Dividend and interest expense on short sales All other expense GMO Benchmark-Free Allocation Fund GMO Global Asset Allocation Fund GMO Emerging Markets Fund GMO Emerging Markets ex-China Fund GMO Global Developed Equity Allocation Fund GMO Global Equity Allocation Fund GMO International Developed Equity Allocation Fund GMO International Equity Allocation Fund GMO International Equity Fund GMO Quality Fund GMO U.S. Equity Fund GMO U.S. Small Cap Value Fund GMO Emerging Country Debt Fund GMO High Yield Fund GMO Multi-Asset Credit Fund GMO Opportunistic Income Fund GMO Alternative Allocation Fund GMO U.S. Treasury Fund GMO Benchmark-Free Allocation Fund GMO Global Asset Allocation Fund GMO Emerging Markets Fund GMO Emerging Markets ex-China Fund GMO Global Developed Equity Allocation Fund GMO Global Equity Allocation Fund GMO International Developed Equity Allocation Fund GMO International Equity Allocation Fund GMO International Equity Fund GMO Quality Fund GMO U.S. Equity Fund GMO U.S. Small Cap Value Fund GMO Emerging Country Debt Fund GMO High Yield Fund GMO Multi-Asset Credit Fund GMO Opportunistic Income Fund GMO Alternative Allocation Fund GMO U.S. Treasury Fund ETF Class Class III ETF Class Class III ETF Class Class III ETF Class Class III ETF Class Class III ETF Class Class III ETF Class Class III ETF Class Class III ETF Class Class III ETF Class Class III ETF Class Class III ETF Class Class VI ETF Class Class III ETF Class Class VI ETF Class ETF Class Class VI ETF Class Class VI ETF Class Class VI Market Risk [Member] Management and Operational Risk [Member] Market Risk – Equities [Member] Non-U.S. Investment Risk [Member] Market Risk – Fixed Income [Member] Derivatives and Short Sales Risk [Member] Smaller Company Risk [Member] Futures Contracts Risk [Member] Currency Risk [Member] Fund of Funds Risk [Member] Commodities Risk [Member] Event-Driven Risk [Member] Illiquidity Risk [Member] Leveraging Risk [Member] Counterparty Risk [Member] Market Disruption and Geopolitical Risk [Member] Market Risk – Asset-Backed Securities [Member] Focused Investment Risk [Member] Large Transactions Risk [Member] Value Investing Risk [Member] ETF Risks [Member] Credit Risk [Member] Consumer Price Index (returns reflect no deduction for fees, expenses, or taxes) Bloomberg U.S. Treasury Inflation Notes: 1-10 Year Index (returns reflect no deduction for fees, expenses, or taxes) Bloomberg U.S. Aggregate Index (reflects no deduction for fees, expenses, or taxes) MSCI World Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) GMO Global Asset Allocation Index (Fund benchmark) MSCI Emerging Markets Index (reflects no deduction for fees or expenses, but are net of withholding tax on dividend reinvestment) MSCI Emerging Markets ex-China Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestment) MSCI World Index (Fund benchmark) (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) MSCI ACWI + MSCI ACWI (Fund benchmark) (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) MSCI World ex USA Index (Fund benchmark) (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) MSCI EAFE Index (Fund benchmark) (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) MSCI ACWI ex USA (Fund benchmark) (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) MSCI World ex USA Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) MSCI EAFE Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) S&P 500 Index (returns reflect no deduction for fees, expenses, or taxes) S&P Composite 1500 Index (returns reflect no deduction for fees, expenses, or taxes) S&P SmallCap 600 Value Index (returns reflect no deduction for fees, expenses, or taxes) J.P. Morgan EMBI Global Diversified +1 (Composite index) (Fund benchmark) Markit iBoxx USD Liquid High Yield Index (Fund benchmark) (returns reflect no deduction for fees, expenses, or taxes, but are net of withholding tax on dividend reinvestments) Bloomberg U.S. Securitized Index (returns reflect no deduction for fees, expenses, or taxes) Bloomberg U.S. Aggregate Index (returns reflect no deduction for fees, expenses, or taxes) FTSE 3-Month Treasury Bill Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments) FTSE 3-Month Treasury Bill Index (returns reflect no deduction for fees, expenses, or taxes) doc_ GMO_ US_ Small_ Cap_ Value_ Fund Member index_ Bloomberg_ US_ Aggregate_ Index_reflects_no_deduction_for_fees_expenses_or_taxes Member index_ SP_500_ Index_returns_reflect_no_deduction_for_fees_expenses_or_taxes Member S000065871 Member doc_ GMO_ Emerging_ Markets_ Fund Member S000005487 Member C000281177 Member Non USInvestment Risk Member C000281167 Member C000014927 Member Counterparty