v3.26.3
Shareholder Report, Holdings (Details)
Aug. 31, 2026
Fidelity Advisor Investment Grade Bond Fund - Class M | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 34.30%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 10.30%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.30%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 61.00%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.40%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.30%
Fidelity Advisor Investment Grade Bond Fund - Class M | United States  
Holdings [Line Items]  
Percent of Net Asset Value 91.40%
Fidelity Advisor Investment Grade Bond Fund - Class M | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Investment Grade Bond Fund - Class M | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Advisor Investment Grade Bond Fund - Class M | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Advisor Investment Grade Bond Fund - Class M | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Advisor Investment Grade Bond Fund - Class M | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Investment Grade Bond Fund - Class M | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Investment Grade Bond Fund - Class M | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Investment Grade Bond Fund - Class M | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class M | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 44.60%
Fidelity Advisor Investment Grade Bond Fund - Class M | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.30%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.40%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.20%
Fidelity Advisor Investment Grade Bond Fund - Class M | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.70%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Investment Grade Bond Fund - Class M | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 34.30%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 10.30%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.30%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 61.00%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.40%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.30%
Fidelity Advisor Investment Grade Bond Fund - Class C | United States  
Holdings [Line Items]  
Percent of Net Asset Value 91.40%
Fidelity Advisor Investment Grade Bond Fund - Class C | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Investment Grade Bond Fund - Class C | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Advisor Investment Grade Bond Fund - Class C | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Advisor Investment Grade Bond Fund - Class C | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Advisor Investment Grade Bond Fund - Class C | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Investment Grade Bond Fund - Class C | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Investment Grade Bond Fund - Class C | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Investment Grade Bond Fund - Class C | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class C | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 44.60%
Fidelity Advisor Investment Grade Bond Fund - Class C | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.30%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.40%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.20%
Fidelity Advisor Investment Grade Bond Fund - Class C | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.70%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Investment Grade Bond Fund - Class C | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Short-Term Bond Fund - Class C | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Advisor Short-Term Bond Fund - Class C | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class C | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Short-Term Bond Fund - Class C | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class C | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Short-Term Bond Fund - Class C | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class C | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class C | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class C | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Short-Term Bond Fund - Class C | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Short-Term Bond Fund - Class C | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.30%
Fidelity Advisor Short-Term Bond Fund - Class C | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.90%
Fidelity Advisor Short-Term Bond Fund - Class C | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class C | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 21.30%
Fidelity Advisor Short-Term Bond Fund - Class C | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.60%
Fidelity Advisor Short-Term Bond Fund - Class C | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class C | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
Fidelity Advisor Short-Term Bond Fund - Class C | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Short-Term Bond Fund - Class C | United States  
Holdings [Line Items]  
Percent of Net Asset Value 78.60%
Fidelity Advisor Short-Term Bond Fund - Class C | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
Fidelity Advisor Short-Term Bond Fund - Class C | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class C | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Short-Term Bond Fund - Class C | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity Advisor Short-Term Bond Fund - Class C | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Advisor Short-Term Bond Fund - Class C | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Short-Term Bond Fund - Class C | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
Fidelity Advisor Short-Term Bond Fund - Class C | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Advisor Short-Term Bond Fund - Class C | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class C | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Advisor Short-Term Bond Fund - Class C | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 39.10%
Fidelity Advisor Short-Term Bond Fund - Class C | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class C | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Advisor Short-Term Bond Fund - Class C | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Short-Term Bond Fund - Class C | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Short-Term Bond Fund - Class C | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Tactical Bond Fund - Class Z | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 27.10%
Fidelity Advisor Tactical Bond Fund - Class Z | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 19.00%
Fidelity Advisor Tactical Bond Fund - Class Z | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class Z | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Tactical Bond Fund - Class Z | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Tactical Bond Fund - Class Z | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class Z | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class Z | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class Z | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Tactical Bond Fund - Class Z | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Tactical Bond Fund - Class Z | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Advisor Tactical Bond Fund - Class Z | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Tactical Bond Fund - Class Z | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class Z | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity Advisor Tactical Bond Fund - Class Z | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
Fidelity Advisor Tactical Bond Fund - Class Z | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Advisor Tactical Bond Fund - Class Z | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 11.90%
Fidelity Advisor Tactical Bond Fund - Class Z | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class Z | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity Advisor Tactical Bond Fund - Class Z | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class Z | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Advisor Tactical Bond Fund - Class Z | United States  
Holdings [Line Items]  
Percent of Net Asset Value 83.80%
