v3.26.1
S000004439 [Member] Average Annual Total Returns
12 Months Ended 60 Months Ended 120 Months Ended 245 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 Microcap Index (Returns do not reflect deductions for fees, expenses or taxes)        
Prospectus [Line Items]        
Average Annual Return, Percent 22.98% 7.32% 9.58%  
iShares Micro-Cap ETF        
Prospectus [Line Items]        
Average Annual Return, Percent 22.80% 7.07% 9.40%  
Performance Inception Date       Aug. 12, 2005
iShares Micro-Cap ETF | After Taxes on Distributions        
Prospectus [Line Items]        
Average Annual Return, Percent 22.38% 6.75% 9.05%  
iShares Micro-Cap ETF | After Taxes on Distributions and Sales        
Prospectus [Line Items]        
Average Annual Return, Percent 13.64% 5.45% 7.60%