v3.26.1
Shareholder Report, Line Graph (Details) 74200166800_Putnam Mortgage Opportunities Fund_Class R6_TSR Annual {Class R6} - USD ($)
12 Months Ended
May 31, 2025
May 31, 2024
May 31, 2023
May 31, 2022
May 31, 2021
May 31, 2020
May 31, 2019
May 31, 2018
May 31, 2017
May 31, 2016
May 31, 2026
Class R6                      
Account Value [Line Items]                      
Line Graph and Table Measure Name                     Class R6
Accumulated Value $ 15,483 $ 14,455 $ 12,746 $ 12,291 $ 12,174 $ 11,214 $ 12,110 $ 11,763 $ 10,967 $ 10,000 $ 16,652
Bloomberg U.S. Aggregate Index [Member]                      
Account Value [Line Items]                      
Line Graph and Table Measure Name                     Bloomberg U.S. Aggregate Index
Accumulated Value 11,258 10,676 10,538 10,769 11,734 11,781 10,768 10,120 10,158 10,000 $ 11,836
ICE BofA U.S. Treasury Bill Index [Member]                      
Account Value [Line Items]                      
Line Graph and Table Measure Name                     ICE BofA U.S. Treasury Bill Index
Accumulated Value 12,112 11,554 10,956 10,624 10,617 10,604 10,403 10,168 10,045 10,000 $ 12,597
Bloomberg U.S. MBS Index [Member]                      
Account Value [Line Items]                      
Line Graph and Table Measure Name                     Bloomberg U.S. MBS Index
Accumulated Value $ 10,798 $ 10,198 $ 10,147 $ 10,426 $ 11,282 $ 11,335 $ 10,641 $ 10,085 $ 10,116 $ 10,000 $ 11,537