v3.26.1
Shareholder Report, Line Graph (Details) 190992_Buffalo Blue Chip Growth Fund_Institutional Class_TSR Annual {Institutional Class} - USD ($)
12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Mar. 31, 2022
Mar. 31, 2021
Mar. 31, 2020
Jul. 01, 2019
Mar. 31, 2026
Institutional Class                
Account Value [Line Items]                
Line Graph and Table Measure Name               Buffalo Blue Chip Growth Fund Institutional Class
Accumulated Value $ 522,381 $ 496,741 $ 356,872 $ 396,385 $ 358,981 $ 228,618 $ 250,000 $ 611,947
Russell 3000 Index [Member]                
Account Value [Line Items]                
Line Graph and Table Measure Name               Russell 3000 Index
Accumulated Value 499,505 465,873 360,323 394,141 352,149 216,670 250,000 $ 589,843
Russell 1000 Growth Index [Member]                
Account Value [Line Items]                
Line Graph and Table Measure Name               Russell 1000 Growth Index
Accumulated Value $ 596,426 $ 553,461 $ 398,183 $ 446,902 $ 388,688 $ 238,834 $ 250,000 $ 708,628