S000000585 [Member] Annual Total Returns - BARON OPPORTUNITY FUND |
12 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2025 |
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Prospectus [Line Items] | |||||||||||
| Annual Return Caption [Text] | Average Annual Total Returns for the periods ended December 31, 2025 | ||||||||||
| BARON OPPORTUNITY FUND | |||||||||||
| Prospectus [Line Items] | |||||||||||
| Annual Return [Percent] | 19.43% | 39.89% | 49.55% | (42.96%) | 12.01% | 88.75% | 40.29% | 8.05% | 40.51% | (4.84%) | |