| Form N-CSR Cover | 12 Months Ended |
| Sep. 30, 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 | Sep. 30, 2024 |
| Shareholder Report | 12 Months Ended |
| Sep. 30, 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 | Sep. 30, 2024 |
| Fidelity Advisor Strategic Real Return Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Strategic Real Return Fund |
| Class Name | Fidelity Advisor® Strategic Real Return Fund Class C |
| Trading Symbol | FCSRX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains information about Fidelity® Strategic Real Return Fund for the period October 1, 2023 to September 30, 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 | $ 178 |
| Expense Ratio, Percent | 1.70% |
| Factors Affecting Performance [Text Block] | What affected the Fund's performance this period? • • SM , the fund benefited from favorable security selection, while asset class positioning also boosted the portfolio's result. • • • • |
| 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"><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.</span> |
| Line Graph [Table Text Block] | How did the Fund perform over the past 10 years? CUMULATIVE PERFORMANCE September 30, 2014 through September 30, 2024. Initial investment of $10,000. Class C $10,000 $9,327 $9,693 $9,835 $10,072 $10,273 $10,067 $11,903 $11,334 $11,894 $13,166 Fidelity Strategic Real Return Composite Index℠ $10,000 $9,493 $10,027 $10,145 $10,425 $10,858 $10,823 $12,800 $12,237 $13,014 $14,403 Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index $10,000 $9,917 $10,570 $10,493 $10,536 $11,286 $12,424 $13,069 $11,557 $11,701 $12,847 Bloomberg U.S. Aggregate Bond Index $10,000 $10,294 $10,829 $10,836 $10,705 $11,807 $12,632 $12,518 $10,691 $10,760 $12,004 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) 8.77% 4.77% 2.79% Class C 9.77% 4.77% 2.79% Fidelity Strategic Real Return Composite Index℠ 10.68% 5.81% 3.72% Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index 9.79% 2.62% 2.54% Bloomberg U.S. Aggregate Bond Index 11.57% 0.33% 1.84% 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 | $ 506,480,321 |
| Holdings Count | shares | 400 |
| Advisory Fees Paid, Amount | $ 3,117,645 |
| Investment Company Portfolio Turnover | 23% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 400 Total Advisory Fee $ Portfolio Turnover 23 % |
| Holdings [Text Block] | U.S. Government and U.S. Government Agency Obligations 23.7 AAA 0.0 AA 0.0 A 0.3 BBB 2.4 BB 7.2 B 15.7 CCC,CC,C 1.2 Not Rated 4.8 Equities 42.0 Short-Term Investments and Net Other Assets (Liabilities) 2.7 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. Floating-Rate debt 24.7 Inflation-Protected Debt 23.9 Commodities & Related Investments 14.7 Commodity Equities 13.8 Real Estate Income 11.8 REITs 9.2 Global Infrastructure Equities 1.5 MLPs 0.0 Gold-Miners Equities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets) United States 90.2 Canada 3.5 Brazil 1.0 South Africa 0.7 Finland 0.7 United Kingdom 0.6 Australia 0.6 Zambia 0.4 Netherlands 0.4 Others 1.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) US Treasury Notes 19.2 Fidelity Commodity Strategy Central Fund 14.7 US Treasury Bonds 4.5 Exxon Mobil Corp 1.1 Equinix Inc 0.9 Prologis Inc 0.9 Shell PLC 0.8 Archer-Daniels-Midland Co 0.7 Teck Resources Ltd Class B 0.7 Ventas Inc 0.7 44.2 |
| Material Fund Change [Text Block] | How has the Fund changed? This is a summary of certain changes to the Fund since October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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 October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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-B40"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098</span> |
| Updated Prospectus Email Address | fidfunddocuments@fidelity.com</span>" id="sjs-B41"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com</span> |
| Updated Prospectus Web Address | fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B42"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec</span> |
| Fidelity Advisor Strategic Real Return Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Strategic Real Return Fund |
| Class Name | Fidelity Advisor® Strategic Real Return Fund Class I |
| Trading Symbol | FSIRX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains information about Fidelity® Strategic Real Return Fund for the period October 1, 2023 to September 30, 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 | $ 74 |
| Expense Ratio, Percent | 0.70% |
| Factors Affecting Performance [Text Block] | What affected the Fund's performance this period? • • SM , the fund benefited from favorable security selection, while asset class positioning also boosted the portfolio's result. • • • • |
| 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-B59"><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.</span> |
| Line Graph [Table Text Block] | How did the Fund perform over the past 10 years? CUMULATIVE PERFORMANCE September 30, 2014 through September 30, 2024. Initial investment of $10,000. Class I $10,000 $9,420 $9,902 $10,156 $10,505 $10,822 $10,709 $12,792 $12,297 $12,953 $14,371 Fidelity Strategic Real Return Composite Index℠ $10,000 $9,493 $10,027 $10,145 $10,425 $10,858 $10,823 $12,800 $12,237 $13,014 $14,403 Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index $10,000 $9,917 $10,570 $10,493 $10,536 $11,286 $12,424 $13,069 $11,557 $11,701 $12,847 Bloomberg U.S. Aggregate Bond Index $10,000 $10,294 $10,829 $10,836 $10,705 $11,807 $12,632 $12,518 $10,691 $10,760 $12,004 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 10.94% 5.84% 3.69% Fidelity Strategic Real Return Composite Index℠ 10.68% 5.81% 3.72% Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index 9.79% 2.62% 2.54% Bloomberg U.S. Aggregate Bond Index 11.57% 0.33% 1.84% 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 | $ 506,480,321 |
| Holdings Count | shares | 400 |
| Advisory Fees Paid, Amount | $ 3,117,645 |
| Investment Company Portfolio Turnover | 23% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 400 Total Advisory Fee $ Portfolio Turnover 23 % |
| Holdings [Text Block] | U.S. Government and U.S. Government Agency Obligations 23.7 AAA 0.0 AA 0.0 A 0.3 BBB 2.4 BB 7.2 B 15.7 CCC,CC,C 1.2 Not Rated 4.8 Equities 42.0 Short-Term Investments and Net Other Assets (Liabilities) 2.7 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. Floating-Rate debt 24.7 Inflation-Protected Debt 23.9 Commodities & Related Investments 14.7 Commodity Equities 13.8 Real Estate Income 11.8 REITs 9.2 Global Infrastructure Equities 1.5 MLPs 0.0 Gold-Miners Equities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets) United States 90.2 Canada 3.5 Brazil 1.0 South Africa 0.7 Finland 0.7 United Kingdom 0.6 Australia 0.6 Zambia 0.4 Netherlands 0.4 Others 1.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) US Treasury Notes 19.2 Fidelity Commodity Strategy Central Fund 14.7 US Treasury Bonds 4.5 Exxon Mobil Corp 1.1 Equinix Inc 0.9 Prologis Inc 0.9 Shell PLC 0.8 Archer-Daniels-Midland Co 0.7 Teck Resources Ltd Class B 0.7 Ventas Inc 0.7 44.2 |
| Material Fund Change [Text Block] | How has the Fund changed? This is a summary of certain changes to the Fund since October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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 October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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-B73"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098</span> |
| Updated Prospectus Email Address | fidfunddocuments@fidelity.com</span>" id="sjs-B74"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com</span> |
| Updated Prospectus Web Address | fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B75"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec</span> |
| Fidelity Advisor Strategic Real Return Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Strategic Real Return Fund |
| Class Name | Fidelity Advisor® Strategic Real Return Fund Class A |
| Trading Symbol | FSRAX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains information about Fidelity® Strategic Real Return Fund for the period October 1, 2023 to September 30, 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 | $ 100 |
| Expense Ratio, Percent | 0.95% |
| Factors Affecting Performance [Text Block] | What affected the Fund's performance this period? • • SM , the fund benefited from favorable security selection, while asset class positioning also boosted the portfolio's result. • • • • |
| 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-B92"><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.</span> |
| Line Graph [Table Text Block] | How did the Fund perform over the past 10 years? CUMULATIVE PERFORMANCE September 30, 2014 through September 30, 2024. Initial investment of $10,000 and the current sales charge was paid. Class A $9,600 $9,026 $9,461 $9,672 $9,977 $10,262 $10,131 $12,062 $11,568 $12,139 $13,438 Fidelity Strategic Real Return Composite Index℠ $10,000 $9,493 $10,027 $10,145 $10,425 $10,858 $10,823 $12,800 $12,237 $13,014 $14,403 Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index $10,000 $9,917 $10,570 $10,493 $10,536 $11,286 $12,424 $13,069 $11,557 $11,701 $12,847 Bloomberg U.S. Aggregate Bond Index $10,000 $10,294 $10,829 $10,836 $10,705 $11,807 $12,632 $12,518 $10,691 $10,760 $12,004 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) 6.27% 4.68% 3.00% Class A (without 4.00% sales charge) 10.70% 5.54% 3.42% Fidelity Strategic Real Return Composite Index℠ 10.68% 5.81% 3.72% Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index 9.79% 2.62% 2.54% Bloomberg U.S. Aggregate Bond Index 11.57% 0.33% 1.84% 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 | $ 506,480,321 |
| Holdings Count | shares | 400 |
| Advisory Fees Paid, Amount | $ 3,117,645 |
| Investment Company Portfolio Turnover | 23% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 400 Total Advisory Fee $ Portfolio Turnover 23 % |
| Holdings [Text Block] | U.S. Government and U.S. Government Agency Obligations 23.7 AAA 0.0 AA 0.0 A 0.3 BBB 2.4 BB 7.2 B 15.7 CCC,CC,C 1.2 Not Rated 4.8 Equities 42.0 Short-Term Investments and Net Other Assets (Liabilities) 2.7 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. Floating-Rate debt 24.7 Inflation-Protected Debt 23.9 Commodities & Related Investments 14.7 Commodity Equities 13.8 Real Estate Income 11.8 REITs 9.2 Global Infrastructure Equities 1.5 MLPs 0.0 Gold-Miners Equities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets) United States 90.2 Canada 3.5 Brazil 1.0 South Africa 0.7 Finland 0.7 United Kingdom 0.6 Australia 0.6 Zambia 0.4 Netherlands 0.4 Others 1.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) US Treasury Notes 19.2 Fidelity Commodity Strategy Central Fund 14.7 US Treasury Bonds 4.5 Exxon Mobil Corp 1.1 Equinix Inc 0.9 Prologis Inc 0.9 Shell PLC 0.8 Archer-Daniels-Midland Co 0.7 Teck Resources Ltd Class B 0.7 Ventas Inc 0.7 44.2 |
