Shareholder Report, Line Graph (Details) 74200010800_Franklin Biotechnology Discovery Fund_Class C_TSR Annual {Class C} - USD ($) |
12 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Apr. 30, 2025 |
Apr. 30, 2024 |
Apr. 30, 2023 |
Apr. 30, 2022 |
Apr. 30, 2021 |
Apr. 30, 2020 |
Apr. 30, 2019 |
Apr. 30, 2018 |
Apr. 30, 2017 |
Apr. 30, 2016 |
Apr. 30, 2026 |
|
| Class C | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Class C | ||||||||||
| Accumulated Value | $ 14,829 | $ 15,506 | $ 13,276 | $ 12,096 | $ 17,036 | $ 13,813 | $ 11,744 | $ 12,024 | $ 11,914 | $ 10,000 | $ 24,293 |
| Russell 3000 Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | Russell 3000 Index | ||||||||||
| Accumulated Value | 30,227 | 27,133 | 22,186 | 21,857 | 22,560 | 14,948 | 15,106 | 13,406 | 11,858 | 10,000 | $ 39,601 |
| NASDAQ Biotechnology Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | NASDAQ Biotechnology Index | ||||||||||
| Accumulated Value | 15,187 | 14,837 | 14,926 | 13,405 | 17,344 | 13,902 | 11,917 | 11,602 | 11,103 | 10,000 | $ 20,899 |
| S&P 500 Index [Member] | |||||||||||
| Account Value [Line Items] | |||||||||||
| Line Graph and Table Measure Name | S&P 500 Index | ||||||||||
| Accumulated Value | $ 31,574 | $ 28,167 | $ 22,963 | $ 22,367 | $ 22,320 | $ 15,289 | $ 15,158 | $ 13,356 | $ 11,792 | $ 10,000 | $ 41,379 |