v3.25.4
S000000877 [Member] Average Annual Total Returns
 12 Months Ended 60 Months Ended 120 Months Ended 167 Months Ended 469 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Russell 3000® Index (reflects no deductions for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Percent [1] 17.15% 13.15% 14.29%    
Russell 2000® Growth Index (reflects no deductions for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Percent [1] 13.01% 3.18% 9.57%    
Russell 2000® Index (reflects no deductions for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Percent [1] 12.81% 6.09% 9.62%    
Investor Class shares          
Prospectus [Line Items]          
Average Annual Return, Percent (10.44%) 2.52% 10.56%    
Performance Inception Date         Dec. 06, 1986
Investor Class shares | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Percent (12.10%) 0.97% 8.89%    
Performance Inception Date         Dec. 06, 1986
Investor Class shares | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Percent (4.97%) 2.00% 8.52%    
Performance Inception Date         Dec. 06, 1986
Institutional Class Shares          
Prospectus [Line Items]          
Average Annual Return, Percent (10.33%) 2.64% 10.71%    
Performance Inception Date       Jan. 31, 2012  
[1] All rights in the Russell 3000, Russell 2000 and Russell 2000 Growth indexes vest in the relevant LSE Group company, which owns these indexes. Russell® is a trademark of the relevant LSE Group company and is used by any other LSE Group company under license. These indexes are calculated by or on behalf of FTSE International Limited or its affiliate, agent or partner. The LSE Group does not accept any liability whatsoever to any person arising out of (a) the use of, reliance on, or any error in these indexes or (b) investment in or operation of the Fund or the suitability of these indexes for the purpose they are being used herein.