S000003995 [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 2050 Fund | Class A Shares | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 12.62% | 14.80% | 20.74% | (15.37%) | 16.28% | 13.15% | 20.07% | (9.61%) | 19.91% | 6.81% |