GMO Resources Fund Performance Management - GMO Resources Fund	Feb. 28, 2025
Prospectus [Line Items]
Bar Chart and Performance Table [Heading]	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Performance</span>
Performance Narrative [Text Block]	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 MSCI ACWI Commodity Producers Index and a broad-based securities market index intended solely to represent, in satisfaction of regulatory requirements, the overall global equity market. 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 Past Does Not Indicate Future [Text]	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;"> Past performance </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">(before and after taxes) is not an indication of future performance.</span>
Performance Information Illustrates Variability of Returns [Text]	<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 MSCI ACWI Commodity Producers Index and a broad-based securities market index intended solely to represent, in satisfaction of regulatory requirements, the overall global equity market.</span>
Bar Chart [Heading]	<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]	Highest Quarter:38.17%4Q 2020Lowest Quarter:-35.58%1Q 2020Year-to-Date:-5.90%As of3/31/2025
Performance Table Heading	<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, 2024</span>
Performance Table Uses Highest Federal Rate	<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 </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">tax rates and do not reflect the impact of state and local taxes.</span>
Performance Table Not Relevant to Tax Deferred	<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 </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">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). </span>
Performance Table One Class of after Tax Shown [Text]	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;">After-tax returns are shown for Class III shares only; after-tax </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">returns for other classes will vary. Updated performance information for the Fund is available at </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">www.gmo.com</span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">.</span>
Index No Deduction for Fees, Expenses, or Taxes [Text]	<span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:0.0pt;">(returns reflect no </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">deduction for fees or expenses, </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">but are net of withholding tax </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">on dividend reinvestments)</span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:0.0pt;">(returns reflect no </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">deduction for fees or expenses, </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">but are net of withholding tax </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">on dividend reinvestments)</span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:0.0pt;">(returns reflect no </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">deduction for fees or expenses, </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">but are net of withholding tax </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">on dividend reinvestments)</span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:0.0pt;">(returns reflect no </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">deduction for fees or expenses, </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">but are net of withholding tax </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">on dividend reinvestments)</span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:0.0pt;">(returns reflect no </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">deduction for fees or expenses, </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">but are net of withholding tax </span><span style="color:#000000;font-family:Times New Roman;font-size:7.9pt;margin-left:7.9pt;">on dividend reinvestments)</span>
Performance Availability Website Address [Text]	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;">www.gmo.com</span>
Class III
Prospectus [Line Items]
Year to Date Return, Label [Optional Text]	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;">Year-to-Date:</span>
Bar Chart, Year to Date Return	(5.90%)
Bar Chart, Year to Date Return, Date	Mar. 31, 2025
Highest Quarterly Return, Label [Optional Text]	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;">Highest Quarter:</span>
Highest Quarterly Return	38.17%
Highest Quarterly Return, Date	Dec. 31, 2020
Lowest Quarterly Return, Label [Optional Text]	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;">Lowest Quarter:</span>
Lowest Quarterly Return	(35.58%)
Lowest Quarterly Return, Date	Mar. 31, 2020

GMO Resources Fund Performance Management - GMO Resources Fund

Feb. 28, 2025

Bar Chart and Performance Table [Heading]

Performance

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 MSCI ACWI Commodity Producers Index and a broad-based securities market index intended solely to represent, in satisfaction of regulatory requirements, the overall global equity market. 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 Past Does Not Indicate Future [Text]

Past performance (before and after taxes) is not an indication of future performance.

Performance Information Illustrates Variability of Returns [Text]

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 MSCI ACWI Commodity Producers Index and a broad-based securities market index intended solely to represent, in satisfaction of regulatory requirements, the overall global equity market.

Bar Chart [Heading]

Annual Total Returns/Class III Shares Years Ending December 31

Bar Chart Closing [Text Block]

Highest Quarter:38.17%4Q 2020Lowest Quarter:-35.58%1Q 2020Year-to-Date:-5.90%As of3/31/2025

Performance Table Heading

Average Annual Total Returns Periods Ending December 31, 2024

Performance Table Uses Highest Federal Rate

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

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]

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.

Index No Deduction for Fees, Expenses, or Taxes [Text]

(returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)(returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)(returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)(returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)(returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)

Performance Availability Website Address [Text]

www.gmo.com

Class III

Prospectus [Line Items]

Year to Date Return, Label [Optional Text]

Year-to-Date:

Bar Chart, Year to Date Return

(5.90%)

Bar Chart, Year to Date Return, Date

Mar. 31, 2025

Highest Quarterly Return, Label [Optional Text]

Highest Quarter: