v3.26.3
Investment Risks
Oct. 30, 2026
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | LeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Leverage Risk. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly.
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease.
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | CorrelationToIndexMember  
Prospectus Line Items  
Risk [Text Block] Correlation to Index. The performance of the fund and its benchmark index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from the index. Errors in the construction or calculation of the index may occur from time to time and may not be identified and corrected for some period of time, which may have an adverse impact on the fund and its shareholders.
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Entities located in foreign countries can be affected by adverse political, regulatory, market, or economic developments in those countries.
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | PassiveManagementRiskMember  
Prospectus Line Items  
Risk [Text Block] Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund's benchmark index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund's performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers. The fund will be concentrated to approximately the same extent that the fund's benchmark index concentrates in the securities of issuers in a particular industry or group of industries.
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | LeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Leverage Risk. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly.
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) involve greater risk of default or price changes due to changes in the credit quality of the issuer. The value of lower-quality debt securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments.
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | SecuritizedDebtSecuritiesExposureMember  
Prospectus Line Items  
Risk [Text Block] Securitized Debt Securities Exposure. Securitized debt securities are dependent on the cash flows generated by the underlying assets and can be significantly affected by changes in interest rates, the availability of information concerning the underlying assets and their structure, and the creditworthiness of the originators of the loans or other receivables or the entities providing credit support.
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | HighPortfolioTurnoverMember  
Prospectus Line Items  
Risk [Text Block] High Portfolio Turnover. High portfolio turnover (more than 100%) may result in increased transaction costs and potentially higher capital gains or losses. The effects of higher than normal portfolio turnover may adversely affect the fund's performance.
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | USGovernmentObligationsRiskMember  
Prospectus Line Items  
Risk [Text Block] U.S. Government Obligations Risk. Certain securities in which the fund may invest, including securities issued by certain U.S. Government agencies and U.S. Government sponsored enterprises, are not guaranteed by the U.S. Government or supported by the full faith and credit of the United States.
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | FinancialServicesConcentrationMember  
Prospectus Line Items  
Risk [Text Block] Financial Services Concentration. Changes in government regulation and interest rates and economic downturns can have a significant negative effect on issuers in the financial services sector, including the price of their securities or their ability to meet their payment obligations.
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease.
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt or money market security to decrease.
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | LeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Leverage Risk. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly.
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) and certain types of other securities involve greater risk of default or price changes due to changes in the credit quality of the issuer. The value of lower-quality debt securities and certain types of other securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments and can be difficult to resell. Investments in covenant-lite loans carry more risk than traditional loans as they allow issuers to engage in activities that would otherwise be difficult or impossible under a traditional loan agreement. In the event of default, covenant-lite obligations have lower recovery values as the lender may not have the opportunity to negotiate with the borrower prior to default.
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | ManagementRiskMember  
Prospectus Line Items  
Risk [Text Block] Management Risk. The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies .
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | HighPortfolioTurnoverMember  
Prospectus Line Items  
Risk [Text Block] High Portfolio Turnover. High portfolio turnover (more than 100%) may result in increased transaction costs and potentially higher capital gains or losses. The effects of higher than normal portfolio turnover may adversely affect the fund's performance.
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. Foreign exchange rates also can be extremely volatile.
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | SustainabilityRiskMember  
Prospectus Line Items  
Risk [Text Block] Sustainability Risk. Application of Fidelity Management & Research Company LLC's (FMR) (the Adviser) ESG rating process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG rating process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices.
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | LeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Leverage Risk. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly.
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) involve greater risk of default or price changes due to changes in the credit quality of the issuer. The value of lower-quality debt securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments.
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | ManagementRiskMember  
Prospectus Line Items  
Risk [Text Block] Management Risk. The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies .
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | HighPortfolioTurnoverMember  
Prospectus Line Items  
Risk [Text Block] High Portfolio Turnover. High portfolio turnover (more than 100%) may result in increased transaction costs and potentially higher capital gains or losses. The effects of higher than normal portfolio turnover may adversely affect the fund's performance.
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | SustainabilityRiskMember  
Prospectus Line Items  
Risk [Text Block] Sustainability Risk. Application of Fidelity Management & Research Company LLC's (FMR) (the Adviser) ESG rating process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG rating process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices.
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | LeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Leverage Risk. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly.
