S000003999 [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 2035 Fund | Class A | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 9.53% | 11.72% | 15.18% | (10.33%) | 9.67% | 7.64% | 15.42% | (7.80%) | 15.85% | 6.29% |