Class K Shares [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 LIFEPATH INDEX RETIREMENT FUND | Class K Shares | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 12.48% | 7.15% | 11.47% | (15.20%) | 6.92% | 12.22% | 15.90% | (3.51%) | 10.75% | 5.82% |