| Material Fund Change [Text Block] | How has the Fund changed? This is a summary of certain changes to the Fund since October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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 October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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-B106"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098</span> |
| Updated Prospectus Email Address | fidfunddocuments@fidelity.com</span>" id="sjs-B107"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com</span> |
| Updated Prospectus Web Address | fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B108"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec</span> |
| Fidelity Strategic Real Return Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Strategic Real Return Fund |
| Class Name | Fidelity® Strategic Real Return Fund Class K6 |
| Trading Symbol | FSRKX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains information about Fidelity® Strategic Real Return Fund for the period October 1, 2023 to September 30, 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 1-800-835-5092 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 | 1-800-835-5092 |
| 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 K6 $ 0.51 % |
| Expenses Paid, Amount | $ 53 |
| Expense Ratio, Percent | 0.51% |
| Factors Affecting Performance [Text Block] | What affected the Fund's performance this period? • • SM , the fund benefited from favorable security selection, while asset class positioning also boosted the portfolio's result. • • • • |
| 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-B125"><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.</span> |
| Line Graph [Table Text Block] | How did the Fund perform over the life of Fund? CUMULATIVE PERFORMANCE October 8, 2019 through September 30, 2024. Initial investment of $10,000. Class K6 $10,000 $9,919 $11,860 $11,424 $12,045 $13,391 Fidelity Strategic Real Return Composite Index℠ $10,000 $9,956 $11,775 $11,257 $11,971 $13,250 Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index $10,000 $10,932 $11,499 $10,169 $10,296 $11,304 Bloomberg U.S. Aggregate Bond Index $10,000 $10,631 $10,535 $8,997 $9,055 $10,103 2019 2020 2021 2022 2023 2024 |
| Average Annual Return [Table Text Block] | AVERAGE ANNUAL TOTAL RETURNS: 1 Year Life of Fund A Class K6 11.18% 6.04% Fidelity Strategic Real Return Composite Index℠ 10.68% 5.81% Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index 9.79% 2.49% Bloomberg U.S. Aggregate Bond Index 11.57% 0.21% A From October 8, 2019 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 | Oct. 08, 2019 |
| 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 | $ 506,480,321 |
| Holdings Count | shares | 400 |
| Advisory Fees Paid, Amount | $ 3,117,645 |
| Investment Company Portfolio Turnover | 23% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 400 Total Advisory Fee $ Portfolio Turnover 23 % |
| Holdings [Text Block] | U.S. Government and U.S. Government Agency Obligations 23.7 AAA 0.0 AA 0.0 A 0.3 BBB 2.4 BB 7.2 B 15.7 CCC,CC,C 1.2 Not Rated 4.8 Equities 42.0 Short-Term Investments and Net Other Assets (Liabilities) 2.7 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. Floating-Rate debt 24.7 Inflation-Protected Debt 23.9 Commodities & Related Investments 14.7 Commodity Equities 13.8 Real Estate Income 11.8 REITs 9.2 Global Infrastructure Equities 1.5 MLPs 0.0 Gold-Miners Equities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets) United States 90.2 Canada 3.5 Brazil 1.0 South Africa 0.7 Finland 0.7 United Kingdom 0.6 Australia 0.6 Zambia 0.4 Netherlands 0.4 Others 1.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) US Treasury Notes 19.2 Fidelity Commodity Strategy Central Fund 14.7 US Treasury Bonds 4.5 Exxon Mobil Corp 1.1 Equinix Inc 0.9 Prologis Inc 0.9 Shell PLC 0.8 Archer-Daniels-Midland Co 0.7 Teck Resources Ltd Class B 0.7 Ventas Inc 0.7 44.2 |
| Material Fund Change [Text Block] | How has the Fund changed? This is a summary of certain changes to the Fund since October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-835-5092 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 October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-835-5092 or by sending an e-mail to fidfunddocuments fidelity.com . |
| Updated Prospectus Phone Number | 1-800-835-5092</span>" id="sjs-B140"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-835-5092</span> |
| Updated Prospectus Email Address | fidfunddocuments@fidelity.com</span>" id="sjs-B141"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com</span> |
| Updated Prospectus Web Address | fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B142"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec</span> |
| Fidelity Advisor Strategic Real Return Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Strategic Real Return Fund |
| Class Name | Fidelity Advisor® Strategic Real Return Fund Class Z |
| Trading Symbol | FIQDX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains information about Fidelity® Strategic Real Return Fund for the period October 1, 2023 to September 30, 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 | $ 64 |
| Expense Ratio, Percent | 0.61% |
| Factors Affecting Performance [Text Block] | What affected the Fund's performance this period? • • SM , the fund benefited from favorable security selection, while asset class positioning also boosted the portfolio's result. • • • • |
| 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-B159"><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.</span> |
| Line Graph [Table Text Block] | How did the Fund perform over the life of Fund? CUMULATIVE PERFORMANCE October 2, 2018 through September 30, 2024. Initial investment of $10,000. Class Z $10,000 $10,276 $10,178 $12,174 $11,712 $12,335 $13,710 Fidelity Strategic Real Return Composite Index℠ $10,000 $10,371 $10,338 $12,226 $11,688 $12,430 $13,757 Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index $10,000 $10,718 $11,799 $12,411 $10,975 $11,112 $12,200 Bloomberg U.S. Aggregate Bond Index $10,000 $11,027 $11,797 $11,692 $9,985 $10,049 $11,212 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 11.14% 5.93% 5.40% Fidelity Strategic Real Return Composite Index℠ 10.68% 5.81% 5.46% Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index 9.79% 2.62% 3.37% Bloomberg U.S. Aggregate Bond Index 11.57% 0.33% 1.92% 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 | $ 506,480,321 |
| Holdings Count | shares | 400 |
| Advisory Fees Paid, Amount | $ 3,117,645 |
| Investment Company Portfolio Turnover | 23% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 400 Total Advisory Fee $ Portfolio Turnover 23 % |
| Holdings [Text Block] | U.S. Government and U.S. Government Agency Obligations 23.7 AAA 0.0 AA 0.0 A 0.3 BBB 2.4 BB 7.2 B 15.7 CCC,CC,C 1.2 Not Rated 4.8 Equities 42.0 Short-Term Investments and Net Other Assets (Liabilities) 2.7 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. Floating-Rate debt 24.7 Inflation-Protected Debt 23.9 Commodities & Related Investments 14.7 Commodity Equities 13.8 Real Estate Income 11.8 REITs 9.2 Global Infrastructure Equities 1.5 MLPs 0.0 Gold-Miners Equities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets) United States 90.2 Canada 3.5 Brazil 1.0 South Africa 0.7 Finland 0.7 United Kingdom 0.6 Australia 0.6 Zambia 0.4 Netherlands 0.4 Others 1.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) US Treasury Notes 19.2 Fidelity Commodity Strategy Central Fund 14.7 US Treasury Bonds 4.5 Exxon Mobil Corp 1.1 Equinix Inc 0.9 Prologis Inc 0.9 Shell PLC 0.8 Archer-Daniels-Midland Co 0.7 Teck Resources Ltd Class B 0.7 Ventas Inc 0.7 44.2 |
| Material Fund Change [Text Block] | How has the Fund changed? This is a summary of certain changes to the Fund since October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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 October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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-B174"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098</span> |
| Updated Prospectus Email Address | fidfunddocuments@fidelity.com</span>" id="sjs-B175"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com</span> |
| Updated Prospectus Web Address | fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B176"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec</span> |
| Fidelity Advisor Strategic Real Return Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Strategic Real Return Fund |
| Class Name | Fidelity Advisor® Strategic Real Return Fund Class M |
| Trading Symbol | FSRTX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains information about Fidelity® Strategic Real Return Fund for the period October 1, 2023 to September 30, 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 | $ 100 |
| Expense Ratio, Percent | 0.95% |
| Factors Affecting Performance [Text Block] | What affected the Fund's performance this period? • • SM , the fund benefited from favorable security selection, while asset class positioning also boosted the portfolio's result. • • • • |
| 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-B193"><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.</span> |
| Line Graph [Table Text Block] | How did the Fund perform over the past 10 years? CUMULATIVE PERFORMANCE September 30, 2014 through September 30, 2024. Initial investment of $10,000 and the current sales charge was paid. Class M $9,600 $9,016 $9,448 $9,659 $9,961 $10,233 $10,102 $12,038 $11,546 $12,117 $13,413 Fidelity Strategic Real Return Composite Index℠ $10,000 $9,493 $10,027 $10,145 $10,425 $10,858 $10,823 $12,800 $12,237 $13,014 $14,403 Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index $10,000 $9,917 $10,570 $10,493 $10,536 $11,286 $12,424 $13,069 $11,557 $11,701 $12,847 Bloomberg U.S. Aggregate Bond Index $10,000 $10,294 $10,829 $10,836 $10,705 $11,807 $12,632 $12,518 $10,691 $10,760 $12,004 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) 6.27% 4.70% 2.98% Class M (without 4.00% sales charge) 10.70% 5.56% 3.40% Fidelity Strategic Real Return Composite Index℠ 10.68% 5.81% 3.72% Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index 9.79% 2.62% 2.54% Bloomberg U.S. Aggregate Bond Index 11.57% 0.33% 1.84% 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 | $ 506,480,321 |
