v3.26.1
S000013702 [Member] Average Annual Total Returns
12 Months Ended 60 Months Ended 120 Months Ended 226 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Bloomberg U.S. Universal Index (Returns do not reflect deductions for fees, expenses or taxes)        
Prospectus [Line Items]        
Average Annual Return, Percent 7.58% 0.06% 2.44%  
Bloomberg U.S. MBS Index (Returns do not reflect deductions for fees, expenses or taxes)        
Prospectus [Line Items]        
Average Annual Return, Percent 8.58% 0.15% 1.59%  
iShares MBS ETF        
Prospectus [Line Items]        
Average Annual Return, Percent 8.45% 0.08% 1.49%  
Performance Inception Date       Mar. 13, 2007
iShares MBS ETF | After Taxes on Distributions        
Prospectus [Line Items]        
Average Annual Return, Percent 6.58% (1.12%) 0.38%  
iShares MBS ETF | After Taxes on Distributions and Sales        
Prospectus [Line Items]        
Average Annual Return, Percent 4.96% (0.46%) 0.65%