v3.26.1
GMO Quality Fund Average Annual Total Returns
 12 Months Ended 60 Months Ended 74 Months Ended 75 Months Ended 120 Months Ended 229 Months Ended 263 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   19.69% 14.64%     15.95%   10.68%
Performance Inception Date Feb. 06, 2004              
Class III | After Taxes on Distributions                
Prospectus [Line Items]                
Average Annual Return, Percent   16.63% 12.61%     13.50%   8.81%
Class III | After Taxes on Distributions and Sales                
Prospectus [Line Items]                
Average Annual Return, Percent   13.59% 11.30%     12.54%   8.42%
Class III | S&P 500 Index (returns reflect no deduction for fees, expenses, or taxes)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent   17.88% 14.43%     14.82%   10.62%
Class IV                
Prospectus [Line Items]                
Average Annual Return, Percent   19.72% 14.70%     16.01%   10.72%
Performance Inception Date Feb. 06, 2004              
Class IV | S&P 500 Index (returns reflect no deduction for fees, expenses, or taxes)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent   17.88% 14.43%     14.82%   10.62%
Class VI                
Prospectus [Line Items]                
Average Annual Return, Percent   19.80% 14.75%     16.06% 11.70%  
Performance Inception Date Dec. 08, 2006              
Class VI | S&P 500 Index (returns reflect no deduction for fees, expenses, or taxes)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent   17.88% 14.43%     14.82% 10.76%  
Class R6                
Prospectus [Line Items]                
Average Annual Return, Percent   19.72% 14.65% 15.85%      
Performance Inception Date Nov. 12, 2019              
Class R6 | S&P 500 Index (returns reflect no deduction for fees, expenses, or taxes)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent   17.88% 14.43% 15.60%        
Class I                
Prospectus [Line Items]                
Average Annual Return, Percent   19.54% 14.52%   16.32%    
Performance Inception Date Sep. 26, 2019              
Class I | S&P 500 Index (returns reflect no deduction for fees, expenses, or taxes)[Member]                
Prospectus [Line Items]                
Average Annual Return, Percent   17.88% 14.43%   15.99%