Fidelity Advisor Tactical Bond Fund - Class Z | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Tactical Bond Fund - Class Z | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Advisor Tactical Bond Fund - Class Z | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class Z | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Tactical Bond Fund - Class Z | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Tactical Bond Fund - Class Z | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class Z | Brazil  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Tactical Bond Fund - Class Z | Dominican Republic  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class Z | Israel  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Tactical Bond Fund - Class Z | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Advisor Tactical Bond Fund - Class Z | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Advisor Tactical Bond Fund - Class Z | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Advisor Tactical Bond Fund - Class Z | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class Z | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Advisor Tactical Bond Fund - Class Z | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.50%
Fidelity Advisor Tactical Bond Fund - Class Z | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.00%
Fidelity Advisor Tactical Bond Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class Z | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class Z | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Tactical Bond Fund - Class Z | AAAlternativeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Tactical Bond Fund - Class Z | AAMunicipalSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class Z | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class A | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 27.10%
Fidelity Advisor Tactical Bond Fund - Class A | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 19.00%
Fidelity Advisor Tactical Bond Fund - Class A | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class A | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Tactical Bond Fund - Class A | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Tactical Bond Fund - Class A | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class A | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class A | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class A | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Tactical Bond Fund - Class A | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Tactical Bond Fund - Class A | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Advisor Tactical Bond Fund - Class A | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Tactical Bond Fund - Class A | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class A | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity Advisor Tactical Bond Fund - Class A | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
Fidelity Advisor Tactical Bond Fund - Class A | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Advisor Tactical Bond Fund - Class A | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 11.90%
Fidelity Advisor Tactical Bond Fund - Class A | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class A | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity Advisor Tactical Bond Fund - Class A | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class A | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Advisor Tactical Bond Fund - Class A | United States  
Holdings [Line Items]  
Percent of Net Asset Value 83.80%
Fidelity Advisor Tactical Bond Fund - Class A | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Tactical Bond Fund - Class A | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Advisor Tactical Bond Fund - Class A | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class A | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Tactical Bond Fund - Class A | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Tactical Bond Fund - Class A | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class A | Brazil  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Tactical Bond Fund - Class A | Dominican Republic  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class A | Israel  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Tactical Bond Fund - Class A | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Advisor Tactical Bond Fund - Class A | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Advisor Tactical Bond Fund - Class A | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Advisor Tactical Bond Fund - Class A | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class A | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Advisor Tactical Bond Fund - Class A | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.50%
Fidelity Advisor Tactical Bond Fund - Class A | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.00%
Fidelity Advisor Tactical Bond Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class A | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class A | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Tactical Bond Fund - Class A | AAAlternativeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Tactical Bond Fund - Class A | AAMunicipalSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class A | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity SAI Sustainable Core Plus Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 35.80%
Fidelity SAI Sustainable Core Plus Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
Fidelity SAI Sustainable Core Plus Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
Fidelity SAI Sustainable Core Plus Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity SAI Sustainable Core Plus Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity SAI Sustainable Core Plus Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity SAI Sustainable Core Plus Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity SAI Sustainable Core Plus Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity SAI Sustainable Core Plus Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity SAI Sustainable Core Plus Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity SAI Sustainable Core Plus Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 64.30%
Fidelity SAI Sustainable Core Plus Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity SAI Sustainable Core Plus Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity SAI Sustainable Core Plus Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.00%
Fidelity SAI Sustainable Core Plus Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.40%
Fidelity SAI Sustainable Core Plus Bond Fund | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.00%
Fidelity SAI Sustainable Core Plus Bond Fund | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity SAI Sustainable Core Plus Bond Fund | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity SAI Sustainable Core Plus Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity SAI Sustainable Core Plus Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity SAI Sustainable Core Plus Bond Fund | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity SAI Sustainable Core Plus Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 86.60%
Fidelity SAI Sustainable Core Plus Bond Fund | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity SAI Sustainable Core Plus Bond Fund | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity SAI Sustainable Core Plus Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity SAI Sustainable Core Plus Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity SAI Sustainable Core Plus Bond Fund | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity SAI Sustainable Core Plus Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity SAI Sustainable Core Plus Bond Fund | France  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity SAI Sustainable Core Plus Bond Fund | Italy  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity SAI Sustainable Core Plus Bond Fund | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity SAI Sustainable Core Plus Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 47.20%
Fidelity SAI Sustainable Core Plus Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 25.20%
Fidelity SAI Sustainable Core Plus Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 17.10%
Fidelity SAI Sustainable Core Plus Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
Fidelity SAI Sustainable Core Plus Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity SAI Sustainable Core Plus Bond Fund | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity SAI Sustainable Core Plus Bond Fund | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity SAI Sustainable Core Plus Bond Fund | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity SAI Sustainable Core Plus Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity SAI Sustainable Core Plus Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity SAI Sustainable Core Plus Bond Fund | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity SAI Sustainable Core Plus Bond Fund | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Short-Term Bond Fund - Class I | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Advisor Short-Term Bond Fund - Class I | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class I | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Short-Term Bond Fund - Class I | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class I | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Short-Term Bond Fund - Class I | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class I | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class I | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class I | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Short-Term Bond Fund - Class I | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Short-Term Bond Fund - Class I | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.30%
