v3.25.3
Shareholder Report, Holdings (Details)
Aug. 31, 2025
Fidelity Series Investment Grade Securitized Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 28.40%
Fidelity Series Investment Grade Securitized Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 23.60%
Fidelity Series Investment Grade Securitized Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 19.70%
Fidelity Series Investment Grade Securitized Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Series Investment Grade Securitized Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.70%
Fidelity Series Investment Grade Securitized Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.10%
Fidelity Series Investment Grade Securitized Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Series Investment Grade Securitized Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
Fidelity Series Investment Grade Securitized Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Series Investment Grade Securitized Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Series Investment Grade Securitized Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 93.30%
Fidelity Series Investment Grade Securitized Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 11.10%
Fidelity Series Investment Grade Securitized Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Series Investment Grade Securitized Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Series Investment Grade Securitized Fund | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Series Investment Grade Securitized Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Series Investment Grade Securitized Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 100.00%
Fidelity Series Investment Grade Securitized Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Series Investment Grade Securitized Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 90.90%
Fidelity Series Investment Grade Securitized Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 19.10%
Fidelity Series Investment Grade Securitized Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 6.70%
Fidelity Series Investment Grade Securitized Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Series Investment Grade Securitized Fund | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Mortgage Securities Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 31.50%
Fidelity Mortgage Securities Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 25.10%
Fidelity Mortgage Securities Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 23.00%
Fidelity Mortgage Securities Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 13.80%
Fidelity Mortgage Securities Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Mortgage Securities Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Mortgage Securities Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Mortgage Securities Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Mortgage Securities Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Mortgage Securities Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Mortgage Securities Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 102.80%
Fidelity Mortgage Securities Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.10%
Fidelity Mortgage Securities Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Mortgage Securities Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Mortgage Securities Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
Fidelity Mortgage Securities Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Mortgage Securities Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 100.00%
Fidelity Mortgage Securities Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Mortgage Securities Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 98.40%
Fidelity Mortgage Securities Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.60%
Fidelity Mortgage Securities Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Mortgage Securities Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Mortgage Securities Fund | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Mortgage Securities Fund - Class Z | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 31.50%
Fidelity Advisor Mortgage Securities Fund - Class Z | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 25.10%
Fidelity Advisor Mortgage Securities Fund - Class Z | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 23.00%
Fidelity Advisor Mortgage Securities Fund - Class Z | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 13.80%
Fidelity Advisor Mortgage Securities Fund - Class Z | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Advisor Mortgage Securities Fund - Class Z | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Advisor Mortgage Securities Fund - Class Z | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Mortgage Securities Fund - Class Z | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Advisor Mortgage Securities Fund - Class Z | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Advisor Mortgage Securities Fund - Class Z | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Mortgage Securities Fund - Class Z | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 102.80%
Fidelity Advisor Mortgage Securities Fund - Class Z | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.10%
Fidelity Advisor Mortgage Securities Fund - Class Z | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Mortgage Securities Fund - Class Z | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Mortgage Securities Fund - Class Z | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
Fidelity Advisor Mortgage Securities Fund - Class Z | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Mortgage Securities Fund - Class Z | United States  
Holdings [Line Items]  
Percent of Net Asset Value 100.00%
Fidelity Advisor Mortgage Securities Fund - Class Z | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Mortgage Securities Fund - Class Z | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 98.40%
Fidelity Advisor Mortgage Securities Fund - Class Z | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.60%
Fidelity Advisor Mortgage Securities Fund - Class Z | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Mortgage Securities Fund - Class Z | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Mortgage Securities Fund - Class Z | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Mortgage Securities Fund - Class M | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 31.50%
Fidelity Advisor Mortgage Securities Fund - Class M | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 25.10%
Fidelity Advisor Mortgage Securities Fund - Class M | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 23.00%
Fidelity Advisor Mortgage Securities Fund - Class M | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 13.80%
Fidelity Advisor Mortgage Securities Fund - Class M | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Advisor Mortgage Securities Fund - Class M | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Advisor Mortgage Securities Fund - Class M | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Mortgage Securities Fund - Class M | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Advisor Mortgage Securities Fund - Class M | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Advisor Mortgage Securities Fund - Class M | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Mortgage Securities Fund - Class M | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 102.80%
Fidelity Advisor Mortgage Securities Fund - Class M | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.10%
