v3.26.1
Shareholder Report, Average Annual Return (Details) 190988_Buffalo International Fund_Institutional Class_TSR Annual {Institutional Class}
12 Months Ended 60 Months Ended 81 Months Ended
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2026
Institutional Class      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Buffalo International Fund Institutional Class    
Average Annual Return, Percent 9.34% 3.95% 7.10%
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% 8.87%
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% 8.97%