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S000015626 [Member] Average Annual Total Returns
12 Months Ended 60 Months Ended 120 Months Ended 224 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%  
FTSE Nareit All Mortgage Capped Index (Returns do not reflect deductions for fees, expenses or taxes)        
Prospectus [Line Items]        
Average Annual Return, Percent 13.97% 2.24% 4.53%  
iShares Mortgage Real Estate ETF        
Prospectus [Line Items]        
Average Annual Return, Percent 13.24% 1.66% 3.90%  
Performance Inception Date       May 01, 2007
iShares Mortgage Real Estate ETF | After Taxes on Distributions        
Prospectus [Line Items]        
Average Annual Return, Percent 9.98% (1.26%) 0.94%  
iShares Mortgage Real Estate ETF | After Taxes on Distributions and Sales        
Prospectus [Line Items]        
Average Annual Return, Percent 8.40% 0.24% 1.91%