| Holdings Count | shares | 400 |
| Advisory Fees Paid, Amount | $ 3,117,645 |
| Investment Company Portfolio Turnover | 23% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 400 Total Advisory Fee $ Portfolio Turnover 23 % |
| Holdings [Text Block] | U.S. Government and U.S. Government Agency Obligations 23.7 AAA 0.0 AA 0.0 A 0.3 BBB 2.4 BB 7.2 B 15.7 CCC,CC,C 1.2 Not Rated 4.8 Equities 42.0 Short-Term Investments and Net Other Assets (Liabilities) 2.7 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. Floating-Rate debt 24.7 Inflation-Protected Debt 23.9 Commodities & Related Investments 14.7 Commodity Equities 13.8 Real Estate Income 11.8 REITs 9.2 Global Infrastructure Equities 1.5 MLPs 0.0 Gold-Miners Equities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets) United States 90.2 Canada 3.5 Brazil 1.0 South Africa 0.7 Finland 0.7 United Kingdom 0.6 Australia 0.6 Zambia 0.4 Netherlands 0.4 Others 1.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) US Treasury Notes 19.2 Fidelity Commodity Strategy Central Fund 14.7 US Treasury Bonds 4.5 Exxon Mobil Corp 1.1 Equinix Inc 0.9 Prologis Inc 0.9 Shell PLC 0.8 Archer-Daniels-Midland Co 0.7 Teck Resources Ltd Class B 0.7 Ventas Inc 0.7 44.2 |
| Material Fund Change [Text Block] | How has the Fund changed? This is a summary of certain changes to the Fund since October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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 October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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-B207"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-877-208-0098</span> |
| Updated Prospectus Email Address | fidfunddocuments@fidelity.com</span>" id="sjs-B208"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com</span> |
| Updated Prospectus Web Address | fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B209"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec</span> |
| Fidelity Strategic Real Return Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Strategic Real Return Fund |
| Class Name | Fidelity® Strategic Real Return Fund |
| Trading Symbol | FSRRX |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains information about Fidelity® Strategic Real Return Fund for the period October 1, 2023 to September 30, 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® Strategic Real Return Fund $ 0.70 % |
| Expenses Paid, Amount | $ 73 |
| Expense Ratio, Percent | 0.70% |
| Factors Affecting Performance [Text Block] | What affected the Fund's performance this period? • • SM , the fund benefited from favorable security selection, while asset class positioning also boosted the portfolio's result. • • • • |
| 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-B226"><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.</span> |
| Line Graph [Table Text Block] | How did the Fund perform over the past 10 years? CUMULATIVE PERFORMANCE September 30, 2014 through September 30, 2024. Initial investment of $10,000. Fidelity® Strategic Real Return Fund $10,000 $9,423 $9,903 $10,152 $10,500 $10,826 $10,703 $12,791 $12,299 $12,939 $14,353 Fidelity Strategic Real Return Composite Index℠ $10,000 $9,493 $10,027 $10,145 $10,425 $10,858 $10,823 $12,800 $12,237 $13,014 $14,403 Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index $10,000 $9,917 $10,570 $10,493 $10,536 $11,286 $12,424 $13,069 $11,557 $11,701 $12,847 Bloomberg U.S. Aggregate Bond Index $10,000 $10,294 $10,829 $10,836 $10,705 $11,807 $12,632 $12,518 $10,691 $10,760 $12,004 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® Strategic Real Return Fund 10.93% 5.80% 3.68% Fidelity Strategic Real Return Composite Index℠ 10.68% 5.81% 3.72% Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index 9.79% 2.62% 2.54% Bloomberg U.S. Aggregate Bond Index 11.57% 0.33% 1.84% 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 | $ 506,480,321 |
| Holdings Count | shares | 400 |
| Advisory Fees Paid, Amount | $ 3,117,645 |
| Investment Company Portfolio Turnover | 23% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 400 Total Advisory Fee $ Portfolio Turnover 23 % |
| Holdings [Text Block] | U.S. Government and U.S. Government Agency Obligations 23.7 AAA 0.0 AA 0.0 A 0.3 BBB 2.4 BB 7.2 B 15.7 CCC,CC,C 1.2 Not Rated 4.8 Equities 42.0 Short-Term Investments and Net Other Assets (Liabilities) 2.7 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. Floating-Rate debt 24.7 Inflation-Protected Debt 23.9 Commodities & Related Investments 14.7 Commodity Equities 13.8 Real Estate Income 11.8 REITs 9.2 Global Infrastructure Equities 1.5 MLPs 0.0 Gold-Miners Equities 0.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's net assets) United States 90.2 Canada 3.5 Brazil 1.0 South Africa 0.7 Finland 0.7 United Kingdom 0.6 Australia 0.6 Zambia 0.4 Netherlands 0.4 Others 1.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) US Treasury Notes 19.2 Fidelity Commodity Strategy Central Fund 14.7 US Treasury Bonds 4.5 Exxon Mobil Corp 1.1 Equinix Inc 0.9 Prologis Inc 0.9 Shell PLC 0.8 Archer-Daniels-Midland Co 0.7 Teck Resources Ltd Class B 0.7 Ventas Inc 0.7 44.2 |
| Material Fund Change [Text Block] | How has the Fund changed? This is a summary of certain changes to the Fund since October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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 October 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by November 29, 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-B240"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-8544</span> |
| Updated Prospectus Email Address | fidfunddocuments@fidelity.com</span>" id="sjs-B241"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">fidfunddocuments@fidelity.com</span> |
| Updated Prospectus Web Address | fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B242"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec</span> |
| Shareholder Report, Line Graph (Details) - USD ($) | 12 Months Ended | 60 Months Ended | 72 Months Ended | 84 Months Ended | 120 Months Ended | 132 Months Ended | ||||||||||
| Sep. 30, 2024 | Sep. 30, 2024 | Sep. 30, 2024 | Sep. 30, 2024 | Sep. 30, 2024 | Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2014 | |
| C000048840_0_LG_BBIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-G5"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span> | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,000 | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,294 | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,829 | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,836 | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,705 | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 11,807 | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,632 | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,518 | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,691 | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,760 | |||||||||||||||
| C000048840_0_BBIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,004 | $ 12,004 | $ 12,004 | $ 12,004 | $ 12,004 | $ 12,004 | ||||||||||
| C000048840_2_BBIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 11.57% | |||||||||||||||
| C000048840_2_BBIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 0.33% | |||||||||||||||
| C000048840_2_BBIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 1.84% | |||||||||||||||
| C000048842_0_LG_BBIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-G50"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span> | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,294 | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,829 | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,836 | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,705 | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,807 | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,632 | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,518 | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,691 | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,760 | |||||||||||||||
| C000048842_0_BBIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,004 | $ 12,004 | 12,004 | 12,004 | $ 12,004 | $ 12,004 | ||||||||||
| C000048842_2_BBIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 11.57% | |||||||||||||||
| C000048842_2_BBIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 0.33% | |||||||||||||||
| C000048842_2_BBIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 1.84% | |||||||||||||||
| C000048838_0_LG_BBIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-G95"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span> | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,294 | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,829 | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,836 | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,705 | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,807 | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,632 | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,518 | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,691 | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,760 | |||||||||||||||
| C000048838_0_BBIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,004 | $ 12,004 | $ 12,004 | 12,004 | $ 12,004 | $ 12,004 | ||||||||||
| C000048838_2_BBIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 11.57% | |||||||||||||||
| C000048838_2_BBIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 0.33% | |||||||||||||||
| C000048838_2_BBIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 1.84% | |||||||||||||||
| C000214978_0_LG_BBIndexMember_6YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-D140"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span> | |||||||||||||||
| C000214978_0_BBIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000214978_0_BBIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,631 | |||||||||||||||
| C000214978_0_BBIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,535 | |||||||||||||||
| C000214978_0_BBIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 8,997 | |||||||||||||||
| C000214978_0_BBIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,055 | |||||||||||||||
