v3.26.1
Shareholder Report, Average Annual Return (Details) 190988_Buffalo International Fund_Investor Class_TSR Annual {Investor Class}
12 Months Ended 60 Months Ended 120 Months Ended
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2026
Investor Class      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Buffalo International Fund Investor Class    
Average Annual Return, Percent 9.21% 3.80% 8.55%
FTSE Global All Cap ex US Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name FTSE Global All Cap ex US Index    
Average Annual Return, Percent 25.86% 7.45% 8.85%
FTSE All-World ex US Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name FTSE All-World ex US Index    
Average Annual Return, Percent 25.56% 7.63% 8.99%