Fidelity Advisor Short-Term Bond Fund - Class I | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.90%
Fidelity Advisor Short-Term Bond Fund - Class I | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class I | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 21.30%
Fidelity Advisor Short-Term Bond Fund - Class I | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.60%
Fidelity Advisor Short-Term Bond Fund - Class I | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class I | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
Fidelity Advisor Short-Term Bond Fund - Class I | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Short-Term Bond Fund - Class I | United States  
Holdings [Line Items]  
Percent of Net Asset Value 78.60%
Fidelity Advisor Short-Term Bond Fund - Class I | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
Fidelity Advisor Short-Term Bond Fund - Class I | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class I | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Short-Term Bond Fund - Class I | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity Advisor Short-Term Bond Fund - Class I | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Advisor Short-Term Bond Fund - Class I | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Short-Term Bond Fund - Class I | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
Fidelity Advisor Short-Term Bond Fund - Class I | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Advisor Short-Term Bond Fund - Class I | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class I | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Advisor Short-Term Bond Fund - Class I | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 39.10%
Fidelity Advisor Short-Term Bond Fund - Class I | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class I | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Advisor Short-Term Bond Fund - Class I | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Short-Term Bond Fund - Class I | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Short-Term Bond Fund - Class I | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.90%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 21.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.60%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Short-Term Bond Fund - Class Z | United States  
Holdings [Line Items]  
Percent of Net Asset Value 78.60%
Fidelity Advisor Short-Term Bond Fund - Class Z | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class Z | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Short-Term Bond Fund - Class Z | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity Advisor Short-Term Bond Fund - Class Z | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Advisor Short-Term Bond Fund - Class Z | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Short-Term Bond Fund - Class Z | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Advisor Short-Term Bond Fund - Class Z | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Advisor Short-Term Bond Fund - Class Z | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 39.10%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity SAI Low Duration Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 19.10%
Fidelity SAI Low Duration Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
Fidelity SAI Low Duration Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity SAI Low Duration Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity SAI Low Duration Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity SAI Low Duration Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity SAI Low Duration Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity SAI Low Duration Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity SAI Low Duration Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity SAI Low Duration Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity SAI Low Duration Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 30.50%
Fidelity SAI Low Duration Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.70%
Fidelity SAI Low Duration Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity SAI Low Duration Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 30.60%
Fidelity SAI Low Duration Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity SAI Low Duration Bond Fund | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity SAI Low Duration Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity SAI Low Duration Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.10%
Fidelity SAI Low Duration Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 75.20%
Fidelity SAI Low Duration Bond Fund | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity SAI Low Duration Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity SAI Low Duration Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity SAI Low Duration Bond Fund | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity SAI Low Duration Bond Fund | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity SAI Low Duration Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity SAI Low Duration Bond Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity SAI Low Duration Bond Fund | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity SAI Low Duration Bond Fund | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity SAI Low Duration Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 30.50%
Fidelity SAI Low Duration Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 47.90%
Fidelity SAI Low Duration Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.50%
Fidelity SAI Low Duration Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity SAI Low Duration Bond Fund | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity SAI Low Duration Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.10%
Fidelity SAI Total Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 27.60%
Fidelity SAI Total Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.90%
Fidelity SAI Total Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity SAI Total Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity SAI Total Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity SAI Total Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity SAI Total Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity SAI Total Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity SAI Total Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity SAI Total Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity SAI Total Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 55.40%
Fidelity SAI Total Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity SAI Total Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity SAI Total Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 6.80%
Fidelity SAI Total Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.40%
Fidelity SAI Total Bond Fund | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.00%
Fidelity SAI Total Bond Fund | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity SAI Total Bond Fund | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity SAI Total Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.90%
Fidelity SAI Total Bond Fund | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity SAI Total Bond Fund | QDDMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity SAI Total Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 87.70%
Fidelity SAI Total Bond Fund | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity SAI Total Bond Fund | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity SAI Total Bond Fund | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity SAI Total Bond Fund | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity SAI Total Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity SAI Total Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity SAI Total Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity SAI Total Bond Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity SAI Total Bond Fund | France  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity SAI Total Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 39.50%
Fidelity SAI Total Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 23.00%
Fidelity SAI Total Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.90%
Fidelity SAI Total Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.50%
Fidelity SAI Total Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.80%