| C000214978_0_BBIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,103 | $ 10,103 | $ 10,103 | $ 10,103 | $ 10,103 | 10,103 | ||||||||||
| C000214978_2_BBIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 11.57% | |||||||||||||||
| C000214978_2_BBIndexMember_LOCMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 0.21% | |||||||||||||||
| C000205021_0_LG_BBIndexMember_7YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-E167"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span> | |||||||||||||||
| C000205021_0_BBIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000205021_0_BBIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,027 | |||||||||||||||
| C000205021_0_BBIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,797 | |||||||||||||||
| C000205021_0_BBIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,692 | |||||||||||||||
| C000205021_0_BBIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,985 | |||||||||||||||
| C000205021_0_BBIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,049 | |||||||||||||||
| C000205021_0_BBIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 11,212 | $ 11,212 | 11,212 | $ 11,212 | 11,212 | $ 11,212 | ||||||||||
| C000205021_2_BBIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 11.57% | |||||||||||||||
| C000205021_2_BBIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 0.33% | |||||||||||||||
| C000205021_2_BBIndexMember_LOCMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 1.92% | |||||||||||||||
| C000048841_0_LG_BBIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-G200"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span> | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,294 | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,829 | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,836 | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,705 | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,807 | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,632 | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,518 | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,691 | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,760 | |||||||||||||||
| C000048841_0_BBIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,004 | $ 12,004 | 12,004 | 12,004 | $ 12,004 | $ 12,004 | ||||||||||
| C000048841_2_BBIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 11.57% | |||||||||||||||
| C000048841_2_BBIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 0.33% | |||||||||||||||
| C000048841_2_BBIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 1.84% | |||||||||||||||
| C000048837_0_LG_BBIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index</span>" id="sjs-G245"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Aggregate Bond Index</span> | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,294 | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,829 | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,836 | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,705 | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,807 | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,632 | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,518 | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,691 | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,760 | |||||||||||||||
| C000048837_0_BBIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,004 | $ 12,004 | 12,004 | 12,004 | $ 12,004 | $ 12,004 | ||||||||||
| C000048837_2_BBIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 11.57% | |||||||||||||||
| C000048837_2_BBIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 0.33% | |||||||||||||||
| C000048837_2_BBIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 1.84% | |||||||||||||||
| C000048840_LG_ClassMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Class C</span>" id="sjs-G290"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class C</span> | |||||||||||||||
| C000048840_ClassMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048840_ClassMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,327 | |||||||||||||||
| C000048840_ClassMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,693 | |||||||||||||||
| C000048840_ClassMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,835 | |||||||||||||||
| C000048840_ClassMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,072 | |||||||||||||||
| C000048840_ClassMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,273 | |||||||||||||||
| C000048840_ClassMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,067 | |||||||||||||||
| C000048840_ClassMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,903 | |||||||||||||||
| C000048840_ClassMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,334 | |||||||||||||||
| C000048840_ClassMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,894 | |||||||||||||||
| C000048840_ClassMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 13,166 | $ 13,166 | 13,166 | 13,166 | $ 13,166 | $ 13,166 | ||||||||||
| C000048840_LG_1_AdditionalIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Fidelity Strategic Real Return Composite Index℠</span>" id="sjs-G326"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity Strategic Real Return Composite Index℠</span> | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,493 | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,027 | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,145 | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,425 | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,858 | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,823 | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,800 | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,237 | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,014 | |||||||||||||||
| C000048840_1_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 14,403 | 14,403 | 14,403 | 14,403 | 14,403 | $ 14,403 | ||||||||||
| C000048840_LG_2_AdditionalIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span>" id="sjs-G362"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span> | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,917 | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,570 | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,493 | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,536 | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,286 | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,424 | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,069 | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,557 | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,701 | |||||||||||||||
| C000048840_2_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,847 | $ 12,847 | 12,847 | 12,847 | $ 12,847 | $ 12,847 | ||||||||||
| C000048840_ClassMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 8.77% | |||||||||||||||
| C000048840_ClassMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 4.77% | |||||||||||||||
| C000048840_ClassMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.79% | |||||||||||||||
| C000048840_NoLoadClassMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 9.77% | |||||||||||||||
| C000048840_NoLoadClassMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 4.77% | |||||||||||||||
| C000048840_NoLoadClassMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.79% | |||||||||||||||
| C000048840_0_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.68% | |||||||||||||||
| C000048840_0_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.81% | |||||||||||||||
| C000048840_0_AdditionalIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3.72% | |||||||||||||||
| C000048840_1_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 9.79% | |||||||||||||||
| C000048840_1_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.62% | |||||||||||||||
| C000048840_1_AdditionalIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.54% | |||||||||||||||
| C000048842_LG_ClassMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Class I</span>" id="sjs-G434"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class I</span> | |||||||||||||||
| C000048842_ClassMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048842_ClassMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,420 | |||||||||||||||
| C000048842_ClassMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,902 | |||||||||||||||
| C000048842_ClassMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,156 | |||||||||||||||
| C000048842_ClassMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,505 | |||||||||||||||
| C000048842_ClassMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,822 | |||||||||||||||
| C000048842_ClassMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,709 | |||||||||||||||
| C000048842_ClassMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,792 | |||||||||||||||
| C000048842_ClassMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,297 | |||||||||||||||
| C000048842_ClassMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,953 | |||||||||||||||
| C000048842_ClassMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 14,371 | $ 14,371 | 14,371 | 14,371 | $ 14,371 | $ 14,371 | ||||||||||
| C000048842_LG_1_AdditionalIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Fidelity Strategic Real Return Composite Index℠</span>" id="sjs-G470"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity Strategic Real Return Composite Index℠</span> | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,493 | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,027 | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,145 | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,425 | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,858 | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,823 | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,800 | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,237 | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,014 | |||||||||||||||
| C000048842_1_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 14,403 | 14,403 | 14,403 | 14,403 | 14,403 | $ 14,403 | ||||||||||
| C000048842_LG_2_AdditionalIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span>" id="sjs-G506"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span> | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,917 | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,570 | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,493 | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,536 | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,286 | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,424 | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,069 | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,557 | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,701 | |||||||||||||||
