Fidelity SAI U.S. Treasury Bond Index Fund (FUTBX) N-CSR 24 Oct 24 Certified annual shareholder report (management investment company) Financial data

Form N-CSR Cover

Form N-CSR Cover	12 Months Ended
	Aug. 31, 2024
Shareholder Report [Line Items]
Document Type	N-CSR
Amendment Flag	false
Registrant Name	Fidelity Salem Street Trust
Entity Central Index Key	0000035315
Entity Investment Company Type	N-1A
Document Period End Date	Aug. 31, 2024

Shareholder Report

Shareholder Report	12 Months Ended
	Aug. 31, 2024 USD ($) shares
Shareholder Report [Line Items]
Document Type	N-CSR
Amendment Flag	false
Registrant Name	Fidelity Salem Street Trust
Entity Central Index Key	0000035315
Entity Investment Company Type	N-1A
Document Period End Date	Aug. 31, 2024
Fidelity Flex Conservative Income Bond Fund
Shareholder Report [Line Items]
Fund Name	Fidelity Flex® Conservative Income Bond Fund
Class Name	Fidelity Flex® Conservative Income Bond Fund
Trading Symbol	FJTDX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity Flex® Conservative Income Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-800-544-3455
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity Flex® Conservative Income Bond Fund $ A 0.00 % B A Amount represents less than $.50 B Amount represents less than 0.005%
Expenses Paid, Amount	$ 0
Expense Ratio, Percent	0%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B26">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE May 31, 2018 through August 31, 2024. Initial investment of $10,000. Fidelity Flex® Conservative Income Bond Fund   $10,000 $10,066   $10,348   $10,565   $10,614   $10,637   $11,153   Bloomberg U.S. 3-6 Month Treasury Bill Index   $10,000 $10,050   $10,302   $10,457   $10,466   $10,495   $10,945   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,054   $11,077   $11,794   $11,784   $10,427   $10,303     2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year Life of Fund A Fidelity Flex® Conservative Income Bond Fund 6.11% 2.72% 2.73% Bloomberg U.S. 3-6 Month Treasury Bill Index 5.55% 2.32% 2.34% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.62% A   From May 31, 2018   Visit www.401k.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	May 31, 2018
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 447,221,578
Holdings Count | shares	313
Advisory Fees Paid, Amount	$ 0
Investment Company Portfolio Turnover	72%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 313 Total Advisory Fee $ Portfolio Turnover 72 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 16.5 AAA 14.1 AA 2.5 A 24.8 BBB 19.4 Short-Term Investments and Net Other Assets (Liabilities) 22.7 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 46.6 U.S. Treasury Obligations 16.5 Asset-Backed Securities 14.1 Other Investments 0.1 Short-Term Investments and Net Other Assets (Liabilities) 22.7 ASSET ALLOCATION (% of Fund's net assets) United States 84.0 United Kingdom 3.5 Canada 3.3 Germany 3.2 Switzerland 1.3 Japan 1.1 Netherlands 1.0 France 0.9 Denmark 0.7 Others 1.0 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Bill 11.6     US Treasury Notes 4.9     Royal Bank of Canada 1.5     Bank of America Corp 1.3     Volkswagen Group of America Finance LLC 1.3     Goldman Sachs Group Inc/The 1.3     General Motors Financial Co Inc 1.1     Morgan Stanley 1.0     JPMorgan Chase & Co 1.0     Barclays PLC 1.0       26.0
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-3455 or by sending an e-mail to fidfunddocuments fidelity.com . The fund added a contractual proxy and shareholder meeting expense cap during the reporting period. The fund's principal investment strategies were modified during the reporting period, as described in the prospectus.
Material Fund Change Expenses [Text Block]	The fund added a contractual proxy and shareholder meeting expense cap during the reporting period.
Material Fund Change Strategies [Text Block]	The fund's principal investment strategies were modified during the reporting period, as described in the prospectus.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-3455 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-800-544-3455</span>" id="sjs-B42">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-3455&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B43">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B44">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Tactical Bond Fund - Class M
Shareholder Report [Line Items]
Fund Name	Fidelity® Tactical Bond Fund
Class Name	Fidelity Advisor® Tactical Bond Fund Class M
Trading Symbol	FTYMX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Tactical Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.95 %
Expenses Paid, Amount	$ 98
Expense Ratio, Percent	0.95%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B61">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE February 10, 2022 through August 31, 2024. Initial investment of $10,000 and the current sales charge was paid. Class M   $9,600 $8,887   $8,910   Bloomberg U.S. Aggregate Bond Index   $10,000 $9,301   $9,190     2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year Life of Fund A Class M (incl. 4.00% sales charge)   3.29% -1.64% Class M (without 4.00% sales charge) 7.60% -0.06% Bloomberg U.S. Aggregate Bond Index 7.30% -0.55% A   From February 10, 2022   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Feb. 10, 2022
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 56,713,648
Holdings Count | shares	95
Advisory Fees Paid, Amount	$ 295,549
Investment Company Portfolio Turnover	32%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 95 Total Advisory Fee $ Portfolio Turnover 32 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 57.1 AAA 0.6 AA 0.5 A 3.3 BBB 11.6 BB 9.5 B 8.6 CCC,CC,C 1.6 D 0.1 Not Rated 3.1 Equities 0.7 Short-Term Investments and Net Other Assets (Liabilities) 3.3 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 57.1 Corporate Bonds 16.1 Bank Loan Obligations 9.0 Foreign Government and Government Agency Obligations 4.8 Asset-Backed Securities 4.5 Preferred Securities 2.3 CMOs and Other Mortgage Related Securities 1.5 Municipal Securities 0.7 Common Stocks 0.4 Alternative Funds 0.3 Short-Term Investments and Net Other Assets (Liabilities) 3.3 ASSET ALLOCATION (% of Fund's net assets)   United States 85.4 Canada 2.0 United Kingdom 1.9 Mexico 1.7 Germany 1.3 Grand Cayman (Uk Overseas Ter) 1.1 Brazil 1.1 Japan 1.0 Dominican Republic 0.9 Others 3.6 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 44.7     US Treasury Bonds 12.4     Domino's Pizza Master Issuer LLC 1.5     Bank of Nova Scotia/The 1.2     Japan Government 1.0     Petroleos Mexicanos 0.9     Dominican Republic 0.9     Kinder Morgan Inc 0.9     DPL Inc 0.8     Planet Fitness Master Issuer LLC 0.8       65.1
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Material Fund Change Expenses [Text Block]	The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B76">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B77">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B78">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Investment Grade Bond Fund - Class M
Shareholder Report [Line Items]
Fund Name	Fidelity® Investment Grade Bond Fund
Class Name	Fidelity Advisor® Investment Grade Bond Fund Class M
Trading Symbol	FGBTX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Investment Grade Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.75 %
Expenses Paid, Amount	$ 78
Expense Ratio, Percent	0.75%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B95">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the past 10 years?      CUMULATIVE PERFORMANCE August 31, 2014 through August 31, 2024. Initial investment of $10,000 and the current sales charge was paid. Class M   $9,600 $9,593   $10,189   $10,291   $10,161   $11,187   $12,115   $12,210   $10,756   $10,654   $11,454   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,156   $10,761   $10,814   $10,701   $11,789   $12,553   $12,542   $11,098   $10,965   $11,765     2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year 10 Year Class M (incl. 4.00% sales charge)   3.21% -0.34% 1.37% Class M (without 4.00% sales charge) 7.51% 0.47% 1.78% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.64%   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 10,877,326,398
Holdings Count | shares	3,997
Advisory Fees Paid, Amount	$ 26,423,417
Investment Company Portfolio Turnover	232%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 3,997 Total Advisory Fee $ Portfolio Turnover 232 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 61.9 AAA 7.6 AA 0.6 A 6.0 BBB 16.7 BB 3.3 B 0.9 CCC,CC,C 0.0 Not Rated 3.7 QUALITY DIVERSIFICATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)%   We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 51.8 Corporate Bonds 24.5 U.S. Government Agency - Mortgage Securities 10.1 Asset-Backed Securities 7.1 CMOs and Other Mortgage Related Securities 6.8 Preferred Securities 0.2 Foreign Government and Government Agency Obligations 0.1 Other Investments 0.1 Municipal Securities 0.0 Bank Loan Obligations 0.0 ASSET ALLOCATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)% United States 90.5 Grand Cayman (UK Overseas Ter) 4.2 Germany 1.1 Mexico 0.7 United Kingdom 0.7 Ireland 0.5 Switzerland 0.5 Bailiwick Of Jersey 0.4 Italy 0.3 Others 1.1 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 43.0     US Treasury Bonds 8.8     Uniform Mortgage Backed Securities 3.4     Fannie Mae Mortgage pass-thru certificates 3.2     Freddie Mac Gold Pool 1.7     Ginnie Mae II Pool 1.6     Citigroup Inc 1.5     Bank of America Corp 1.2     Charter Communications Operating LLC / Charter Communications Operating Capital 1.0     Bayer US Finance II LLC 0.9       66.3
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's contractual management fee was reduced during the reporting period.
Material Fund Change Expenses [Text Block]	The fund's contractual management fee was reduced during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B109">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B110">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B111">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Short-Term Bond Fund - Class M
Shareholder Report [Line Items]
Fund Name	Fidelity® Short-Term Bond Fund
Class Name	Fidelity Advisor® Short-Term Bond Fund Class M
Trading Symbol	FBNTX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Short-Term Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.51 %
Expenses Paid, Amount	$ 53
Expense Ratio, Percent	0.51%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B128">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE July 12, 2016 through August 31, 2024. Initial investment of $10,000 and the current sales charge was paid. Class M   $9,850 $9,859   $9,939   $9,950   $10,360   $10,745   $10,765   $10,293   $10,508   Bloomberg U.S. 1-3 Year Government/Credit Bond Index   $10,000 $10,001   $10,091   $10,107   $10,573   $10,961   $11,004   $10,566   $10,731   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,020   $10,069   $9,963   $10,977   $11,687   $11,678   $10,333   $10,209     2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year Life of Fund A Class M (incl. 1.50% sales charge)   4.91% 1.25% 1.39% Class M (without 1.50% sales charge) 6.51% 1.56% 1.58% Bloomberg U.S. 1-3 Year Government/Credit Bond Index 6.25% 1.52% 1.62% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.13% A   From July 12, 2016   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Jul. 12, 2016
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 2,346,008,597
Holdings Count | shares	491
Advisory Fees Paid, Amount	$ 4,742,667
Investment Company Portfolio Turnover	68%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 491 Total Advisory Fee $ Portfolio Turnover 68 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 26.4 AAA 22.3 AA 2.9 A 21.6 BBB 20.4 BB 1.3 B 0.3 Not Rated 3.4 Short-Term Investments and Net Other Assets (Liabilities) 1.4 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 45.1 U.S. Treasury Obligations 26.1 Asset-Backed Securities 19.3 CMOs and Other Mortgage Related Securities 7.2 Other Investments 0.6 U.S. Government Agency - Mortgage Securities 0.3 Short-Term Investments and Net Other Assets (Liabilities) 1.4 ASSET ALLOCATION (% of Fund's net assets)   United States 77.7 Grand Cayman (Uk Overseas Ter) 4.4 Canada 3.6 United Kingdom 3.3 Germany 3.1 France 2.1 Ireland 1.2 Japan 1.0 Italy 0.7 Others 2.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 26.1     JPMorgan Chase & Co 1.4     Wells Fargo & Co 1.2     Barclays PLC 1.0     Athene Global Funding 0.9     AerCap Ireland Capital DAC / AerCap Global Aviation Trust 0.9     General Motors Financial Co Inc 0.9     American Express Co 0.8     Citigroup Inc 0.8     Ford Motor Credit Co LLC 0.8       34.8
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses
Material Fund Change Expenses [Text Block]	The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B143">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B144">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B145">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity SAI Sustainable Core Plus Bond Fund
Shareholder Report [Line Items]
Fund Name	Fidelity® SAI Sustainable Core Plus Bond Fund
Class Name	Fidelity® SAI Sustainable Core Plus Bond Fund
Trading Symbol	FIABX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® SAI Sustainable Core Plus Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-800-544-3455
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® SAI Sustainable Core Plus Bond Fund $ 0.36 %
Expenses Paid, Amount	$ 37
Expense Ratio, Percent	0.36%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • Application of FMR's environmental, social, and governance (ESG) ratings process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance.
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B162">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE April 13, 2022 through August 31, 2024. Initial investment of $10,000. Fidelity® SAI Sustainable Core Plus Bond Fund   $10,000 $9,587   $9,551   Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index   $10,000 $9,703   $9,590   Bloomberg U.S. Aggregate Bond Index   $10,000 $9,696   $9,581     2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year Life of Fund A Fidelity® SAI Sustainable Core Plus Bond Fund 7.31% 1.04% Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index 7.26% 1.19% Bloomberg U.S. Aggregate Bond Index 7.30% 1.16% A   From April 13, 2022   Visit www.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Apr. 13, 2022
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 83,384,427
Holdings Count | shares	690
Advisory Fees Paid, Amount	$ 160,853
Investment Company Portfolio Turnover	364%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 690 Total Advisory Fee $ Portfolio Turnover 364 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 69.8 AAA 4.6 AA 0.5 A 7.6 BBB 12.0 BB 2.8 B 2.6 CCC,CC,C 0.9 Not Rated 1.3 Equities 0.0 QUALITY DIVERSIFICATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (2.1)%   We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 49.4 Corporate Bonds 25.7 U.S. Government Agency - Mortgage Securities 20.4 Asset-Backed Securities 5.5 CMOs and Other Mortgage Related Securities 0.4 Foreign Government and Government Agency Obligations 0.3 Preferred Securities 0.2 Bank Loan Obligations 0.2 Common Stocks 0.0 ASSET ALLOCATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (2.1)% United States 88.3 Grand Cayman (Uk Overseas Ter) 3.4 United Kingdom 1.5 Bailiwick Of Jersey 1.3 Canada 0.9 Netherlands 0.7 Multi-national 0.6 France 0.6 Germany 0.5 Others 2.2 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 34.9     US Treasury Bonds 10.4     Uniform Mortgage Backed Securities 9.3     Ginnie Mae II Pool 5.4     US Treasury Bill 4.1     Fannie Mae Mortgage pass-thru certificates 3.9     Freddie Mac Gold Pool 1.6     Morgan Stanley 1.2     Bank of America Corp 0.9     AES Corp/The 0.7       72.4
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-3455 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's contractual management fee was reduced during the reporting period. The fund modified its principal investment risks during the reporting period.
Material Fund Change Expenses [Text Block]	The fund's contractual management fee was reduced during the reporting period.
Material Fund Change Risks Change [Text Block]	The fund modified its principal investment risks during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-3455 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-800-544-3455</span>" id="sjs-B178">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-3455&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B179">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B180">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Tactical Bond Fund - Class I
Shareholder Report [Line Items]
Fund Name	Fidelity® Tactical Bond Fund
Class Name	Fidelity Advisor® Tactical Bond Fund Class I
Trading Symbol	FBAHX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Tactical Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.70 %
Expenses Paid, Amount	$ 72
Expense Ratio, Percent	0.70%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B197">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE February 10, 2022 through August 31, 2024. Initial investment of $10,000. Class I   $10,000 $9,270   $9,317   Bloomberg U.S. Aggregate Bond Index   $10,000 $9,301   $9,190     2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year Life of Fund A Class I 7.86% 0.19% Bloomberg U.S. Aggregate Bond Index 7.30% -0.55% A   From February 10, 2022   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Feb. 10, 2022
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 56,713,648
Holdings Count | shares	95
Advisory Fees Paid, Amount	$ 295,549
Investment Company Portfolio Turnover	32%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 95 Total Advisory Fee $ Portfolio Turnover 32 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 57.1 AAA 0.6 AA 0.5 A 3.3 BBB 11.6 BB 9.5 B 8.6 CCC,CC,C 1.6 D 0.1 Not Rated 3.1 Equities 0.7 Short-Term Investments and Net Other Assets (Liabilities) 3.3 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 57.1 Corporate Bonds 16.1 Bank Loan Obligations 9.0 Foreign Government and Government Agency Obligations 4.8 Asset-Backed Securities 4.5 Preferred Securities 2.3 CMOs and Other Mortgage Related Securities 1.5 Municipal Securities 0.7 Common Stocks 0.4 Alternative Funds 0.3 Short-Term Investments and Net Other Assets (Liabilities) 3.3 ASSET ALLOCATION (% of Fund's net assets)   United States 85.4 Canada 2.0 United Kingdom 1.9 Mexico 1.7 Germany 1.3 Grand Cayman (Uk Overseas Ter) 1.1 Brazil 1.1 Japan 1.0 Dominican Republic 0.9 Others 3.6 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 44.7     US Treasury Bonds 12.4     Domino's Pizza Master Issuer LLC 1.5     Bank of Nova Scotia/The 1.2     Japan Government 1.0     Petroleos Mexicanos 0.9     Dominican Republic 0.9     Kinder Morgan Inc 0.9     DPL Inc 0.8     Planet Fitness Master Issuer LLC 0.8       65.1
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Material Fund Change Expenses [Text Block]	The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B212">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B213">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B214">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Short-Term Bond Fund - Class C
Shareholder Report [Line Items]
Fund Name	Fidelity® Short-Term Bond Fund
Class Name	Fidelity Advisor® Short-Term Bond Fund Class C
Trading Symbol	FANCX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Short-Term Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.36 %
Expenses Paid, Amount	$ 140
Expense Ratio, Percent	1.36%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B231">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE July 12, 2016 through August 31, 2024. Initial investment of $10,000. Class C   $10,000 $10,001   $10,003   $9,917   $10,250   $10,530   $10,469   $9,928   $10,050   Bloomberg U.S. 1-3 Year Government/Credit Bond Index   $10,000 $10,001   $10,091   $10,107   $10,573   $10,961   $11,004   $10,566   $10,731   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,020   $10,069   $9,963   $10,977   $11,687   $11,678   $10,333   $10,209     2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year Life of Fund A Class C  (incl. contingent deferred sales charge) 4.50% 0.68% 0.73% Class C 5.50% 0.68% 0.73% Bloomberg U.S. 1-3 Year Government/Credit Bond Index 6.25% 1.52% 1.62% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.13% A   From July 12, 2016   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Jul. 12, 2016
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 2,346,008,597
Holdings Count | shares	491
Advisory Fees Paid, Amount	$ 4,742,667
Investment Company Portfolio Turnover	68%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 491 Total Advisory Fee $ Portfolio Turnover 68 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 26.4 AAA 22.3 AA 2.9 A 21.6 BBB 20.4 BB 1.3 B 0.3 Not Rated 3.4 Short-Term Investments and Net Other Assets (Liabilities) 1.4 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 45.1 U.S. Treasury Obligations 26.1 Asset-Backed Securities 19.3 CMOs and Other Mortgage Related Securities 7.2 Other Investments 0.6 U.S. Government Agency - Mortgage Securities 0.3 Short-Term Investments and Net Other Assets (Liabilities) 1.4 ASSET ALLOCATION (% of Fund's net assets)   United States 77.7 Grand Cayman (Uk Overseas Ter) 4.4 Canada 3.6 United Kingdom 3.3 Germany 3.1 France 2.1 Ireland 1.2 Japan 1.0 Italy 0.7 Others 2.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 26.1     JPMorgan Chase & Co 1.4     Wells Fargo & Co 1.2     Barclays PLC 1.0     Athene Global Funding 0.9     AerCap Ireland Capital DAC / AerCap Global Aviation Trust 0.9     General Motors Financial Co Inc 0.9     American Express Co 0.8     Citigroup Inc 0.8     Ford Motor Credit Co LLC 0.8       34.8
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses
Material Fund Change Expenses [Text Block]	The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B246">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B247">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B248">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Short-Term Bond Fund - Class A
Shareholder Report [Line Items]
Fund Name	Fidelity® Short-Term Bond Fund
Class Name	Fidelity Advisor® Short-Term Bond Fund Class A
Trading Symbol	FBNAX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Short-Term Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.50 %
Expenses Paid, Amount	$ 52
Expense Ratio, Percent	0.50%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B265">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE July 12, 2016 through August 31, 2024. Initial investment of $10,000 and the current sales charge was paid. Class A   $9,850 $9,859   $9,941   $9,952   $10,364   $10,750   $10,771   $10,299   $10,516   Bloomberg U.S. 1-3 Year Government/Credit Bond Index   $10,000 $10,001   $10,091   $10,107   $10,573   $10,961   $11,004   $10,566   $10,731   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,020   $10,069   $9,963   $10,977   $11,687   $11,678   $10,333   $10,209     2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year Life of Fund A Class A (incl. 1.50% sales charge)   4.92% 1.26% 1.40% Class A (without 1.50% sales charge) 6.52% 1.57% 1.59% Bloomberg U.S. 1-3 Year Government/Credit Bond Index 6.25% 1.52% 1.62% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.13% A   From July 12, 2016   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Jul. 12, 2016
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 2,346,008,597
Holdings Count | shares	491
Advisory Fees Paid, Amount	$ 4,742,667
Investment Company Portfolio Turnover	68%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 491 Total Advisory Fee $ Portfolio Turnover 68 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 26.4 AAA 22.3 AA 2.9 A 21.6 BBB 20.4 BB 1.3 B 0.3 Not Rated 3.4 Short-Term Investments and Net Other Assets (Liabilities) 1.4 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 45.1 U.S. Treasury Obligations 26.1 Asset-Backed Securities 19.3 CMOs and Other Mortgage Related Securities 7.2 Other Investments 0.6 U.S. Government Agency - Mortgage Securities 0.3 Short-Term Investments and Net Other Assets (Liabilities) 1.4 ASSET ALLOCATION (% of Fund's net assets)   United States 77.7 Grand Cayman (Uk Overseas Ter) 4.4 Canada 3.6 United Kingdom 3.3 Germany 3.1 France 2.1 Ireland 1.2 Japan 1.0 Italy 0.7 Others 2.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 26.1     JPMorgan Chase & Co 1.4     Wells Fargo & Co 1.2     Barclays PLC 1.0     Athene Global Funding 0.9     AerCap Ireland Capital DAC / AerCap Global Aviation Trust 0.9     General Motors Financial Co Inc 0.9     American Express Co 0.8     Citigroup Inc 0.8     Ford Motor Credit Co LLC 0.8       34.8
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses
Material Fund Change Expenses [Text Block]	The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B280">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B281">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B282">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Short-Term Bond Fund - Class I
Shareholder Report [Line Items]
Fund Name	Fidelity® Short-Term Bond Fund
Class Name	Fidelity Advisor® Short-Term Bond Fund Class I
Trading Symbol	FBNIX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Short-Term Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.30 %
Expenses Paid, Amount	$ 31
