v3.25.2
S000023506 [Member] Average Annual Total Returns
 12 Months Ended 60 Months Ended 120 Months Ended 194 Months Ended
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Bloomberg U.S. Universal Index (Returns do not reflect deductions for fees, expenses or taxes)        
Prospectus [Line Items]        
Average Annual Return, Percent [1] 2.04% 0.06% 1.73%  
Bloomberg U.S. Agency Bond Index (Returns do not reflect deductions for fees, expenses or taxes)        
Prospectus [Line Items]        
Average Annual Return, Percent 3.16% 0.79% 1.55%  
iShares Agency Bond ETF        
Prospectus [Line Items]        
Average Annual Return, Percent 3.04% 0.91% 1.56%  
Performance Inception Date       Nov. 05, 2008
iShares Agency Bond ETF | After Taxes on Distributions        
Prospectus [Line Items]        
Average Annual Return, Percent 1.59% 0.00% 0.72%  
iShares Agency Bond ETF | After Taxes on Distributions and Sales        
Prospectus [Line Items]        
Average Annual Return, Percent 1.79% 0.32% 0.84%  
[1] The Fund has added this broad-based index in response to new regulatory requirements.