| C000048842_2_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,847 | $ 12,847 | 12,847 | 12,847 | $ 12,847 | $ 12,847 | ||||||||||
| C000048842_NoLoadClassMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.94% | |||||||||||||||
| C000048842_NoLoadClassMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.84% | |||||||||||||||
| C000048842_NoLoadClassMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3.69% | |||||||||||||||
| C000048842_0_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.68% | |||||||||||||||
| C000048842_0_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.81% | |||||||||||||||
| C000048842_0_AdditionalIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3.72% | |||||||||||||||
| C000048842_1_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 9.79% | |||||||||||||||
| C000048842_1_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.62% | |||||||||||||||
| C000048842_1_AdditionalIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.54% | |||||||||||||||
| C000048838_LG_ClassMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Class A</span>" id="sjs-G569"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class A</span> | |||||||||||||||
| C000048838_ClassMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,600 | |||||||||||||||
| C000048838_ClassMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,026 | |||||||||||||||
| C000048838_ClassMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,461 | |||||||||||||||
| C000048838_ClassMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,672 | |||||||||||||||
| C000048838_ClassMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,977 | |||||||||||||||
| C000048838_ClassMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,262 | |||||||||||||||
| C000048838_ClassMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,131 | |||||||||||||||
| C000048838_ClassMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,062 | |||||||||||||||
| C000048838_ClassMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,568 | |||||||||||||||
| C000048838_ClassMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,139 | |||||||||||||||
| C000048838_ClassMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 13,438 | $ 13,438 | 13,438 | 13,438 | $ 13,438 | $ 13,438 | ||||||||||
| C000048838_LG_1_AdditionalIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Fidelity Strategic Real Return Composite Index℠</span>" id="sjs-G605"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity Strategic Real Return Composite Index℠</span> | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,493 | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,027 | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,145 | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,425 | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,858 | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,823 | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,800 | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,237 | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,014 | |||||||||||||||
| C000048838_1_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 14,403 | 14,403 | 14,403 | 14,403 | 14,403 | $ 14,403 | ||||||||||
| C000048838_LG_2_AdditionalIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span>" id="sjs-G641"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span> | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,917 | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,570 | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,493 | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,536 | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,286 | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,424 | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,069 | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,557 | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,701 | |||||||||||||||
| C000048838_2_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,847 | $ 12,847 | $ 12,847 | 12,847 | $ 12,847 | $ 12,847 | ||||||||||
| C000048838_ClassMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 6.27% | |||||||||||||||
| C000048838_ClassMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 4.68% | |||||||||||||||
| C000048838_ClassMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3% | |||||||||||||||
| C000048838_NoLoadClassMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.70% | |||||||||||||||
| C000048838_NoLoadClassMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.54% | |||||||||||||||
| C000048838_NoLoadClassMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3.42% | |||||||||||||||
| C000048838_0_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.68% | |||||||||||||||
| C000048838_0_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.81% | |||||||||||||||
| C000048838_0_AdditionalIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3.72% | |||||||||||||||
| C000048838_1_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 9.79% | |||||||||||||||
| C000048838_1_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.62% | |||||||||||||||
| C000048838_1_AdditionalIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.54% | |||||||||||||||
| C000214978_LG_ClassMember_6YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Class K6</span>" id="sjs-D713"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class K6</span> | |||||||||||||||
| C000214978_ClassMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000214978_ClassMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,919 | |||||||||||||||
| C000214978_ClassMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,860 | |||||||||||||||
| C000214978_ClassMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,424 | |||||||||||||||
| C000214978_ClassMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,045 | |||||||||||||||
| C000214978_ClassMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 13,391 | $ 13,391 | $ 13,391 | 13,391 | $ 13,391 | 13,391 | ||||||||||
| C000214978_LG_1_AdditionalIndexMember_6YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Fidelity Strategic Real Return Composite Index℠</span>" id="sjs-D734"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity Strategic Real Return Composite Index℠</span> | |||||||||||||||
| C000214978_1_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000214978_1_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,956 | |||||||||||||||
| C000214978_1_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,775 | |||||||||||||||
| C000214978_1_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,257 | |||||||||||||||
| C000214978_1_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,971 | |||||||||||||||
| C000214978_1_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,250 | 13,250 | $ 13,250 | 13,250 | 13,250 | 13,250 | ||||||||||
| C000214978_LG_2_AdditionalIndexMember_6YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span>" id="sjs-D755"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span> | |||||||||||||||
| C000214978_2_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000214978_2_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,932 | |||||||||||||||
| C000214978_2_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,499 | |||||||||||||||
| C000214978_2_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,169 | |||||||||||||||
| C000214978_2_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,296 | |||||||||||||||
| C000214978_2_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 11,304 | 11,304 | $ 11,304 | $ 11,304 | 11,304 | 11,304 | ||||||||||
| C000214978_NoLoadClassMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 11.18% | |||||||||||||||
| C000214978_NoLoadClassMember_2023-10-01_2024-09-30Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 6.04% | |||||||||||||||
| C000214978_0_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.68% | |||||||||||||||
| C000214978_0_AdditionalIndexMember_LOCMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.81% | |||||||||||||||
| C000214978_1_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 9.79% | |||||||||||||||
| C000214978_1_AdditionalIndexMember_LOCMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.49% | |||||||||||||||
| C000205021_LG_ClassMember_7YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Class Z</span>" id="sjs-E794"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class Z</span> | |||||||||||||||
| C000205021_ClassMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000205021_ClassMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,276 | |||||||||||||||
| C000205021_ClassMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,178 | |||||||||||||||
| C000205021_ClassMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,174 | |||||||||||||||
| C000205021_ClassMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,712 | |||||||||||||||
| C000205021_ClassMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,335 | |||||||||||||||
| C000205021_ClassMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 13,710 | 13,710 | 13,710 | $ 13,710 | 13,710 | 13,710 | ||||||||||
| C000205021_LG_1_AdditionalIndexMember_7YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Fidelity Strategic Real Return Composite Index℠</span>" id="sjs-E818"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity Strategic Real Return Composite Index℠</span> | |||||||||||||||
| C000205021_1_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000205021_1_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,371 | |||||||||||||||
| C000205021_1_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,338 | |||||||||||||||
| C000205021_1_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,226 | |||||||||||||||
| C000205021_1_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,688 | |||||||||||||||
| C000205021_1_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,430 | |||||||||||||||
| C000205021_1_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,757 | 13,757 | 13,757 | $ 13,757 | 13,757 | 13,757 | ||||||||||
| C000205021_LG_2_AdditionalIndexMember_7YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span>" id="sjs-E842"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span> | |||||||||||||||