Expense Ratio, Percent	0.30%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B299">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE July 12, 2016 through August 31, 2024. Initial investment of $10,000. Class I   $10,000 $10,011   $10,109   $10,136   $10,570   $10,980   $11,017   $10,550   $10,791   Bloomberg U.S. 1-3 Year Government/Credit Bond Index   $10,000 $10,001   $10,091   $10,107   $10,573   $10,961   $11,004   $10,566   $10,731   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,020   $10,069   $9,963   $10,977   $11,687   $11,678   $10,333   $10,209     2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year Life of Fund A Class I 6.73% 1.73% 1.75% Bloomberg U.S. 1-3 Year Government/Credit Bond Index 6.25% 1.52% 1.62% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.13% A   From July 12, 2016   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Jul. 12, 2016
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 2,346,008,597
Holdings Count | shares	491
Advisory Fees Paid, Amount	$ 4,742,667
Investment Company Portfolio Turnover	68%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 491 Total Advisory Fee $ Portfolio Turnover 68 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 26.4 AAA 22.3 AA 2.9 A 21.6 BBB 20.4 BB 1.3 B 0.3 Not Rated 3.4 Short-Term Investments and Net Other Assets (Liabilities) 1.4 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 45.1 U.S. Treasury Obligations 26.1 Asset-Backed Securities 19.3 CMOs and Other Mortgage Related Securities 7.2 Other Investments 0.6 U.S. Government Agency - Mortgage Securities 0.3 Short-Term Investments and Net Other Assets (Liabilities) 1.4 ASSET ALLOCATION (% of Fund's net assets)   United States 77.7 Grand Cayman (Uk Overseas Ter) 4.4 Canada 3.6 United Kingdom 3.3 Germany 3.1 France 2.1 Ireland 1.2 Japan 1.0 Italy 0.7 Others 2.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 26.1     JPMorgan Chase & Co 1.4     Wells Fargo & Co 1.2     Barclays PLC 1.0     Athene Global Funding 0.9     AerCap Ireland Capital DAC / AerCap Global Aviation Trust 0.9     General Motors Financial Co Inc 0.9     American Express Co 0.8     Citigroup Inc 0.8     Ford Motor Credit Co LLC 0.8       34.8
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses • Expense reductions
Material Fund Change Expenses [Text Block]	The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses • Expense reductions
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B314">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B315">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B316">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Investment Grade Bond Fund
Shareholder Report [Line Items]
Fund Name	Fidelity® Investment Grade Bond Fund
Class Name	Fidelity® Investment Grade Bond Fund
Trading Symbol	FBNDX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Investment Grade Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-800-544-8544
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Investment Grade Bond Fund $ 0.45 %
Expenses Paid, Amount	$ 47
Expense Ratio, Percent	0.45%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B333">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the past 10 years?      CUMULATIVE PERFORMANCE August 31, 2014 through August 31, 2024. Initial investment of $10,000. Fidelity® Investment Grade Bond Fund   $10,000 $10,028   $10,688   $10,834   $10,733   $11,854   $12,877   $13,015   $11,515   $11,425   $12,320   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,156   $10,761   $10,814   $10,701   $11,789   $12,553   $12,542   $11,098   $10,965   $11,765     2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year 10 Year Fidelity® Investment Grade Bond Fund 7.83% 0.77% 2.11% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.64%   Visit www.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 10,877,326,398
Holdings Count | shares	3,997
Advisory Fees Paid, Amount	$ 26,423,417
Investment Company Portfolio Turnover	232%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 3,997 Total Advisory Fee $ Portfolio Turnover 232 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 61.9 AAA 7.6 AA 0.6 A 6.0 BBB 16.7 BB 3.3 B 0.9 CCC,CC,C 0.0 Not Rated 3.7 QUALITY DIVERSIFICATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)%   We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 51.8 Corporate Bonds 24.5 U.S. Government Agency - Mortgage Securities 10.1 Asset-Backed Securities 7.1 CMOs and Other Mortgage Related Securities 6.8 Preferred Securities 0.2 Foreign Government and Government Agency Obligations 0.1 Other Investments 0.1 Municipal Securities 0.0 Bank Loan Obligations 0.0 ASSET ALLOCATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)% United States 90.5 Grand Cayman (UK Overseas Ter) 4.2 Germany 1.1 Mexico 0.7 United Kingdom 0.7 Ireland 0.5 Switzerland 0.5 Bailiwick Of Jersey 0.4 Italy 0.3 Others 1.1 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 43.0     US Treasury Bonds 8.8     Uniform Mortgage Backed Securities 3.4     Fannie Mae Mortgage pass-thru certificates 3.2     Freddie Mac Gold Pool 1.7     Ginnie Mae II Pool 1.6     Citigroup Inc 1.5     Bank of America Corp 1.2     Charter Communications Operating LLC / Charter Communications Operating Capital 1.0     Bayer US Finance II LLC 0.9       66.3
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's contractual management fee was reduced during the reporting period.
Material Fund Change Expenses [Text Block]	The fund's contractual management fee was reduced during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-800-544-8544</span>" id="sjs-B347">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-8544&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B348">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B349">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Tactical Bond Fund - Class C
Shareholder Report [Line Items]
Fund Name	Fidelity® Tactical Bond Fund
Class Name	Fidelity Advisor® Tactical Bond Fund Class C
Trading Symbol	FTKCX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Tactical Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.70 %
Expenses Paid, Amount	$ 176
Expense Ratio, Percent	1.70%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B366">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE February 10, 2022 through August 31, 2024. Initial investment of $10,000. Class C   $10,000 $9,210   $9,174   Bloomberg U.S. Aggregate Bond Index   $10,000 $9,301   $9,190     2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year Life of Fund A Class C  (incl. contingent deferred sales charge) 5.79% -0.80% Class C 6.79% -0.80% Bloomberg U.S. Aggregate Bond Index 7.30% -0.55% A   From February 10, 2022   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Feb. 10, 2022
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 56,713,648
Holdings Count | shares	95
Advisory Fees Paid, Amount	$ 295,549
Investment Company Portfolio Turnover	32%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 95 Total Advisory Fee $ Portfolio Turnover 32 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 57.1 AAA 0.6 AA 0.5 A 3.3 BBB 11.6 BB 9.5 B 8.6 CCC,CC,C 1.6 D 0.1 Not Rated 3.1 Equities 0.7 Short-Term Investments and Net Other Assets (Liabilities) 3.3 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 57.1 Corporate Bonds 16.1 Bank Loan Obligations 9.0 Foreign Government and Government Agency Obligations 4.8 Asset-Backed Securities 4.5 Preferred Securities 2.3 CMOs and Other Mortgage Related Securities 1.5 Municipal Securities 0.7 Common Stocks 0.4 Alternative Funds 0.3 Short-Term Investments and Net Other Assets (Liabilities) 3.3 ASSET ALLOCATION (% of Fund's net assets)   United States 85.4 Canada 2.0 United Kingdom 1.9 Mexico 1.7 Germany 1.3 Grand Cayman (Uk Overseas Ter) 1.1 Brazil 1.1 Japan 1.0 Dominican Republic 0.9 Others 3.6 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 44.7     US Treasury Bonds 12.4     Domino's Pizza Master Issuer LLC 1.5     Bank of Nova Scotia/The 1.2     Japan Government 1.0     Petroleos Mexicanos 0.9     Dominican Republic 0.9     Kinder Morgan Inc 0.9     DPL Inc 0.8     Planet Fitness Master Issuer LLC 0.8       65.1
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Material Fund Change Expenses [Text Block]	The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B381">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B382">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B383">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity SAI Total Bond Fund
Shareholder Report [Line Items]
Fund Name	Fidelity® SAI Total Bond Fund
Class Name	Fidelity® SAI Total Bond Fund
Trading Symbol	FSMTX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® SAI Total Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-800-544-3455
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® SAI Total Bond Fund $ 0.29 %
Expenses Paid, Amount	$ 30
Expense Ratio, Percent	0.29%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B400">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE October 25, 2018 through August 31, 2024. Initial investment of $10,000. Fidelity® SAI Total Bond Fund   $10,000 $11,067   $11,859   $12,193   $10,847   $10,891   $11,836   Bloomberg U.S. Universal Bond Index   $10,000 $11,125   $11,839   $11,944   $10,528   $10,486   $11,317   Bloomberg U.S. Aggregate Bond Index   $10,000 $11,154   $11,876   $11,866   $10,499   $10,374   $11,131     2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year Life of Fund A Fidelity® SAI Total Bond Fund 8.67% 1.35% 2.92% Bloomberg U.S. Universal Bond Index 7.92% 0.34% 2.14% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.85% A   From October 25, 2018   Visit www.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Oct. 25, 2018
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 20,001,646,047
Holdings Count | shares	6,421
Advisory Fees Paid, Amount	$ 56,941,200
Investment Company Portfolio Turnover	222%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 6,421 Total Advisory Fee $ Portfolio Turnover 222 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 51.0 AAA 9.6 AA 1.4 A 9.5 BBB 18.2 BB 4.4 B 5.9 CCC,CC,C 1.2 D 0.0 Not Rated 4.1 Equities 0.1 QUALITY DIVERSIFICATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (5.4)%   We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 31.4 U.S. Treasury Obligations 28.8 U.S. Government Agency - Mortgage Securities 22.2 Asset-Backed Securities 8.0 CMOs and Other Mortgage Related Securities 7.9 Bank Loan Obligations 5.0 Foreign Government and Government Agency Obligations 1.3 Preferred Securities 0.5 Common Stocks 0.1 Other Investments 0.1 Supranational Obligations 0.1 Preferred Stocks 0.0 ASSET ALLOCATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (5.4)% United States 85.3 Grand Cayman (UK Overseas Ter) 4.4 United Kingdom 1.7 Mexico 1.3 Germany 1.3 Ireland 0.9 Switzerland 0.8 France 0.5 Canada 0.4 Others 3.4 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 19.5     US Treasury Bonds 9.3     Fannie Mae Mortgage pass-thru certificates 7.5     Ginnie Mae II Pool 5.6     Uniform Mortgage Backed Securities 4.2     Freddie Mac Gold Pool 4.0     JPMorgan Chase & Co 1.5     Petroleos Mexicanos 1.1     Bank of America Corp 1.1     Freddie Mac Multiclass Mortgage participation certificates 1.1       54.9
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-3455 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's contractual management fee was reduced during the reporting period.
Material Fund Change Expenses [Text Block]	The fund's contractual management fee was reduced during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-3455 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-800-544-3455</span>" id="sjs-B415">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-3455&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B416">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B417">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Tactical Bond Fund - Class Z
Shareholder Report [Line Items]
Fund Name	Fidelity® Tactical Bond Fund
Class Name	Fidelity Advisor® Tactical Bond Fund Class Z
Trading Symbol	FBAPX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Tactical Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.61 %
Expenses Paid, Amount	$ 63
Expense Ratio, Percent	0.61%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B434">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE February 10, 2022 through August 31, 2024. Initial investment of $10,000. Class Z   $10,000 $9,275   $9,330   Bloomberg U.S. Aggregate Bond Index   $10,000 $9,301   $9,190     2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year Life of Fund A Class Z 7.95% 0.28% Bloomberg U.S. Aggregate Bond Index 7.30% -0.55% A   From February 10, 2022   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Feb. 10, 2022
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 56,713,648
Holdings Count | shares	95
Advisory Fees Paid, Amount	$ 295,549
Investment Company Portfolio Turnover	32%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 95 Total Advisory Fee $ Portfolio Turnover 32 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 57.1 AAA 0.6 AA 0.5 A 3.3 BBB 11.6 BB 9.5 B 8.6 CCC,CC,C 1.6 D 0.1 Not Rated 3.1 Equities 0.7 Short-Term Investments and Net Other Assets (Liabilities) 3.3 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 57.1 Corporate Bonds 16.1 Bank Loan Obligations 9.0 Foreign Government and Government Agency Obligations 4.8 Asset-Backed Securities 4.5 Preferred Securities 2.3 CMOs and Other Mortgage Related Securities 1.5 Municipal Securities 0.7 Common Stocks 0.4 Alternative Funds 0.3 Short-Term Investments and Net Other Assets (Liabilities) 3.3 ASSET ALLOCATION (% of Fund's net assets)   United States 85.4 Canada 2.0 United Kingdom 1.9 Mexico 1.7 Germany 1.3 Grand Cayman (Uk Overseas Ter) 1.1 Brazil 1.1 Japan 1.0 Dominican Republic 0.9 Others 3.6 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 44.7     US Treasury Bonds 12.4     Domino's Pizza Master Issuer LLC 1.5     Bank of Nova Scotia/The 1.2     Japan Government 1.0     Petroleos Mexicanos 0.9     Dominican Republic 0.9     Kinder Morgan Inc 0.9     DPL Inc 0.8     Planet Fitness Master Issuer LLC 0.8       65.1
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Material Fund Change Expenses [Text Block]	The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B449">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B450">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B451">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Intermediate Bond Fund
Shareholder Report [Line Items]
Fund Name	Fidelity® Intermediate Bond Fund
Class Name	Fidelity® Intermediate Bond Fund
Trading Symbol	FTHRX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Intermediate Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-800-544-8544
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Intermediate Bond Fund $ 0.45 %
Expenses Paid, Amount	$ 47
Expense Ratio, Percent	0.45%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B468">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the past 10 years?      CUMULATIVE PERFORMANCE August 31, 2014 through August 31, 2024. Initial investment of $10,000. Fidelity® Intermediate Bond Fund   $10,000 $10,108   $10,566   $10,683   $10,569   $11,434   $12,140   $12,245   $11,196   $11,279   $12,101   Bloomberg U.S. Intermediate Government/Credit Bond Index   $10,000 $10,147   $10,561   $10,647   $10,539   $11,395   $12,073   $12,093   $11,101   $11,162   $11,956   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,156   $10,761   $10,814   $10,701   $11,789   $12,553   $12,542   $11,098   $10,965   $11,765     2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year 10 Year Fidelity® Intermediate Bond Fund 7.29% 1.14% 1.93% Bloomberg U.S. Intermediate Government/Credit Bond Index 7.11% 0.96% 1.80% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.64%   Visit www.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 3,775,557,706
Holdings Count | shares	720
Advisory Fees Paid, Amount	$ 9,954,199
Investment Company Portfolio Turnover	53%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 720 Total Advisory Fee $ Portfolio Turnover 53 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 40.7 AAA 11.8 AA 0.6 A 17.7 BBB 23.2 BB 2.2 B 0.7 CCC,CC,C 0.0 Not Rated 2.1 Short-Term Investments and Net Other Assets (Liabilities) 1.0 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 41.9 U.S. Treasury Obligations 40.3 Asset-Backed Securities 11.3 CMOs and Other Mortgage Related Securities 4.9 U.S. Government Agency - Mortgage Securities 0.4 Other Investments 0.1 Foreign Government and Government Agency Obligations 0.1 Short-Term Investments and Net Other Assets (Liabilities) 1.0 ASSET ALLOCATION (% of Fund's net assets)   United States 83.8 United Kingdom 3.8 Grand Cayman (UK Overseas Ter) 2.7 Germany 1.7 Japan 1.6 Ireland 1.4 Canada 1.2 France 1.2 Mexico 0.8 Others 1.8 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 40.3     Bank of America Corp 1.8     JPMorgan Chase & Co 1.6     Morgan Stanley 1.3     Gmf Floorplan Owner Revolving Tr 1.2     Wells Fargo & Co 1.0     Mitsubishi UFJ Financial Group Inc 0.8     Ford Motor Credit Co LLC 0.8     Societe Generale SA 0.7     Citigroup Inc 0.7       50.2
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's contractual management fee was reduced during the reporting period.
Material Fund Change Expenses [Text Block]	The fund's contractual management fee was reduced during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-800-544-8544</span>" id="sjs-B482">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-8544&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B483">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B484">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Investment Grade Bond Fund - Class A
Shareholder Report [Line Items]
Fund Name	Fidelity® Investment Grade Bond Fund
Class Name	Fidelity Advisor® Investment Grade Bond Fund Class A
Trading Symbol	FGBAX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Investment Grade Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.75 %
Expenses Paid, Amount	$ 78
Expense Ratio, Percent	0.75%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B501">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the past 10 years?      CUMULATIVE PERFORMANCE August 31, 2014 through August 31, 2024. Initial investment of $10,000 and the current sales charge was paid. Class A   $9,600 $9,596   $10,196   $10,302   $10,173   $11,201   $12,131   $12,239   $10,781   $10,679   $11,480   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,156   $10,761   $10,814   $10,701   $11,789   $12,553   $12,542   $11,098   $10,965   $11,765     2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year 10 Year Class A (incl. 4.00% sales charge)   3.20% -0.32% 1.39% Class A (without 4.00% sales charge) 7.51% 0.49% 1.80% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.64%   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 10,877,326,398
Holdings Count | shares	3,997
Advisory Fees Paid, Amount	$ 26,423,417
Investment Company Portfolio Turnover	232%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 3,997 Total Advisory Fee $ Portfolio Turnover 232 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 61.9 AAA 7.6 AA 0.6 A 6.0 BBB 16.7 BB 3.3 B 0.9 CCC,CC,C 0.0 Not Rated 3.7 QUALITY DIVERSIFICATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)%   We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 51.8 Corporate Bonds 24.5 U.S. Government Agency - Mortgage Securities 10.1 Asset-Backed Securities 7.1 CMOs and Other Mortgage Related Securities 6.8 Preferred Securities 0.2 Foreign Government and Government Agency Obligations 0.1 Other Investments 0.1 Municipal Securities 0.0 Bank Loan Obligations 0.0 ASSET ALLOCATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)% United States 90.5 Grand Cayman (UK Overseas Ter) 4.2 Germany 1.1 Mexico 0.7 United Kingdom 0.7 Ireland 0.5 Switzerland 0.5 Bailiwick Of Jersey 0.4 Italy 0.3 Others 1.1 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 43.0     US Treasury Bonds 8.8     Uniform Mortgage Backed Securities 3.4     Fannie Mae Mortgage pass-thru certificates 3.2     Freddie Mac Gold Pool 1.7     Ginnie Mae II Pool 1.6     Citigroup Inc 1.5     Bank of America Corp 1.2     Charter Communications Operating LLC / Charter Communications Operating Capital 1.0     Bayer US Finance II LLC 0.9       66.3
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's contractual management fee was reduced during the reporting period.
Material Fund Change Expenses [Text Block]	The fund's contractual management fee was reduced during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B515">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B516">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B517">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Tactical Bond Fund - Class A
Shareholder Report [Line Items]
Fund Name	Fidelity® Tactical Bond Fund
Class Name	Fidelity Advisor® Tactical Bond Fund Class A
Trading Symbol	FTKAX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Tactical Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.95 %
Expenses Paid, Amount	$ 98
Expense Ratio, Percent	0.95%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B534">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE February 10, 2022 through August 31, 2024. Initial investment of $10,000 and the current sales charge was paid. Class A   $9,600 $8,887   $8,910   Bloomberg U.S. Aggregate Bond Index   $10,000 $9,301   $9,190     2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year Life of Fund A Class A (incl. 4.00% sales charge)   3.29% -1.64% Class A (without 4.00% sales charge) 7.59% -0.06% Bloomberg U.S. Aggregate Bond Index 7.30% -0.55% A   From February 10, 2022   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Feb. 10, 2022
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 56,713,648
Holdings Count | shares	95
Advisory Fees Paid, Amount	$ 295,549
Investment Company Portfolio Turnover	32%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 95 Total Advisory Fee $ Portfolio Turnover 32 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 57.1 AAA 0.6 AA 0.5 A 3.3 BBB 11.6 BB 9.5 B 8.6 CCC,CC,C 1.6 D 0.1 Not Rated 3.1 Equities 0.7 Short-Term Investments and Net Other Assets (Liabilities) 3.3 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 57.1 Corporate Bonds 16.1 Bank Loan Obligations 9.0 Foreign Government and Government Agency Obligations 4.8 Asset-Backed Securities 4.5 Preferred Securities 2.3 CMOs and Other Mortgage Related Securities 1.5 Municipal Securities 0.7 Common Stocks 0.4 Alternative Funds 0.3 Short-Term Investments and Net Other Assets (Liabilities) 3.3 ASSET ALLOCATION (% of Fund's net assets)   United States 85.4 Canada 2.0 United Kingdom 1.9 Mexico 1.7 Germany 1.3 Grand Cayman (Uk Overseas Ter) 1.1 Brazil 1.1 Japan 1.0 Dominican Republic 0.9 Others 3.6 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 44.7     US Treasury Bonds 12.4     Domino's Pizza Master Issuer LLC 1.5     Bank of Nova Scotia/The 1.2     Japan Government 1.0     Petroleos Mexicanos 0.9     Dominican Republic 0.9     Kinder Morgan Inc 0.9     DPL Inc 0.8     Planet Fitness Master Issuer LLC 0.8       65.1
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Material Fund Change Expenses [Text Block]	The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B549">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B550">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B551">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Tactical Bond Fund
Shareholder Report [Line Items]
Fund Name	Fidelity® Tactical Bond Fund
Class Name	Fidelity® Tactical Bond Fund
Trading Symbol	FBAGX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Tactical Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-800-544-8544
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Tactical Bond Fund $ 0.70 %
Expenses Paid, Amount	$ 72
Expense Ratio, Percent	0.70%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B568">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE February 10, 2022 through August 31, 2024. Initial investment of $10,000. Fidelity® Tactical Bond Fund   $10,000 $9,270   $9,317   Bloomberg U.S. Aggregate Bond Index   $10,000 $9,301   $9,190     2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year Life of Fund A Fidelity® Tactical Bond Fund 7.86% 0.19% Bloomberg U.S. Aggregate Bond Index 7.30% -0.55% A   From February 10, 2022   Visit www.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Feb. 10, 2022
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 56,713,648
Holdings Count | shares	95
Advisory Fees Paid, Amount	$ 295,549
Investment Company Portfolio Turnover	32%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 95 Total Advisory Fee $ Portfolio Turnover 32 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 57.1 AAA 0.6 AA 0.5 A 3.3 BBB 11.6 BB 9.5 B 8.6 CCC,CC,C 1.6 D 0.1 Not Rated 3.1 Equities 0.7 Short-Term Investments and Net Other Assets (Liabilities) 3.3 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 57.1 Corporate Bonds 16.1 Bank Loan Obligations 9.0 Foreign Government and Government Agency Obligations 4.8 Asset-Backed Securities 4.5 Preferred Securities 2.3 CMOs and Other Mortgage Related Securities 1.5 Municipal Securities 0.7 Common Stocks 0.4 Alternative Funds 0.3 Short-Term Investments and Net Other Assets (Liabilities) 3.3 ASSET ALLOCATION (% of Fund's net assets)   United States 85.4 Canada 2.0 United Kingdom 1.9 Mexico 1.7 Germany 1.3 Grand Cayman (Uk Overseas Ter) 1.1 Brazil 1.1 Japan 1.0 Dominican Republic 0.9 Others 3.6 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 44.7     US Treasury Bonds 12.4     Domino's Pizza Master Issuer LLC 1.5     Bank of Nova Scotia/The 1.2     Japan Government 1.0     Petroleos Mexicanos 0.9     Dominican Republic 0.9     Kinder Morgan Inc 0.9     DPL Inc 0.8     Planet Fitness Master Issuer LLC 0.8       65.1
