S000000586 [Member] Annual Total Returns - BARON FIFTH AVENUE GROWTH 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 FIFTH AVENUE GROWTH FUND | |||||||||||
| Prospectus [Line Items] | |||||||||||
| Annual Return [Percent] | 18.00% | 37.38% | 57.20% | (50.62%) | 10.92% | 50.42% | 33.97% | 1.10% | 40.64% | (2.06%) | |