S000000853 [Member] Annual Total Returns |
12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
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 |
|
| Parnassus Mid Cap Fund | Investor Shares | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 12.85% | 9.99% | 12.67% | (21.56%) | 16.39% | 14.88% | 28.75% | (6.64%) | 15.79% | 16.07% |