Fidelity SAI Total Bond Fund | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity SAI Total Bond Fund | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity SAI Total Bond Fund | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity SAI Total Bond Fund | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity SAI Total Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity SAI Total Bond Fund | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity SAI Total Bond Fund | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Short-Term Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Short-Term Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Short-Term Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Short-Term Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Short-Term Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Short-Term Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Short-Term Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Short-Term Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Short-Term Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Short-Term Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Short-Term Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.30%
Fidelity Short-Term Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.90%
Fidelity Short-Term Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Short-Term Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 21.30%
Fidelity Short-Term Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.60%
Fidelity Short-Term Bond Fund | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Short-Term Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
Fidelity Short-Term Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Short-Term Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 78.60%
Fidelity Short-Term Bond Fund | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
Fidelity Short-Term Bond Fund | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Short-Term Bond Fund | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Short-Term Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity Short-Term Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Short-Term Bond Fund | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Short-Term Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
Fidelity Short-Term Bond Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Short-Term Bond Fund | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Short-Term Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Short-Term Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 39.10%
Fidelity Short-Term Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Short-Term Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Short-Term Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Short-Term Bond Fund | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Short-Term Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Short-Term Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity SAI Enhanced Core Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 30.30%
Fidelity SAI Enhanced Core Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 13.20%
Fidelity SAI Enhanced Core Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
Fidelity SAI Enhanced Core Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 6.60%
Fidelity SAI Enhanced Core Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity SAI Enhanced Core Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity SAI Enhanced Core Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity SAI Enhanced Core Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity SAI Enhanced Core Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity SAI Enhanced Core Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity SAI Enhanced Core Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 68.10%
Fidelity SAI Enhanced Core Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity SAI Enhanced Core Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity SAI Enhanced Core Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.30%
Fidelity SAI Enhanced Core Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 17.00%
Fidelity SAI Enhanced Core Bond Fund | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity SAI Enhanced Core Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity SAI Enhanced Core Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 91.90%
Fidelity SAI Enhanced Core Bond Fund | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity SAI Enhanced Core Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity SAI Enhanced Core Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity SAI Enhanced Core Bond Fund | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity SAI Enhanced Core Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity SAI Enhanced Core Bond Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity SAI Enhanced Core Bond Fund | Korea, Republic of  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity SAI Enhanced Core Bond Fund | Spain  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity SAI Enhanced Core Bond Fund | Australia  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity SAI Enhanced Core Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 41.70%
Fidelity SAI Enhanced Core Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 32.50%
Fidelity SAI Enhanced Core Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 26.00%
Fidelity SAI Enhanced Core Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity SAI Enhanced Core Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity SAI Enhanced Core Bond Fund | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity SAI Enhanced Core Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity SAI Enhanced Core Bond Fund | AAMunicipalSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity SAI Enhanced Core Bond Fund | AAUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Tactical Bond Fund - Class M | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 27.10%
Fidelity Advisor Tactical Bond Fund - Class M | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 19.00%
Fidelity Advisor Tactical Bond Fund - Class M | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class M | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Tactical Bond Fund - Class M | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Tactical Bond Fund - Class M | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class M | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class M | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class M | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Tactical Bond Fund - Class M | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Tactical Bond Fund - Class M | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Advisor Tactical Bond Fund - Class M | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Tactical Bond Fund - Class M | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class M | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity Advisor Tactical Bond Fund - Class M | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
Fidelity Advisor Tactical Bond Fund - Class M | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Advisor Tactical Bond Fund - Class M | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 11.90%
Fidelity Advisor Tactical Bond Fund - Class M | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class M | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity Advisor Tactical Bond Fund - Class M | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class M | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Advisor Tactical Bond Fund - Class M | United States  
Holdings [Line Items]  
Percent of Net Asset Value 83.80%
Fidelity Advisor Tactical Bond Fund - Class M | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Tactical Bond Fund - Class M | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Advisor Tactical Bond Fund - Class M | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class M | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Tactical Bond Fund - Class M | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Tactical Bond Fund - Class M | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class M | Brazil  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Tactical Bond Fund - Class M | Dominican Republic  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class M | Israel  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Tactical Bond Fund - Class M | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Advisor Tactical Bond Fund - Class M | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Advisor Tactical Bond Fund - Class M | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Advisor Tactical Bond Fund - Class M | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class M | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Advisor Tactical Bond Fund - Class M | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.50%
Fidelity Advisor Tactical Bond Fund - Class M | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.00%
