v3.26.1
Shareholder Report, Average Annual Return (Details) 190996_Buffalo 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 Growth Fund Institutional Class    
Average Annual Return, Percent 9.32% 8.23% 11.15%
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 3000 Growth Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 3000 Growth Index    
Average Annual Return, Percent 18.75% 12.05% 16.10%