| C000205021_2_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000205021_2_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,718 | |||||||||||||||
| C000205021_2_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,799 | |||||||||||||||
| C000205021_2_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,411 | |||||||||||||||
| C000205021_2_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,975 | |||||||||||||||
| C000205021_2_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,112 | |||||||||||||||
| C000205021_2_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,200 | $ 12,200 | 12,200 | $ 12,200 | 12,200 | $ 12,200 | ||||||||||
| C000205021_NoLoadClassMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 11.14% | |||||||||||||||
| C000205021_NoLoadClassMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.93% | |||||||||||||||
| C000205021_NoLoadClassMember_2023-10-01_2024-09-30Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.40% | |||||||||||||||
| C000205021_0_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.68% | |||||||||||||||
| C000205021_0_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.81% | |||||||||||||||
| C000205021_0_AdditionalIndexMember_LOCMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.46% | |||||||||||||||
| C000205021_1_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 9.79% | |||||||||||||||
| C000205021_1_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.62% | |||||||||||||||
| C000205021_1_AdditionalIndexMember_LOCMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3.37% | |||||||||||||||
| C000048841_LG_ClassMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Class M</span>" id="sjs-G893"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Class M</span> | |||||||||||||||
| C000048841_ClassMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,600 | |||||||||||||||
| C000048841_ClassMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,016 | |||||||||||||||
| C000048841_ClassMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,448 | |||||||||||||||
| C000048841_ClassMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,659 | |||||||||||||||
| C000048841_ClassMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,961 | |||||||||||||||
| C000048841_ClassMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,233 | |||||||||||||||
| C000048841_ClassMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,102 | |||||||||||||||
| C000048841_ClassMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,038 | |||||||||||||||
| C000048841_ClassMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,546 | |||||||||||||||
| C000048841_ClassMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,117 | |||||||||||||||
| C000048841_ClassMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 13,413 | $ 13,413 | 13,413 | 13,413 | 13,413 | $ 13,413 | ||||||||||
| C000048841_LG_1_AdditionalIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Fidelity Strategic Real Return Composite Index℠</span>" id="sjs-G929"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity Strategic Real Return Composite Index℠</span> | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,493 | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,027 | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,145 | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,425 | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,858 | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,823 | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,800 | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,237 | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,014 | |||||||||||||||
| C000048841_1_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 14,403 | 14,403 | 14,403 | 14,403 | 14,403 | $ 14,403 | ||||||||||
| C000048841_LG_2_AdditionalIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span>" id="sjs-G965"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span> | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,917 | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,570 | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,493 | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,536 | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,286 | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,424 | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,069 | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,557 | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 11,701 | |||||||||||||||
| C000048841_2_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,847 | $ 12,847 | 12,847 | 12,847 | $ 12,847 | $ 12,847 | ||||||||||
| C000048841_ClassMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 6.27% | |||||||||||||||
| C000048841_ClassMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 4.70% | |||||||||||||||
| C000048841_ClassMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.98% | |||||||||||||||
| C000048841_NoLoadClassMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.70% | |||||||||||||||
| C000048841_NoLoadClassMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.56% | |||||||||||||||
| C000048841_NoLoadClassMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3.40% | |||||||||||||||
| C000048841_0_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.68% | |||||||||||||||
| C000048841_0_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.81% | |||||||||||||||
| C000048841_0_AdditionalIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3.72% | |||||||||||||||
| C000048841_1_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 9.79% | |||||||||||||||
| C000048841_1_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.62% | |||||||||||||||
| C000048841_1_AdditionalIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.54% | |||||||||||||||
| C000048837_LG_ClassMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Fidelity® Strategic Real Return Fund</span>" id="sjs-G1037"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® Strategic Real Return Fund</span> | |||||||||||||||
| C000048837_ClassMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048837_ClassMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,423 | |||||||||||||||
| C000048837_ClassMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,903 | |||||||||||||||
| C000048837_ClassMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,152 | |||||||||||||||
| C000048837_ClassMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,500 | |||||||||||||||
| C000048837_ClassMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,826 | |||||||||||||||
| C000048837_ClassMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,703 | |||||||||||||||
| C000048837_ClassMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,791 | |||||||||||||||
| C000048837_ClassMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,299 | |||||||||||||||
| C000048837_ClassMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,939 | |||||||||||||||
| C000048837_ClassMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 14,353 | $ 14,353 | 14,353 | 14,353 | $ 14,353 | $ 14,353 | ||||||||||
| C000048837_LG_1_AdditionalIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Fidelity Strategic Real Return Composite Index℠</span>" id="sjs-G1073"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity Strategic Real Return Composite Index℠</span> | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,000 | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 9,493 | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,027 | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,145 | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,425 | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,858 | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 10,823 | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,800 | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 12,237 | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 13,014 | |||||||||||||||
| C000048837_1_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | 14,403 | 14,403 | 14,403 | 14,403 | 14,403 | $ 14,403 | ||||||||||
| C000048837_LG_2_AdditionalIndexMember_11YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span>" id="sjs-G1109"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index</span> | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,000 | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 9,917 | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,570 | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,493 | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 10,536 | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 11,286 | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,424 | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 13,069 | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 11,557 | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 11,701 | |||||||||||||||
| C000048837_2_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Account Value | $ 12,847 | $ 12,847 | $ 12,847 | $ 12,847 | $ 12,847 | $ 12,847 | ||||||||||
| C000048837_NoLoadClassMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.93% | |||||||||||||||
| C000048837_NoLoadClassMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.80% | |||||||||||||||
| C000048837_NoLoadClassMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3.68% | |||||||||||||||
| C000048837_0_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 10.68% | |||||||||||||||
| C000048837_0_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 5.81% | |||||||||||||||
| C000048837_0_AdditionalIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 3.72% | |||||||||||||||
| C000048837_1_AdditionalIndexMember_1YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 9.79% | |||||||||||||||
| C000048837_1_AdditionalIndexMember_5YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.62% | |||||||||||||||
| C000048837_1_AdditionalIndexMember_10YRMember | ||||||||||||||||
| Account Value [Line Items] | ||||||||||||||||
| Average Annual Return, Percent | 2.54% |
| Shareholder Report, Holdings (Details) | Sep. 30, 2024 |
| Fidelity Advisor Strategic Real Return Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.20% |
