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Risk/Return Detail Data - FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO - USD ($)
 12 Months Ended 24 Months Ended 36 Months Ended 60 Months Ended 84 Months Ended 96 Months Ended 120 Months Ended
Oct. 30, 2025
Oct. 30, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Oct. 30, 2025
Oct. 30, 2025
Oct. 30, 2025
Oct. 30, 2025
Oct. 30, 2025
Oct. 30, 2025
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | Fidelity SAI Investment Grade Securitized Fund                                    
Prospectus Line Items                                    
Management Fees (as a percentage of Assets) 0.28%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.03%                                  
Expenses (as a percentage of Assets) 0.31%                                  
Expense Example, with Redemption, 1 Year $ 32                                  
Expense Example, with Redemption, 3 Years 100                                  
Expense Example, with Redemption, 5 Years 174                                  
Expense Example, with Redemption, 10 Years $ 393                                  
Annual Return, Inception Date May 17, 2023                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   1.42%                     2.60% [1]          
Annual Return [Percent]     1.42%                              
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund: Fidelity® SAI Investment Grade Securitized Fund                                  
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® SAI Investment Grade Securitized Fund seeks a high level of current income.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Shareholder Fee, Other $ 0                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 715 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 715.00%                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in investment-grade securitized debt securities (those of medium and high quality) and repurchase agreements for those securities. Securitized debt securities are interests in pools of mortgages, loans, receivables, or other assets, and include such instruments as mortgage-backed securities, commercial mortgage-backed securities, and other asset-backed securities that are issued by the U.S. Government, its agencies or instrumentalities, foreign governments, financial institutions, trusts and corporations. Payment of principal or interest on securitized debt instruments generally depends on the cash flows generated by the underlying assets and may be supported by letters of credit, surety bonds, or other credit enhancements. Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Investing in U.S. Government securities issued by entities that are chartered or sponsored by Congress but whose securities are neither issued nor guaranteed by the U.S. Treasury. Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. Securitized Index. Allocating assets across different market sectors and maturities. Investing in domestic and foreign issuers. Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Investing in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] www.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 6.86%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Sep. 30, 2024                                  
Highest Quarterly Return 5.51%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Dec. 31, 2024                                  
Lowest Quarterly Return (3.16%)                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares .                                  
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares .                                  
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | After Taxes on Distributions | Fidelity SAI Investment Grade Securitized Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   (0.59%)                     0.62% [1]          
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | After Taxes on Distributions and Sales | Fidelity SAI Investment Grade Securitized Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   0.86%                     1.15% [1]          
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                     2.51%          
FidelitySAIInvestmentGradeSecuritizedFund-PRO | Fidelity SAI Investment Grade Securitized Fund | LB371                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Securitized Index                                
Average Annual Return, Percent   1.46%                     2.49%          
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | Fidelity Sustainability Bond Index Fund                                    
Prospectus Line Items                                    
Management Fees (as a percentage of Assets) 0.10%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.00%                                  
Expenses (as a percentage of Assets) 0.10%                                  
Expense Example, with Redemption, 1 Year $ 10                                  
Expense Example, with Redemption, 3 Years 32                                  
Expense Example, with Redemption, 5 Years 56                                  
Expense Example, with Redemption, 10 Years $ 128                                  
Annual Return, Inception Date Jun. 19, 2018                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   1.23%                         (0.41%) 1.19% [2]    
Annual Return [Percent]     1.23% 5.43% (12.90%) (1.98%) 7.49% 8.29%                    
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund: Fidelity® Sustainability Bond Index Fund                                  
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® Sustainability Bond Index Fund seeks to provide investment results that correspond to the aggregate price and interest performance of the debt securities in the Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Shareholder Fee, Other $ 0                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 70 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 70.00%                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in bonds included in the Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index. The Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index is composed of U.S. dollar denominated, investment-grade fixed-rate debt issues, including government, corporate, asset-backed, and mortgage-backed securities, and follows the rules of the Bloomberg U.S. Aggregate Bond Index. MSCI ESG Research applies additional sector and ESG criteria for security eligibility in the index and adjusts the sector weights of the index to match the exposures of the Bloomberg U.S. Aggregate Bond Index. Companies showing involvement above certain thresholds in adult entertainment, alcohol, gambling, tobacco, military weapons, civilian firearms, nuclear power, and genetically modified organisms are excluded. The index is rebalanced monthly. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Using statistical sampling techniques based on duration, maturity, interest rate sensitivity, security structure, and credit quality to attempt to replicate the returns of the Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index using a smaller number of securities. Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] www.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 6.01%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Dec. 31, 2023                                  
Highest Quarterly Return 6.51%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Mar. 31, 2022                                  
Lowest Quarterly Return (5.71%)                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | After Taxes on Distributions | Fidelity Sustainability Bond Index Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   (0.18%)                         (1.37%) 0.15% [2]    
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | After Taxes on Distributions and Sales | Fidelity Sustainability Bond Index Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   0.75%                         (0.69%) 0.49% [2]    
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                         (0.33%) 1.32%    
FidelitySustainabilityBondIndexFund-PRO | Fidelity Sustainability Bond Index Fund | IXYQV                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index                                
Average Annual Return, Percent   1.27%                         (0.30%) 1.33%    
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | Fidelity Conservative Income Bond Fund                                    
Prospectus Line Items                                    
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.10%                                  
Expenses (as a percentage of Assets) 0.30%                                  
Fee Waiver or Reimbursement [3] (0.05%)                                  
Net Expenses (as a percentage of Assets) 0.25%                                  
Expense Example, with Redemption, 1 Year $ 26                                  
Expense Example, with Redemption, 3 Years 90                                  
Expense Example, with Redemption, 5 Years 162                                  
Expense Example, with Redemption, 10 Years $ 374                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   5.41%                         2.70%     2.12%
Annual Return [Percent]     5.41% 5.84% 1.26% none 1.15% 2.99% 1.82% 1.40% 1.05% 0.45%            
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Conservative Income Bond Fund /Fidelity® Conservative Income Bond Fund                                  
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® Conservative Income Bond Fund seeks to obtain a high level of current income consistent with preservation of capital.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Shareholder Fee, Other $ 0                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Fee Waiver or Reimbursement over Assets, Date of Termination Dec. 31, 2026                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 73 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 73.00%                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in U.S. dollar-denominated money market and high quality investment-grade debt securities of all types, and repurchase agreements for those securities. Debt securities, including money market securities, are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, and mortgage and other asset-backed securities. Money market securities include bank certificates of deposit, bankers' acceptances, bank time deposits, notes, commercial paper, and U.S. Government securities. High quality investment grade securities in which the fund invests include securities or issuers (i) rated at least A- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO) or similarly rated by the Adviser, and (ii) for securities with a credit maturity within one year, rated at least BBB or its equivalent by all NRSROs that rate the security and similarly rated by the Adviser. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Potentially entering into reverse repurchase agreements. Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. 3-6 Month Treasury Bill Index. Normally maintaining a dollar-weighted average maturity of one year or less. Normally investing in securities with a maximum maturity of four years. Allocating assets across different market sectors and maturities. Investing more than 25% of total assets in the financial services industries. Investing in domestic and foreign issuers. Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] www.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 3.45%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Jun. 30, 2020                                  