Risk Member doc_ GMO_ US_ Treasury_ Fund Member S000012211 Member index_ MSCI_ EAFE_ Index_returns_reflect_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestments Member doc_ GMO_ Quality_ Fund Member S000004081 Member doc_ GMO_ Global_ Equity_ Allocation_ Fund Member C000281174 Member Market Risk Asset Backed Securities Member doc_ GMO_ International_ Equity_ Fund Member doc_ GMO_ Emerging_ Country_ Debt_ Fund Member S000061716 Member C000011437 Member index_ MSCI_ ACWI_ex_ USA_ Fund_benchmark_returns_reflect_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestments Member S000007516 Member C000020548 Member S000089451 Member C000281171 Member index_ SP_ Composite_1500_ Index_returns_reflect_no_deduction_for_fees_expenses_or_taxes Member doc_ GMO_ International_ Equity_ Allocation_ Fund Member S000004922 Member S000004224 Member C000281165 Member C000013327 Member C000281175 Member doc_ GMO_ Global_ Developed_ Equity_ Allocation_ Fund Member C000199930 Member doc_ GMO_ International_ Developed_ Equity_ Allocation_ Fund Member Fund Of Funds Risk Member S000005486 Member doc_ GMO_ Benchmark Free_ Allocation_ Fund Member doc_ GMO_ Emerging_ Markets_ex China_ Fund Member C000033342 Member index_ SP_ Small Cap_600_ Value_ Index_returns_reflect_no_deduction_for_fees_expenses_or_taxes Member S000004911 Member index_ MSCI_ World_ex_ USA_ Index_ Fund_benchmark_returns_reflect_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestments Member S000004084 Member C000013269 Member doc_ GMO_ Multi Asset_ Credit_ Fund Member Market Risk Member S000065268 Member C000014938 Member Event Driven Risk Member C000011423 Member C000281164 Member index_ JP_ Morgan_ EMBI_ Global_ Diversified_1_ Composite_index_ Fund_benchmark Member Market Disruption And Geopolitical Risk Member index_ Consumer_ Price_ Index_returns_reflect_no_deduction_for_fees_expenses_or_taxes Member C000281176 Member C000075084 Member index_ FTSE_3 Month_ Treasury_ Bill_ Index_returns_reflect_no_deduction_for_fees_expenses_or_taxes Member C000212810 Member doc_ GMO_ Alternative_ Allocation_ Fund Member C000281170 Member CreditRiskMember C000014930 Member index_ MSCI_ World_ Index_returns_reflect_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestments Member C000281180 Member Management And Operational Risk Member index_ MSCI_ World_ Index_ Fund_benchmark_returns_reflect_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestments Member index_ Bloomberg_ US_ Securitized_ Index_returns_reflect_no_deduction_for_fees_expenses_or_taxes Member index_ MSCI_ ACWI_ Member S000005485 Member C000014936 Member C000011881 Member Currency Risk Member ETFRisks Member C000281169 Member Illiquidity Risk Member C000211299 Member C000281178 Member S000005488 Member C000228647 Member C000281163 Member index_ MSCI_ EAFE_ Index_ Fund_benchmark_returns_reflect_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestments Member index_ GMO_ Global_ Asset_ Allocation_ Index_ Fund_benchmark Member S000072426 Member index_ FTSE_3 Month_ Treasury_ Bill_ Index_returns_reflect_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestments Member C000281166 Member S000005490 Member C000014933 Member Value Investing Risk Member doc_ GMO_ US_ Equity_ Fund Member S000025186 Member index_ MSCI_ Emerging_ Markets_ex China_ Index_returns_reflect_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestment Member Market Risk Equities Member doc_ GMO_ Opportunistic_ Income_ Fund Member index_ MSCI_ Emerging_ Markets_ Index_reflects_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestment Member Smaller Company Risk Member Futures Contracts Risk Member index_ MSCI_ World_ex_ USA_ Index_returns_reflect_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestments Member C000281172 Member C000281179 Member Leveraging Risk Member Derivatives And Short Sales Risk Member index_ Bloomberg_ US_ Treasury_ Inflation_ Notes_110_ Year_ Index_returns_reflect_no_deduction_for_fees_expenses_or_taxes Member Focused Investment Risk Member index_ Markit_i Boxx_ USD_ Liquid_ High_ Yield_ Index_ Fund_benchmark_returns_reflect_no_deduction_for_fees_expenses_or_taxes_but_are_net_of_withholding_tax_on_dividend_reinvestments Member Large Transactions Risk Member C000281168 Member doc_ GMO_ Global_ Asset_ Allocation_ Fund Member Market Risk Fixed Income Member C000281173 Member doc_ GMO_ High_ Yield_ Fund Member Commodities Risk Member index_ Bloomberg_ US_ Aggregate_ Index_returns_reflect_no_deduction_for_fees_expenses_or_taxes Member index_ MSCI_ ACWI_ Fund_benchmark_returns_reflect_no_deduction_for_fees_or_expenses_but_are_net_of_withholding_tax_on_dividend_reinvestments Member