v3.25.3
S000070577 [Member] Expense Example - Putnam Sustainable Retirement 2065 Fund
Jul. 31, 2025
USD ($)
Class R3  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 102
Expense Example, with Redemption, 3 Years 318
Expense Example, with Redemption, 5 Years 2,992
Expense Example, with Redemption, 10 Years 8,037
Class Y  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 61
Expense Example, with Redemption, 3 Years 192
Expense Example, with Redemption, 5 Years 2,824
Expense Example, with Redemption, 10 Years 7,863
Class R6  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 51
Expense Example, with Redemption, 3 Years 160
Expense Example, with Redemption, 5 Years 2,781
Expense Example, with Redemption, 10 Years 7,816
Class R5  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 61
Expense Example, with Redemption, 3 Years 192
Expense Example, with Redemption, 5 Years 2,824
Expense Example, with Redemption, 10 Years 7,863
Class R4  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 77
Expense Example, with Redemption, 3 Years 240
Expense Example, with Redemption, 5 Years 2,887
Expense Example, with Redemption, 10 Years 7,929
Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 657
Expense Example, with Redemption, 3 Years 831
Expense Example, with Redemption, 5 Years 3,338
Expense Example, with Redemption, 10 Years 8,093
Class R  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 127
Expense Example, with Redemption, 3 Years 396
Expense Example, with Redemption, 5 Years 3,095
Expense Example, with Redemption, 10 Years 8,142
Class C  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 263
Expense Example, with Redemption, 3 Years 505
Expense Example, with Redemption, 5 Years 3,240
Expense Example, with Redemption, 10 Years $ 8,202