%
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 24, 2011
GMO Emerging Domestic Opportunities Fund | MSCI Emerging Markets Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) | Class II
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(14.92%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	(4.80%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 24, 2011
GMO Emerging Domestic Opportunities Fund | MSCI Emerging Markets Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) | Class III
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(14.92%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	(2.29%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Jun. 29, 2012
GMO Emerging Domestic Opportunities Fund | MSCI Emerging Markets Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) | Class IV
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(14.92%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	(4.44%)
Inception Date	rr_AverageAnnualReturnInceptionDate	May 02, 2012
GMO Emerging Domestic Opportunities Fund | MSCI Emerging Markets Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) | Class V
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(14.92%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	(9.08%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Nov. 29, 2013
GMO Emerging Domestic Opportunities Fund | MSCI Emerging Markets Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) | Class VI
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(14.92%)
5 Years	rr_AverageAnnualReturnYear05
10 Years	rr_AverageAnnualReturnYear10
Incept.	rr_AverageAnnualReturnSinceInception	(1.72%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 19, 2011

[1] Grantham, Mayo, Van Otterloo & Co. LLC ("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, 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 any portion of custody expenses that exceeds 0.10% of the Fund's average daily net assets. GMO also has contractually agreed to waive or reduce the Fund's management fees and shareholder service fees to the extent necessary to offset the management fees and shareholder service fees paid to GMO that are directly or indirectly borne by the Fund or a class of shares of the Fund as a result of the Fund's direct or indirect investments in other series of GMO Trust ("GMO Funds"). Management fees and shareholder service fees will not be waived below zero. This reimbursement and waiver will continue through at least June 30, 2017, and may not be terminated prior to this date without the action or consent of the Fund's Board of Trustees.

[2] These indirect expenses include commissions paid to brokers by the Fund for executing transactions in unaffiliated underlying funds ("transaction fees"). Net fees and expenses of underlying funds (before addition of transaction fees) and indirect transaction fees were approximately 0.04% and 0.07%, respectively.

[3] after expense reimbursement/waiver (Fund and underlying fund expenses)