Fidelity Advisor Tactical Bond Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class M | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class M | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Tactical Bond Fund - Class M | AAAlternativeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Tactical Bond Fund - Class M | AAMunicipalSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class M | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class I | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 27.10%
Fidelity Advisor Tactical Bond Fund - Class I | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 19.00%
Fidelity Advisor Tactical Bond Fund - Class I | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class I | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Tactical Bond Fund - Class I | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Tactical Bond Fund - Class I | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class I | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class I | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class I | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Tactical Bond Fund - Class I | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Tactical Bond Fund - Class I | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Advisor Tactical Bond Fund - Class I | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Tactical Bond Fund - Class I | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class I | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity Advisor Tactical Bond Fund - Class I | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
Fidelity Advisor Tactical Bond Fund - Class I | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Advisor Tactical Bond Fund - Class I | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 11.90%
Fidelity Advisor Tactical Bond Fund - Class I | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class I | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity Advisor Tactical Bond Fund - Class I | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class I | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Advisor Tactical Bond Fund - Class I | United States  
Holdings [Line Items]  
Percent of Net Asset Value 83.80%
Fidelity Advisor Tactical Bond Fund - Class I | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Tactical Bond Fund - Class I | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Advisor Tactical Bond Fund - Class I | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class I | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Tactical Bond Fund - Class I | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Tactical Bond Fund - Class I | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class I | Brazil  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Tactical Bond Fund - Class I | Dominican Republic  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class I | Israel  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Tactical Bond Fund - Class I | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Advisor Tactical Bond Fund - Class I | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Advisor Tactical Bond Fund - Class I | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Advisor Tactical Bond Fund - Class I | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class I | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Advisor Tactical Bond Fund - Class I | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.50%
Fidelity Advisor Tactical Bond Fund - Class I | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.00%
Fidelity Advisor Tactical Bond Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class I | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class I | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Tactical Bond Fund - Class I | AAAlternativeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Tactical Bond Fund - Class I | AAMunicipalSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class I | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class M | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Advisor Short-Term Bond Fund - Class M | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class M | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Short-Term Bond Fund - Class M | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class M | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Short-Term Bond Fund - Class M | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class M | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class M | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class M | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Short-Term Bond Fund - Class M | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Short-Term Bond Fund - Class M | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.30%
Fidelity Advisor Short-Term Bond Fund - Class M | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.90%
Fidelity Advisor Short-Term Bond Fund - Class M | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class M | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 21.30%
Fidelity Advisor Short-Term Bond Fund - Class M | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.60%
Fidelity Advisor Short-Term Bond Fund - Class M | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class M | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
Fidelity Advisor Short-Term Bond Fund - Class M | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Short-Term Bond Fund - Class M | United States  
Holdings [Line Items]  
Percent of Net Asset Value 78.60%
Fidelity Advisor Short-Term Bond Fund - Class M | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
Fidelity Advisor Short-Term Bond Fund - Class M | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class M | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Short-Term Bond Fund - Class M | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity Advisor Short-Term Bond Fund - Class M | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Advisor Short-Term Bond Fund - Class M | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Short-Term Bond Fund - Class M | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
Fidelity Advisor Short-Term Bond Fund - Class M | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Advisor Short-Term Bond Fund - Class M | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class M | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Advisor Short-Term Bond Fund - Class M | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 39.10%
Fidelity Advisor Short-Term Bond Fund - Class M | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class M | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Advisor Short-Term Bond Fund - Class M | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Short-Term Bond Fund - Class M | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Short-Term Bond Fund - Class M | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Intermediate Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 41.40%
Fidelity Intermediate Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Intermediate Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Intermediate Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Intermediate Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Intermediate Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Intermediate Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Intermediate Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Intermediate Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Intermediate Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Intermediate Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 41.60%
Fidelity Intermediate Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.60%
Fidelity Intermediate Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Intermediate Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 17.40%
Fidelity Intermediate Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 22.70%
Fidelity Intermediate Bond Fund | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Intermediate Bond Fund | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Intermediate Bond Fund | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Intermediate Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Intermediate Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Intermediate Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 80.40%
Fidelity Intermediate Bond Fund | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Intermediate Bond Fund | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Intermediate Bond Fund | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Intermediate Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Intermediate Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Intermediate Bond Fund | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Intermediate Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Intermediate Bond Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Intermediate Bond Fund | Italy  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Intermediate Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 41.40%