| Fidelity Advisor Strategic Real Return Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| Fidelity Advisor Strategic Real Return Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Strategic Real Return Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Advisor Strategic Real Return Fund - Class C | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Advisor Strategic Real Return Fund - Class C | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity Advisor Strategic Real Return Fund - Class C | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDUSGovernmentandUSGovernmentAgencyObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDAAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.30% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.20% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDCCCCCCMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42% |
| Fidelity Advisor Strategic Real Return Fund - Class C | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 90.20% |
| Fidelity Advisor Strategic Real Return Fund - Class C | Canada | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| Fidelity Advisor Strategic Real Return Fund - Class C | Brazil | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Strategic Real Return Fund - Class C | South Africa | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | Finland | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | United Kingdom | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Advisor Strategic Real Return Fund - Class C | Australia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Advisor Strategic Real Return Fund - Class C | Zambia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class C | Netherlands | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class C | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| Fidelity Advisor Strategic Real Return Fund - Class C | AAFloatingRatedebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | AAInflationProtectedDebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.90% |
| Fidelity Advisor Strategic Real Return Fund - Class C | AACommoditiesRelatedInvestmentsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Advisor Strategic Real Return Fund - Class C | AACommodityEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Strategic Real Return Fund - Class C | AARealEstateIncomeMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.80% |
| Fidelity Advisor Strategic Real Return Fund - Class C | AAREITsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| Fidelity Advisor Strategic Real Return Fund - Class C | AAGlobalInfrastructureEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.50% |
| Fidelity Advisor Strategic Real Return Fund - Class C | AAMLPsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class C | AAGoldMinersEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.20% |
| Fidelity Advisor Strategic Real Return Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| Fidelity Advisor Strategic Real Return Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Strategic Real Return Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Advisor Strategic Real Return Fund - Class I | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Advisor Strategic Real Return Fund - Class I | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity Advisor Strategic Real Return Fund - Class I | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDUSGovernmentandUSGovernmentAgencyObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDAAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.30% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.20% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDCCCCCCMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42% |
| Fidelity Advisor Strategic Real Return Fund - Class I | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 90.20% |
| Fidelity Advisor Strategic Real Return Fund - Class I | Canada | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| Fidelity Advisor Strategic Real Return Fund - Class I | Brazil | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Strategic Real Return Fund - Class I | South Africa | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | Finland | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | United Kingdom | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Advisor Strategic Real Return Fund - Class I | Australia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Advisor Strategic Real Return Fund - Class I | Zambia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class I | Netherlands | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class I | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| Fidelity Advisor Strategic Real Return Fund - Class I | AAFloatingRatedebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | AAInflationProtectedDebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.90% |
| Fidelity Advisor Strategic Real Return Fund - Class I | AACommoditiesRelatedInvestmentsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Advisor Strategic Real Return Fund - Class I | AACommodityEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Strategic Real Return Fund - Class I | AARealEstateIncomeMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.80% |
| Fidelity Advisor Strategic Real Return Fund - Class I | AAREITsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| Fidelity Advisor Strategic Real Return Fund - Class I | AAGlobalInfrastructureEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.50% |
| Fidelity Advisor Strategic Real Return Fund - Class I | AAMLPsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class I | AAGoldMinersEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.20% |
| Fidelity Advisor Strategic Real Return Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| Fidelity Advisor Strategic Real Return Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Strategic Real Return Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Advisor Strategic Real Return Fund - Class A | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Advisor Strategic Real Return Fund - Class A | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity Advisor Strategic Real Return Fund - Class A | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDUSGovernmentandUSGovernmentAgencyObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDAAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.30% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.20% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDCCCCCCMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42% |
| Fidelity Advisor Strategic Real Return Fund - Class A | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 90.20% |
| Fidelity Advisor Strategic Real Return Fund - Class A | Canada | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| Fidelity Advisor Strategic Real Return Fund - Class A | Brazil | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Strategic Real Return Fund - Class A | South Africa | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | Finland | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | United Kingdom | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Advisor Strategic Real Return Fund - Class A | Australia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Advisor Strategic Real Return Fund - Class A | Zambia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class A | Netherlands | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class A | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| Fidelity Advisor Strategic Real Return Fund - Class A | AAFloatingRatedebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | AAInflationProtectedDebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.90% |
| Fidelity Advisor Strategic Real Return Fund - Class A | AACommoditiesRelatedInvestmentsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Advisor Strategic Real Return Fund - Class A | AACommodityEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Strategic Real Return Fund - Class A | AARealEstateIncomeMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.80% |
| Fidelity Advisor Strategic Real Return Fund - Class A | AAREITsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| Fidelity Advisor Strategic Real Return Fund - Class A | AAGlobalInfrastructureEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.50% |
| Fidelity Advisor Strategic Real Return Fund - Class A | AAMLPsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class A | AAGoldMinersEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Strategic Real Return Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.20% |
| Fidelity Strategic Real Return Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Strategic Real Return Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| Fidelity Strategic Real Return Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Strategic Real Return Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Strategic Real Return Fund - Class K6 | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Strategic Real Return Fund - Class K6 | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity Strategic Real Return Fund - Class K6 | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Strategic Real Return Fund - Class K6 | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Strategic Real Return Fund - Class K6 | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Strategic Real Return Fund - Class K6 | QDUSGovernmentandUSGovernmentAgencyObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.70% |
| Fidelity Strategic Real Return Fund - Class K6 | QDAAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Strategic Real Return Fund - Class K6 | QDAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Strategic Real Return Fund - Class K6 | QDAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.30% |
| Fidelity Strategic Real Return Fund - Class K6 | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Strategic Real Return Fund - Class K6 | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.20% |
| Fidelity Strategic Real Return Fund - Class K6 | QDBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.70% |
| Fidelity Strategic Real Return Fund - Class K6 | QDCCCCCCMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Strategic Real Return Fund - Class K6 | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| Fidelity Strategic Real Return Fund - Class K6 | QDEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42% |
| Fidelity Strategic Real Return Fund - Class K6 | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| Fidelity Strategic Real Return Fund - Class K6 | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 90.20% |
