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S000004338 [Member] Average Annual Total Returns
12 Months Ended 60 Months Ended 120 Months Ended 293 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Russell 3000 Index (Returns do not reflect deductions for fees, expenses or taxes)        
Prospectus [Line Items]        
Average Annual Return, Percent 17.15% 13.15% 14.29%  
Russell Midcap Index (Returns do not reflect deductions for fees, expenses or taxes)        
Prospectus [Line Items]        
Average Annual Return, Percent 10.60% 8.67% 11.01%  
iShares Russell Mid-Cap ETF        
Prospectus [Line Items]        
Average Annual Return, Percent 10.42% 8.50% 10.84%  
Performance Inception Date       Jul. 17, 2001
iShares Russell Mid-Cap ETF | After Taxes on Distributions        
Prospectus [Line Items]        
Average Annual Return, Percent 10.06% 8.13% 10.41%  
iShares Russell Mid-Cap ETF | After Taxes on Distributions and Sales        
Prospectus [Line Items]        
Average Annual Return, Percent 6.39% 6.64% 8.84%