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Material Fund Change Expenses [Text Block]	The fund's transfer agent and pricing & bookkeeping fees were changed to a fixed rate effective December 1, 2023, through February 29, 2024, in anticipation of the transition to a new management fee structure. Effective March 1, 2024, the fund's management contract was amended to incorporate administrative services previously covered under separate services agreements (transfer agent and pricing & bookkeeping). The amended contract incorporates a management fee rate that may vary by class. The Adviser or an affiliate pays certain expenses of managing and operating the fund out of each class's management fee.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-800-544-8544</span>" id="sjs-B583">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-8544&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B584">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B585">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity SAI Short-Term Bond Fund
Shareholder Report [Line Items]
Fund Name	Fidelity® SAI Short-Term Bond Fund
Class Name	Fidelity® SAI Short-Term Bond Fund
Trading Symbol	FZOMX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® SAI Short-Term Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-800-544-3455
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® SAI Short-Term Bond Fund $ 0.21 %
Expenses Paid, Amount	$ 22
Expense Ratio, Percent	0.21%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B602">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE September 15, 2020 through August 31, 2024. Initial investment of $10,000. Fidelity® SAI Short-Term Bond Fund   $10,000 $10,054   $9,651   $9,863   $10,515   Bloomberg U.S. 1-3 Year Government/Credit Bond Index   $10,000 $10,039   $9,639   $9,791   $10,403   Bloomberg U.S. Aggregate Bond Index   $10,000 $9,977   $8,828   $8,723   $9,359     2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year Life of Fund A Fidelity® SAI Short-Term Bond Fund 6.60% 1.28% Bloomberg U.S. 1-3 Year Government/Credit Bond Index 6.25% 1.00% Bloomberg U.S. Aggregate Bond Index 7.30% -1.66% A   From September 15, 2020   Visit www.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Sep. 15, 2020
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 4,058,303,792
Holdings Count | shares	612
Advisory Fees Paid, Amount	$ 7,024,400
Investment Company Portfolio Turnover	59%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 612 Total Advisory Fee $ Portfolio Turnover 59 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 31.0 AAA 18.2 AA 2.7 A 22.0 BBB 22.0 BB 1.3 B 0.0 Not Rated 1.5 Short-Term Investments and Net Other Assets (Liabilities) 1.3 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 48.0 U.S. Treasury Obligations 30.9 Asset-Backed Securities 16.4 CMOs and Other Mortgage Related Securities 3.2 Other Investments 0.1 U.S. Government Agency - Mortgage Securities 0.1 Short-Term Investments and Net Other Assets (Liabilities) 1.3 ASSET ALLOCATION (% of Fund's net assets)   United States 78.8 United Kingdom 4.4 Germany 3.0 Canada 3.0 Grand Cayman (Uk Overseas Ter) 2.8 France 2.0 Japan 1.1 Ireland 1.0 Denmark 0.8 Others 3.1 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 30.9     JPMorgan Chase & Co 1.5     Bank of America Corp 1.4     Wells Fargo & Co 1.4     HSBC Holdings PLC 1.3     Citigroup Inc 1.0     General Motors Financial Co Inc 0.9     Barclays PLC 0.8     Danske Bank A/S 0.8     Ford Motor Credit Co LLC 0.8       40.8
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-3455 or by sending an e-mail to fidfunddocuments fidelity.com . The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee Effective October 28, 2023, the fund's management fee structure changed. The fund's contractual management fee was reduced during the reporting period. The fund's contractual expense cap was removed during the reporting period. The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee Effective October 28, 2023, the fund's management fee structure changed. The fund's contractual management fee was reduced during the reporting period. The fund's contractual expense cap was removed during the reporting period.
Material Fund Change Expenses [Text Block]	The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee Effective October 28, 2023, the fund's management fee structure changed. The fund's contractual management fee was reduced during the reporting period. The fund's contractual expense cap was removed during the reporting period. The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee Effective October 28, 2023, the fund's management fee structure changed. The fund's contractual management fee was reduced during the reporting period. The fund's contractual expense cap was removed during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-3455 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-800-544-3455</span>" id="sjs-B617">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-3455&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B618">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B619">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity SAI Low Duration Income Fund
Shareholder Report [Line Items]
Fund Name	Fidelity® SAI Low Duration Income Fund
Class Name	Fidelity® SAI Low Duration Income Fund
Trading Symbol	FZOLX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® SAI Low Duration Income Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-800-544-3455
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® SAI Low Duration Income Fund $ 0.20 %
Expenses Paid, Amount	$ 21
Expense Ratio, Percent	0.20%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B636">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE September 15, 2020 through August 31, 2024. Initial investment of $10,000. Fidelity® SAI Low Duration Income Fund   $10,000 $10,023   $9,985   $10,438   $11,064   Bloomberg US Treasury Bill: 6-9 Months Index   $10,000 $10,011   $9,972   $10,282   $10,835   Bloomberg U.S. Aggregate Bond Index   $10,000 $9,977   $8,828   $8,723   $9,359     2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year Life of Fund A Fidelity® SAI Low Duration Income Fund 6.00% 2.59% Bloomberg US Treasury Bill: 6-9 Months Index 5.37% 2.04% Bloomberg U.S. Aggregate Bond Index 7.30% -1.66% A   From September 15, 2020   Visit www.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Sep. 15, 2020
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 7,497,139,118
Holdings Count | shares	439
Advisory Fees Paid, Amount	$ 13,369,647
Investment Company Portfolio Turnover	68%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 439 Total Advisory Fee $ Portfolio Turnover 68 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 14.9 AAA 24.4 AA 2.7 A 22.5 BBB 19.6 BB 0.2 Not Rated 6.9 Short-Term Investments and Net Other Assets (Liabilities) 8.8 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 44.8 Asset-Backed Securities 22.9 U.S. Treasury Obligations 21.1 CMOs and Other Mortgage Related Securities 2.4 Short-Term Investments and Net Other Assets (Liabilities) 8.8 ASSET ALLOCATION (% of Fund's net assets) United States 80.6 Canada 3.4 Germany 3.0 Grand Cayman (UK Overseas Ter) 2.8 United Kingdom 2.8 Japan 1.5 Switzerland 1.4 Netherlands 1.2 Ireland 1.0 Others 2.3 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 14.9     US Treasury Bill 6.2     Bank of America Corp 1.3     Morgan Stanley 1.3     General Motors Financial Co Inc 1.2     Wells Fargo & Co 1.1     American Express Co 1.0     Barclays PLC 1.0     Goldman Sachs Group Inc/The 1.0     HSBC USA Inc 1.0       30.0
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-3455 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's contractual management fee was reduced during the reporting period. The fund reduced its contractual expense cap during the reporting period.
Material Fund Change Expenses [Text Block]	The fund's contractual management fee was reduced during the reporting period. The fund reduced its contractual expense cap during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-3455 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-800-544-3455</span>" id="sjs-B651">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-3455&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B652">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B653">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Short-Term Bond Fund
Shareholder Report [Line Items]
Fund Name	Fidelity® Short-Term Bond Fund
Class Name	Fidelity® Short-Term Bond Fund
Trading Symbol	FSHBX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Short-Term Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-800-544-8544
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Short-Term Bond Fund $ 0.30 %
Expenses Paid, Amount	$ 31
Expense Ratio, Percent	0.30%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B670">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the past 10 years?      CUMULATIVE PERFORMANCE August 31, 2014 through August 31, 2024. Initial investment of $10,000. Fidelity® Short-Term Bond Fund   $10,000 $10,072   $10,252   $10,358   $10,379   $10,843   $11,256   $11,314   $10,839   $11,089   $11,836   Bloomberg U.S. 1-3 Year Government/Credit Bond Index   $10,000 $10,081   $10,232   $10,324   $10,340   $10,818   $11,214   $11,258   $10,810   $10,979   $11,666   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,156   $10,761   $10,814   $10,701   $11,789   $12,553   $12,542   $11,098   $10,965   $11,765     2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year 10 Year Fidelity® Short-Term Bond Fund 6.73% 1.77% 1.70% Bloomberg U.S. 1-3 Year Government/Credit Bond Index 6.25% 1.52% 1.55% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.64%   Visit www.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 2,346,008,597
Holdings Count | shares	491
Advisory Fees Paid, Amount	$ 4,742,667
Investment Company Portfolio Turnover	68%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 491 Total Advisory Fee $ Portfolio Turnover 68 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 26.4 AAA 22.3 AA 2.9 A 21.6 BBB 20.4 BB 1.3 B 0.3 Not Rated 3.4 Short-Term Investments and Net Other Assets (Liabilities) 1.4 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 45.1 U.S. Treasury Obligations 26.1 Asset-Backed Securities 19.3 CMOs and Other Mortgage Related Securities 7.2 Other Investments 0.6 U.S. Government Agency - Mortgage Securities 0.3 Short-Term Investments and Net Other Assets (Liabilities) 1.4 ASSET ALLOCATION (% of Fund's net assets)   United States 77.7 Grand Cayman (Uk Overseas Ter) 4.4 Canada 3.6 United Kingdom 3.3 Germany 3.1 France 2.1 Ireland 1.2 Japan 1.0 Italy 0.7 Others 2.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 26.1     JPMorgan Chase & Co 1.4     Wells Fargo & Co 1.2     Barclays PLC 1.0     Athene Global Funding 0.9     AerCap Ireland Capital DAC / AerCap Global Aviation Trust 0.9     General Motors Financial Co Inc 0.9     American Express Co 0.8     Citigroup Inc 0.8     Ford Motor Credit Co LLC 0.8       34.8
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 or by sending an e-mail to fidfunddocuments fidelity.com . The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses
Material Fund Change Expenses [Text Block]	The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-800-544-8544</span>" id="sjs-B684">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-8544&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B685">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B686">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Short-Term Bond Fund - Class Z
Shareholder Report [Line Items]
Fund Name	Fidelity® Short-Term Bond Fund
Class Name	Fidelity Advisor® Short-Term Bond Fund Class Z
Trading Symbol	FIKTX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Short-Term Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.25 %
Expenses Paid, Amount	$ 26
Expense Ratio, Percent	0.25%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B703">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE October 2, 2018 through August 31, 2024. Initial investment of $10,000. Class Z   $10,000 $10,450   $10,858   $10,923   $10,475   $10,725   $11,439   Bloomberg U.S. 1-3 Year Government/Credit Bond Index   $10,000 $10,467   $10,851   $10,893   $10,460   $10,624   $11,288   Bloomberg U.S. Aggregate Bond Index   $10,000 $11,086   $11,804   $11,794   $10,436   $10,311   $11,064     2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year Life of Fund A Class Z 6.66% 1.82% 2.30% Bloomberg U.S. 1-3 Year Government/Credit Bond Index 6.25% 1.52% 2.07% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.72% A   From October 2, 2018   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Oct. 02, 2018
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 2,346,008,597
Holdings Count | shares	491
Advisory Fees Paid, Amount	$ 4,742,667
Investment Company Portfolio Turnover	68%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 491 Total Advisory Fee $ Portfolio Turnover 68 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 26.4 AAA 22.3 AA 2.9 A 21.6 BBB 20.4 BB 1.3 B 0.3 Not Rated 3.4 Short-Term Investments and Net Other Assets (Liabilities) 1.4 QUALITY DIVERSIFICATION (% of Fund's net assets)     We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     Corporate Bonds 45.1 U.S. Treasury Obligations 26.1 Asset-Backed Securities 19.3 CMOs and Other Mortgage Related Securities 7.2 Other Investments 0.6 U.S. Government Agency - Mortgage Securities 0.3 Short-Term Investments and Net Other Assets (Liabilities) 1.4 ASSET ALLOCATION (% of Fund's net assets)   United States 77.7 Grand Cayman (Uk Overseas Ter) 4.4 Canada 3.6 United Kingdom 3.3 Germany 3.1 France 2.1 Ireland 1.2 Japan 1.0 Italy 0.7 Others 2.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 26.1     JPMorgan Chase & Co 1.4     Wells Fargo & Co 1.2     Barclays PLC 1.0     Athene Global Funding 0.9     AerCap Ireland Capital DAC / AerCap Global Aviation Trust 0.9     General Motors Financial Co Inc 0.9     American Express Co 0.8     Citigroup Inc 0.8     Ford Motor Credit Co LLC 0.8       34.8
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses • Expense reductions The class' contractual expense cap was removed during the reporting period.
Material Fund Change Expenses [Text Block]	The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Management fee • Operating expenses • Expense reductions The class' contractual expense cap was removed during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B718">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B719">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B720">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Investment Grade Bond Fund - Class C
Shareholder Report [Line Items]
Fund Name	Fidelity® Investment Grade Bond Fund
Class Name	Fidelity Advisor® Investment Grade Bond Fund Class C
Trading Symbol	FGBCX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Investment Grade Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.52 %
Expenses Paid, Amount	$ 157
Expense Ratio, Percent	1.52%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B737">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the past 10 years?      CUMULATIVE PERFORMANCE August 31, 2014 through August 31, 2024. Initial investment of $10,000. Class C   $10,000 $9,921   $10,474   $10,502   $10,280   $11,231   $12,069   $12,083   $10,564   $10,463   $11,249   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,156   $10,761   $10,814   $10,701   $11,789   $12,553   $12,542   $11,098   $10,965   $11,765     2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year 10 Year Class C  (incl. contingent deferred sales charge) 5.68% -0.28% 1.18% Class C 6.68% -0.28% 1.18% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.64%   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 10,877,326,398
Holdings Count | shares	3,997
Advisory Fees Paid, Amount	$ 26,423,417
Investment Company Portfolio Turnover	232%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 3,997 Total Advisory Fee $ Portfolio Turnover 232 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 61.9 AAA 7.6 AA 0.6 A 6.0 BBB 16.7 BB 3.3 B 0.9 CCC,CC,C 0.0 Not Rated 3.7 QUALITY DIVERSIFICATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)%   We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 51.8 Corporate Bonds 24.5 U.S. Government Agency - Mortgage Securities 10.1 Asset-Backed Securities 7.1 CMOs and Other Mortgage Related Securities 6.8 Preferred Securities 0.2 Foreign Government and Government Agency Obligations 0.1 Other Investments 0.1 Municipal Securities 0.0 Bank Loan Obligations 0.0 ASSET ALLOCATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)% United States 90.5 Grand Cayman (UK Overseas Ter) 4.2 Germany 1.1 Mexico 0.7 United Kingdom 0.7 Ireland 0.5 Switzerland 0.5 Bailiwick Of Jersey 0.4 Italy 0.3 Others 1.1 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 43.0     US Treasury Bonds 8.8     Uniform Mortgage Backed Securities 3.4     Fannie Mae Mortgage pass-thru certificates 3.2     Freddie Mac Gold Pool 1.7     Ginnie Mae II Pool 1.6     Citigroup Inc 1.5     Bank of America Corp 1.2     Charter Communications Operating LLC / Charter Communications Operating Capital 1.0     Bayer US Finance II LLC 0.9       66.3
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's contractual management fee was reduced during the reporting period.
Material Fund Change Expenses [Text Block]	The fund's contractual management fee was reduced during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B751">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B752">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B753">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Investment Grade Bond Fund - Class I
Shareholder Report [Line Items]
Fund Name	Fidelity® Investment Grade Bond Fund
Class Name	Fidelity Advisor® Investment Grade Bond Fund Class I
Trading Symbol	FGBPX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Investment Grade Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.50 %
Expenses Paid, Amount	$ 52
Expense Ratio, Percent	0.50%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B770">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the past 10 years?      CUMULATIVE PERFORMANCE August 31, 2014 through August 31, 2024. Initial investment of $10,000. Class I   $10,000 $10,023   $10,677   $10,818   $10,712   $11,824   $12,839   $12,972   $11,458   $11,379   $12,263   Bloomberg U.S. Aggregate Bond Index   $10,000 $10,156   $10,761   $10,814   $10,701   $11,789   $12,553   $12,542   $11,098   $10,965   $11,765     2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year 10 Year Class I 7.77% 0.73% 2.06% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.64%   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 10,877,326,398
Holdings Count | shares	3,997
Advisory Fees Paid, Amount	$ 26,423,417
Investment Company Portfolio Turnover	232%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 3,997 Total Advisory Fee $ Portfolio Turnover 232 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 61.9 AAA 7.6 AA 0.6 A 6.0 BBB 16.7 BB 3.3 B 0.9 CCC,CC,C 0.0 Not Rated 3.7 QUALITY DIVERSIFICATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)%   We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 51.8 Corporate Bonds 24.5 U.S. Government Agency - Mortgage Securities 10.1 Asset-Backed Securities 7.1 CMOs and Other Mortgage Related Securities 6.8 Preferred Securities 0.2 Foreign Government and Government Agency Obligations 0.1 Other Investments 0.1 Municipal Securities 0.0 Bank Loan Obligations 0.0 ASSET ALLOCATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)% United States 90.5 Grand Cayman (UK Overseas Ter) 4.2 Germany 1.1 Mexico 0.7 United Kingdom 0.7 Ireland 0.5 Switzerland 0.5 Bailiwick Of Jersey 0.4 Italy 0.3 Others 1.1 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 43.0     US Treasury Bonds 8.8     Uniform Mortgage Backed Securities 3.4     Fannie Mae Mortgage pass-thru certificates 3.2     Freddie Mac Gold Pool 1.7     Ginnie Mae II Pool 1.6     Citigroup Inc 1.5     Bank of America Corp 1.2     Charter Communications Operating LLC / Charter Communications Operating Capital 1.0     Bayer US Finance II LLC 0.9       66.3
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's contractual management fee was reduced during the reporting period.
Material Fund Change Expenses [Text Block]	The fund's contractual management fee was reduced during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B784">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B785">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B786">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>
Fidelity Advisor Investment Grade Bond Fund - Class Z
Shareholder Report [Line Items]
Fund Name	Fidelity® Investment Grade Bond Fund
Class Name	Fidelity Advisor® Investment Grade Bond Fund Class Z
Trading Symbol	FIKQX
Annual or Semi-Annual Statement [Text Block]	This annual shareholder report contains information about Fidelity® Investment Grade Bond Fund for the period September 1, 2023 to August 31, 2024.
Shareholder Report Annual or Semi-Annual	annual shareholder report
Additional Information [Text Block]	You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Material Fund Change Notice [Text Block]	This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number	1-877-208-0098
Additional Information Email	fidfunddocuments@fidelity.com
Additional Information Website	fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block]	What were your Fund costs for the last year? (based on hypothetical $10,000 investment) FUND COST (PREVIOUS YEAR) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.36 %
Expenses Paid, Amount	$ 37
Expense Ratio, Percent	0.36%
Factors Affecting Performance [Text Block]	What affected the Fund's performance this period? • • • • • •
Performance Past Does Not Indicate Future [Text]	The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B803">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">The Fund's past performance is not a good predictor of the Fund's future performance.&lt;/span>
Line Graph [Table Text Block]	How did the Fund perform over the life of Fund?      CUMULATIVE PERFORMANCE October 2, 2018 through August 31, 2024. Initial investment of $10,000. Class Z   $10,000 $11,097   $12,064   $12,218   $10,809   $10,750   $11,601   Bloomberg U.S. Aggregate Bond Index   $10,000 $11,086   $11,804   $11,794   $10,436   $10,311   $11,064     2018 2019 2020 2021 2022 2023 2024
Average Annual Return [Table Text Block]	AVERAGE ANNUAL TOTAL RETURNS:     1 Year 5 Year Life of Fund A Class Z 7.91% 0.89% 2.54% Bloomberg U.S. Aggregate Bond Index 7.30% -0.04% 1.72% A   From October 2, 2018   Visit institutional.fidelity.com for more recent performance information.   The Fund's past performance is not a good predictor of the Fund's future performance.  The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Performance Inception Date	Oct. 02, 2018
No Deduction of Taxes [Text Block]	The graph and table do not reflect the deduction of taxes that a shareholder would pay on fund distributions or redemption of fund shares.
Net Assets	$ 10,877,326,398
Holdings Count | shares	3,997
Advisory Fees Paid, Amount	$ 26,423,417
Investment Company Portfolio Turnover	232%
Additional Fund Statistics [Text Block]	Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 3,997 Total Advisory Fee $ Portfolio Turnover 232 %
Holdings [Text Block]	U.S. Government and U.S. Government Agency Obligations 61.9 AAA 7.6 AA 0.6 A 6.0 BBB 16.7 BB 3.3 B 0.9 CCC,CC,C 0.0 Not Rated 3.7 QUALITY DIVERSIFICATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)%   We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.     U.S. Treasury Obligations 51.8 Corporate Bonds 24.5 U.S. Government Agency - Mortgage Securities 10.1 Asset-Backed Securities 7.1 CMOs and Other Mortgage Related Securities 6.8 Preferred Securities 0.2 Foreign Government and Government Agency Obligations 0.1 Other Investments 0.1 Municipal Securities 0.0 Bank Loan Obligations 0.0 ASSET ALLOCATION (% of Fund's net assets)   Short-Term Investments and Net Other Assets (Liabilities) - (0.7)% United States 90.5 Grand Cayman (UK Overseas Ter) 4.2 Germany 1.1 Mexico 0.7 United Kingdom 0.7 Ireland 0.5 Switzerland 0.5 Bailiwick Of Jersey 0.4 Italy 0.3 Others 1.1 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)
Largest Holdings [Text Block]	TOP HOLDINGS (% of Fund's net assets)     US Treasury Notes 43.0     US Treasury Bonds 8.8     Uniform Mortgage Backed Securities 3.4     Fannie Mae Mortgage pass-thru certificates 3.2     Freddie Mac Gold Pool 1.7     Ginnie Mae II Pool 1.6     Citigroup Inc 1.5     Bank of America Corp 1.2     Charter Communications Operating LLC / Charter Communications Operating Capital 1.0     Bayer US Finance II LLC 0.9       66.3
Material Fund Change [Text Block]	How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com . The fund's contractual management fee was reduced during the reporting period.
Material Fund Change Expenses [Text Block]	The fund's contractual management fee was reduced during the reporting period.
Summary of Change Legend [Text Block]	This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-877-208-0098 or by sending an e-mail to fidfunddocuments fidelity.com .
Updated Prospectus Phone Number	1-877-208-0098</span>" id="sjs-B818">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098&lt;/span>
Updated Prospectus Email Address	fidfunddocuments@fidelity.com</span>" id="sjs-B819">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com&lt;/span>
Updated Prospectus Web Address	fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B820">&lt;span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec&lt;/span>

