v3.26.1
GMO International Opportunistic Value Fund Average Annual Total Returns
 12 Months Ended 15 Months Ended 17 Months Ended 60 Months Ended 120 Months Ended 317 Months Ended
Feb. 28, 2025
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Class III              
Prospectus [Line Items]              
Average Annual Return, Percent   5.25%     5.90% 4.59% 5.85%
Performance Inception Date Jul. 29, 1998            
Class III | After Taxes on Distributions              
Prospectus [Line Items]              
Average Annual Return, Percent   2.61%     4.20% 3.37% 5.02%
Class III | After Taxes on Distributions and Sales              
Prospectus [Line Items]              
Average Annual Return, Percent   4.29%     4.50% 3.58% 4.96%
Class III | MSCI World ex USA Value 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]   6.65%     5.50% 4.54% 4.89%
Class III | MSCI World ex USA 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]   4.70%     5.10% 5.26% 4.63%
Class IV              
Prospectus [Line Items]              
Average Annual Return, Percent   5.37% 9.48%    
Performance Inception Date Sep. 25, 2023            
Class IV | MSCI World ex USA Value 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]   6.65% 11.73%        
Class IV | MSCI World ex USA 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]   4.70% 11.76%        
Class I              
Prospectus [Line Items]              
Average Annual Return, Percent   5.10%   8.46%  
Performance Inception Date Aug. 14, 2023            
Class I | MSCI World ex USA Value 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]   6.65%   10.69%      
Class I | MSCI World ex USA 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]   4.70%   8.40%      
[1] Index performance from inception is presented beginning on July 31, 1998 due to the unavailability of daily index returns prior to 2001. 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.