S000034349 [Member] Expense Example - William Blair Emerging Markets Small Cap Growth Fund |
Dec. 31, 2025
USD ($)
|
|---|---|
| Class I | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 117 |
| Expense Example, with Redemption, 3 Years | 425 |
| Expense Example, with Redemption, 5 Years | 755 |
| Expense Example, with Redemption, 10 Years | 1,689 |
| Class N | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 143 |
| Expense Example, with Redemption, 3 Years | 506 |
| Expense Example, with Redemption, 5 Years | 895 |
| Expense Example, with Redemption, 10 Years | 1,984 |
| Class R6 | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 112 |
| Expense Example, with Redemption, 3 Years | 397 |
| Expense Example, with Redemption, 5 Years | 702 |
| Expense Example, with Redemption, 10 Years | $ 1,571 |