Highest Quarterly Return 1.90%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Mar. 31, 2020                                  
Lowest Quarterly Return (1.04%)                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | After Taxes on Distributions | Fidelity Conservative Income Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   3.33%                         1.63%     1.27%
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | After Taxes on Distributions and Sales | Fidelity Conservative Income Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   3.29%                         1.62%     1.26%
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                         (0.33%)     1.35%
FidelityConservativeIncomeBondFund-RetailPRO | Fidelity Conservative Income Bond Fund | LB151                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. 3-6 Month Treasury Bill Index                                
Average Annual Return, Percent   5.33%                         2.52%     1.83%
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | Fidelity Sustainable Core Plus Bond Fund                                    
Prospectus Line Items                                    
Management Fees (as a percentage of Assets) 0.35%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.10%                                  
Expenses (as a percentage of Assets) 0.45%                                  
Expense Example, with Redemption, 1 Year $ 46                                  
Expense Example, with Redemption, 3 Years 144                                  
Expense Example, with Redemption, 5 Years 252                                  
Expense Example, with Redemption, 10 Years $ 567                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   1.65%                       0.40% [4]        
Annual Return [Percent]     1.65% 6.51%                            
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Core Plus Bond Fund /Fidelity® Sustainable Core Plus Bond Fund                                  
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® Sustainable Core Plus Bond Fund seeks a high level of current income.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Shareholder Fee, Other $ 0                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 201 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 201.00%                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in debt securities of all types that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).  A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Evaluating each security in which the fund invests using both a traditional bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or sponsor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) ESG factors related to the security's underlying pool of assets; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team. The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, vulnerability to the physical impacts of climate change, and research and investment into products, services, and energies that reduce emissions and/or provide opportunities to transition to less carbon-intensive products or operations. An assessment of an issuer's social profile includes, but is not limited to, its approach to diversity and inclusion, human capital management, data privacy, product safety and human rights. With respect to governance, the independence and diversity of an issuer's board, its compensation practices and board oversight of critical ESG issues are considered as part of the assessment. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. Investing in debt securities of issuers that the Adviser believes deliver tangible environmental or social impact through core business operations. An assessment of the impact characteristics of an issuer may involve corporate engagement and an analysis of issuer alignment with the United Nations Sustainable Development Goals using qualitative analysis as well as proprietary or third-party data. For example, issuers that provide access to clean water, education, or clean energy through their core business may be considered to deliver tangible impact. When evaluating securitized debt securities (including mortgage-backed securities, commercial mortgage-backed securities, and other asset-backed securities), generally considering the issuer's ESG rating along with ESG factors related to the underlying pool of assets, such as energy efficiency and environmental impact of the underlying assets; providing access to affordable housing or opportunities for first time home ownership; and compliance with fair lending laws. In addition to its focus on debt securities with positive ESG characteristics, analyzing the credit quality of the issuer, the issuer's potential for success, the credit, currency, and economic risks of the security and its issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Allocating assets across investment-grade, high yield, and emerging market debt securities. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Investing up to 20% of assets in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). Managing the fund to have similar overall interest rate risk to the Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index. Investing in domestic and foreign issuers. Allocating assets across different asset classes, market sectors, and maturities. Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] www.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 6.30%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Dec. 31, 2023                                  
Highest Quarterly Return 6.91%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Sep. 30, 2023                                  
Lowest Quarterly Return (3.12%)                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | After Taxes on Distributions | Fidelity Sustainable Core Plus Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   0.02%                       (1.08%) [4]        
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Core Plus Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   0.99%                       (0.32%) [4]        
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                       0.36%        
FidelitySustainableCorePlusBondFund-RetailPRO | Fidelity Sustainable Core Plus Bond Fund | IXYQV                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index                                
Average Annual Return, Percent   1.27%                       0.39%        
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | Fidelity Series Sustainable Investment Grade Bond Fund                                    
Prospectus Line Items                                    
Management Fees (as a percentage of Assets) 0.00%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.02%                                  
Expenses (as a percentage of Assets) 0.02%                                  
Fee Waiver or Reimbursement [5] (0.02%)                                  
Net Expenses (as a percentage of Assets) 0.00%                                  
Expense Example, with Redemption, 1 Year $ 0                                  
Expense Example, with Redemption, 3 Years 0                                  
Expense Example, with Redemption, 5 Years 4                                  
Expense Example, with Redemption, 10 Years $ 19                                  
Annual Return, Inception Date May 11, 2023                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   1.26%                     1.86% [6]          
Annual Return [Percent]     1.26%                              
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund: Fidelity® Series Sustainable Investment Grade Bond Fund                                  
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® Series Sustainable Investment Grade Bond Fund seeks a high level of current income.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Shareholder Fee, Other $ 0                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Fee Waiver or Reimbursement over Assets, Date of Termination December 31, 2028                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 235 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 235.00%                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in investment-grade debt securities (those of medium and high quality) of all types that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).  Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Evaluating each security in which the fund invests using both a traditional bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or sponsor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) ESG factors related to the security's underlying pool of assets; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team. The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, vulnerability to the physical impacts of climate change, and research and investment into products, services, and energies that reduce emissions and/or provide opportunities to transition to less carbon-intensive products or operations. An assessment of an issuer's social profile includes, but is not limited to, its approach to diversity and inclusion, human capital management, data privacy, product safety and human rights. With respect to governance, the independence and diversity of an issuer's board, its compensation practices and board oversight of critical ESG issues are considered as part of the assessment. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. Investing in debt securities of issuers that the Adviser believes deliver tangible environmental or social impact through core business operations. An assessment of the impact characteristics of an issuer may involve corporate engagement and an analysis of issuer alignment with the United Nations Sustainable Development Goals using qualitative analysis as well as proprietary or third-party data. For example, issuers that provide access to clean water, education, or clean energy through their core business may be considered to deliver tangible impact. When evaluating securitized debt securities (including mortgage-backed securities, commercial mortgage-backed securities, and other asset-backed securities), generally considering the issuer's ESG rating along with ESG factors related to the underlying pool of assets, such as energy efficiency and environmental impact of the underlying assets; providing access to affordable housing or opportunities for first time home ownership; and compliance with fair lending laws. In addition to its focus on debt securities with positive ESG characteristics, analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Allocating assets across different market sectors and maturities. Investing in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). Managing the fund to have similar overall interest rate risk to the Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index. Investing in domestic and foreign issuers. Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. The performance shown does not reflect the impact of any fees paid at the fee-based account or plan level, if applicable. Visit www.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] www.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 6.23%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Sep. 30, 2024                                  
Highest Quarterly Return 5.17%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Dec. 31, 2024                                  
Lowest Quarterly Return (3.10%)                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares .                                  