Shareholder Report, Line Graph

Shareholder Report, Line Graph (Details) - USD ($)

12 Months Ended

36 Months Ended

60 Months Ended

84 Months Ended

108 Months Ended

120 Months Ended

132 Months Ended

Aug. 31, 2024

Aug. 31, 2024

Aug. 31, 2024

Aug. 31, 2024

Aug. 31, 2024

Aug. 31, 2024

Aug. 31, 2024

Aug. 31, 2023

Aug. 31, 2022

Aug. 31, 2021

Aug. 31, 2020

Aug. 31, 2019

Aug. 31, 2018

Aug. 31, 2017

Aug. 31, 2016

Aug. 31, 2015

Aug. 31, 2014

C000200823_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000200823_1_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000200823_1_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.62%

C000234193_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000234193_0_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

(0.55%)

C000019124_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000019124_0_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000019124_0_BBIndexMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.64%

C000171438_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000171438_1_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000171438_1_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.13%

C000235214_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000235214_1_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.16%

C000234194_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000234194_0_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

(0.55%)

C000171439_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000171439_1_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000171439_1_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.13%

C000171437_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000171437_1_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000171437_1_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.13%

C000171440_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000171440_1_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000171440_1_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.13%

C000019120_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000019120_0_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000019120_0_BBIndexMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.64%

C000234192_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000234192_0_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

(0.55%)

C000201533_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000201533_1_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000201533_1_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.85%

C000234190_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000234190_0_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

(0.55%)

C000048836_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000048836_1_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000048836_1_BBIndexMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.64%

C000019121_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000019121_0_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000019121_0_BBIndexMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.64%

C000234191_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000234191_0_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

(0.55%)

C000234189_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000234189_0_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

(0.55%)

C000221556_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000221556_1_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

(1.66%)

C000221555_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000221555_1_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

(1.66%)

C000019128_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000019128_1_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000019128_1_BBIndexMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.64%

C000205020_1_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000205020_1_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000205020_1_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.72%

C000019123_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000019123_0_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000019123_0_BBIndexMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.64%

C000019125_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000019125_0_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000019125_0_BBIndexMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.64%

C000205019_0_BBIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.30%

C000205019_0_BBIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.04%)

C000205019_0_BBIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.72%

C000200823_LG_ClassMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Fidelity Flex® Conservative Income Bond Fund</span>" id="sjs-E194">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity Flex® Conservative Income Bond Fund&lt;/span>

C000200823_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

$ 10,000

C000200823_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

$ 10,066

C000200823_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

$ 10,348

C000200823_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

$ 10,565

C000200823_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

$ 10,614

C000200823_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

$ 10,637

C000200823_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,153

$ 11,153

$ 11,153

$ 11,153

$ 11,153

$ 11,153

$ 11,153

C000200823_LG_1_AdditionalIndexMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. 3-6 Month Treasury Bill Index</span>" id="sjs-E218">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. 3-6 Month Treasury Bill Index&lt;/span>

C000200823_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,000

C000200823_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,050

C000200823_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,302

C000200823_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,457

C000200823_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,466

C000200823_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,495

C000200823_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

10,945

10,945

10,945

$ 10,945

10,945

10,945

10,945

C000200823_LG_2_AdditionalIndexMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-E242">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000200823_2_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,000

