S000004436 [Member] Average Annual Total Returns

12 Months Ended

60 Months Ended

120 Months Ended

251 Months Ended

Dec. 31, 2025

Dec. 31, 2025

Dec. 31, 2025

Dec. 31, 2025

MSCI USA Index (Returns do not reflect deductions for fees, expenses or taxes)

Prospectus [Line Items]

Average Annual Return, Percent

17.75%

13.87%

14.79%

MSCI USA Extended ESG Select Index (Spliced) (Returns do not reflect deductions for fees, expenses or taxes)

Prospectus [Line Items]

Average Annual Return, Percent

^[1]

16.10%

12.75%

14.79%

iShares ESG Optimized MSCI USA ETF

Prospectus [Line Items]

Average Annual Return, Percent

15.72%

12.47%

14.43%

Performance Inception Date

Jan. 24, 2005

iShares ESG Optimized MSCI USA ETF | After Taxes on Distributions

Prospectus [Line Items]

Average Annual Return, Percent

15.45%

12.14%

14.05%

iShares ESG Optimized MSCI USA ETF | After Taxes on Distributions and Sales

Prospectus [Line Items]

Average Annual Return, Percent

9.47%

9.90%

12.07%

[1]	The MSCI USA Extended ESG Select Index (Spliced) reflects the performance of the MSCI USA ESG Select Index through May 31, 2018 and the MSCI USA Extended ESG Select Index thereafter, which reflect the times when each index was the Underlying Index of the Fund.