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares .                                  
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | After Taxes on Distributions | Fidelity Series Sustainable Investment Grade Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   (0.64%)                     (0.05%) [6]          
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | After Taxes on Distributions and Sales | Fidelity Series Sustainable Investment Grade Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   0.74%                     0.62% [6]          
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                     1.79%          
FidelitySeriesSustainableInvestmentGradeBondFund-PRO | Fidelity Series Sustainable Investment Grade Bond Fund | IXYQV                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index                                
Average Annual Return, Percent   1.27%                     1.80%          
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | Fidelity SAI Sustainable Low Duration Bond Fund                                    
Prospectus Line Items                                    
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.23%                                  
Expenses (as a percentage of Assets) 0.43%                                  
Fee Waiver or Reimbursement [7] (0.23%)                                  
Net Expenses (as a percentage of Assets) 0.20%                                  
Expense Example, with Redemption, 1 Year $ 20                                  
Expense Example, with Redemption, 3 Years 107                                  
Expense Example, with Redemption, 5 Years 210                                  
Expense Example, with Redemption, 10 Years $ 512                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   5.34%                       4.33% [8]        
Annual Return [Percent]     5.34% 5.36%                            
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund: Fidelity® SAI Sustainable Low Duration Bond Fund                                  
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® SAI Sustainable Low Duration Bond Fund seeks to obtain a high level of current income consistent with preservation of capital.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Shareholder Fee, Other $ 0                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Fee Waiver or Reimbursement over Assets, Date of Termination Dec. 31, 2026                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 57 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 57.00%                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in investment-grade debt securities (those of medium and high quality) of all types that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).  Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Evaluating each security in which the fund invests using both a traditional bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or sponsor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) ESG factors related to the security's underlying pool of assets; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team. The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, vulnerability to the physical impacts of climate change, and research and investment into products, services, and energies that reduce emissions and/or provide opportunities to transition to less carbon-intensive products or operations. An assessment of an issuer's social profile includes, but is not limited to, its approach to diversity and inclusion, human capital management, data privacy, product safety and human rights. With respect to governance, the independence and diversity of an issuer's board, its compensation practices and board oversight of critical ESG issues are considered as part of the assessment. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. Investing in debt securities of issuers that the Adviser believes deliver tangible environmental or social impact through core business operations. An assessment of the impact characteristics of an issuer may involve corporate engagement and an analysis of issuer alignment with the United Nations Sustainable Development Goals using qualitative analysis as well as proprietary or third-party data. For example, issuers that provide access to clean water, education, or clean energy through their core business may be considered to deliver tangible impact. When evaluating securitized debt securities (including mortgage-backed securities, commercial mortgage-backed securities, and other asset-backed securities), generally considering the issuer's ESG rating along with ESG factors related to the underlying pool of assets, such as energy efficiency and environmental impact of the underlying assets; providing access to affordable housing or opportunities for first time home ownership; and compliance with fair lending laws. In addition to its focus on debt securities with positive ESG characteristics, analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Normally maintaining a duration of 1 year or less. Managing the fund to have similar overall interest rate risk to the Bloomberg US Treasury Bill: 6-9 Months Index. Normally maintaining a dollar-weighted average maturity of two years or less. Allocating assets across different market sectors and maturities. Investing more than 25% of total assets in the financial services industries. Investing in domestic and foreign issuers. Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] www.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 3.57%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Dec. 31, 2023                                  
Highest Quarterly Return 1.72%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Jun. 30, 2023                                  
Lowest Quarterly Return 1.00%                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | After Taxes on Distributions | Fidelity SAI Sustainable Low Duration Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   3.95%                       3.16% [8]        
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | After Taxes on Distributions and Sales | Fidelity SAI Sustainable Low Duration Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   3.27%                       2.84% [8]        
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | IXXXY                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg US Treasury Bill: 6-9 Months Index                                
Average Annual Return, Percent   4.88%                       3.62%        
FidelitySAISustainableLowDurationBondFund-PRO | Fidelity SAI Sustainable Low Duration Bond Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                       0.36%        
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | Fidelity Advisor Sustainable Core Plus Bond Fund - Class A                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 4.00%                                  
Maximum Deferred Sales Charge (as a percentage) [9] 0.00%                                  
Management Fees (as a percentage of Assets) 0.35%                                  
Distribution and Service (12b-1) Fees 0.25%                                  
Other Expenses (as a percentage of Assets): 0.07%                                  
Expenses (as a percentage of Assets) 0.67%                                  
Fee Waiver or Reimbursement (0.00%)                                  
Net Expenses (as a percentage of Assets) 0.67%                                  
Expense Example, with Redemption, 1 Year $ 466                                  
Expense Example, with Redemption, 3 Years 606                                  
Expense Example, with Redemption, 5 Years 758                                  
Expense Example, with Redemption, 10 Years 1,201                                  
Expense Example, No Redemption, 1 Year 466                                  
Expense Example, No Redemption, 3 Years 606                                  
Expense Example, No Redemption, 5 Years 758                                  
Expense Example, No Redemption, 10 Years $ 1,201                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   (2.64%)                       (1.31%) [10]        
Annual Return [Percent]     1.42% 6.27%                            
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | Fidelity Advisor Sustainable Core Plus Bond Fund - Class M                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 4.00%                                  
Maximum Deferred Sales Charge (as a percentage) [9] 0.00%                                  
Management Fees (as a percentage of Assets) 0.35%                                  
Distribution and Service (12b-1) Fees 0.25%                                  
Other Expenses (as a percentage of Assets): 0.14%                                  
Expenses (as a percentage of Assets) 0.74%                                  
Fee Waiver or Reimbursement (0.00%)                                  
Net Expenses (as a percentage of Assets) 0.74%                                  