Fidelity Intermediate Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 42.00%
Fidelity Intermediate Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Intermediate Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 11.00%
Fidelity Intermediate Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.60%
Fidelity Intermediate Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Intermediate Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Flex Conservative Income Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 16.20%
Fidelity Flex Conservative Income Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 9.10%
Fidelity Flex Conservative Income Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Flex Conservative Income Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Flex Conservative Income Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Flex Conservative Income Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Flex Conservative Income Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Flex Conservative Income Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Flex Conservative Income Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Flex Conservative Income Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Flex Conservative Income Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 25.30%
Fidelity Flex Conservative Income Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.40%
Fidelity Flex Conservative Income Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
Fidelity Flex Conservative Income Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 30.30%
Fidelity Flex Conservative Income Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.40%
Fidelity Flex Conservative Income Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Flex Conservative Income Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 17.30%
Fidelity Flex Conservative Income Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 82.80%
Fidelity Flex Conservative Income Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 4.60%
Fidelity Flex Conservative Income Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Flex Conservative Income Bond Fund | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Flex Conservative Income Bond Fund | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Flex Conservative Income Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Flex Conservative Income Bond Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 4.60%
Fidelity Flex Conservative Income Bond Fund | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Flex Conservative Income Bond Fund | Australia  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Flex Conservative Income Bond Fund | Denmark  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Flex Conservative Income Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 25.30%
Fidelity Flex Conservative Income Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.00%
Fidelity Flex Conservative Income Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 13.20%
Fidelity Flex Conservative Income Bond Fund | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Flex Conservative Income Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 17.30%
Fidelity Advisor Tactical Bond Fund - Class C | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 27.10%
Fidelity Advisor Tactical Bond Fund - Class C | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 19.00%
Fidelity Advisor Tactical Bond Fund - Class C | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class C | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Tactical Bond Fund - Class C | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Tactical Bond Fund - Class C | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class C | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class C | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class C | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Tactical Bond Fund - Class C | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Tactical Bond Fund - Class C | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Advisor Tactical Bond Fund - Class C | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Tactical Bond Fund - Class C | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class C | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity Advisor Tactical Bond Fund - Class C | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
Fidelity Advisor Tactical Bond Fund - Class C | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Advisor Tactical Bond Fund - Class C | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 11.90%
Fidelity Advisor Tactical Bond Fund - Class C | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class C | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity Advisor Tactical Bond Fund - Class C | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class C | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Advisor Tactical Bond Fund - Class C | United States  
Holdings [Line Items]  
Percent of Net Asset Value 83.80%
Fidelity Advisor Tactical Bond Fund - Class C | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Tactical Bond Fund - Class C | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Advisor Tactical Bond Fund - Class C | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class C | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Tactical Bond Fund - Class C | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Tactical Bond Fund - Class C | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Tactical Bond Fund - Class C | Brazil  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Tactical Bond Fund - Class C | Dominican Republic  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Tactical Bond Fund - Class C | Israel  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Tactical Bond Fund - Class C | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Advisor Tactical Bond Fund - Class C | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Advisor Tactical Bond Fund - Class C | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Advisor Tactical Bond Fund - Class C | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class C | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Advisor Tactical Bond Fund - Class C | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.50%
Fidelity Advisor Tactical Bond Fund - Class C | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.00%
Fidelity Advisor Tactical Bond Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Advisor Tactical Bond Fund - Class C | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Advisor Tactical Bond Fund - Class C | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Tactical Bond Fund - Class C | AAAlternativeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Tactical Bond Fund - Class C | AAMunicipalSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Tactical Bond Fund - Class C | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 34.30%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 10.30%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.30%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 61.00%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.40%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.30%
Fidelity Advisor Investment Grade Bond Fund - Class A | United States  
Holdings [Line Items]  
Percent of Net Asset Value 91.40%
Fidelity Advisor Investment Grade Bond Fund - Class A | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Investment Grade Bond Fund - Class A | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Advisor Investment Grade Bond Fund - Class A | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Advisor Investment Grade Bond Fund - Class A | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Advisor Investment Grade Bond Fund - Class A | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Investment Grade Bond Fund - Class A | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Investment Grade Bond Fund - Class A | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Investment Grade Bond Fund - Class A | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class A | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 44.60%
Fidelity Advisor Investment Grade Bond Fund - Class A | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.30%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.40%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.20%
Fidelity Advisor Investment Grade Bond Fund - Class A | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.70%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Investment Grade Bond Fund - Class A | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity SAI Short-Term Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 40.70%