Fidelity Advisor Mortgage Securities Fund - Class M | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Mortgage Securities Fund - Class M | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Mortgage Securities Fund - Class M | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
Fidelity Advisor Mortgage Securities Fund - Class M | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Mortgage Securities Fund - Class M | United States  
Holdings [Line Items]  
Percent of Net Asset Value 100.00%
Fidelity Advisor Mortgage Securities Fund - Class M | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Mortgage Securities Fund - Class M | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 98.40%
Fidelity Advisor Mortgage Securities Fund - Class M | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.60%
Fidelity Advisor Mortgage Securities Fund - Class M | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Mortgage Securities Fund - Class M | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Mortgage Securities Fund - Class M | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Mortgage Securities Fund - Class I | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 31.50%
Fidelity Advisor Mortgage Securities Fund - Class I | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 25.10%
Fidelity Advisor Mortgage Securities Fund - Class I | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 23.00%
Fidelity Advisor Mortgage Securities Fund - Class I | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 13.80%
Fidelity Advisor Mortgage Securities Fund - Class I | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Advisor Mortgage Securities Fund - Class I | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Advisor Mortgage Securities Fund - Class I | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Mortgage Securities Fund - Class I | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Advisor Mortgage Securities Fund - Class I | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Advisor Mortgage Securities Fund - Class I | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Mortgage Securities Fund - Class I | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 102.80%
Fidelity Advisor Mortgage Securities Fund - Class I | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.10%
Fidelity Advisor Mortgage Securities Fund - Class I | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Mortgage Securities Fund - Class I | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Mortgage Securities Fund - Class I | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
Fidelity Advisor Mortgage Securities Fund - Class I | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Mortgage Securities Fund - Class I | United States  
Holdings [Line Items]  
Percent of Net Asset Value 100.00%
Fidelity Advisor Mortgage Securities Fund - Class I | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Mortgage Securities Fund - Class I | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 98.40%
Fidelity Advisor Mortgage Securities Fund - Class I | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.60%
Fidelity Advisor Mortgage Securities Fund - Class I | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Mortgage Securities Fund - Class I | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Mortgage Securities Fund - Class I | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Mortgage Securities Fund - Class C | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 31.50%
Fidelity Advisor Mortgage Securities Fund - Class C | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 25.10%
Fidelity Advisor Mortgage Securities Fund - Class C | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 23.00%
Fidelity Advisor Mortgage Securities Fund - Class C | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 13.80%
Fidelity Advisor Mortgage Securities Fund - Class C | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Advisor Mortgage Securities Fund - Class C | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Advisor Mortgage Securities Fund - Class C | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Mortgage Securities Fund - Class C | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Advisor Mortgage Securities Fund - Class C | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Advisor Mortgage Securities Fund - Class C | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Mortgage Securities Fund - Class C | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 102.80%
Fidelity Advisor Mortgage Securities Fund - Class C | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.10%
Fidelity Advisor Mortgage Securities Fund - Class C | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Mortgage Securities Fund - Class C | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Mortgage Securities Fund - Class C | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
Fidelity Advisor Mortgage Securities Fund - Class C | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Mortgage Securities Fund - Class C | United States  
Holdings [Line Items]  
Percent of Net Asset Value 100.00%
Fidelity Advisor Mortgage Securities Fund - Class C | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Mortgage Securities Fund - Class C | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 98.40%
Fidelity Advisor Mortgage Securities Fund - Class C | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.60%
Fidelity Advisor Mortgage Securities Fund - Class C | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Mortgage Securities Fund - Class C | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Mortgage Securities Fund - Class C | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Mortgage Securities Fund - Class A | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 31.50%
Fidelity Advisor Mortgage Securities Fund - Class A | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 25.10%
Fidelity Advisor Mortgage Securities Fund - Class A | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 23.00%
Fidelity Advisor Mortgage Securities Fund - Class A | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 13.80%
Fidelity Advisor Mortgage Securities Fund - Class A | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Advisor Mortgage Securities Fund - Class A | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Advisor Mortgage Securities Fund - Class A | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Mortgage Securities Fund - Class A | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Advisor Mortgage Securities Fund - Class A | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Advisor Mortgage Securities Fund - Class A | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Mortgage Securities Fund - Class A | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 102.80%
Fidelity Advisor Mortgage Securities Fund - Class A | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 9.10%
Fidelity Advisor Mortgage Securities Fund - Class A | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Mortgage Securities Fund - Class A | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Mortgage Securities Fund - Class A | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.10%
Fidelity Advisor Mortgage Securities Fund - Class A | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Mortgage Securities Fund - Class A | United States  
Holdings [Line Items]  
Percent of Net Asset Value 100.00%
Fidelity Advisor Mortgage Securities Fund - Class A | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Mortgage Securities Fund - Class A | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 98.40%