Expense Example, with Redemption, 1 Year $ 473                                  
Expense Example, with Redemption, 3 Years 627                                  
Expense Example, with Redemption, 5 Years 795                                  
Expense Example, with Redemption, 10 Years 1,282                                  
Expense Example, No Redemption, 1 Year 473                                  
Expense Example, No Redemption, 3 Years 627                                  
Expense Example, No Redemption, 5 Years 795                                  
Expense Example, No Redemption, 10 Years $ 1,282                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   (2.66%)                       (1.31%) [11]        
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | Fidelity Advisor Sustainable Core Plus Bond Fund - Class C                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%                                  
Maximum Deferred Sales Charge (as a percentage) [12] 1.00%                                  
Management Fees (as a percentage of Assets) 0.35%                                  
Distribution and Service (12b-1) Fees 1.00%                                  
Other Expenses (as a percentage of Assets): 0.14%                                  
Expenses (as a percentage of Assets) 1.49%                                  
Fee Waiver or Reimbursement (0.00%)                                  
Net Expenses (as a percentage of Assets) 1.49%                                  
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                                  
Expense Example, with Redemption, 1 Year $ 252                                  
Expense Example, with Redemption, 3 Years 471                                  
Expense Example, with Redemption, 5 Years 813                                  
Expense Example, with Redemption, 10 Years 1,557                                  
Expense Example, No Redemption, 1 Year 152                                  
Expense Example, No Redemption, 3 Years 471                                  
Expense Example, No Redemption, 5 Years 813                                  
Expense Example, No Redemption, 10 Years $ 1,557                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   (0.33%)                       (0.56%) [13]        
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | Fidelity Advisor Sustainable Core Plus Bond Fund - Class I                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%                                  
Maximum Deferred Sales Charge (as a percentage) 0.00%                                  
Management Fees (as a percentage of Assets) 0.35%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.14%                                  
Expenses (as a percentage of Assets) 0.49%                                  
Fee Waiver or Reimbursement [14] (0.04%)                                  
Net Expenses (as a percentage of Assets) 0.45%                                  
Expense Example, with Redemption, 1 Year $ 46                                  
Expense Example, with Redemption, 3 Years 152                                  
Expense Example, with Redemption, 5 Years 269                                  
Expense Example, with Redemption, 10 Years 611                                  
Expense Example, No Redemption, 1 Year 46                                  
Expense Example, No Redemption, 3 Years 152                                  
Expense Example, No Redemption, 5 Years 269                                  
Expense Example, No Redemption, 10 Years $ 611                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   1.66%                       0.44% [15]        
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | Fidelity Advisor Sustainable Core Plus Bond Fund - Class Z                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%                                  
Maximum Deferred Sales Charge (as a percentage) 0.00%                                  
Management Fees (as a percentage of Assets) 0.35%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.05%                                  
Expenses (as a percentage of Assets) 0.40%                                  
Fee Waiver or Reimbursement [14] (0.04%)                                  
Net Expenses (as a percentage of Assets) 0.36%                                  
Expense Example, with Redemption, 1 Year $ 37                                  
Expense Example, with Redemption, 3 Years 123                                  
Expense Example, with Redemption, 5 Years 219                                  
Expense Example, with Redemption, 10 Years 500                                  
Expense Example, No Redemption, 1 Year 37                                  
Expense Example, No Redemption, 3 Years 123                                  
Expense Example, No Redemption, 5 Years 219                                  
Expense Example, No Redemption, 10 Years $ 500                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   1.85%                       0.53% [16]        
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Core Plus Bond Fund /Fidelity Advisor® Sustainable Core Plus Bond Fund A, M, C, I, Z                                    
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® Sustainable Core Plus Bond Fund seeks a high level of current income.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 23 of the prospectus and in the sales charge waiver appendix to the prospectus.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Fee Waiver or Reimbursement over Assets, Date of Termination Dec. 31, 2026                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 201 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 201.00%                                  
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 0.75% and 0.25%, respectively.                                  
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 23 of the prospectus                                  
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in debt securities of all types that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).  A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Evaluating each security in which the fund invests using both a traditional bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or sponsor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) ESG factors related to the security's underlying pool of assets; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team. The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, vulnerability to the physical impacts of climate change, and research and investment into products, services, and energies that reduce emissions and/or provide opportunities to transition to less carbon-intensive products or operations. An assessment of an issuer's social profile includes, but is not limited to, its approach to diversity and inclusion, human capital management, data privacy, product safety and human rights. With respect to governance, the independence and diversity of an issuer's board, its compensation practices and board oversight of critical ESG issues are considered as part of the assessment. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. Investing in debt securities of issuers that the Adviser believes deliver tangible environmental or social impact through core business operations. An assessment of the impact characteristics of an issuer may involve corporate engagement and an analysis of issuer alignment with the United Nations Sustainable Development Goals using qualitative analysis as well as proprietary or third-party data. For example, issuers that provide access to clean water, education, or clean energy through their core business may be considered to deliver tangible impact. When evaluating securitized debt securities (including mortgage-backed securities, commercial mortgage-backed securities, and other asset-backed securities), generally considering the issuer's ESG rating along with ESG factors related to the underlying pool of assets, such as energy efficiency and environmental impact of the underlying assets; providing access to affordable housing or opportunities for first time home ownership; and compliance with fair lending laws. In addition to its focus on debt securities with positive ESG characteristics, analyzing the credit quality of the issuer, the issuer's potential for success, the credit, currency, and economic risks of the security and its issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Allocating assets across investment-grade, high yield, and emerging market debt securities. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Investing up to 20% of assets in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). Managing the fund to have similar overall interest rate risk to the Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index. Investing in domestic and foreign issuers. Allocating assets across different asset classes, market sectors, and maturities. Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] institutional.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.                                  
