v3.25.3
S000051718 [Member] Expense Example - Putnam Sustainable Retirement 2060 Fund
Jul. 31, 2025
USD ($)
Class R5 Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 61
Expense Example, with Redemption, 3 Years 192
Expense Example, with Redemption, 5 Years 335
Expense Example, with Redemption, 10 Years 750
Class R4 Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 77
Expense Example, with Redemption, 3 Years 240
Expense Example, with Redemption, 5 Years 417
Expense Example, with Redemption, 10 Years 930
Class R3 Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 102
Expense Example, with Redemption, 3 Years 318
Expense Example, with Redemption, 5 Years 552
Expense Example, with Redemption, 10 Years 1,224
Class A Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 657
Expense Example, with Redemption, 3 Years 831
Expense Example, with Redemption, 5 Years 1,019
Expense Example, with Redemption, 10 Years 1,563
Class C Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 263
Expense Example, with Redemption, 3 Years 505
Expense Example, with Redemption, 5 Years 871
Expense Example, with Redemption, 10 Years 1,699
Class R Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 127
Expense Example, with Redemption, 3 Years 396
Expense Example, with Redemption, 5 Years 686
Expense Example, with Redemption, 10 Years 1,511
Class Y Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 61
Expense Example, with Redemption, 3 Years 192
Expense Example, with Redemption, 5 Years 335
Expense Example, with Redemption, 10 Years 750
Class R6 Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 51
Expense Example, with Redemption, 3 Years 160
Expense Example, with Redemption, 5 Years 279
Expense Example, with Redemption, 10 Years $ 629