Investor P [Member] Annual Total Returns |
12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Investor P [Member] | iShares Municipal Bond Index Fund | Investor P Shares | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 3.44% | 0.95% | 6.32% | (8.84%) | 1.29% | 4.69% | 7.25% | 1.24% | 3.83% | 0.48% |