C000200823_2_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,054

C000200823_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

11,077

C000200823_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

11,794

C000200823_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,784

C000200823_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,427

C000200823_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 10,303

$ 10,303

$ 10,303

$ 10,303

10,303

10,303

10,303

C000200823_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.11%

C000200823_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

2.72%

C000200823_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

2.73%

C000200823_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

5.55%

C000200823_0_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

2.32%

C000200823_0_AdditionalIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

2.34%

C000234193_LG_ClassMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class M</span>" id="sjs-C284">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class M&lt;/span>

C000234193_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

9,600

C000234193_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

8,887

C000234193_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 8,910

$ 8,910

$ 8,910

8,910

8,910

8,910

8,910

C000234193_LG_1_AdditionalIndexMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-C296">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000234193_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000234193_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,301

C000234193_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,190

$ 9,190

9,190

9,190

9,190

9,190

$ 9,190

C000234193_ClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

3.29%

C000234193_ClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

(1.64%)

C000234193_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.60%

C000234193_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

(0.06%)

C000019124_LG_ClassMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class M</span>" id="sjs-H320">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class M&lt;/span>

C000019124_ClassMember_AsOf_2014Member

Account Value [Line Items]

Account Value

$ 9,600

C000019124_ClassMember_AsOf_2015Member

Account Value [Line Items]

Account Value

$ 9,593

C000019124_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

$ 10,189

C000019124_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

$ 10,291

C000019124_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,161

C000019124_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,187

C000019124_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,115

C000019124_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,210

C000019124_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,756

C000019124_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,654

C000019124_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,454

11,454

11,454

11,454

11,454

11,454

$ 11,454

C000019124_LG_1_AdditionalIndexMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-H356">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000019124_1_AdditionalIndexMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000019124_1_AdditionalIndexMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,156

C000019124_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,761

C000019124_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,814

C000019124_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,701

C000019124_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,789

C000019124_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,553

C000019124_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,542

C000019124_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,098

C000019124_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,965

C000019124_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,765

11,765

$ 11,765

11,765

$ 11,765

$ 11,765

$ 11,765

C000019124_ClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

3.21%

C000019124_ClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.34%)

C000019124_ClassMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.37%

C000019124_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.51%

C000019124_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

0.47%

C000019124_NoLoadClassMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.78%

C000171438_LG_ClassMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class M</span>" id="sjs-F410">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class M&lt;/span>

C000171438_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

9,850

C000171438_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

9,859

C000171438_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

9,939

C000171438_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

9,950

C000171438_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,360

C000171438_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,745

C000171438_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,765

C000171438_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,293

C000171438_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 10,508

10,508

$ 10,508

10,508

$ 10,508

$ 10,508

10,508

C000171438_LG_1_AdditionalIndexMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. 1-3 Year Government/Credit Bond Index</span>" id="sjs-F440">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. 1-3 Year Government/Credit Bond Index&lt;/span>

C000171438_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,000

C000171438_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,001

C000171438_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,091

C000171438_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,107

C000171438_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,573

C000171438_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,961

C000171438_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,004

C000171438_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,566

C000171438_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

10,731

10,731

10,731

10,731

$ 10,731

10,731

10,731

C000171438_LG_2_AdditionalIndexMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-F470">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000171438_2_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,000

C000171438_2_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,020

C000171438_2_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,069

C000171438_2_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

9,963

C000171438_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,977

C000171438_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

11,687

C000171438_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,678

C000171438_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,333

C000171438_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 10,209

$ 10,209

$ 10,209

10,209

$ 10,209

10,209

10,209

C000171438_ClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

4.91%

C000171438_ClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.25%

C000171438_ClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

1.39%

C000171438_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.51%

C000171438_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.56%

C000171438_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

1.58%

C000171438_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.25%

C000171438_0_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.52%

C000171438_0_AdditionalIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.62%

C000235214_LG_ClassMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Fidelity® SAI Sustainable Core Plus Bond Fund</span>" id="sjs-C527">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® SAI Sustainable Core Plus Bond Fund&lt;/span>

C000235214_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000235214_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,587

C000235214_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,551

$ 9,551

$ 9,551

9,551

9,551

9,551

9,551

C000235214_LG_1_AdditionalIndexMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index</span>" id="sjs-C539">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg MSCI U.S. Aggregate ESG Choice Bond Index&lt;/span>

C000235214_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000235214_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,703

C000235214_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

9,590

$ 9,590

9,590

9,590

9,590

9,590

9,590

C000235214_LG_2_AdditionalIndexMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-C551">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000235214_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000235214_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,696

C000235214_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,581

$ 9,581

9,581

9,581

9,581

9,581

9,581

C000235214_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.31%

C000235214_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

1.04%

C000235214_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.26%

C000235214_0_AdditionalIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.19%

C000234194_LG_ClassMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class I</span>" id="sjs-C575">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class I&lt;/span>

C000234194_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000234194_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,270

C000234194_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,317

$ 9,317

9,317

9,317

9,317

9,317

9,317

C000234194_LG_1_AdditionalIndexMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-C587">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000234194_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000234194_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,301

C000234194_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,190

$ 9,190

9,190

9,190

$ 9,190

9,190

9,190

C000234194_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.86%

C000234194_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

0.19%

C000171439_LG_ClassMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class C</span>" id="sjs-F605">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class C&lt;/span>

C000171439_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,000

C000171439_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,001

C000171439_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,003

C000171439_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

9,917

C000171439_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,250

C000171439_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,530

C000171439_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,469

C000171439_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,928

C000171439_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 10,050

10,050

10,050

10,050

$ 10,050

10,050

10,050

C000171439_LG_1_AdditionalIndexMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. 1-3 Year Government/Credit Bond Index</span>" id="sjs-F635">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. 1-3 Year Government/Credit Bond Index&lt;/span>

C000171439_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,000

C000171439_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,001

C000171439_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,091

C000171439_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,107

C000171439_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,573

C000171439_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,961

C000171439_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,004

C000171439_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,566

C000171439_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

10,731

10,731

10,731

10,731

$ 10,731

10,731

10,731

C000171439_LG_2_AdditionalIndexMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-F665">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000171439_2_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,000

C000171439_2_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,020

C000171439_2_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,069

C000171439_2_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

9,963

C000171439_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,977

C000171439_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

11,687

C000171439_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,678

C000171439_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,333

C000171439_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 10,209

10,209

$ 10,209

10,209

$ 10,209

10,209

10,209

C000171439_ClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

4.50%

C000171439_ClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

0.68%

C000171439_ClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

0.73%

C000171439_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

5.50%

C000171439_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

0.68%

C000171439_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

0.73%

C000171439_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.25%

C000171439_0_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.52%

C000171439_0_AdditionalIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.62%

C000171437_LG_ClassMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class A</span>" id="sjs-F722">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class A&lt;/span>

C000171437_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

9,850

C000171437_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

9,859

C000171437_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

9,941

C000171437_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

9,952

C000171437_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,364

C000171437_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,750

C000171437_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,771

C000171437_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,299

C000171437_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 10,516

10,516

$ 10,516

10,516

$ 10,516

10,516

10,516

C000171437_LG_1_AdditionalIndexMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. 1-3 Year Government/Credit Bond Index</span>" id="sjs-F752">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. 1-3 Year Government/Credit Bond Index&lt;/span>

C000171437_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,000

C000171437_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,001

C000171437_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,091

C000171437_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,107

C000171437_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,573

C000171437_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,961

C000171437_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,004

C000171437_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,566

C000171437_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

10,731

10,731

10,731

10,731

$ 10,731

10,731

10,731

C000171437_LG_2_AdditionalIndexMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-F782">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000171437_2_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,000

C000171437_2_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,020

C000171437_2_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,069

C000171437_2_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

9,963

C000171437_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,977

C000171437_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

11,687

C000171437_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,678

C000171437_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,333

C000171437_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 10,209

10,209

$ 10,209

10,209

$ 10,209

10,209

10,209

C000171437_ClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

4.92%

C000171437_ClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.26%

C000171437_ClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

1.40%

C000171437_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.52%

C000171437_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.57%

C000171437_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

1.59%

C000171437_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.25%

C000171437_0_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.52%

C000171437_0_AdditionalIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.62%

C000171440_LG_ClassMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class I</span>" id="sjs-F839">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class I&lt;/span>

C000171440_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,000

C000171440_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,011

C000171440_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,109

C000171440_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,136

C000171440_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,570

C000171440_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,980

C000171440_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,017

C000171440_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,550

C000171440_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 10,791

10,791

$ 10,791

10,791

$ 10,791

10,791

10,791

C000171440_LG_1_AdditionalIndexMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. 1-3 Year Government/Credit Bond Index</span>" id="sjs-F869">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. 1-3 Year Government/Credit Bond Index&lt;/span>

C000171440_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,000

C000171440_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,001

C000171440_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,091

C000171440_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,107

C000171440_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,573

C000171440_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,961

C000171440_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,004

C000171440_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,566

C000171440_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

10,731

10,731

10,731

10,731

$ 10,731

10,731

10,731

C000171440_LG_2_AdditionalIndexMember_9YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-F899">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000171440_2_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,000

C000171440_2_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,020

C000171440_2_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,069

C000171440_2_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

9,963

C000171440_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,977

C000171440_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

11,687

C000171440_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,678

C000171440_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,333

C000171440_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 10,209

10,209

$ 10,209

10,209

$ 10,209

10,209

$ 10,209

C000171440_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.73%

C000171440_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.73%

C000171440_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

1.75%

C000171440_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.25%

C000171440_0_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.52%

C000171440_0_AdditionalIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1.62%

C000019120_LG_ClassMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Fidelity® Investment Grade Bond Fund</span>" id="sjs-H947">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® Investment Grade Bond Fund&lt;/span>

C000019120_ClassMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000019120_ClassMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,028

C000019120_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,688

C000019120_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,834

C000019120_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,733

C000019120_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,854

C000019120_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,877

C000019120_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

13,015

C000019120_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,515

C000019120_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

11,425

C000019120_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 12,320

12,320

$ 12,320

12,320

12,320

12,320

$ 12,320

C000019120_LG_1_AdditionalIndexMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-H983">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000019120_1_AdditionalIndexMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000019120_1_AdditionalIndexMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,156

C000019120_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,761

C000019120_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,814

C000019120_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,701

C000019120_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,789

C000019120_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,553

C000019120_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,542

C000019120_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,098

C000019120_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,965

C000019120_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,765

$ 11,765

$ 11,765

11,765

11,765

$ 11,765

$ 11,765

C000019120_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.83%

C000019120_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

0.77%

C000019120_NoLoadClassMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

2.11%

C000234192_LG_ClassMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class C</span>" id="sjs-C1028">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class C&lt;/span>

C000234192_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000234192_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,210

C000234192_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,174

$ 9,174

$ 9,174

9,174

9,174

$ 9,174

9,174

C000234192_LG_1_AdditionalIndexMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-C1040">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000234192_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000234192_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,301

C000234192_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,190

$ 9,190

9,190

$ 9,190

9,190

9,190

9,190

C000234192_ClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

5.79%

C000234192_ClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

(0.80%)

C000234192_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.79%

C000234192_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

(0.80%)

C000201533_LG_ClassMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Fidelity® SAI Total Bond Fund</span>" id="sjs-E1064">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® SAI Total Bond Fund&lt;/span>

C000201533_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,000

C000201533_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,067

C000201533_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

11,859

C000201533_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,193

C000201533_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,847

C000201533_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,891

C000201533_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,836

11,836

11,836

$ 11,836

11,836

11,836

11,836

C000201533_LG_1_AdditionalIndexMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Universal Bond Index</span>" id="sjs-E1088">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Universal Bond Index&lt;/span>

C000201533_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,000

C000201533_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,125

C000201533_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

11,839

C000201533_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

11,944

C000201533_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,528

C000201533_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,486

C000201533_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

11,317

11,317

11,317

$ 11,317

11,317

11,317

11,317

C000201533_LG_2_AdditionalIndexMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-E1112">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000201533_2_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,000

C000201533_2_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,154

C000201533_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

11,876

C000201533_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

11,866

C000201533_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,499

C000201533_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,374

C000201533_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,131

$ 11,131

$ 11,131

$ 11,131

11,131

11,131

11,131

C000201533_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

8.67%

C000201533_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.35%

C000201533_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

2.92%

C000201533_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.92%

C000201533_0_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

0.34%

C000201533_0_AdditionalIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

2.14%

C000234190_LG_ClassMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class Z</span>" id="sjs-C1154">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class Z&lt;/span>

C000234190_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000234190_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,275

C000234190_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,330

$ 9,330

$ 9,330

9,330

9,330

9,330

9,330

C000234190_LG_1_AdditionalIndexMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-C1166">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000234190_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000234190_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,301

C000234190_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,190

$ 9,190

9,190

9,190

9,190

9,190

$ 9,190

C000234190_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.95%

C000234190_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

0.28%

C000048836_LG_ClassMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Fidelity® Intermediate Bond Fund</span>" id="sjs-H1184">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® Intermediate Bond Fund&lt;/span>

C000048836_ClassMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000048836_ClassMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,108

C000048836_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,566

C000048836_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,683

C000048836_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,569

C000048836_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,434

C000048836_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,140

C000048836_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,245

C000048836_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,196

C000048836_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

11,279

C000048836_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 12,101

12,101

12,101

12,101

12,101

12,101

$ 12,101

C000048836_LG_1_AdditionalIndexMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Intermediate Government/Credit Bond Index</span>" id="sjs-H1220">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Intermediate Government/Credit Bond Index&lt;/span>

C000048836_1_AdditionalIndexMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000048836_1_AdditionalIndexMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,147

C000048836_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,561

C000048836_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,647

C000048836_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,539

C000048836_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,395

C000048836_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,073

C000048836_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,093

C000048836_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,101

C000048836_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

11,162

C000048836_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

11,956

11,956

11,956

11,956

11,956

11,956

$ 11,956

C000048836_LG_2_AdditionalIndexMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-H1256">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000048836_2_AdditionalIndexMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000048836_2_AdditionalIndexMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,156

C000048836_2_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,761

C000048836_2_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,814

C000048836_2_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,701

C000048836_2_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,789

C000048836_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,553

C000048836_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,542

C000048836_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,098

C000048836_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,965

C000048836_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,765

11,765

$ 11,765

11,765

11,765

$ 11,765

$ 11,765

C000048836_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.29%

C000048836_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.14%

C000048836_NoLoadClassMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.93%

C000048836_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.11%

C000048836_0_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

0.96%

C000048836_0_AdditionalIndexMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.80%

C000019121_LG_ClassMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class A</span>" id="sjs-H1310">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class A&lt;/span>

C000019121_ClassMember_AsOf_2014Member

Account Value [Line Items]

Account Value

9,600

C000019121_ClassMember_AsOf_2015Member

Account Value [Line Items]

Account Value

9,596

C000019121_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,196

C000019121_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,302

C000019121_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,173

C000019121_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,201

C000019121_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,131

C000019121_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,239

C000019121_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,781

C000019121_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,679

C000019121_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,480

11,480

$ 11,480

11,480

11,480

$ 11,480

$ 11,480

C000019121_LG_1_AdditionalIndexMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-H1346">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000019121_1_AdditionalIndexMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000019121_1_AdditionalIndexMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,156

C000019121_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,761

C000019121_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,814

C000019121_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,701

C000019121_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,789

C000019121_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,553

C000019121_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,542

C000019121_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,098

C000019121_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,965

C000019121_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,765

$ 11,765

$ 11,765

11,765

11,765

$ 11,765

$ 11,765

C000019121_ClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

3.20%

C000019121_ClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.32%)

C000019121_ClassMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.39%

C000019121_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.51%

C000019121_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

0.49%

C000019121_NoLoadClassMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.80%

C000234191_LG_ClassMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class A</span>" id="sjs-C1400">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class A&lt;/span>

C000234191_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

9,600

C000234191_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

8,887

C000234191_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 8,910

$ 8,910

$ 8,910

8,910

8,910

$ 8,910

8,910

C000234191_LG_1_AdditionalIndexMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-C1412">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000234191_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000234191_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,301

C000234191_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,190

$ 9,190

9,190

9,190

9,190

9,190

9,190

C000234191_ClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

3.29%

C000234191_ClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

(1.64%)

C000234191_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.59%

C000234191_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

(0.06%)

C000234189_LG_ClassMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Fidelity® Tactical Bond Fund</span>" id="sjs-C1436">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® Tactical Bond Fund&lt;/span>

C000234189_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000234189_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,270

C000234189_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,317

$ 9,317

9,317

9,317

9,317

9,317

9,317

C000234189_LG_1_AdditionalIndexMember_3YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-C1448">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000234189_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,000

C000234189_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,301

C000234189_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,190

$ 9,190

$ 9,190

9,190

9,190

9,190

9,190

C000234189_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.86%

C000234189_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

0.19%

C000221556_LG_ClassMember_5YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Fidelity® SAI Short-Term Bond Fund</span>" id="sjs-D1466">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® SAI Short-Term Bond Fund&lt;/span>

C000221556_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,000

C000221556_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,054

C000221556_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

9,651

C000221556_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,863

C000221556_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 10,515

10,515

$ 10,515

10,515

10,515

10,515

10,515

C000221556_LG_1_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. 1-3 Year Government/Credit Bond Index</span>" id="sjs-D1484">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. 1-3 Year Government/Credit Bond Index&lt;/span>

C000221556_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,000

C000221556_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,039

C000221556_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

9,639

C000221556_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

9,791

C000221556_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

10,403

10,403

$ 10,403

10,403

10,403

10,403

10,403

C000221556_LG_2_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-D1502">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000221556_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,000

C000221556_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

9,977

C000221556_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

8,828

C000221556_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

8,723

C000221556_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,359

9,359

$ 9,359

9,359

9,359

9,359

9,359

C000221556_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.60%

C000221556_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

1.28%

C000221556_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.25%

C000221556_0_AdditionalIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

1%

C000221555_LG_ClassMember_5YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Fidelity® SAI Low Duration Income Fund</span>" id="sjs-D1532">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® SAI Low Duration Income Fund&lt;/span>

