v3.26.1
GMO Resources Fund Average Annual Total Returns
 12 Months Ended 47 Months Ended 59 Months Ended 60 Months Ended 120 Months Ended 153 Months Ended 168 Months Ended
Feb. 28, 2026
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Class III                
Prospectus [Line Items]                
Average Annual Return, Percent   23.06%     4.08% 11.99%   6.18%
Performance Inception Date Dec. 28, 2011              
Class III | After Taxes on Distributions                
Prospectus [Line Items]                
Average Annual Return, Percent   21.57%     1.92% 10.37%   4.66%
Class III | After Taxes on Distributions and Sales                
Prospectus [Line Items]                
Average Annual Return, Percent   14.28%     2.63% 9.57%   4.57%
Class III | MSCI ACWI Commodity Producers Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent [1]   32.48%     15.01% 10.23%   4.24%
Class III | MSCI ACWI (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent [1]   22.34%     11.19% 11.72%   11.24%
Class IV                
Prospectus [Line Items]                
Average Annual Return, Percent   23.12%     4.14% 12.04% 6.10%  
Performance Inception Date Mar. 20, 2013              
Class IV | MSCI ACWI Commodity Producers Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent [1]   32.48%     15.01% 10.23% 4.50%  
Class IV | MSCI ACWI (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent [1]   22.34%     11.19% 11.72% 10.45%  
Class VI                
Prospectus [Line Items]                
Average Annual Return, Percent   23.15% (1.42%)      
Performance Inception Date Feb. 08, 2022              
Class VI | MSCI ACWI Commodity Producers Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent [1]   32.48% 8.80%          
Class VI | MSCI ACWI (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent [1]   22.34% 10.94%          
Class R6                
Prospectus [Line Items]                
Average Annual Return, Percent   23.08%   2.20%    
Performance Inception Date Jan. 22, 2021              
Class R6 | MSCI ACWI Commodity Producers Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent [1]   32.48%   13.78%        
Class R6 | MSCI ACWI (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent [1]   22.34%   10.63%        
Class I                
Prospectus [Line Items]                
Average Annual Return, Percent   22.95%   2.10%    
Performance Inception Date Jan. 22, 2021              
Class I | MSCI ACWI Commodity Producers Index (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent [1]   32.48%   13.78%        
Class I | MSCI ACWI (returns reflect no deduction for fees or expenses, but are net of withholding tax on dividend reinvestments)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent [1]   22.34%   10.63%        
[1] 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.