Investor A C and Institutional [Member] Expense Example, No Redemption - Investor A, C and Institutional - BlackRock Short Duration Muni Fund - Investor C Shares |
Jun. 30, 2026
USD ($)
|
|---|---|
| Prospectus [Line Items] | |
| Expense Example, No Redemption, 1 Year | $ 139 |
| Expense Example, No Redemption, 3 Years | 453 |
| Expense Example, No Redemption, 5 Years | 789 |
| Expense Example, No Redemption, 10 Years | $ 1,521 |