| Fidelity Strategic Real Return Fund - Class K6 | Canada | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| Fidelity Strategic Real Return Fund - Class K6 | Brazil | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Strategic Real Return Fund - Class K6 | South Africa | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Strategic Real Return Fund - Class K6 | Finland | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Strategic Real Return Fund - Class K6 | United Kingdom | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Strategic Real Return Fund - Class K6 | Australia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Strategic Real Return Fund - Class K6 | Zambia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Strategic Real Return Fund - Class K6 | Netherlands | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Strategic Real Return Fund - Class K6 | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| Fidelity Strategic Real Return Fund - Class K6 | AAFloatingRatedebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.70% |
| Fidelity Strategic Real Return Fund - Class K6 | AAInflationProtectedDebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.90% |
| Fidelity Strategic Real Return Fund - Class K6 | AACommoditiesRelatedInvestmentsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Strategic Real Return Fund - Class K6 | AACommodityEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Strategic Real Return Fund - Class K6 | AARealEstateIncomeMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.80% |
| Fidelity Strategic Real Return Fund - Class K6 | AAREITsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| Fidelity Strategic Real Return Fund - Class K6 | AAGlobalInfrastructureEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.50% |
| Fidelity Strategic Real Return Fund - Class K6 | AAMLPsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Strategic Real Return Fund - Class K6 | AAGoldMinersEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Strategic Real Return Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.20% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDUSGovernmentandUSGovernmentAgencyObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDAAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.30% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.20% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDCCCCCCMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 90.20% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | Canada | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | Brazil | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | South Africa | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | Finland | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | United Kingdom | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | Australia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | Zambia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | Netherlands | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | AAFloatingRatedebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | AAInflationProtectedDebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.90% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | AACommoditiesRelatedInvestmentsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | AACommodityEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | AARealEstateIncomeMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.80% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | AAREITsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | AAGlobalInfrastructureEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.50% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | AAMLPsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | AAGoldMinersEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.20% |
| Fidelity Advisor Strategic Real Return Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| Fidelity Advisor Strategic Real Return Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Strategic Real Return Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Advisor Strategic Real Return Fund - Class M | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Advisor Strategic Real Return Fund - Class M | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity Advisor Strategic Real Return Fund - Class M | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDUSGovernmentandUSGovernmentAgencyObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDAAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.30% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.20% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDCCCCCCMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42% |
| Fidelity Advisor Strategic Real Return Fund - Class M | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 90.20% |
| Fidelity Advisor Strategic Real Return Fund - Class M | Canada | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| Fidelity Advisor Strategic Real Return Fund - Class M | Brazil | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Strategic Real Return Fund - Class M | South Africa | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | Finland | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | United Kingdom | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Advisor Strategic Real Return Fund - Class M | Australia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Advisor Strategic Real Return Fund - Class M | Zambia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class M | Netherlands | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Advisor Strategic Real Return Fund - Class M | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| Fidelity Advisor Strategic Real Return Fund - Class M | AAFloatingRatedebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | AAInflationProtectedDebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.90% |
| Fidelity Advisor Strategic Real Return Fund - Class M | AACommoditiesRelatedInvestmentsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Advisor Strategic Real Return Fund - Class M | AACommodityEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Strategic Real Return Fund - Class M | AARealEstateIncomeMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.80% |
| Fidelity Advisor Strategic Real Return Fund - Class M | AAREITsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| Fidelity Advisor Strategic Real Return Fund - Class M | AAGlobalInfrastructureEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.50% |
| Fidelity Advisor Strategic Real Return Fund - Class M | AAMLPsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class M | AAGoldMinersEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Strategic Real Return Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Strategic Real Return Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 19.20% |
| Fidelity Strategic Real Return Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Strategic Real Return Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.50% |
| Fidelity Strategic Real Return Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Strategic Real Return Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Strategic Real Return Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.90% |
| Fidelity Strategic Real Return Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity Strategic Real Return Fund | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Strategic Real Return Fund | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Strategic Real Return Fund | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Strategic Real Return Fund | QDUSGovernmentandUSGovernmentAgencyObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.70% |
| Fidelity Strategic Real Return Fund | QDAAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Strategic Real Return Fund | QDAAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Strategic Real Return Fund | QDAMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.30% |
| Fidelity Strategic Real Return Fund | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Strategic Real Return Fund | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.20% |
| Fidelity Strategic Real Return Fund | QDBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.70% |
| Fidelity Strategic Real Return Fund | QDCCCCCCMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Strategic Real Return Fund | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.80% |
| Fidelity Strategic Real Return Fund | QDEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42% |
| Fidelity Strategic Real Return Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.70% |
| Fidelity Strategic Real Return Fund | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 90.20% |
| Fidelity Strategic Real Return Fund | Canada | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.50% |
| Fidelity Strategic Real Return Fund | Brazil | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Strategic Real Return Fund | South Africa | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Strategic Real Return Fund | Finland | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Strategic Real Return Fund | United Kingdom | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Strategic Real Return Fund | Australia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Strategic Real Return Fund | Zambia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Strategic Real Return Fund | Netherlands | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Strategic Real Return Fund | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| Fidelity Strategic Real Return Fund | AAFloatingRatedebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.70% |
| Fidelity Strategic Real Return Fund | AAInflationProtectedDebtMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.90% |
| Fidelity Strategic Real Return Fund | AACommoditiesRelatedInvestmentsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14.70% |
| Fidelity Strategic Real Return Fund | AACommodityEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Strategic Real Return Fund | AARealEstateIncomeMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.80% |
| Fidelity Strategic Real Return Fund | AAREITsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.20% |
| Fidelity Strategic Real Return Fund | AAGlobalInfrastructureEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.50% |
| Fidelity Strategic Real Return Fund | AAMLPsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Strategic Real Return Fund | AAGoldMinersEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Strategic Real Return Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
