v3.26.1
Shareholder Report, Line Graph (Details) 190988_Buffalo International 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 International Fund Institutional Class
Accumulated Value $ 363,233 $ 370,684 $ 333,722 $ 334,031 $ 327,223 $ 215,113 $ 250,000 $ 397,164
FTSE Global All Cap ex US Index [Member]                
Account Value [Line Items]                
Line Graph and Table Measure Name               FTSE Global All Cap ex US Index
Accumulated Value 352,550 331,809 291,815 308,474 309,832 203,358 250,000 $ 443,718
FTSE All-World ex US Index [Member]                
Account Value [Line Items]                
Line Graph and Table Measure Name               FTSE All-World ex US Index
Accumulated Value $ 355,596 $ 333,437 $ 292,513 $ 307,323 $ 309,158 $ 204,783 $ 250,000 $ 446,491