S000030470 [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 |
|
| Putnam Sustainable Retirement 2055 Fund | Class A | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 13.12% | 15.29% | 22.02% | (15.90%) | 17.14% | 13.87% | 20.44% | (9.76%) | 20.44% | 6.77% |