S000069167 [Member] Annual Total Returns |
12 Months Ended | |||
|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| William Blair Emerging Markets Debt Fund | Class I | ||||
| Prospectus [Line Items] | ||||
| Annual Return [Percent] | 16.09% | 9.06% | 13.41% | (16.93%) |