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 6.12%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Dec. 31, 2023                                  
Highest Quarterly Return 6.85%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Sep. 30, 2023                                  
Lowest Quarterly Return (3.18%)                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Core Plus Bond Fund - Class A                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   (4.13%)                       (2.69%) [10]        
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Core Plus Bond Fund - Class A                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   (1.57%)                       (1.58%) [10]        
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                       0.36%        
FidelitySustainableCorePlusBondFund-AMCIZPRO | Fidelity Sustainable Core Plus Bond Fund | IXYQV                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index                                
Average Annual Return, Percent   1.27%                       0.39%        
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | Fidelity Series Corporate Bond Fund                                    
Prospectus Line Items                                    
Management Fees (as a percentage of Assets) 0.00%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.00%                                  
Expenses (as a percentage of Assets) 0.00%                                  
Expense Example, with Redemption, 1 Year $ 0                                  
Expense Example, with Redemption, 3 Years 0                                  
Expense Example, with Redemption, 5 Years 0                                  
Expense Example, with Redemption, 10 Years $ 0                                  
Annual Return, Inception Date Aug. 17, 2018                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   3.11%                         0.72% 2.56% [17]    
Annual Return [Percent]     3.11% 9.07% (16.32%) (0.98%) 11.22% 14.44%                    
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund: Fidelity® Series Corporate Bond Fund                                  
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® Series Corporate Bond Fund seeks a high level of current income.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Shareholder Fee, Other $ 0                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 39 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 39.00%                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in corporate bonds and other corporate debt securities and repurchase agreements for those securities. Corporate debt securities are bonds and other debt securities issued by corporations and other business structures to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Corporate debt securities include repurchase agreements with corporate counterparties and other securities, such as hybrids and synthetic securities, believed to have corporate debt-like characteristics, (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures). A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Normally investing primarily in investment-grade corporate debt securities and repurchase agreements for those securities. Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. Credit Bond Index. Investing in domestic and foreign issuers. Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Investing in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. Investing in Fidelity's Central funds (specialized investment vehicles used by Fidelity® funds to invest in particular security types or investment disciplines) consistent with the asset classes discussed above.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. The performance shown does not reflect the impact of any fees paid at the fee-based account or plan level, if applicable. Visit www.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] www.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 7.22%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Jun. 30, 2020                                  
Highest Quarterly Return 10.62%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Mar. 31, 2022                                  
Lowest Quarterly Return (7.63%)                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | After Taxes on Distributions | Fidelity Series Corporate Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   1.36%                         (0.78%) 1.00% [17]    
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | After Taxes on Distributions and Sales | Fidelity Series Corporate Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   1.94%                         (0.05%) 1.33% [17]    
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                         (0.33%) 1.24%    
FidelitySeriesCorporateBondFund-PRO | Fidelity Series Corporate Bond Fund | LB004                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Credit Bond Index                                
Average Annual Return, Percent   2.03%                         0.23% 2.19%    
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | Fidelity Sustainable Low Duration Bond Fund                                    
Prospectus Line Items                                    
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.10%                                  
Expenses (as a percentage of Assets) 0.30%                                  
Fee Waiver or Reimbursement [18] (0.05%)                                  
Net Expenses (as a percentage of Assets) 0.25%                                  
Expense Example, with Redemption, 1 Year $ 26                                  
Expense Example, with Redemption, 3 Years 90                                  
Expense Example, with Redemption, 5 Years 162                                  
Expense Example, with Redemption, 10 Years $ 374                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   5.31%                       4.20% [19]        
Annual Return [Percent]     5.31% 5.27%                            
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Low Duration Bond Fund /Fidelity® Sustainable Low Duration Bond Fund                                  
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® Sustainable Low Duration Bond Fund seeks to obtain a high level of current income consistent with preservation of capital.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Shareholder Fee, Other $ 0                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Fee Waiver or Reimbursement over Assets, Date of Termination Dec. 31, 2026                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 58 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 58.00%                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in investment-grade debt securities (those of medium and high quality) of all types that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).  Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Evaluating each security in which the fund invests using both a traditional bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or sponsor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) ESG factors related to the security's underlying pool of assets; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team. The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, vulnerability to the physical impacts of climate change, and research and investment into products, services, and energies that reduce emissions and/or provide opportunities to transition to less carbon-intensive products or operations. An assessment of an issuer's social profile includes, but is not limited to, its approach to diversity and inclusion, human capital management, data privacy, product safety and human rights. With respect to governance, the independence and diversity of an issuer's board, its compensation practices and board oversight of critical ESG issues are considered as part of the assessment. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. Investing in debt securities of issuers that the Adviser believes deliver tangible environmental or social impact through core business operations. An assessment of the impact characteristics of an issuer may involve corporate engagement and an analysis of issuer alignment with the United Nations Sustainable Development Goals using qualitative analysis as well as proprietary or third-party data. For example, issuers that provide access to clean water, education, or clean energy through their core business may be considered to deliver tangible impact. When evaluating securitized debt securities (including mortgage-backed securities, commercial mortgage-backed securities, and other asset-backed securities), generally considering the issuer's ESG rating along with ESG factors related to the underlying pool of assets, such as energy efficiency and environmental impact of the underlying assets; providing access to affordable housing or opportunities for first time home ownership; and compliance with fair lending laws. In addition to its focus on debt securities with positive ESG characteristics, analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Normally maintaining a duration of 1 year or less. Managing the fund to have similar overall interest rate risk to the Bloomberg US Treasury Bill: 6-9 Months Index. Normally maintaining a dollar-weighted average maturity of two years or less. Allocating assets across different market sectors and maturities. Investing more than 25% of total assets in the financial services industries. Investing in domestic and foreign issuers. Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] www.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 3.49%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Dec. 31, 2023                                  
Highest Quarterly Return 1.75%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Jun. 30, 2023                                  
Lowest Quarterly Return 0.99%                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | After Taxes on Distributions | Fidelity Sustainable Low Duration Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   3.42%                       2.81% [19]        
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Low Duration Bond Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   3.26%                       2.65% [19]        
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | IXXXY                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg US Treasury Bill: 6-9 Months Index                                
Average Annual Return, Percent   4.88%                       3.62%        
FidelitySustainableLowDurationBondFund-RetailPRO | Fidelity Sustainable Low Duration Bond Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                       0.36%        
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | Fidelity Advisor Conservative Income Bond Fund - Class A                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 1.50%                                  
Maximum Deferred Sales Charge (as a percentage) [20] 0.00%                                  
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 0.15%                                  
Other Expenses (as a percentage of Assets): 0.13%                                  
Expenses (as a percentage of Assets) 0.48%                                  
Fee Waiver or Reimbursement [21] (0.03%)                                  
Net Expenses (as a percentage of Assets) 0.45%                                  
Expense Example, with Redemption, 1 Year $ 195                                  
Expense Example, with Redemption, 3 Years 298                                  
Expense Example, with Redemption, 5 Years 411                                  
Expense Example, with Redemption, 10 Years $ 741                                  
Annual Return, Inception Date May 25, 2023                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   3.62%                     4.48% [22]          
Annual Return [Percent]     5.20%                              
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | Fidelity Advisor Conservative Income Bond Fund - Class I                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%                                  
Maximum Deferred Sales Charge (as a percentage) 0.00%                                  
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.17%                                  
Expenses (as a percentage of Assets) 0.37%                                  
Fee Waiver or Reimbursement [21] (0.12%)                                  
Net Expenses (as a percentage of Assets) 0.25%                                  
Expense Example, with Redemption, 1 Year $ 26                                  
Expense Example, with Redemption, 3 Years 102                                  
Expense Example, with Redemption, 5 Years 191                                  
Expense Example, with Redemption, 10 Years $ 452                                  
Annual Return, Inception Date May 25, 2023                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   5.41%                     5.67% [23]          
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | Fidelity Advisor Conservative Income Bond Fund - Class Z                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%                                  
Maximum Deferred Sales Charge (as a percentage) 0.00%                                  
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.05%                                  
Expenses (as a percentage of Assets) 0.25%                                  
Fee Waiver or Reimbursement [21] (0.05%)                                  
Net Expenses (as a percentage of Assets) 0.20%                                  
Expense Example, with Redemption, 1 Year $ 20                                  
Expense Example, with Redemption, 3 Years 74                                  
Expense Example, with Redemption, 5 Years 134                                  
Expense Example, with Redemption, 10 Years $ 311                                  
Annual Return, Inception Date May 25, 2023                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   5.46%                     5.72% [24]          
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Conservative Income Bond Fund /Fidelity Advisor® Conservative Income Bond Fund A, I, Z                                    
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® Conservative Income Bond Fund seeks to obtain a high level of current income consistent with preservation of capital.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 250,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 31 of the prospectus   and in the sales charge waiver appendix to the prospectus.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Fee Waiver or Reimbursement over Assets, Date of Termination Dec. 31, 2026                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 73 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 73.00%                                  
Expenses Deferred Charges [Text Block] Purchases of $250,000 or more will not be subject to a front-end sales charge, but may be subject to a 0.50% contingent deferred sales charge (CDSC) if the intermediary firm has elected an upfront finder's fee at the time the shares are purchased, or a 0.75% CDSC if the shares purchased are recordkept in a Fidelity Advisor ® 401(k) Retirement Plan.                                  