C000221555_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,000

C000221555_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,023

C000221555_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

9,985

C000221555_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,438

C000221555_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,064

11,064

$ 11,064

11,064

11,064

11,064

11,064

C000221555_LG_1_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg US Treasury Bill: 6-9 Months Index</span>" id="sjs-D1550">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg US Treasury Bill: 6-9 Months Index&lt;/span>

C000221555_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,000

C000221555_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,011

C000221555_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

9,972

C000221555_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,282

C000221555_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

10,835

10,835

$ 10,835

10,835

10,835

10,835

10,835

C000221555_LG_2_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-D1568">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000221555_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,000

C000221555_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

9,977

C000221555_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

8,828

C000221555_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

8,723

C000221555_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 9,359

9,359

$ 9,359

9,359

9,359

9,359

$ 9,359

C000221555_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6%

C000221555_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

2.59%

C000221555_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

5.37%

C000221555_0_AdditionalIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

2.04%

C000019128_LG_ClassMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Fidelity® Short-Term Bond Fund</span>" id="sjs-H1598">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® Short-Term Bond Fund&lt;/span>

C000019128_ClassMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000019128_ClassMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,072

C000019128_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,252

C000019128_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,358

C000019128_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,379

C000019128_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,843

C000019128_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

11,256

C000019128_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

11,314

C000019128_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,839

C000019128_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

11,089

C000019128_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,836

11,836

11,836

11,836

11,836

11,836

$ 11,836

C000019128_LG_1_AdditionalIndexMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. 1-3 Year Government/Credit Bond Index</span>" id="sjs-H1634">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. 1-3 Year Government/Credit Bond Index&lt;/span>

C000019128_1_AdditionalIndexMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000019128_1_AdditionalIndexMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,081

C000019128_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,232

C000019128_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,324

C000019128_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,340

C000019128_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,818

C000019128_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

11,214

C000019128_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

11,258

C000019128_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,810

C000019128_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,979

C000019128_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

11,666

11,666

11,666

11,666

11,666

11,666

$ 11,666

C000019128_LG_2_AdditionalIndexMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-H1670">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000019128_2_AdditionalIndexMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000019128_2_AdditionalIndexMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,156

C000019128_2_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,761

C000019128_2_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,814

C000019128_2_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,701

C000019128_2_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,789

C000019128_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,553

C000019128_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,542

C000019128_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,098

C000019128_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,965

C000019128_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,765

11,765

$ 11,765

$ 11,765

11,765

$ 11,765

$ 11,765

C000019128_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.73%

C000019128_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.77%

C000019128_NoLoadClassMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.70%

C000019128_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.25%

C000019128_0_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.52%

C000019128_0_AdditionalIndexMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.55%

C000205020_LG_ClassMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class Z</span>" id="sjs-E1724">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class Z&lt;/span>

C000205020_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,000

C000205020_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,450

C000205020_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,858

C000205020_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,923

C000205020_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,475

C000205020_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,725

C000205020_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,439

11,439

$ 11,439

$ 11,439

11,439

$ 11,439

11,439

C000205020_LG_1_AdditionalIndexMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. 1-3 Year Government/Credit Bond Index</span>" id="sjs-E1748">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. 1-3 Year Government/Credit Bond Index&lt;/span>

C000205020_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,000

C000205020_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

10,467

C000205020_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

10,851

C000205020_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

10,893

C000205020_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,460

C000205020_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,624

C000205020_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

11,288

11,288

11,288

$ 11,288

11,288

11,288

11,288

C000205020_LG_2_AdditionalIndexMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-E1772">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000205020_2_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,000

C000205020_2_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,086

C000205020_2_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

11,804

C000205020_2_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

11,794

C000205020_2_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,436

C000205020_2_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,311

C000205020_2_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,064

11,064

$ 11,064

$ 11,064

11,064

11,064

$ 11,064

C000205020_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.66%

C000205020_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.82%

C000205020_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

2.30%

C000205020_0_AdditionalIndexMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.25%

C000205020_0_AdditionalIndexMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.52%

C000205020_0_AdditionalIndexMember_LOCMember

Account Value [Line Items]

Average Annual Return, Percent

2.07%

C000019123_LG_ClassMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class C</span>" id="sjs-H1814">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class C&lt;/span>

C000019123_ClassMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000019123_ClassMember_AsOf_2015Member

Account Value [Line Items]

Account Value

9,921

C000019123_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,474

C000019123_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,502

C000019123_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,280

C000019123_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,231

C000019123_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,069

C000019123_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,083

C000019123_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,564

C000019123_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,463

C000019123_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,249

11,249

$ 11,249

11,249

11,249

11,249

$ 11,249

C000019123_LG_1_AdditionalIndexMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-H1850">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000019123_1_AdditionalIndexMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000019123_1_AdditionalIndexMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,156

C000019123_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,761

C000019123_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,814

C000019123_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,701

C000019123_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,789

C000019123_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,553

C000019123_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,542

C000019123_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,098

C000019123_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,965

C000019123_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,765

11,765

$ 11,765

11,765

11,765

$ 11,765

$ 11,765

C000019123_ClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

5.68%

C000019123_ClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.28%)

C000019123_ClassMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.18%

C000019123_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

6.68%

C000019123_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

(0.28%)

C000019123_NoLoadClassMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

1.18%

C000019125_LG_ClassMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class I</span>" id="sjs-H1904">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class I&lt;/span>

C000019125_ClassMember_AsOf_2014Member

Account Value [Line Items]

Account Value

10,000

C000019125_ClassMember_AsOf_2015Member

Account Value [Line Items]

Account Value

10,023

C000019125_ClassMember_AsOf_2016Member

Account Value [Line Items]

Account Value

10,677

C000019125_ClassMember_AsOf_2017Member

Account Value [Line Items]

Account Value

10,818

C000019125_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,712

C000019125_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,824

C000019125_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,839

C000019125_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,972

C000019125_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,458

C000019125_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

11,379

C000019125_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 12,263

12,263

$ 12,263

12,263

12,263

$ 12,263

$ 12,263

C000019125_LG_1_AdditionalIndexMember_11YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-H1940">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000019125_1_AdditionalIndexMember_AsOf_2014Member

Account Value [Line Items]

Account Value

$ 10,000

C000019125_1_AdditionalIndexMember_AsOf_2015Member

Account Value [Line Items]

Account Value

$ 10,156

C000019125_1_AdditionalIndexMember_AsOf_2016Member

Account Value [Line Items]

Account Value

$ 10,761

C000019125_1_AdditionalIndexMember_AsOf_2017Member

Account Value [Line Items]

Account Value

$ 10,814

C000019125_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,701

C000019125_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,789

C000019125_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,553

C000019125_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,542

C000019125_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

11,098

C000019125_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,965

C000019125_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,765

11,765

$ 11,765

$ 11,765

11,765

$ 11,765

$ 11,765

C000019125_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.77%

C000019125_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

0.73%

C000019125_NoLoadClassMember_10YRMember

Account Value [Line Items]

Average Annual Return, Percent

2.06%

C000205019_LG_ClassMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Class Z</span>" id="sjs-E1985">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class Z&lt;/span>

C000205019_ClassMember_AsOf_2018Member

Account Value [Line Items]

Account Value

10,000

C000205019_ClassMember_AsOf_2019Member

Account Value [Line Items]

Account Value

11,097

C000205019_ClassMember_AsOf_2020Member

Account Value [Line Items]

Account Value

12,064

C000205019_ClassMember_AsOf_2021Member

Account Value [Line Items]

Account Value

12,218

C000205019_ClassMember_AsOf_2022Member

Account Value [Line Items]

Account Value

10,809

C000205019_ClassMember_AsOf_2023Member

Account Value [Line Items]

Account Value

10,750

C000205019_ClassMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,601

11,601

$ 11,601

$ 11,601

11,601

$ 11,601

11,601

C000205019_LG_1_AdditionalIndexMember_7YRMember

Account Value [Line Items]

Line Graph and Table Measure Name

Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-E2009">&lt;span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index&lt;/span>

C000205019_1_AdditionalIndexMember_AsOf_2018Member

Account Value [Line Items]

Account Value

$ 10,000

C000205019_1_AdditionalIndexMember_AsOf_2019Member

Account Value [Line Items]

Account Value

$ 11,086

C000205019_1_AdditionalIndexMember_AsOf_2020Member

Account Value [Line Items]

Account Value

$ 11,804

C000205019_1_AdditionalIndexMember_AsOf_2021Member

Account Value [Line Items]

Account Value

$ 11,794

C000205019_1_AdditionalIndexMember_AsOf_2022Member

Account Value [Line Items]

Account Value

$ 10,436

C000205019_1_AdditionalIndexMember_AsOf_2023Member

Account Value [Line Items]

Account Value

$ 10,311

C000205019_1_AdditionalIndexMember_AsOf_2024Member

Account Value [Line Items]

Account Value

$ 11,064

$ 11,064

$ 11,064

$ 11,064

$ 11,064

$ 11,064

$ 11,064

C000205019_NoLoadClassMember_1YRMember

Account Value [Line Items]

Average Annual Return, Percent

7.91%

C000205019_NoLoadClassMember_5YRMember

Account Value [Line Items]

Average Annual Return, Percent

0.89%

C000205019_NoLoadClassMember_2023-09-01_2024-08-31Member

Account Value [Line Items]