Fidelity Advisor Mortgage Securities Fund - Class A | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.60%
Fidelity Advisor Mortgage Securities Fund - Class A | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Mortgage Securities Fund - Class A | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Mortgage Securities Fund - Class A | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Limited Term Bond Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Limited Term Bond Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Limited Term Bond Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Limited Term Bond Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Limited Term Bond Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Limited Term Bond Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Limited Term Bond Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Limited Term Bond Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Limited Term Bond Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Limited Term Bond Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Limited Term Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
Fidelity Limited Term Bond Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Limited Term Bond Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Limited Term Bond Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Limited Term Bond Fund | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Limited Term Bond Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Limited Term Bond Fund | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 35.30%
Fidelity Limited Term Bond Fund | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Limited Term Bond Fund | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Limited Term Bond Fund | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Limited Term Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Limited Term Bond Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 74.40%
Fidelity Limited Term Bond Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
Fidelity Limited Term Bond Fund | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Limited Term Bond Fund | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Limited Term Bond Fund | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Limited Term Bond Fund | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Limited Term Bond Fund | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Limited Term Bond Fund | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Limited Term Bond Fund | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Limited Term Bond Fund | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Limited Term Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Limited Term Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Limited Term Bond Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.20%
Fidelity Limited Term Bond Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Limited Term Bond Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 66.40%
Fidelity Limited Term Bond Fund | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Limited Term Bond Fund | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Limited Term Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Limited Term Bond Fund | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Limited Term Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class Z | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Advisor Limited Term Bond Fund - Class Z | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Limited Term Bond Fund - Class Z | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Limited Term Bond Fund - Class Z | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Limited Term Bond Fund - Class Z | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class Z | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class Z | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class Z | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class Z | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Limited Term Bond Fund - Class Z | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 35.30%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Limited Term Bond Fund - Class Z | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class Z | United States  
Holdings [Line Items]  
Percent of Net Asset Value 74.40%
Fidelity Advisor Limited Term Bond Fund - Class Z | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
Fidelity Advisor Limited Term Bond Fund - Class Z | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Limited Term Bond Fund - Class Z | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Advisor Limited Term Bond Fund - Class Z | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Limited Term Bond Fund - Class Z | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Limited Term Bond Fund - Class Z | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Limited Term Bond Fund - Class Z | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Advisor Limited Term Bond Fund - Class Z | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Advisor Limited Term Bond Fund - Class Z | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Limited Term Bond Fund - Class Z | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Limited Term Bond Fund - Class Z | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Advisor Limited Term Bond Fund - Class Z | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.20%
Fidelity Advisor Limited Term Bond Fund - Class Z | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Advisor Limited Term Bond Fund - Class Z | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 66.40%
Fidelity Advisor Limited Term Bond Fund - Class Z | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Advisor Limited Term Bond Fund - Class Z | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Limited Term Bond Fund - Class Z | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Limited Term Bond Fund - Class Z | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Limited Term Bond Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class M | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Advisor Limited Term Bond Fund - Class M | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Limited Term Bond Fund - Class M | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Limited Term Bond Fund - Class M | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Limited Term Bond Fund - Class M | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class M | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class M | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class M | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class M | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Limited Term Bond Fund - Class M | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Limited Term Bond Fund - Class M | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
Fidelity Advisor Limited Term Bond Fund - Class M | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Advisor Limited Term Bond Fund - Class M | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Advisor Limited Term Bond Fund - Class M | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Advisor Limited Term Bond Fund - Class M | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Limited Term Bond Fund - Class M | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Limited Term Bond Fund - Class M | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 35.30%