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 250,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 31 of the prospectus                                  
Expense Breakpoint, Minimum Investment Required [Amount] $ 250,000                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in U.S. dollar-denominated money market and high quality investment-grade debt securities of all types, and repurchase agreements for those securities. Debt securities, including money market securities, are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, and mortgage and other asset-backed securities. Money market securities include bank certificates of deposit, bankers' acceptances, bank time deposits, notes, commercial paper, and U.S. Government securities. High quality investment grade securities in which the fund invests include securities or issuers (i) rated at least A- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO) or similarly rated by the Adviser, and (ii) for securities with a credit maturity within one year, rated at least BBB or its equivalent by all NRSROs that rate the security and similarly rated by the Adviser. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Potentially entering into reverse repurchase agreements. Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. 3-6 Month Treasury Bill Index. Normally maintaining a dollar-weighted average maturity of one year or less. Normally investing in securities with a maximum maturity of four years. Allocating assets across different market sectors and maturities. Investing more than 25% of total assets in the financial services industries. Investing in domestic and foreign issuers. Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional .fidelity.com for more recent performance information .                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] institutional .fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown .                                  
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown .                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 3.29%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Sep. 30, 2024                                  
Highest Quarterly Return 1.55%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Dec. 31, 2024                                  
Lowest Quarterly Return 1.02%                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | After Taxes on Distributions | Fidelity Advisor Conservative Income Bond Fund - Class A                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   1.63%                     2.45% [22]          
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | After Taxes on Distributions and Sales | Fidelity Advisor Conservative Income Bond Fund - Class A                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   2.20%                     2.58% [22]          
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                     3.42%          
FidelityAdvisorConservativeIncomeBondFund-ClassAIZ-PRO | Fidelity Conservative Income Bond Fund | LB151                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. 3-6 Month Treasury Bill Index                                
Average Annual Return, Percent   5.33%                     5.42%          
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | Fidelity Advisor Sustainable Low Duration Bond Fund - Class A                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 1.50%                                  
Maximum Deferred Sales Charge (as a percentage) [25] 0.00%                                  
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 0.15%                                  
Other Expenses (as a percentage of Assets): 0.12%                                  
Expenses (as a percentage of Assets) 0.47%                                  
Fee Waiver or Reimbursement [26] (0.02%)                                  
Net Expenses (as a percentage of Assets) 0.45%                                  
Expenses Deferred Charges [Text Block] Purchases of $250,000 or more will not be subject to a front-end sales charge, but may be subject to a 0.50% contingent deferred sales charge (CDSC) if the intermediary firm has elected an upfront finder's fee at the time the shares are purchased, or a 0.75% CDSC if the shares purchased are recordkept in a Fidelity Advisor ® 401(k) Retirement Plan.                                  
Expense Example, with Redemption, 1 Year $ 195                                  
Expense Example, with Redemption, 3 Years 296                                  
Expense Example, with Redemption, 5 Years 406                                  
Expense Example, with Redemption, 10 Years 730                                  
Expense Example, No Redemption, 1 Year 195                                  
Expense Example, No Redemption, 3 Years 296                                  
Expense Example, No Redemption, 5 Years 406                                  
Expense Example, No Redemption, 10 Years $ 730                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   3.52%                       3.42% [27]        
Annual Return [Percent]     5.10% 5.05%                            
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | Fidelity Advisor Sustainable Low Duration Bond Fund - Class M                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 1.50%                                  
Maximum Deferred Sales Charge (as a percentage) [28] 0.00%                                  
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 0.15%                                  
Other Expenses (as a percentage of Assets): 0.07%                                  
Expenses (as a percentage of Assets) 0.42%                                  
Fee Waiver or Reimbursement (0.00%)                                  
Net Expenses (as a percentage of Assets) 0.42%                                  
Expenses Deferred Charges [Text Block] Purchases of $250,000 or more will not be subject to a front-end sales charge but may be subject to a 0.25% CDSC if a finder's fee is paid at the time the shares are purchased.                                  
