v3.25.3
Shareholder Report, Line Graph (Details) - USD ($)
12 Months Ended 36 Months Ended 48 Months Ended 96 Months Ended 108 Months Ended 132 Months Ended
Aug. 31, 2025
Aug. 31, 2025
Aug. 31, 2025
Aug. 31, 2025
Aug. 31, 2025
Aug. 31, 2025
C000235234_LG_ClassMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® Sustainable Low Duration Bond Fund</span>      
C000235234_ClassMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value $ 10,000          
C000235234_ClassMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 10,001          
C000235234_ClassMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,404          
C000235234_ClassMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 11,006          
C000235234_LG_1_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg US Treasury Bill: 6-9 Months Index</span>      
C000235234_1_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235234_1_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,990          
C000235234_1_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,301          
C000235234_1_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,854          
C000235234_LG_2_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span>      
C000235234_2_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235234_2_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,696          
C000235234_2_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,581          
C000235234_2_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,280          
C000235233_LG_ClassMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class Z</span>      
C000235233_ClassMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235233_ClassMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 10,003          
C000235233_ClassMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,411          
C000235233_ClassMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 11,019          
C000235233_LG_1_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg US Treasury Bill: 6-9 Months Index</span>      
C000235233_1_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235233_1_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,990          
C000235233_1_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,301          
C000235233_1_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,854          
C000235233_LG_2_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span>      
C000235233_2_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235233_2_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,696          
C000235233_2_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,581          
C000235233_2_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,280          
C000235230_LG_ClassMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class M</span>      
C000235230_ClassMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 9,850          
C000235230_ClassMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,845          
C000235230_ClassMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,224          
C000235230_ClassMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,796          
C000235230_LG_1_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg US Treasury Bill: 6-9 Months Index</span>      
C000235230_1_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235230_1_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,990          
C000235230_1_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,301          
C000235230_1_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,854          
C000235230_LG_2_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span>      
C000235230_2_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235230_2_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,696          
C000235230_2_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,581          
C000235230_2_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,280          
C000235232_LG_ClassMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class I</span>      
C000235232_ClassMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235232_ClassMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 10,001          
C000235232_ClassMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,404          
C000235232_ClassMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 11,006          
C000235232_LG_1_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg US Treasury Bill: 6-9 Months Index</span>      
C000235232_1_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235232_1_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,990          
C000235232_1_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,301          
C000235232_1_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,854          
C000235232_LG_2_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span>      
C000235232_2_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235232_2_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,696          
C000235232_2_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,581          
C000235232_2_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,280          
C000235231_LG_ClassMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class C</span>      
C000235231_ClassMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235231_ClassMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,957          
C000235231_ClassMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,253          
C000235231_ClassMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,735          
C000235231_LG_1_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg US Treasury Bill: 6-9 Months Index</span>      
C000235231_1_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235231_1_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,990          
C000235231_1_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,301          
C000235231_1_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,854          
C000235231_LG_2_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span>      
C000235231_2_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235231_2_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,696          
C000235231_2_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,581          
C000235231_2_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,280          
C000235229_LG_ClassMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class A</span>      
C000235229_ClassMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 9,850          
C000235229_ClassMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,845          
C000235229_ClassMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,221          
C000235229_ClassMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,791          
C000235229_LG_1_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg US Treasury Bill: 6-9 Months Index</span>      
C000235229_1_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235229_1_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,990          
C000235229_1_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 10,301          
C000235229_1_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,854          
C000235229_LG_2_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span>      
C000235229_2_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235229_2_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,696          
C000235229_2_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,581          
C000235229_2_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,280          
C000235217_LG_ClassMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® Sustainable Core Plus Bond Fund</span>      
C000235217_ClassMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235217_ClassMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,592          
C000235217_ClassMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,547          
C000235217_ClassMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,275          
C000235217_LG_1_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index</span>      
C000235217_1_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235217_1_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,702          
C000235217_1_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,590          
C000235217_1_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,286          
C000235217_LG_2_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span>      
C000235217_2_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235217_2_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,696          
C000235217_2_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,581          
C000235217_2_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,280          
C000235220_LG_ClassMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class Z</span>      
C000235220_ClassMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235220_ClassMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,595          
C000235220_ClassMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,559          
C000235220_ClassMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,308          
C000235220_LG_1_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index</span>      
C000235220_1_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235220_1_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,702          
C000235220_1_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,590          
C000235220_1_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,286          
C000235220_LG_2_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span>      
C000235220_2_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235220_2_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,696          
C000235220_2_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,581          
C000235220_2_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,280          
C000235222_LG_ClassMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class M</span>      
C000235222_ClassMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 9,600          
C000235222_ClassMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,202          
C000235222_ClassMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,139          
C000235222_ClassMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 9,814          
C000235222_LG_1_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index</span>      
C000235222_1_AdditionalIndexMember_AsOf_2022Member            
Account Value [Line Items]            
Accumulated Value 10,000          
C000235222_1_AdditionalIndexMember_AsOf_2023Member            
Account Value [Line Items]            
Accumulated Value 9,702          
C000235222_1_AdditionalIndexMember_AsOf_2024Member            
Account Value [Line Items]            
Accumulated Value 9,590          
C000235222_1_AdditionalIndexMember_AsOf_2025Member            
Account Value [Line Items]            
Accumulated Value 10,286          
C000235222_LG_2_AdditionalIndexMember_4YRMember            
Account Value [Line Items]            
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Line Graph and Table Measure Name           <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span>
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Line Graph and Table Measure Name   <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. 3-6 Month Treasury Bill Index</span>        
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Line Graph and Table Measure Name   <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span>        
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