Fidelity Advisor Limited Term Bond Fund - Class M | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Limited Term Bond Fund - Class M | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Limited Term Bond Fund - Class M | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Limited Term Bond Fund - Class M | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class M | United States  
Holdings [Line Items]  
Percent of Net Asset Value 74.40%
Fidelity Advisor Limited Term Bond Fund - Class M | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
Fidelity Advisor Limited Term Bond Fund - Class M | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Limited Term Bond Fund - Class M | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Advisor Limited Term Bond Fund - Class M | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Limited Term Bond Fund - Class M | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Limited Term Bond Fund - Class M | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Limited Term Bond Fund - Class M | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Advisor Limited Term Bond Fund - Class M | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Advisor Limited Term Bond Fund - Class M | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Limited Term Bond Fund - Class M | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Limited Term Bond Fund - Class M | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Advisor Limited Term Bond Fund - Class M | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.20%
Fidelity Advisor Limited Term Bond Fund - Class M | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Advisor Limited Term Bond Fund - Class M | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 66.40%
Fidelity Advisor Limited Term Bond Fund - Class M | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Advisor Limited Term Bond Fund - Class M | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Limited Term Bond Fund - Class M | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Limited Term Bond Fund - Class M | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Limited Term Bond Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class I | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Advisor Limited Term Bond Fund - Class I | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Limited Term Bond Fund - Class I | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Limited Term Bond Fund - Class I | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Limited Term Bond Fund - Class I | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class I | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class I | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class I | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class I | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Limited Term Bond Fund - Class I | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Limited Term Bond Fund - Class I | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
Fidelity Advisor Limited Term Bond Fund - Class I | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Advisor Limited Term Bond Fund - Class I | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Advisor Limited Term Bond Fund - Class I | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Advisor Limited Term Bond Fund - Class I | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Limited Term Bond Fund - Class I | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Limited Term Bond Fund - Class I | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 35.30%
Fidelity Advisor Limited Term Bond Fund - Class I | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Limited Term Bond Fund - Class I | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Limited Term Bond Fund - Class I | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Limited Term Bond Fund - Class I | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class I | United States  
Holdings [Line Items]  
Percent of Net Asset Value 74.40%
Fidelity Advisor Limited Term Bond Fund - Class I | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
Fidelity Advisor Limited Term Bond Fund - Class I | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Limited Term Bond Fund - Class I | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Advisor Limited Term Bond Fund - Class I | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Limited Term Bond Fund - Class I | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Limited Term Bond Fund - Class I | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Limited Term Bond Fund - Class I | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Advisor Limited Term Bond Fund - Class I | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Advisor Limited Term Bond Fund - Class I | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Limited Term Bond Fund - Class I | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Limited Term Bond Fund - Class I | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Advisor Limited Term Bond Fund - Class I | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.20%
Fidelity Advisor Limited Term Bond Fund - Class I | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Advisor Limited Term Bond Fund - Class I | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 66.40%
Fidelity Advisor Limited Term Bond Fund - Class I | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Advisor Limited Term Bond Fund - Class I | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Limited Term Bond Fund - Class I | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Limited Term Bond Fund - Class I | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Limited Term Bond Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class C | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Advisor Limited Term Bond Fund - Class C | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Limited Term Bond Fund - Class C | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Limited Term Bond Fund - Class C | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Limited Term Bond Fund - Class C | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class C | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class C | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class C | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class C | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Limited Term Bond Fund - Class C | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Limited Term Bond Fund - Class C | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
Fidelity Advisor Limited Term Bond Fund - Class C | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Advisor Limited Term Bond Fund - Class C | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Advisor Limited Term Bond Fund - Class C | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Advisor Limited Term Bond Fund - Class C | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Limited Term Bond Fund - Class C | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Limited Term Bond Fund - Class C | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 35.30%
Fidelity Advisor Limited Term Bond Fund - Class C | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Limited Term Bond Fund - Class C | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Limited Term Bond Fund - Class C | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Limited Term Bond Fund - Class C | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class C | United States  
Holdings [Line Items]  
Percent of Net Asset Value 74.40%
Fidelity Advisor Limited Term Bond Fund - Class C | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
