v3.26.1
Shareholder Report, Average Annual Return (Details) 190992_Buffalo Blue Chip Growth 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 Blue Chip Growth Fund Institutional Class    
Average Annual Return, Percent 17.15% 11.26% 14.18%
Russell 3000 Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 3000 Index    
Average Annual Return, Percent 18.09% 10.87% 13.56%
Russell 1000 Growth Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 1000 Growth Index    
Average Annual Return, Percent 18.81% 12.76% 16.69%