S000075391 [Member] Investment Objectives and Goals - William Blair Mid Cap Value Fund |
Dec. 31, 2025 |
|---|---|
| Prospectus [Line Items] | |
| Risk/Return [Heading] | WILLIAM BLAIR MID CAP VALUE FUND SUMMARY |
| Objective [Heading] | INVESTMENT OBJECTIVE: |
| Objective, Primary [Text Block] | The William Blair Mid Cap Value Fund seeks long-term capital appreciation. |