v3.26.1
S000023507 [Member] Average Annual Total Returns
 12 Months Ended 55 Months Ended 60 Months Ended 120 Months Ended 206 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
ICE BofA US Municipal Securities Index (Returns do not reflect deductions for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Percent [1] 3.92%   0.81% 2.37%  
ICE Short Maturity AMT-Free US National Municipal Index (Spliced) (Returns do not reflect deductions for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Percent [2] 3.75%   1.45% 1.62%  
ICE AMT-Free US National Municipal Index (Returns do not reflect deductions for fees, expenses or taxes)          
Prospectus [Line Items]          
Average Annual Return, Percent [1],[3] 3.90%    
Performance Inception Date   Jun. 10, 2021      
iShares Short-Term National Muni Bond ETF          
Prospectus [Line Items]          
Average Annual Return, Percent 3.69%   1.35% 1.45%  
Performance Inception Date         Nov. 05, 2008
iShares Short-Term National Muni Bond ETF | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Percent 3.69%   1.35% 1.45%  
iShares Short-Term National Muni Bond ETF | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Percent 3.19%   1.40% 1.43%  
[1] The Fund began comparing its performance to the ICE BofA US Municipal Securities Index on February 28, 2026, as it represents the US national municipal securities market, and will no longer compare its performance to the ICE AMT-Free US National Municipal Index effective approximately one year from February 28, 2026.
[2] The ICE Short Maturity AMT-Free US National Municipal Index (Spliced) reflects the performance of the S&P Short Term National AMT-Free Municipal Bond Index through September 14, 2021 and the ICE Short Maturity AMT-Free US National Municipal Index thereafter, which reflect the times when each index was the Underlying Index of the Fund.
[3] The inception date of the ICE AMT-Free US National Municipal Index was June 10, 2021.