S000003998 [Member] Expense Example, No Redemption - Putnam Sustainable Retirement 2040 Fund - Class C |
Jul. 31, 2025
USD ($)
|
|---|---|
| Prospectus [Line Items] | |
| Expense Example, No Redemption, 1 Year | $ 163 |
| Expense Example, No Redemption, 3 Years | 505 |
| Expense Example, No Redemption, 5 Years | 998 |
| Expense Example, No Redemption, 10 Years | $ 2,166 |