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S000034349 [Member] Investment Objectives and Goals - William Blair Emerging Markets Small Cap Growth Fund
Dec. 31, 2025
Prospectus [Line Items]  
Risk/Return [Heading] WILLIAM BLAIR EMERGING MARKETS SMALL CAP GROWTH FUND SUMMARY
Objective [Heading] INVESTMENT OBJECTIVE:
Objective, Primary [Text Block] The William Blair Emerging Markets Small Cap Growth Fund seeks long-term capital appreciation.