Average Annual Return, Percent

2.54%

Shareholder Report, Holdings (D

Shareholder Report, Holdings (Details)	Aug. 31, 2024
Fidelity Flex Conservative Income Bond Fund | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	11.60%
Fidelity Flex Conservative Income Bond Fund | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	4.90%
Fidelity Flex Conservative Income Bond Fund | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Flex Conservative Income Bond Fund | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Flex Conservative Income Bond Fund | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Flex Conservative Income Bond Fund | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Flex Conservative Income Bond Fund | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Flex Conservative Income Bond Fund | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Flex Conservative Income Bond Fund | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Flex Conservative Income Bond Fund | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Flex Conservative Income Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	16.50%
Fidelity Flex Conservative Income Bond Fund | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	14.10%
Fidelity Flex Conservative Income Bond Fund | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	2.50%
Fidelity Flex Conservative Income Bond Fund | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	24.80%
Fidelity Flex Conservative Income Bond Fund | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	19.40%
Fidelity Flex Conservative Income Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	22.70%
Fidelity Flex Conservative Income Bond Fund | United States
Holdings [Line Items]
Percent of Net Asset Value	84%
Fidelity Flex Conservative Income Bond Fund | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	3.50%
Fidelity Flex Conservative Income Bond Fund | Canada
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Flex Conservative Income Bond Fund | Germany
Holdings [Line Items]
Percent of Net Asset Value	3.20%
Fidelity Flex Conservative Income Bond Fund | Switzerland
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Flex Conservative Income Bond Fund | Japan
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Flex Conservative Income Bond Fund | Netherlands
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Flex Conservative Income Bond Fund | France
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Flex Conservative Income Bond Fund | Denmark
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Flex Conservative Income Bond Fund | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Flex Conservative Income Bond Fund | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	46.60%
Fidelity Flex Conservative Income Bond Fund | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	16.50%
Fidelity Flex Conservative Income Bond Fund | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	14.10%
Fidelity Flex Conservative Income Bond Fund | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Flex Conservative Income Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	22.70%
Fidelity Advisor Tactical Bond Fund - Class M | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	44.70%
Fidelity Advisor Tactical Bond Fund - Class M | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	12.40%
Fidelity Advisor Tactical Bond Fund - Class M | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Tactical Bond Fund - Class M | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Tactical Bond Fund - Class M | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Tactical Bond Fund - Class M | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class M | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class M | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class M | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Tactical Bond Fund - Class M | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Tactical Bond Fund - Class M | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Advisor Tactical Bond Fund - Class M | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Tactical Bond Fund - Class M | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Tactical Bond Fund - Class M | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class M | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	11.60%
Fidelity Advisor Tactical Bond Fund - Class M | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class M | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	9.50%
Fidelity Advisor Tactical Bond Fund - Class M | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	8.60%
Fidelity Advisor Tactical Bond Fund - Class M | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Advisor Tactical Bond Fund - Class M | QDDMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Tactical Bond Fund - Class M | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Advisor Tactical Bond Fund - Class M | QDEquitiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Tactical Bond Fund - Class M | United States
Holdings [Line Items]
Percent of Net Asset Value	85.40%
Fidelity Advisor Tactical Bond Fund - Class M | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	1.90%
Fidelity Advisor Tactical Bond Fund - Class M | Canada
Holdings [Line Items]
Percent of Net Asset Value	2%
Fidelity Advisor Tactical Bond Fund - Class M | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Advisor Tactical Bond Fund - Class M | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Tactical Bond Fund - Class M | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Advisor Tactical Bond Fund - Class M | Mexico
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Advisor Tactical Bond Fund - Class M | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Tactical Bond Fund - Class M | Brazil
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Tactical Bond Fund - Class M | Dominican Republic
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class M | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	16.10%
Fidelity Advisor Tactical Bond Fund - Class M | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Advisor Tactical Bond Fund - Class M | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	4.50%
Fidelity Advisor Tactical Bond Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class M | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	9%
Fidelity Advisor Tactical Bond Fund - Class M | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	4.80%
Fidelity Advisor Tactical Bond Fund - Class M | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	2.30%
Fidelity Advisor Tactical Bond Fund - Class M | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Tactical Bond Fund - Class M | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Tactical Bond Fund - Class M | AACommonStocksMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Tactical Bond Fund - Class M | AAAlternativeFundsMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	43%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	8.80%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	3.20%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Investment Grade Bond Fund - Class M | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	61.90%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	7.60%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	6%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	16.70%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class M | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.70%
Fidelity Advisor Investment Grade Bond Fund - Class M | United States
Holdings [Line Items]
Percent of Net Asset Value	90.50%
Fidelity Advisor Investment Grade Bond Fund - Class M | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Investment Grade Bond Fund - Class M | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Investment Grade Bond Fund - Class M | Switzerland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Investment Grade Bond Fund - Class M | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Investment Grade Bond Fund - Class M | Mexico
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Investment Grade Bond Fund - Class M | GrandCaymanUKOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.20%
Fidelity Advisor Investment Grade Bond Fund - Class M | Ireland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Investment Grade Bond Fund - Class M | BailiwickOfJerseyMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Investment Grade Bond Fund - Class M | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Investment Grade Bond Fund - Class M | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	24.50%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	51.80%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.10%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Investment Grade Bond Fund - Class M | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.20%
Fidelity Advisor Investment Grade Bond Fund - Class M | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	6.80%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class M | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	10.10%
Fidelity Advisor Short-Term Bond Fund - Class M | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Advisor Short-Term Bond Fund - Class M | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class M | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Short-Term Bond Fund - Class M | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Short-Term Bond Fund - Class M | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class M | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class M | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class M | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class M | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class M | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class M | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.40%
Fidelity Advisor Short-Term Bond Fund - Class M | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	22.30%
Fidelity Advisor Short-Term Bond Fund - Class M | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Advisor Short-Term Bond Fund - Class M | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	21.60%
Fidelity Advisor Short-Term Bond Fund - Class M | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	20.40%
Fidelity Advisor Short-Term Bond Fund - Class M | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class M | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Advisor Short-Term Bond Fund - Class M | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Short-Term Bond Fund - Class M | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Advisor Short-Term Bond Fund - Class M | United States
Holdings [Line Items]
Percent of Net Asset Value	77.70%
Fidelity Advisor Short-Term Bond Fund - Class M | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Short-Term Bond Fund - Class M | Canada
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Advisor Short-Term Bond Fund - Class M | Germany
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Advisor Short-Term Bond Fund - Class M | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Short-Term Bond Fund - Class M | France
Holdings [Line Items]
Percent of Net Asset Value	2.10%
Fidelity Advisor Short-Term Bond Fund - Class M | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Advisor Short-Term Bond Fund - Class M | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.40%
Fidelity Advisor Short-Term Bond Fund - Class M | Ireland
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Short-Term Bond Fund - Class M | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Short-Term Bond Fund - Class M | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	45.10%
Fidelity Advisor Short-Term Bond Fund - Class M | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Advisor Short-Term Bond Fund - Class M | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	19.30%
Fidelity Advisor Short-Term Bond Fund - Class M | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Short-Term Bond Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class M | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.20%
Fidelity Advisor Short-Term Bond Fund - Class M | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity SAI Sustainable Core Plus Bond Fund | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	34.90%
Fidelity SAI Sustainable Core Plus Bond Fund | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	10.40%
Fidelity SAI Sustainable Core Plus Bond Fund | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	9.30%
Fidelity SAI Sustainable Core Plus Bond Fund | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	5.40%
Fidelity SAI Sustainable Core Plus Bond Fund | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	4.10%
Fidelity SAI Sustainable Core Plus Bond Fund | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	3.90%
Fidelity SAI Sustainable Core Plus Bond Fund | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity SAI Sustainable Core Plus Bond Fund | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity SAI Sustainable Core Plus Bond Fund | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity SAI Sustainable Core Plus Bond Fund | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity SAI Sustainable Core Plus Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	69.80%
Fidelity SAI Sustainable Core Plus Bond Fund | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	4.60%
Fidelity SAI Sustainable Core Plus Bond Fund | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity SAI Sustainable Core Plus Bond Fund | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	7.60%
Fidelity SAI Sustainable Core Plus Bond Fund | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	12%
Fidelity SAI Sustainable Core Plus Bond Fund | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	2.80%
Fidelity SAI Sustainable Core Plus Bond Fund | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	2.60%
Fidelity SAI Sustainable Core Plus Bond Fund | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity SAI Sustainable Core Plus Bond Fund | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Sustainable Core Plus Bond Fund | QDEquitiesMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity SAI Sustainable Core Plus Bond Fund | United States
Holdings [Line Items]
Percent of Net Asset Value	88.30%
Fidelity SAI Sustainable Core Plus Bond Fund | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity SAI Sustainable Core Plus Bond Fund | Canada
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity SAI Sustainable Core Plus Bond Fund | Germany
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity SAI Sustainable Core Plus Bond Fund | Netherlands
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity SAI Sustainable Core Plus Bond Fund | France
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity SAI Sustainable Core Plus Bond Fund | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	2.20%
Fidelity SAI Sustainable Core Plus Bond Fund | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity SAI Sustainable Core Plus Bond Fund | BailiwickOfJerseyMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Sustainable Core Plus Bond Fund | MultinationalMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity SAI Sustainable Core Plus Bond Fund | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	25.70%
Fidelity SAI Sustainable Core Plus Bond Fund | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	49.40%
Fidelity SAI Sustainable Core Plus Bond Fund | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	5.50%
Fidelity SAI Sustainable Core Plus Bond Fund | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0.20%
Fidelity SAI Sustainable Core Plus Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity SAI Sustainable Core Plus Bond Fund | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.20%
Fidelity SAI Sustainable Core Plus Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity SAI Sustainable Core Plus Bond Fund | AACommonStocksMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity SAI Sustainable Core Plus Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	20.40%
Fidelity Advisor Tactical Bond Fund - Class I | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	44.70%
Fidelity Advisor Tactical Bond Fund - Class I | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	12.40%
Fidelity Advisor Tactical Bond Fund - Class I | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Tactical Bond Fund - Class I | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Tactical Bond Fund - Class I | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Tactical Bond Fund - Class I | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class I | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class I | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class I | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Tactical Bond Fund - Class I | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Tactical Bond Fund - Class I | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Advisor Tactical Bond Fund - Class I | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Tactical Bond Fund - Class I | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Tactical Bond Fund - Class I | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class I | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	11.60%
Fidelity Advisor Tactical Bond Fund - Class I | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class I | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	9.50%
Fidelity Advisor Tactical Bond Fund - Class I | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	8.60%
Fidelity Advisor Tactical Bond Fund - Class I | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Advisor Tactical Bond Fund - Class I | QDDMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Tactical Bond Fund - Class I | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Advisor Tactical Bond Fund - Class I | QDEquitiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Tactical Bond Fund - Class I | United States
Holdings [Line Items]
Percent of Net Asset Value	85.40%
Fidelity Advisor Tactical Bond Fund - Class I | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	1.90%
Fidelity Advisor Tactical Bond Fund - Class I | Canada
Holdings [Line Items]
Percent of Net Asset Value	2%
Fidelity Advisor Tactical Bond Fund - Class I | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Advisor Tactical Bond Fund - Class I | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Tactical Bond Fund - Class I | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Advisor Tactical Bond Fund - Class I | Mexico
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Advisor Tactical Bond Fund - Class I | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Tactical Bond Fund - Class I | Brazil
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Tactical Bond Fund - Class I | Dominican Republic
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class I | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	16.10%
Fidelity Advisor Tactical Bond Fund - Class I | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Advisor Tactical Bond Fund - Class I | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	4.50%
Fidelity Advisor Tactical Bond Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class I | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	9%
Fidelity Advisor Tactical Bond Fund - Class I | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	4.80%
Fidelity Advisor Tactical Bond Fund - Class I | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	2.30%
Fidelity Advisor Tactical Bond Fund - Class I | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Tactical Bond Fund - Class I | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Tactical Bond Fund - Class I | AACommonStocksMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Tactical Bond Fund - Class I | AAAlternativeFundsMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Short-Term Bond Fund - Class C | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Advisor Short-Term Bond Fund - Class C | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class C | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Short-Term Bond Fund - Class C | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Short-Term Bond Fund - Class C | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class C | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class C | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class C | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class C | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class C | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class C | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.40%
Fidelity Advisor Short-Term Bond Fund - Class C | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	22.30%
Fidelity Advisor Short-Term Bond Fund - Class C | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Advisor Short-Term Bond Fund - Class C | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	21.60%
Fidelity Advisor Short-Term Bond Fund - Class C | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	20.40%
Fidelity Advisor Short-Term Bond Fund - Class C | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class C | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Advisor Short-Term Bond Fund - Class C | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Short-Term Bond Fund - Class C | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Advisor Short-Term Bond Fund - Class C | United States
Holdings [Line Items]
Percent of Net Asset Value	77.70%
Fidelity Advisor Short-Term Bond Fund - Class C | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Short-Term Bond Fund - Class C | Canada
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Advisor Short-Term Bond Fund - Class C | Germany
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Advisor Short-Term Bond Fund - Class C | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Short-Term Bond Fund - Class C | France
Holdings [Line Items]
Percent of Net Asset Value	2.10%
Fidelity Advisor Short-Term Bond Fund - Class C | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Advisor Short-Term Bond Fund - Class C | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.40%
Fidelity Advisor Short-Term Bond Fund - Class C | Ireland
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Short-Term Bond Fund - Class C | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Short-Term Bond Fund - Class C | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	45.10%
Fidelity Advisor Short-Term Bond Fund - Class C | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Advisor Short-Term Bond Fund - Class C | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	19.30%
Fidelity Advisor Short-Term Bond Fund - Class C | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Short-Term Bond Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class C | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.20%
Fidelity Advisor Short-Term Bond Fund - Class C | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Short-Term Bond Fund - Class A | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Advisor Short-Term Bond Fund - Class A | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class A | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Short-Term Bond Fund - Class A | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Short-Term Bond Fund - Class A | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class A | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class A | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class A | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class A | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class A | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class A | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.40%
Fidelity Advisor Short-Term Bond Fund - Class A | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	22.30%
Fidelity Advisor Short-Term Bond Fund - Class A | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Advisor Short-Term Bond Fund - Class A | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	21.60%
Fidelity Advisor Short-Term Bond Fund - Class A | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	20.40%
Fidelity Advisor Short-Term Bond Fund - Class A | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class A | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Advisor Short-Term Bond Fund - Class A | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Short-Term Bond Fund - Class A | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Advisor Short-Term Bond Fund - Class A | United States
Holdings [Line Items]
Percent of Net Asset Value	77.70%
Fidelity Advisor Short-Term Bond Fund - Class A | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Short-Term Bond Fund - Class A | Canada
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Advisor Short-Term Bond Fund - Class A | Germany
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Advisor Short-Term Bond Fund - Class A | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Short-Term Bond Fund - Class A | France
Holdings [Line Items]
Percent of Net Asset Value	2.10%
Fidelity Advisor Short-Term Bond Fund - Class A | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Advisor Short-Term Bond Fund - Class A | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.40%
Fidelity Advisor Short-Term Bond Fund - Class A | Ireland
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Short-Term Bond Fund - Class A | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Short-Term Bond Fund - Class A | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	45.10%
Fidelity Advisor Short-Term Bond Fund - Class A | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Advisor Short-Term Bond Fund - Class A | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	19.30%
Fidelity Advisor Short-Term Bond Fund - Class A | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Short-Term Bond Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class A | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.20%
Fidelity Advisor Short-Term Bond Fund - Class A | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Short-Term Bond Fund - Class I | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Advisor Short-Term Bond Fund - Class I | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class I | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Short-Term Bond Fund - Class I | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Short-Term Bond Fund - Class I | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class I | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class I | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class I | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class I | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class I | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class I | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.40%
Fidelity Advisor Short-Term Bond Fund - Class I | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	22.30%
Fidelity Advisor Short-Term Bond Fund - Class I | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Advisor Short-Term Bond Fund - Class I | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	21.60%
Fidelity Advisor Short-Term Bond Fund - Class I | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	20.40%
Fidelity Advisor Short-Term Bond Fund - Class I | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class I | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Advisor Short-Term Bond Fund - Class I | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Short-Term Bond Fund - Class I | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Advisor Short-Term Bond Fund - Class I | United States
Holdings [Line Items]
Percent of Net Asset Value	77.70%
Fidelity Advisor Short-Term Bond Fund - Class I | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Short-Term Bond Fund - Class I | Canada
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Advisor Short-Term Bond Fund - Class I | Germany
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Advisor Short-Term Bond Fund - Class I | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Short-Term Bond Fund - Class I | France
Holdings [Line Items]
Percent of Net Asset Value	2.10%
Fidelity Advisor Short-Term Bond Fund - Class I | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Advisor Short-Term Bond Fund - Class I | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.40%
Fidelity Advisor Short-Term Bond Fund - Class I | Ireland
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Short-Term Bond Fund - Class I | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Short-Term Bond Fund - Class I | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	45.10%
Fidelity Advisor Short-Term Bond Fund - Class I | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Advisor Short-Term Bond Fund - Class I | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	19.30%
Fidelity Advisor Short-Term Bond Fund - Class I | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Short-Term Bond Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class I | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.20%
Fidelity Advisor Short-Term Bond Fund - Class I | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Investment Grade Bond Fund | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	43%
Fidelity Investment Grade Bond Fund | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	8.80%
Fidelity Investment Grade Bond Fund | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Investment Grade Bond Fund | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	3.20%
Fidelity Investment Grade Bond Fund | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Investment Grade Bond Fund | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Investment Grade Bond Fund | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Investment Grade Bond Fund | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Investment Grade Bond Fund | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Investment Grade Bond Fund | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Investment Grade Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	61.90%
Fidelity Investment Grade Bond Fund | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	7.60%
Fidelity Investment Grade Bond Fund | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Investment Grade Bond Fund | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	6%
Fidelity Investment Grade Bond Fund | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	16.70%
Fidelity Investment Grade Bond Fund | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Investment Grade Bond Fund | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Investment Grade Bond Fund | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Investment Grade Bond Fund | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.70%
Fidelity Investment Grade Bond Fund | United States
Holdings [Line Items]
Percent of Net Asset Value	90.50%
Fidelity Investment Grade Bond Fund | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Investment Grade Bond Fund | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Investment Grade Bond Fund | Switzerland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Investment Grade Bond Fund | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Investment Grade Bond Fund | Mexico
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Investment Grade Bond Fund | GrandCaymanUKOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.20%
Fidelity Investment Grade Bond Fund | Ireland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Investment Grade Bond Fund | BailiwickOfJerseyMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Investment Grade Bond Fund | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Investment Grade Bond Fund | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	24.50%
Fidelity Investment Grade Bond Fund | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	51.80%
Fidelity Investment Grade Bond Fund | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.10%
Fidelity Investment Grade Bond Fund | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Investment Grade Bond Fund | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Investment Grade Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Investment Grade Bond Fund | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.20%
Fidelity Investment Grade Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	6.80%
Fidelity Investment Grade Bond Fund | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Investment Grade Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	10.10%
Fidelity Advisor Tactical Bond Fund - Class C | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	44.70%
Fidelity Advisor Tactical Bond Fund - Class C | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	12.40%
Fidelity Advisor Tactical Bond Fund - Class C | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Tactical Bond Fund - Class C | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Tactical Bond Fund - Class C | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Tactical Bond Fund - Class C | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class C | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class C | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class C | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Tactical Bond Fund - Class C | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Tactical Bond Fund - Class C | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Advisor Tactical Bond Fund - Class C | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Tactical Bond Fund - Class C | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Tactical Bond Fund - Class C | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class C | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	11.60%
Fidelity Advisor Tactical Bond Fund - Class C | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class C | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	9.50%
Fidelity Advisor Tactical Bond Fund - Class C | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	8.60%
Fidelity Advisor Tactical Bond Fund - Class C | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Advisor Tactical Bond Fund - Class C | QDDMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Tactical Bond Fund - Class C | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Advisor Tactical Bond Fund - Class C | QDEquitiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Tactical Bond Fund - Class C | United States
Holdings [Line Items]
Percent of Net Asset Value	85.40%
Fidelity Advisor Tactical Bond Fund - Class C | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	1.90%
Fidelity Advisor Tactical Bond Fund - Class C | Canada
Holdings [Line Items]
Percent of Net Asset Value	2%
Fidelity Advisor Tactical Bond Fund - Class C | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Advisor Tactical Bond Fund - Class C | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Tactical Bond Fund - Class C | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Advisor Tactical Bond Fund - Class C | Mexico
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Advisor Tactical Bond Fund - Class C | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Tactical Bond Fund - Class C | Brazil
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Tactical Bond Fund - Class C | Dominican Republic
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class C | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	16.10%
Fidelity Advisor Tactical Bond Fund - Class C | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Advisor Tactical Bond Fund - Class C | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	4.50%
Fidelity Advisor Tactical Bond Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class C | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	9%
Fidelity Advisor Tactical Bond Fund - Class C | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	4.80%
Fidelity Advisor Tactical Bond Fund - Class C | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	2.30%
Fidelity Advisor Tactical Bond Fund - Class C | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Tactical Bond Fund - Class C | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Tactical Bond Fund - Class C | AACommonStocksMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Tactical Bond Fund - Class C | AAAlternativeFundsMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity SAI Total Bond Fund | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	19.50%
Fidelity SAI Total Bond Fund | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	9.30%
Fidelity SAI Total Bond Fund | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	7.50%
Fidelity SAI Total Bond Fund | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	5.60%
Fidelity SAI Total Bond Fund | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	4.20%
Fidelity SAI Total Bond Fund | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	4%
Fidelity SAI Total Bond Fund | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity SAI Total Bond Fund | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity SAI Total Bond Fund | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity SAI Total Bond Fund | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity SAI Total Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	51%
Fidelity SAI Total Bond Fund | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	9.60%
Fidelity SAI Total Bond Fund | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity SAI Total Bond Fund | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	9.50%
Fidelity SAI Total Bond Fund | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	18.20%
Fidelity SAI Total Bond Fund | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	4.40%
Fidelity SAI Total Bond Fund | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	5.90%