Fidelity Advisor Limited Term Bond Fund - Class C | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Limited Term Bond Fund - Class C | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Advisor Limited Term Bond Fund - Class C | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Limited Term Bond Fund - Class C | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Limited Term Bond Fund - Class C | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Limited Term Bond Fund - Class C | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Advisor Limited Term Bond Fund - Class C | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Advisor Limited Term Bond Fund - Class C | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Limited Term Bond Fund - Class C | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Limited Term Bond Fund - Class C | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Advisor Limited Term Bond Fund - Class C | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.20%
Fidelity Advisor Limited Term Bond Fund - Class C | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Advisor Limited Term Bond Fund - Class C | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 66.40%
Fidelity Advisor Limited Term Bond Fund - Class C | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Advisor Limited Term Bond Fund - Class C | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Limited Term Bond Fund - Class C | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Limited Term Bond Fund - Class C | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Limited Term Bond Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class A | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Advisor Limited Term Bond Fund - Class A | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Limited Term Bond Fund - Class A | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Limited Term Bond Fund - Class A | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Advisor Limited Term Bond Fund - Class A | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class A | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class A | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class A | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class A | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Advisor Limited Term Bond Fund - Class A | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Advisor Limited Term Bond Fund - Class A | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.80%
Fidelity Advisor Limited Term Bond Fund - Class A | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Advisor Limited Term Bond Fund - Class A | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Advisor Limited Term Bond Fund - Class A | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.60%
Fidelity Advisor Limited Term Bond Fund - Class A | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Advisor Limited Term Bond Fund - Class A | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Advisor Limited Term Bond Fund - Class A | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 35.30%
Fidelity Advisor Limited Term Bond Fund - Class A | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Limited Term Bond Fund - Class A | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Limited Term Bond Fund - Class A | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Limited Term Bond Fund - Class A | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Advisor Limited Term Bond Fund - Class A | United States  
Holdings [Line Items]  
Percent of Net Asset Value 74.40%
Fidelity Advisor Limited Term Bond Fund - Class A | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
Fidelity Advisor Limited Term Bond Fund - Class A | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Limited Term Bond Fund - Class A | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Advisor Limited Term Bond Fund - Class A | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Limited Term Bond Fund - Class A | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Limited Term Bond Fund - Class A | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Limited Term Bond Fund - Class A | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Advisor Limited Term Bond Fund - Class A | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Advisor Limited Term Bond Fund - Class A | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Limited Term Bond Fund - Class A | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Advisor Limited Term Bond Fund - Class A | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Advisor Limited Term Bond Fund - Class A | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.20%
Fidelity Advisor Limited Term Bond Fund - Class A | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.70%
Fidelity Advisor Limited Term Bond Fund - Class A | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 66.40%
Fidelity Advisor Limited Term Bond Fund - Class A | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Advisor Limited Term Bond Fund - Class A | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Advisor Limited Term Bond Fund - Class A | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Advisor Limited Term Bond Fund - Class A | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Advisor Limited Term Bond Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Limited Term Securitized Completion Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.40%
Fidelity Limited Term Securitized Completion Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.30%
Fidelity Limited Term Securitized Completion Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity Limited Term Securitized Completion Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.00%
Fidelity Limited Term Securitized Completion Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Limited Term Securitized Completion Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Limited Term Securitized Completion Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Limited Term Securitized Completion Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Limited Term Securitized Completion Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Limited Term Securitized Completion Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Limited Term Securitized Completion Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 28.20%
Fidelity Limited Term Securitized Completion Fund | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 44.10%
Fidelity Limited Term Securitized Completion Fund | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity Limited Term Securitized Completion Fund | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Limited Term Securitized Completion Fund | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 17.70%
Fidelity Limited Term Securitized Completion Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Limited Term Securitized Completion Fund | United States  
Holdings [Line Items]  
Percent of Net Asset Value 99.10%
Fidelity Limited Term Securitized Completion Fund | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Limited Term Securitized Completion Fund | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.90%
Fidelity Limited Term Securitized Completion Fund | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 30.10%
Fidelity Limited Term Securitized Completion Fund | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 37.70%
Fidelity Limited Term Securitized Completion Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Limited Term Securitized Completion Fund | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Limited Term Securitized Completion Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%