Shareholder Report, Average Annual Return (Details) 190997_Buffalo Early Stage 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 Early Stage Growth Fund Institutional Class | ||
| Average Annual Return, Percent | 8.73% | (4.23%) | 4.78% |
| 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 2000 Growth Index [Member] | |||
| Average Annual Return [Line Items] | |||
| Line Graph and Table Measure Name | Russell 2000 Growth Index | ||
| Average Annual Return, Percent | 23.58% | 1.62% | 7.50% |