Shareholder Report, Line Graph (Details) 190994_Buffalo Mid Cap Discovery Fund_Investor Class_TSR Annual {Investor Class} - USD ($) |
12 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2023 |
Mar. 31, 2022 |
Mar. 31, 2021 |
Mar. 31, 2020 |
Mar. 31, 2019 |
Mar. 31, 2018 |
Mar. 31, 2017 |
Mar. 31, 2016 |
Mar. 31, 2026 |
|
| Investor Class | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Buffalo Mid Cap Discovery Fund Investor Class | ||||||||||
| Accumulated Value | $ 21,785 | $ 23,356 | $ 19,509 | $ 21,705 | $ 22,747 | $ 13,581 | $ 15,029 | $ 13,621 | $ 11,607 | $ 10,000 | $ 20,305 |
| Russell 3000 Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Russell 3000 Index | ||||||||||
| Accumulated Value | 30,620 | 28,558 | 22,088 | 24,161 | 21,587 | 13,282 | 14,616 | 13,438 | 11,807 | 10,000 | $ 36,157 |
| Russell Midcap Growth Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Russell Midcap Growth Index | ||||||||||
| Accumulated Value | $ 27,577 | $ 26,625 | $ 21,084 | $ 23,047 | $ 23,254 | $ 13,792 | $ 15,231 | $ 13,658 | $ 11,407 | $ 10,000 | $ 30,213 |