Class K [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 |
|
| Class K | BLACKROCK HEALTH SCIENCES OPPORTUNITIES PORTFOLIO | Class K | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 16.38% | 4.22% | 3.93% | (5.60%) | 12.20% | 19.91% | 25.73% | 8.39% | 25.30% | (5.85%) |