Expense Example, with Redemption, 1 Year $ 192                                  
Expense Example, with Redemption, 3 Years 283                                  
Expense Example, with Redemption, 5 Years 382                                  
Expense Example, with Redemption, 10 Years 672                                  
Expense Example, No Redemption, 1 Year 192                                  
Expense Example, No Redemption, 3 Years 283                                  
Expense Example, No Redemption, 5 Years 382                                  
Expense Example, No Redemption, 10 Years $ 672                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   3.54%                       3.44% [29]        
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | Fidelity Advisor Sustainable Low Duration Bond Fund - Class C                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%                                  
Maximum Deferred Sales Charge (as a percentage) [30] 1.00%                                  
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 1.00%                                  
Other Expenses (as a percentage of Assets): 0.08%                                  
Expenses (as a percentage of Assets) 1.28%                                  
Fee Waiver or Reimbursement (0.00%)                                  
Net Expenses (as a percentage of Assets) 1.28%                                  
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                                  
Expense Example, with Redemption, 1 Year $ 230                                  
Expense Example, with Redemption, 3 Years 406                                  
Expense Example, with Redemption, 5 Years 702                                  
Expense Example, with Redemption, 10 Years 1,321                                  
Expense Example, No Redemption, 1 Year 130                                  
Expense Example, No Redemption, 3 Years 406                                  
Expense Example, No Redemption, 5 Years 702                                  
Expense Example, No Redemption, 10 Years $ 1,321                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   3.23%                       3.12% [31]        
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | Fidelity Advisor Sustainable Low Duration Bond Fund - Class I                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%                                  
Maximum Deferred Sales Charge (as a percentage) 0.00%                                  
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.07%                                  
Expenses (as a percentage of Assets) 0.27%                                  
Fee Waiver or Reimbursement [26] (0.02%)                                  
Net Expenses (as a percentage of Assets) 0.25%                                  
Expense Example, with Redemption, 1 Year $ 26                                  
Expense Example, with Redemption, 3 Years 84                                  
Expense Example, with Redemption, 5 Years 149                                  
Expense Example, with Redemption, 10 Years 341                                  
Expense Example, No Redemption, 1 Year 26                                  
Expense Example, No Redemption, 3 Years 84                                  
Expense Example, No Redemption, 5 Years 149                                  
Expense Example, No Redemption, 10 Years $ 341                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   5.31%                       4.20% [32]        
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | Fidelity Advisor Sustainable Low Duration Bond Fund - Class Z                                    
Prospectus Line Items                                    
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%                                  
Maximum Deferred Sales Charge (as a percentage) 0.00%                                  
Management Fees (as a percentage of Assets) 0.20%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.05%                                  
Expenses (as a percentage of Assets) 0.25%                                  
Fee Waiver or Reimbursement [26] (0.05%)                                  
Net Expenses (as a percentage of Assets) 0.20%                                  
Expense Example, with Redemption, 1 Year $ 20                                  
Expense Example, with Redemption, 3 Years 74                                  
Expense Example, with Redemption, 5 Years 134                                  
Expense Example, with Redemption, 10 Years 311                                  
Expense Example, No Redemption, 1 Year 20                                  
Expense Example, No Redemption, 3 Years 74                                  
Expense Example, No Redemption, 5 Years 134                                  
Expense Example, No Redemption, 10 Years $ 311                                  
Annual Return, Inception Date Apr. 13, 2022                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   5.36%                       4.25% [33]        
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Low Duration Bond Fund /Fidelity Advisor® Sustainable Low Duration Bond Fund A, M, C, I, Z                                    
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® Sustainable Low Duration Bond Fund seeks to obtain a high level of current income consistent with preservation of capital.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 250,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 40 of the prospectus   and in the sales charge waiver appendix to the prospectus.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Fee Waiver or Reimbursement over Assets, Date of Termination Dec. 31, 2026                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 58 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 58.00%                                  
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 250,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 40 of the prospectus                                  
Expense Breakpoint, Minimum Investment Required [Amount] $ 250,000                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in investment-grade debt securities (those of medium and high quality) of all types that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).  Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Evaluating each security in which the fund invests using both a traditional bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or sponsor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) ESG factors related to the security's underlying pool of assets; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team. The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, vulnerability to the physical impacts of climate change, and research and investment into products, services, and energies that reduce emissions and/or provide opportunities to transition to less carbon-intensive products or operations. An assessment of an issuer's social profile includes, but is not limited to, its approach to diversity and inclusion, human capital management, data privacy, product safety and human rights. With respect to governance, the independence and diversity of an issuer's board, its compensation practices and board oversight of critical ESG issues are considered as part of the assessment. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. Investing in debt securities of issuers that the Adviser believes deliver tangible environmental or social impact through core business operations. An assessment of the impact characteristics of an issuer may involve corporate engagement and an analysis of issuer alignment with the United Nations Sustainable Development Goals using qualitative analysis as well as proprietary or third-party data. For example, issuers that provide access to clean water, education, or clean energy through their core business may be considered to deliver tangible impact. When evaluating securitized debt securities (including mortgage-backed securities, commercial mortgage-backed securities, and other asset-backed securities), generally considering the issuer's ESG rating along with ESG factors related to the underlying pool of assets, such as energy efficiency and environmental impact of the underlying assets; providing access to affordable housing or opportunities for first time home ownership; and compliance with fair lending laws. In addition to its focus on debt securities with positive ESG characteristics, analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Normally maintaining a duration of 1 year or less. Managing the fund to have similar overall interest rate risk to the Bloomberg US Treasury Bill: 6-9 Months Index. Normally maintaining a dollar-weighted average maturity of two years or less. Allocating assets across different market sectors and maturities. Investing more than 25% of total assets in the financial services industries. Investing in domestic and foreign issuers. Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] institutional.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.                                  
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 3.34%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Dec. 31, 2023                                  
Highest Quarterly Return 1.70%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Jun. 30, 2023                                  
Lowest Quarterly Return 0.94%                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Low Duration Bond Fund - Class A                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   1.71%                       2.11% [27]        
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Low Duration Bond Fund - Class A                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   2.17%                       2.08% [27]        
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | IXXXY                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg US Treasury Bill: 6-9 Months Index                                
Average Annual Return, Percent   4.88%                       3.62%        
FidelitySustainableLowDurationBondFund-AMCIZPRO | Fidelity Sustainable Low Duration Bond Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                       0.36%        
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | Fidelity Short-Term Bond Index Fund                                    
Prospectus Line Items                                    
Management Fees (as a percentage of Assets) 0.03%                                  
Distribution and Service (12b-1) Fees 0.00%                                  
Other Expenses (as a percentage of Assets): 0.00%                                  
Expenses (as a percentage of Assets) 0.03%                                  
Expense Example, with Redemption, 1 Year $ 3                                  
Expense Example, with Redemption, 3 Years 10                                  
Expense Example, with Redemption, 5 Years 17                                  
Expense Example, with Redemption, 10 Years $ 39                                  
Annual Return, Inception Date Oct. 18, 2017                                  
Average Annual Return, Label [Optional Text]   Return Before Taxes                                
Average Annual Return, Percent   3.89%                         1.29%   1.69% [34]  
Annual Return [Percent]     3.89% 4.90% (5.51%) (1.12%) 4.68% 4.95% 1.14%                  
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund                                    
Prospectus Line Items                                    
Risk/Return [Heading] Fund Summary Fund: Fidelity® Short-Term Bond Index Fund                                  
Objective [Heading] Investment Objective                                  
Objective, Primary [Text Block] Fidelity® Short-Term Bond Index Fund seeks to obtain a high level of current income consistent with preservation of capital.                                  
Expense Heading [Optional Text] Fee Table                                  
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below.                                  