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | FinancialServicesConcentrationMember  
Prospectus Line Items  
Risk [Text Block] Financial Services Concentration. Changes in government regulation and interest rates and economic downturns can have a significant negative effect on issuers in the financial services sector, including the price of their securities or their ability to meet their payment obligations.
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease.
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | ManagementRiskMember  
Prospectus Line Items  
Risk [Text Block] Management Risk. The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies .
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | SustainabilityRiskMember  
Prospectus Line Items  
Risk [Text Block] Sustainability Risk. Application of Fidelity Management & Research Company LLC's (FMR) (the Adviser) ESG rating process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG rating process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices.
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | LeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Leverage Risk. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly.
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) involve greater risk of default or price changes due to changes in the credit quality of the issuer. The value of lower-quality debt securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments.
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | LeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Leverage Risk. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly.
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease. Lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds) and certain types of other securities involve greater risk of default or price changes due to changes in the credit quality of the issuer. The value of lower-quality debt securities and certain types of other securities can be more volatile due to increased sensitivity to adverse issuer, political, regulatory, market, or economic developments and can be difficult to resell. Investments in covenant-lite loans carry more risk than traditional loans as they allow issuers to engage in activities that would otherwise be difficult or impossible under a traditional loan agreement. In the event of default, covenant-lite obligations have lower recovery values as the lender may not have the opportunity to negotiate with the borrower prior to default.
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | ManagementRiskMember  
Prospectus Line Items  
Risk [Text Block] Management Risk. The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies .
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | HighPortfolioTurnoverMember  
Prospectus Line Items  
Risk [Text Block] High Portfolio Turnover. High portfolio turnover (more than 100%) may result in increased transaction costs and potentially higher capital gains or losses. The effects of higher than normal portfolio turnover may adversely affect the fund's performance.
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. Foreign exchange rates also can be extremely volatile.
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | SustainabilityRiskMember  
Prospectus Line Items  
Risk [Text Block] Sustainability Risk. Application of Fidelity Management & Research Company LLC's (FMR) (the Adviser) ESG rating process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG rating process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices.
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | LeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Leverage Risk. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly.
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | FinancialServicesConcentrationMember  
Prospectus Line Items  
Risk [Text Block] Financial Services Concentration. Changes in government regulation and interest rates and economic downturns can have a significant negative effect on issuers in the financial services sector, including the price of their securities or their ability to meet their payment obligations.
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease.
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | ManagementRiskMember  
Prospectus Line Items  
Risk [Text Block] Management Risk. The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies .
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | SustainabilityRiskMember  
Prospectus Line Items  
Risk [Text Block] Sustainability Risk. Application of Fidelity Management & Research Company LLC's (FMR) (the Adviser) ESG rating process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG rating process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices.
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | FinancialServicesConcentrationMember  
Prospectus Line Items  
Risk [Text Block] Financial Services Concentration. Changes in government regulation and interest rates and economic downturns can have a significant negative effect on issuers in the financial services sector, including the price of their securities or their ability to meet their payment obligations.
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease.
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt or money market security to decrease.
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | LeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Leverage Risk. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly.
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease.
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | CorrelationToIndexMember  
Prospectus Line Items  
Risk [Text Block] Correlation to Index. The performance of the fund and its benchmark index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from the index. Errors in the construction or calculation of the index may occur from time to time and may not be identified and corrected for some period of time, which may have an adverse impact on the fund and its shareholders.
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | PassiveManagementRiskMember  
Prospectus Line Items  
Risk [Text Block] Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund's benchmark index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund's performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers.
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | LeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Leverage Risk. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly.
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | FinancialServicesConcentrationMember  
Prospectus Line Items  
Risk [Text Block] Financial Services Concentration. Changes in government regulation and interest rates and economic downturns can have a significant negative effect on issuers in the financial services sector, including the price of their securities or their ability to meet their payment obligations.
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease.
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | ManagementRiskMember  
Prospectus Line Items  
Risk [Text Block] Management Risk. The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies .
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | ForeignExposureMember  
Prospectus Line Items  
Risk [Text Block] Foreign Exposure. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | PrepaymentMember  
Prospectus Line Items  
Risk [Text Block] Prepayment. The ability of an issuer of a debt security to repay principal prior to a security's maturity can cause greater price volatility if interest rates change.
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | SustainabilityRiskMember  
Prospectus Line Items  
Risk [Text Block] Sustainability Risk. Application of Fidelity Management & Research Company LLC's (FMR) (the Adviser) ESG rating process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG rating process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices.
Document Type 485BPOS