Fidelity SAI Short-Term Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity SAI Short-Term Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity SAI Short-Term Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity SAI Short-Term Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity SAI Short-Term Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity SAI Short-Term Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity SAI Short-Term Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity SAI Short-Term Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity SAI Short-Term Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity SAI Short-Term Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 40.70%
Fidelity SAI Short-Term Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.40%
Fidelity SAI Short-Term Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity SAI Short-Term Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 20.10%
Fidelity SAI Short-Term Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 19.40%
Fidelity SAI Short-Term Bond Fund | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity SAI Short-Term Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 6.10%
Fidelity SAI Short-Term Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity SAI Short-Term Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 79.40%
Fidelity SAI Short-Term Bond Fund | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.10%
Fidelity SAI Short-Term Bond Fund | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity SAI Short-Term Bond Fund | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity SAI Short-Term Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity SAI Short-Term Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity SAI Short-Term Bond Fund | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity SAI Short-Term Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity SAI Short-Term Bond Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity SAI Short-Term Bond Fund | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity SAI Short-Term Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 40.70%
Fidelity SAI Short-Term Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 41.20%
Fidelity SAI Short-Term Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity SAI Short-Term Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.70%
Fidelity SAI Short-Term Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity SAI Short-Term Bond Fund | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity SAI Short-Term Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Tactical Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 27.10%
Fidelity Tactical Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 19.00%
Fidelity Tactical Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Tactical Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Tactical Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Tactical Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Tactical Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Tactical Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Tactical Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Tactical Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Tactical Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Tactical Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Tactical Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Tactical Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity Tactical Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
Fidelity Tactical Bond Fund | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Tactical Bond Fund | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 11.90%
Fidelity Tactical Bond Fund | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Tactical Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity Tactical Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Tactical Bond Fund | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Tactical Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 83.80%
Fidelity Tactical Bond Fund | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Tactical Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Tactical Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Tactical Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Tactical Bond Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Tactical Bond Fund | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Tactical Bond Fund | Brazil  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Tactical Bond Fund | Dominican Republic  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Tactical Bond Fund | Israel  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Tactical Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.10%
Fidelity Tactical Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Tactical Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Tactical Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Tactical Bond Fund | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Tactical Bond Fund | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.50%
Fidelity Tactical Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.00%
Fidelity Tactical Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Tactical Bond Fund | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Tactical Bond Fund | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Tactical Bond Fund | AAAlternativeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Tactical Bond Fund | AAMunicipalSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Tactical Bond Fund | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 34.30%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 10.30%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.30%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 61.00%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.40%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.30%
Fidelity Advisor Investment Grade Bond Fund - Class Z | United States  
Holdings [Line Items]  
Percent of Net Asset Value 91.40%
Fidelity Advisor Investment Grade Bond Fund - Class Z | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Investment Grade Bond Fund - Class Z | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Advisor Investment Grade Bond Fund - Class Z | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Advisor Investment Grade Bond Fund - Class Z | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Advisor Investment Grade Bond Fund - Class Z | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Investment Grade Bond Fund - Class Z | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Investment Grade Bond Fund - Class Z | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Investment Grade Bond Fund - Class Z | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class Z | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 44.60%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.30%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.40%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.20%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.70%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 34.30%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 10.30%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.30%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 61.00%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.40%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.30%
Fidelity Advisor Investment Grade Bond Fund - Class I | United States  
Holdings [Line Items]  
Percent of Net Asset Value 91.40%
Fidelity Advisor Investment Grade Bond Fund - Class I | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Investment Grade Bond Fund - Class I | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Advisor Investment Grade Bond Fund - Class I | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Advisor Investment Grade Bond Fund - Class I | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Advisor Investment Grade Bond Fund - Class I | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Investment Grade Bond Fund - Class I | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Investment Grade Bond Fund - Class I | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Investment Grade Bond Fund - Class I | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class I | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 44.60%
Fidelity Advisor Investment Grade Bond Fund - Class I | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.30%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.40%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.20%