Shareholder Fees Caption [Optional Text] Shareholder fees                                  
Shareholder Fee, Other $ 0                                  
Operating Expenses Caption [Optional Text] Annual Operating Expenses                                  
Portfolio Turnover [Heading] Portfolio Turnover                                  
Portfolio Turnover [Text Block] The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 55 % of the average value of its portfolio.                                  
Portfolio Turnover, Rate 55.00%                                  
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                                  
Strategy [Heading] Principal Investment Strategies                                  
Strategy Narrative [Text Block] Normally investing at least 80% of assets in securities included in the Bloomberg U.S. 1-5 Year Government/Credit Bond Index. The Bloomberg U.S. 1-5 Year Government/Credit Bond Index is a market value-weighted index of fixed-rate investment-grade debt securities with maturities from one to five years from the U.S. Treasury, U.S. Government-Related, and U.S. Corporate Indexes. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Normally maintaining a dollar-weighted average maturity that generally is expected to be three years or less, consistent with that of the index. Using statistical sampling techniques based on duration, maturity, interest rate sensitivity, security structure, and credit quality to attempt to replicate the returns of the Bloomberg U.S. 1-5 Year Government/Credit Bond Index using a smaller number of securities. Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. Investing in domestic and foreign issuers.                                  
Bar Chart and Performance Table [Heading] Performance                                  
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.                                  
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time.                                  
Performance Availability Website Address [Text] www.fidelity.com                                  
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                                  
Bar Chart [Heading] Year-by-Year Returns                                  
Year to Date Return, Label [Optional Text]    Year-to-Date Return                                  
Bar Chart, Year to Date Return, Date Sep. 30, 2025                                  
Bar Chart, Year to Date Return 4.82%                                  
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                                  
Highest Quarterly Return, Date Sep. 30, 2024                                  
Highest Quarterly Return 3.51%                                  
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                                  
Lowest Quarterly Return, Date Mar. 31, 2022                                  
Lowest Quarterly Return (3.38%)                                  
Performance Table Heading Average Annual Returns                                  
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                                  
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).                                  
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                                  
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | After Taxes on Distributions | Fidelity Short-Term Bond Index Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                                
Average Annual Return, Percent   2.77%                         0.61%   0.93% [34]  
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | After Taxes on Distributions and Sales | Fidelity Short-Term Bond Index Fund                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                                
Average Annual Return, Percent   2.35%                         0.71%   0.98% [34]  
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | LB001                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index                                
Average Annual Return, Percent   1.25%                         (0.33%)   0.99%  
FidelityShort-TermBondIndexFund-PRO | Fidelity Short-Term Bond Index Fund | LB087                                    
Prospectus Line Items                                    
Average Annual Return, Label [Optional Text]   Bloomberg U.S. 1-5 Year Government/Credit Bond Index                                
Average Annual Return, Percent   3.76%                         1.29%   1.74%  
Document Type 485BPOS                                  
Registrant Name Fidelity Salem Street Trust                                  
[1]
A From May 17, 2023 .
[2]
A From June 19, 2018 .
[3]
A Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse the class of shares of the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.25% (the Expense Cap). If at any time during the current fiscal year expenses for the class of shares of the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through December 31, 2026 . FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.
[4]
A From April 13, 2022 .
[5]
A Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, fees and expenses of the Independent Trustees, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.003% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through December 31, 2028 . FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.
[6]
A From May 11, 2023 .
[7]
A Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.20% (the Expense Cap). If at any time during the current fiscal year expenses for the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through December 31, 2026 . FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.
[8]
A From April 13, 2022 .
[9]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 0.75% and 0.25%, respectively.
[10]
A From April 13, 2022 .
[11]
B From April 13, 2022 .
[12]
B On Class C shares redeemed less than one year after purchase.
[13]
C From April 13, 2022 .
[14]
A Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse Class I and Class Z of the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of their respective average net assets, exceed 0. 45% and 0. 36% (the Expense Caps ). If at any time during the current fiscal year expenses for Class I or Class Z of the fund fall below the Expense Caps , FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Caps. These arrangements will remain in effect through December 31, 2026 . FMR may not terminate these arrangements before the expiration date without the approval of the Board of Trustees and may extend them in its discretion after that date.
[15]
D From April 13, 2022 .
[16]
E From April 13, 2022 .
[17]
A From August 17, 2018 .
[18]
A Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse the class of shares of the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of its average net assets, exceed 0.25% (the Expense Cap). If at any time during the current fiscal year expenses for the class of shares of the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through December 31, 2026 . FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.
[19]
A From April 13, 2022 .
[20]
A Purchases of $250,000 or more will not be subject to a front-end sales charge, but may be subject to a 0.50% contingent deferred sales charge (CDSC) if the intermediary firm has elected an upfront finder's fee at the time the shares are purchased, or a 0.75% CDSC if the shares purchased are recordkept in a Fidelity Advisor ® 401(k) Retirement Plan.
[21]
A Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse Class A, Class I, and Class Z of the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of their average net assets, exceed 0.45%, 0.25%, and 0.20% (the Expense Caps). If at any time during the current fiscal year expenses for Class A, Class I, or Class Z of the fund fall below the Expense Caps, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Caps. These arrangements will remain in effect through December 31, 2026 . FMR may not terminate these arrangements before the expiration date without the approval of the Board of Trustees and may extend them in its discretion after that date.
[22]
A From May 25, 2023 .
[23]
B From May 25, 2023 .
[24]
C From May 25, 2023 .
[25]
A Purchases of $250,000 or more will not be subject to a front-end sales charge, but may be subject to a 0.50% contingent deferred sales charge (CDSC) if the intermediary firm has elected an upfront finder's fee at the time the shares are purchased, or a 0.75% CDSC if the shares purchased are recordkept in a Fidelity Advisor ® 401(k) Retirement Plan.
[26]
A Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse Class A, Class I, and Class Z of the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund's securities lending program, if applicable), as a percentage of their respective average net assets, exceed 0. 45%, 0. 25% and 0.20% (the Expense Caps). If at any time during the current fiscal year expenses for Class A, Class I, or Class Z of the fund fall below the Expense Caps, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Caps. These arrangements will remain in effect through December 31, 2026 . FMR may not terminate these arrangements before the expiration date without the approval of the Board of Trustees and may extend them in its discretion after that date.
[27]
A From April 13, 2022 .
[28]
B Purchases of $250,000 or more will not be subject to a front-end sales charge but may be subject to a 0.25% CDSC if a finder's fee is paid at the time the shares are purchased.
[29]
B From April 13, 2022 .
[30]
C On Class C shares redeemed less than one year after purchase.
[31]
C From April 13, 2022 .
[32]
D From April 13, 2022 .
[33]
E From April 13, 2022 .
[34]
A From October 18, 2017 .