Investor A Institutional [Member] Expense Example - Investor A Institutional [Member] - iShares Municipal Bond Index Fund |
Dec. 31, 2025
USD ($)
|
|---|---|
| Investor A | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 51 |
| Expense Example, with Redemption, 3 Years | 182 |
| Expense Example, with Redemption, 5 Years | 325 |
| Expense Example, with Redemption, 10 Years | 740 |
| Institutional | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 26 |
| Expense Example, with Redemption, 3 Years | 94 |
| Expense Example, with Redemption, 5 Years | 168 |
| Expense Example, with Redemption, 10 Years | $ 387 |