Fidelity SAI Total Bond Fund | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity SAI Total Bond Fund | QDDMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity SAI Total Bond Fund | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	4.10%
Fidelity SAI Total Bond Fund | QDEquitiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity SAI Total Bond Fund | United States
Holdings [Line Items]
Percent of Net Asset Value	85.30%
Fidelity SAI Total Bond Fund | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity SAI Total Bond Fund | Canada
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity SAI Total Bond Fund | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Total Bond Fund | Switzerland
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity SAI Total Bond Fund | France
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity SAI Total Bond Fund | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity SAI Total Bond Fund | Mexico
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Total Bond Fund | GrandCaymanUKOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.40%
Fidelity SAI Total Bond Fund | Ireland
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity SAI Total Bond Fund | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	31.40%
Fidelity SAI Total Bond Fund | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	28.80%
Fidelity SAI Total Bond Fund | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	8%
Fidelity SAI Total Bond Fund | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity SAI Total Bond Fund | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	5%
Fidelity SAI Total Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Total Bond Fund | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity SAI Total Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.90%
Fidelity SAI Total Bond Fund | AACommonStocksMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity SAI Total Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	22.20%
Fidelity SAI Total Bond Fund | AASupranationalObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity SAI Total Bond Fund | AAPreferredStocksMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Tactical Bond Fund - Class Z | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	44.70%
Fidelity Advisor Tactical Bond Fund - Class Z | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	12.40%
Fidelity Advisor Tactical Bond Fund - Class Z | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Tactical Bond Fund - Class Z | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Tactical Bond Fund - Class Z | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Tactical Bond Fund - Class Z | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class Z | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class Z | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class Z | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Tactical Bond Fund - Class Z | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Tactical Bond Fund - Class Z | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Advisor Tactical Bond Fund - Class Z | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Tactical Bond Fund - Class Z | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Tactical Bond Fund - Class Z | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class Z | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	11.60%
Fidelity Advisor Tactical Bond Fund - Class Z | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class Z | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	9.50%
Fidelity Advisor Tactical Bond Fund - Class Z | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	8.60%
Fidelity Advisor Tactical Bond Fund - Class Z | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Advisor Tactical Bond Fund - Class Z | QDDMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Tactical Bond Fund - Class Z | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Advisor Tactical Bond Fund - Class Z | QDEquitiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Tactical Bond Fund - Class Z | United States
Holdings [Line Items]
Percent of Net Asset Value	85.40%
Fidelity Advisor Tactical Bond Fund - Class Z | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	1.90%
Fidelity Advisor Tactical Bond Fund - Class Z | Canada
Holdings [Line Items]
Percent of Net Asset Value	2%
Fidelity Advisor Tactical Bond Fund - Class Z | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Advisor Tactical Bond Fund - Class Z | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Tactical Bond Fund - Class Z | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Advisor Tactical Bond Fund - Class Z | Mexico
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Advisor Tactical Bond Fund - Class Z | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Tactical Bond Fund - Class Z | Brazil
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Tactical Bond Fund - Class Z | Dominican Republic
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class Z | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	16.10%
Fidelity Advisor Tactical Bond Fund - Class Z | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Advisor Tactical Bond Fund - Class Z | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	4.50%
Fidelity Advisor Tactical Bond Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class Z | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	9%
Fidelity Advisor Tactical Bond Fund - Class Z | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	4.80%
Fidelity Advisor Tactical Bond Fund - Class Z | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	2.30%
Fidelity Advisor Tactical Bond Fund - Class Z | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Tactical Bond Fund - Class Z | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Tactical Bond Fund - Class Z | AACommonStocksMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Tactical Bond Fund - Class Z | AAAlternativeFundsMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Intermediate Bond Fund | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	40.30%
Fidelity Intermediate Bond Fund | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	1.80%
Fidelity Intermediate Bond Fund | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Intermediate Bond Fund | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Intermediate Bond Fund | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Intermediate Bond Fund | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Intermediate Bond Fund | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Intermediate Bond Fund | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Intermediate Bond Fund | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Intermediate Bond Fund | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Intermediate Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	40.70%
Fidelity Intermediate Bond Fund | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	11.80%
Fidelity Intermediate Bond Fund | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Intermediate Bond Fund | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	17.70%
Fidelity Intermediate Bond Fund | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	23.20%
Fidelity Intermediate Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Intermediate Bond Fund | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	2.20%
Fidelity Intermediate Bond Fund | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Intermediate Bond Fund | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Intermediate Bond Fund | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	2.10%
Fidelity Intermediate Bond Fund | United States
Holdings [Line Items]
Percent of Net Asset Value	83.80%
Fidelity Intermediate Bond Fund | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	3.80%
Fidelity Intermediate Bond Fund | Canada
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Intermediate Bond Fund | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Intermediate Bond Fund | Japan
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Intermediate Bond Fund | France
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Intermediate Bond Fund | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	1.80%
Fidelity Intermediate Bond Fund | Mexico
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Intermediate Bond Fund | GrandCaymanUKOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	2.70%
Fidelity Intermediate Bond Fund | Ireland
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Intermediate Bond Fund | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	41.90%
Fidelity Intermediate Bond Fund | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	40.30%
Fidelity Intermediate Bond Fund | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	11.30%
Fidelity Intermediate Bond Fund | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Intermediate Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Intermediate Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Intermediate Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	4.90%
Fidelity Intermediate Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	43%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	8.80%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	3.20%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Investment Grade Bond Fund - Class A | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	61.90%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	7.60%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	6%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	16.70%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class A | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.70%
Fidelity Advisor Investment Grade Bond Fund - Class A | United States
Holdings [Line Items]
Percent of Net Asset Value	90.50%
Fidelity Advisor Investment Grade Bond Fund - Class A | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Investment Grade Bond Fund - Class A | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Investment Grade Bond Fund - Class A | Switzerland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Investment Grade Bond Fund - Class A | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Investment Grade Bond Fund - Class A | Mexico
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Investment Grade Bond Fund - Class A | GrandCaymanUKOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.20%
Fidelity Advisor Investment Grade Bond Fund - Class A | Ireland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Investment Grade Bond Fund - Class A | BailiwickOfJerseyMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Investment Grade Bond Fund - Class A | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Investment Grade Bond Fund - Class A | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	24.50%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	51.80%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.10%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Investment Grade Bond Fund - Class A | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.20%
Fidelity Advisor Investment Grade Bond Fund - Class A | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	6.80%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class A | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	10.10%
Fidelity Advisor Tactical Bond Fund - Class A | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	44.70%
Fidelity Advisor Tactical Bond Fund - Class A | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	12.40%
Fidelity Advisor Tactical Bond Fund - Class A | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Tactical Bond Fund - Class A | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Tactical Bond Fund - Class A | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Tactical Bond Fund - Class A | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class A | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class A | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class A | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Tactical Bond Fund - Class A | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Tactical Bond Fund - Class A | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Advisor Tactical Bond Fund - Class A | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Tactical Bond Fund - Class A | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Tactical Bond Fund - Class A | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class A | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	11.60%
Fidelity Advisor Tactical Bond Fund - Class A | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class A | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	9.50%
Fidelity Advisor Tactical Bond Fund - Class A | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	8.60%
Fidelity Advisor Tactical Bond Fund - Class A | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Advisor Tactical Bond Fund - Class A | QDDMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Tactical Bond Fund - Class A | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Advisor Tactical Bond Fund - Class A | QDEquitiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Tactical Bond Fund - Class A | United States
Holdings [Line Items]
Percent of Net Asset Value	85.40%
Fidelity Advisor Tactical Bond Fund - Class A | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	1.90%
Fidelity Advisor Tactical Bond Fund - Class A | Canada
Holdings [Line Items]
Percent of Net Asset Value	2%
Fidelity Advisor Tactical Bond Fund - Class A | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Advisor Tactical Bond Fund - Class A | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Tactical Bond Fund - Class A | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Advisor Tactical Bond Fund - Class A | Mexico
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Advisor Tactical Bond Fund - Class A | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Tactical Bond Fund - Class A | Brazil
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Tactical Bond Fund - Class A | Dominican Republic
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Tactical Bond Fund - Class A | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	16.10%
Fidelity Advisor Tactical Bond Fund - Class A | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Advisor Tactical Bond Fund - Class A | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	4.50%
Fidelity Advisor Tactical Bond Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Tactical Bond Fund - Class A | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	9%
Fidelity Advisor Tactical Bond Fund - Class A | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	4.80%
Fidelity Advisor Tactical Bond Fund - Class A | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	2.30%
Fidelity Advisor Tactical Bond Fund - Class A | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Tactical Bond Fund - Class A | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Tactical Bond Fund - Class A | AACommonStocksMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Tactical Bond Fund - Class A | AAAlternativeFundsMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Tactical Bond Fund | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	44.70%
Fidelity Tactical Bond Fund | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	12.40%
Fidelity Tactical Bond Fund | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Tactical Bond Fund | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Tactical Bond Fund | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Tactical Bond Fund | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Tactical Bond Fund | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Tactical Bond Fund | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Tactical Bond Fund | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Tactical Bond Fund | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Tactical Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Tactical Bond Fund | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Tactical Bond Fund | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Tactical Bond Fund | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Tactical Bond Fund | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	11.60%
Fidelity Tactical Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Tactical Bond Fund | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	9.50%
Fidelity Tactical Bond Fund | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	8.60%
Fidelity Tactical Bond Fund | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Tactical Bond Fund | QDDMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Tactical Bond Fund | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Tactical Bond Fund | QDEquitiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Tactical Bond Fund | United States
Holdings [Line Items]
Percent of Net Asset Value	85.40%
Fidelity Tactical Bond Fund | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	1.90%
Fidelity Tactical Bond Fund | Canada
Holdings [Line Items]
Percent of Net Asset Value	2%
Fidelity Tactical Bond Fund | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Tactical Bond Fund | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Tactical Bond Fund | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Tactical Bond Fund | Mexico
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Tactical Bond Fund | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Tactical Bond Fund | Brazil
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Tactical Bond Fund | Dominican Republic
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Tactical Bond Fund | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	16.10%
Fidelity Tactical Bond Fund | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	57.10%
Fidelity Tactical Bond Fund | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	4.50%
Fidelity Tactical Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Tactical Bond Fund | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	9%
Fidelity Tactical Bond Fund | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	4.80%
Fidelity Tactical Bond Fund | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	2.30%
Fidelity Tactical Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Tactical Bond Fund | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Tactical Bond Fund | AACommonStocksMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Tactical Bond Fund | AAAlternativeFundsMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity SAI Short-Term Bond Fund | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	30.90%
Fidelity SAI Short-Term Bond Fund | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity SAI Short-Term Bond Fund | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity SAI Short-Term Bond Fund | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity SAI Short-Term Bond Fund | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Short-Term Bond Fund | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity SAI Short-Term Bond Fund | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity SAI Short-Term Bond Fund | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity SAI Short-Term Bond Fund | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity SAI Short-Term Bond Fund | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity SAI Short-Term Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	31%
Fidelity SAI Short-Term Bond Fund | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	18.20%
Fidelity SAI Short-Term Bond Fund | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	2.70%
Fidelity SAI Short-Term Bond Fund | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	22%
Fidelity SAI Short-Term Bond Fund | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	22%
Fidelity SAI Short-Term Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Short-Term Bond Fund | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Short-Term Bond Fund | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity SAI Short-Term Bond Fund | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity SAI Short-Term Bond Fund | United States
Holdings [Line Items]
Percent of Net Asset Value	78.80%
Fidelity SAI Short-Term Bond Fund | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	4.40%
Fidelity SAI Short-Term Bond Fund | Canada
Holdings [Line Items]
Percent of Net Asset Value	3%
Fidelity SAI Short-Term Bond Fund | Germany
Holdings [Line Items]
Percent of Net Asset Value	3%
Fidelity SAI Short-Term Bond Fund | Japan
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity SAI Short-Term Bond Fund | France
Holdings [Line Items]
Percent of Net Asset Value	2%
Fidelity SAI Short-Term Bond Fund | Denmark
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity SAI Short-Term Bond Fund | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity SAI Short-Term Bond Fund | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	2.80%
Fidelity SAI Short-Term Bond Fund | Ireland
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity SAI Short-Term Bond Fund | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	48%
Fidelity SAI Short-Term Bond Fund | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	30.90%
Fidelity SAI Short-Term Bond Fund | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	16.40%
Fidelity SAI Short-Term Bond Fund | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity SAI Short-Term Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Short-Term Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	3.20%
Fidelity SAI Short-Term Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity SAI Low Duration Income Fund | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	14.90%
Fidelity SAI Low Duration Income Fund | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	6.20%
Fidelity SAI Low Duration Income Fund | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Low Duration Income Fund | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity SAI Low Duration Income Fund | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity SAI Low Duration Income Fund | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity SAI Low Duration Income Fund | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity SAI Low Duration Income Fund | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity SAI Low Duration Income Fund | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity SAI Low Duration Income Fund | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity SAI Low Duration Income Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	14.90%
Fidelity SAI Low Duration Income Fund | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	24.40%
Fidelity SAI Low Duration Income Fund | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	2.70%
Fidelity SAI Low Duration Income Fund | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	22.50%
Fidelity SAI Low Duration Income Fund | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	19.60%
Fidelity SAI Low Duration Income Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	8.80%
Fidelity SAI Low Duration Income Fund | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	0.20%
Fidelity SAI Low Duration Income Fund | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	6.90%
Fidelity SAI Low Duration Income Fund | United States
Holdings [Line Items]
Percent of Net Asset Value	80.60%
Fidelity SAI Low Duration Income Fund | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	2.80%
Fidelity SAI Low Duration Income Fund | Canada
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity SAI Low Duration Income Fund | Germany
Holdings [Line Items]
Percent of Net Asset Value	3%
Fidelity SAI Low Duration Income Fund | Switzerland
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity SAI Low Duration Income Fund | Japan
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity SAI Low Duration Income Fund | Netherlands
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity SAI Low Duration Income Fund | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	2.30%
Fidelity SAI Low Duration Income Fund | GrandCaymanUKOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	2.80%
Fidelity SAI Low Duration Income Fund | Ireland
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity SAI Low Duration Income Fund | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	44.80%
Fidelity SAI Low Duration Income Fund | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	21.10%
Fidelity SAI Low Duration Income Fund | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	22.90%
Fidelity SAI Low Duration Income Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	8.80%
Fidelity SAI Low Duration Income Fund | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	2.40%
Fidelity Short-Term Bond Fund | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Short-Term Bond Fund | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Short-Term Bond Fund | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Short-Term Bond Fund | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Short-Term Bond Fund | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Short-Term Bond Fund | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Short-Term Bond Fund | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Short-Term Bond Fund | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Short-Term Bond Fund | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Short-Term Bond Fund | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Short-Term Bond Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.40%
Fidelity Short-Term Bond Fund | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	22.30%
Fidelity Short-Term Bond Fund | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Short-Term Bond Fund | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	21.60%
Fidelity Short-Term Bond Fund | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	20.40%
Fidelity Short-Term Bond Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Short-Term Bond Fund | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Short-Term Bond Fund | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Short-Term Bond Fund | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Short-Term Bond Fund | United States
Holdings [Line Items]
Percent of Net Asset Value	77.70%
Fidelity Short-Term Bond Fund | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Short-Term Bond Fund | Canada
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Short-Term Bond Fund | Germany
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Short-Term Bond Fund | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Short-Term Bond Fund | France
Holdings [Line Items]
Percent of Net Asset Value	2.10%
Fidelity Short-Term Bond Fund | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Short-Term Bond Fund | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.40%
Fidelity Short-Term Bond Fund | Ireland
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Short-Term Bond Fund | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Short-Term Bond Fund | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	45.10%
Fidelity Short-Term Bond Fund | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Short-Term Bond Fund | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	19.30%
Fidelity Short-Term Bond Fund | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Short-Term Bond Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Short-Term Bond Fund | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.20%
Fidelity Short-Term Bond Fund | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class Z | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	22.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	21.60%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	20.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	1.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | United States
Holdings [Line Items]
Percent of Net Asset Value	77.70%
Fidelity Advisor Short-Term Bond Fund - Class Z | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | Canada
Holdings [Line Items]
Percent of Net Asset Value	3.60%
Fidelity Advisor Short-Term Bond Fund - Class Z | Germany
Holdings [Line Items]
Percent of Net Asset Value	3.10%
Fidelity Advisor Short-Term Bond Fund - Class Z | Japan
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Short-Term Bond Fund - Class Z | France
Holdings [Line Items]
Percent of Net Asset Value	2.10%
Fidelity Advisor Short-Term Bond Fund - Class Z | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	2.90%
Fidelity Advisor Short-Term Bond Fund - Class Z | GrandCaymanUkOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | Ireland
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Short-Term Bond Fund - Class Z | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Short-Term Bond Fund - Class Z | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	45.10%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	26.10%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	19.30%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember
Holdings [Line Items]
Percent of Net Asset Value	1.40%
Fidelity Advisor Short-Term Bond Fund - Class Z | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.20%
Fidelity Advisor Short-Term Bond Fund - Class Z | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	43%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	8.80%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	3.20%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Investment Grade Bond Fund - Class C | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	61.90%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	7.60%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	6%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	16.70%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class C | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.70%
Fidelity Advisor Investment Grade Bond Fund - Class C | United States
Holdings [Line Items]
Percent of Net Asset Value	90.50%
Fidelity Advisor Investment Grade Bond Fund - Class C | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Investment Grade Bond Fund - Class C | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Investment Grade Bond Fund - Class C | Switzerland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Investment Grade Bond Fund - Class C | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Investment Grade Bond Fund - Class C | Mexico
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Investment Grade Bond Fund - Class C | GrandCaymanUKOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.20%
Fidelity Advisor Investment Grade Bond Fund - Class C | Ireland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Investment Grade Bond Fund - Class C | BailiwickOfJerseyMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Investment Grade Bond Fund - Class C | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Investment Grade Bond Fund - Class C | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	24.50%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	51.80%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.10%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Investment Grade Bond Fund - Class C | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.20%
Fidelity Advisor Investment Grade Bond Fund - Class C | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	6.80%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class C | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	10.10%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	43%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	8.80%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	3.20%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Investment Grade Bond Fund - Class I | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	61.90%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	7.60%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	6%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	16.70%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class I | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.70%
Fidelity Advisor Investment Grade Bond Fund - Class I | United States
Holdings [Line Items]
Percent of Net Asset Value	90.50%
Fidelity Advisor Investment Grade Bond Fund - Class I | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Investment Grade Bond Fund - Class I | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Investment Grade Bond Fund - Class I | Switzerland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Investment Grade Bond Fund - Class I | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Investment Grade Bond Fund - Class I | Mexico
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Investment Grade Bond Fund - Class I | GrandCaymanUKOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.20%
Fidelity Advisor Investment Grade Bond Fund - Class I | Ireland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Investment Grade Bond Fund - Class I | BailiwickOfJerseyMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Investment Grade Bond Fund - Class I | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Investment Grade Bond Fund - Class I | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	24.50%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	51.80%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.10%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Investment Grade Bond Fund - Class I | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.20%
Fidelity Advisor Investment Grade Bond Fund - Class I | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	6.80%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class I | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	10.10%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH0Member
Holdings [Line Items]
Percent of Net Asset Value	43%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH1Member
Holdings [Line Items]
Percent of Net Asset Value	8.80%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH2Member
Holdings [Line Items]
Percent of Net Asset Value	3.40%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH3Member
Holdings [Line Items]
Percent of Net Asset Value	3.20%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH4Member
Holdings [Line Items]
Percent of Net Asset Value	1.70%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH5Member
Holdings [Line Items]
Percent of Net Asset Value	1.60%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH6Member
Holdings [Line Items]
Percent of Net Asset Value	1.50%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH7Member
Holdings [Line Items]
Percent of Net Asset Value	1.20%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH8Member
Holdings [Line Items]
Percent of Net Asset Value	1%
Fidelity Advisor Investment Grade Bond Fund - Class Z | TH9Member
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDUSGovernmentandUSGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	61.90%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDAAAMember
Holdings [Line Items]
Percent of Net Asset Value	7.60%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDAAMember
Holdings [Line Items]
Percent of Net Asset Value	0.60%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDAMember
Holdings [Line Items]
Percent of Net Asset Value	6%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDBBBMember
Holdings [Line Items]
Percent of Net Asset Value	16.70%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDBBMember
Holdings [Line Items]
Percent of Net Asset Value	3.30%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDBMember
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDCCCCCCMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class Z | QDNotRatedMember
Holdings [Line Items]
Percent of Net Asset Value	3.70%
Fidelity Advisor Investment Grade Bond Fund - Class Z | United States
Holdings [Line Items]
Percent of Net Asset Value	90.50%
Fidelity Advisor Investment Grade Bond Fund - Class Z | United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Investment Grade Bond Fund - Class Z | Germany
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Investment Grade Bond Fund - Class Z | Switzerland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Investment Grade Bond Fund - Class Z | OtherMember
Holdings [Line Items]
Percent of Net Asset Value	1.10%
Fidelity Advisor Investment Grade Bond Fund - Class Z | Mexico
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Fidelity Advisor Investment Grade Bond Fund - Class Z | GrandCaymanUKOverseasTerMember
Holdings [Line Items]
Percent of Net Asset Value	4.20%
Fidelity Advisor Investment Grade Bond Fund - Class Z | Ireland
Holdings [Line Items]
Percent of Net Asset Value	0.50%
Fidelity Advisor Investment Grade Bond Fund - Class Z | BailiwickOfJerseyMember
Holdings [Line Items]
Percent of Net Asset Value	0.40%
Fidelity Advisor Investment Grade Bond Fund - Class Z | Italy
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AACorporateBondsMember
Holdings [Line Items]
Percent of Net Asset Value	24.50%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAUSTreasuryObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	51.80%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAAssetBackedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	7.10%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAOtherInvestmentsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AABankLoanObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAForeignGovernmentandGovernmentAgencyObligationsMember
Holdings [Line Items]
Percent of Net Asset Value	0.10%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAPreferredSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0.20%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AACMOsandOtherMortgageRelatedSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	6.80%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAMunicipalSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	0%
Fidelity Advisor Investment Grade Bond Fund - Class Z | AAUSGovernmentAgencyMortgageSecuritiesMember
Holdings [Line Items]
Percent of Net Asset Value	10.10%