v3.26.1
Shareholder Report, Average Annual Return (Details) 74200178200_Putnam Floating Rate Income Fund_Class C_TSR Annual {Class C}
12 Months Ended 60 Months Ended 120 Months Ended
Feb. 28, 2026
Feb. 28, 2026
Feb. 28, 2026
Class C      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class C (with sales charge)    
Average Annual Return, Percent 3.98% 5.86% 5.65%
Without Sales Load [Member] | Class C      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Class C    
Average Annual Return, Percent 2.15% 3.98% 3.93%
Bloomberg U.S. Aggregate Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Bloomberg U.S. Aggregate Index    
Average Annual Return, Percent 6.26% 0.42% 1.97%
Morningstar LSTA U.S. Leveraged Loan Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Morningstar LSTA U.S. Leveraged Loan Index    
Average Annual Return, Percent 3.93% 5.82% 5.84%