Shareholder Report, Line Graph (Details) 190993_Buffalo Mid Cap 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 Mid Cap Growth Fund Institutional Class | |||||||
| Accumulated Value | $ 386,614 | $ 401,174 | $ 323,929 | $ 370,036 | $ 375,070 | $ 225,703 | $ 250,000 | $ 361,637 |
| 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 Midcap Growth Index [Member] | ||||||||
| Account Value [Line Items] | ||||||||
| Line Graph and Table Measure Name | Russell Midcap Growth Index | |||||||
| Accumulated Value | $ 425,938 | $ 411,243 | $ 325,652 | $ 355,972 | $ 359,180 | $ 213,025 | $ 250,000 | $ 466,653 |