v3.25.3
S000070577 [Member] Annual Total Returns
12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Putnam Sustainable Retirement 2065 Fund | Class A        
Prospectus [Line Items]        
Annual Return [Percent] 16.53% 23.25% (16.33%) 17.93%