Fidelity Advisor Investment Grade Bond Fund - Class I | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.70%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Investment Grade Bond Fund - Class I | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Short-Term Bond Fund - Class A | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Advisor Short-Term Bond Fund - Class A | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class A | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Short-Term Bond Fund - Class A | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class A | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Short-Term Bond Fund - Class A | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class A | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class A | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Short-Term Bond Fund - Class A | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Short-Term Bond Fund - Class A | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Advisor Short-Term Bond Fund - Class A | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.30%
Fidelity Advisor Short-Term Bond Fund - Class A | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.90%
Fidelity Advisor Short-Term Bond Fund - Class A | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class A | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 21.30%
Fidelity Advisor Short-Term Bond Fund - Class A | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.60%
Fidelity Advisor Short-Term Bond Fund - Class A | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class A | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
Fidelity Advisor Short-Term Bond Fund - Class A | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Advisor Short-Term Bond Fund - Class A | United States  
Holdings [Line Items]  
Percent of Net Asset Value 78.60%
Fidelity Advisor Short-Term Bond Fund - Class A | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
Fidelity Advisor Short-Term Bond Fund - Class A | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Short-Term Bond Fund - Class A | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Short-Term Bond Fund - Class A | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity Advisor Short-Term Bond Fund - Class A | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Advisor Short-Term Bond Fund - Class A | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Short-Term Bond Fund - Class A | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
Fidelity Advisor Short-Term Bond Fund - Class A | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Advisor Short-Term Bond Fund - Class A | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Short-Term Bond Fund - Class A | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Advisor Short-Term Bond Fund - Class A | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 39.10%
Fidelity Advisor Short-Term Bond Fund - Class A | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class A | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Advisor Short-Term Bond Fund - Class A | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Short-Term Bond Fund - Class A | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Advisor Short-Term Bond Fund - Class A | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Short-Term Bond Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Investment Grade Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 34.30%
Fidelity Investment Grade Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 10.30%
Fidelity Investment Grade Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.30%
Fidelity Investment Grade Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Investment Grade Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Investment Grade Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Investment Grade Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Investment Grade Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Investment Grade Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Investment Grade Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Investment Grade Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 61.00%
Fidelity Investment Grade Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
Fidelity Investment Grade Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Investment Grade Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Investment Grade Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.40%
Fidelity Investment Grade Bond Fund | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Investment Grade Bond Fund | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Investment Grade Bond Fund | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Investment Grade Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.30%
Fidelity Investment Grade Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 91.40%
Fidelity Investment Grade Bond Fund | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Investment Grade Bond Fund | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Investment Grade Bond Fund | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Investment Grade Bond Fund | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Investment Grade Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Investment Grade Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Investment Grade Bond Fund | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Investment Grade Bond Fund | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Investment Grade Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Investment Grade Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 44.60%
Fidelity Investment Grade Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.30%
Fidelity Investment Grade Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.40%
Fidelity Investment Grade Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.20%
Fidelity Investment Grade Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.70%
Fidelity Investment Grade Bond Fund | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Investment Grade Bond Fund | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Investment Grade Bond Fund | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Investment Grade Bond Fund | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Short-Term Bond Fund - ETF Class | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Short-Term Bond Fund - ETF Class | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Short-Term Bond Fund - ETF Class | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Short-Term Bond Fund - ETF Class | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Short-Term Bond Fund - ETF Class | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Short-Term Bond Fund - ETF Class | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Short-Term Bond Fund - ETF Class | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Short-Term Bond Fund - ETF Class | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Short-Term Bond Fund - ETF Class | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Short-Term Bond Fund - ETF Class | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Short-Term Bond Fund - ETF Class | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.30%
Fidelity Short-Term Bond Fund - ETF Class | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.90%
Fidelity Short-Term Bond Fund - ETF Class | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Short-Term Bond Fund - ETF Class | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 21.30%
Fidelity Short-Term Bond Fund - ETF Class | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.60%
Fidelity Short-Term Bond Fund - ETF Class | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Short-Term Bond Fund - ETF Class | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
Fidelity Short-Term Bond Fund - ETF Class | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Short-Term Bond Fund - ETF Class | United States  
Holdings [Line Items]  
Percent of Net Asset Value 78.60%
Fidelity Short-Term Bond Fund - ETF Class | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
Fidelity Short-Term Bond Fund - ETF Class | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Short-Term Bond Fund - ETF Class | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Short-Term Bond Fund - ETF Class | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity Short-Term Bond Fund - ETF Class | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Short-Term Bond Fund - ETF Class | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Short-Term Bond Fund - ETF Class | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
Fidelity Short-Term Bond Fund - ETF Class | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Short-Term Bond Fund - ETF Class | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Short-Term Bond Fund - ETF Class | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 43.10%
Fidelity Short-Term Bond Fund - ETF Class | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 39.10%
Fidelity Short-Term Bond Fund - ETF Class | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Short-Term Bond Fund - ETF Class | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Short-Term Bond Fund - ETF Class | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Short-Term Bond Fund - ETF Class | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Short-Term Bond Fund - ETF Class | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Short-Term Bond Fund - ETF Class | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%