| Form N-CSR Cover | 12 Months Ended |
| Aug. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | Fidelity Central Investment Portfolios LLC |
| Entity Central Index Key | 0001303459 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Aug. 31, 2024 |
| Shareholder Report | 12 Months Ended |
| Aug. 31, 2024 USD ($) shares | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | Fidelity Central Investment Portfolios LLC |
| Entity Central Index Key | 0001303459 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Aug. 31, 2024 |
| Fidelity High Income Central Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® High Income Central Fund |
| Class Name | Fidelity® High Income Central Fund |
| No Trading Symbol Flag | true |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains information about Fidelity® High Income Central Fund for the period September 1, 2023 to August 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544. |
| 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 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® High Income Central Fund $ A 0.00 % B A Amount represents less than $.50 B Amount represents less than 0.005% |
| Expenses Paid, Amount | $ 0 |
| Expense Ratio, Percent | 0% |
| Factors Affecting Performance [Text Block] | What affected the Fund's performance this period? • • • • • • • • |
| Performance Past Does Not Indicate Future [Text] | The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B25"><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 August 31, 2014 through August 31, 2024. Initial investment of $10,000. Fidelity® High Income Central Fund $10,000 $9,842 $10,605 $11,623 $12,238 $13,044 $13,233 $15,213 $14,330 $15,315 $17,175 ICE® BofA® US High Yield Constrained Index $10,000 $9,692 $10,586 $11,516 $11,893 $12,675 $13,134 $14,481 $12,970 $13,882 $15,613 Bloomberg U.S. Universal Bond Index $10,000 $10,113 $10,770 $10,915 $10,814 $11,903 $12,666 $12,778 $11,264 $11,219 $12,108 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® High Income Central Fund 12.14% 5.66% 5.56% ICE® BofA® US High Yield Constrained Index 12.47% 4.26% 4.56% Bloomberg U.S. Universal Bond Index 7.92% 0.34% 1.93% 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 | $ 1,387,537,115 |
| Holdings Count | shares | 509 |
| Advisory Fees Paid, Amount | $ 0 |
| Investment Company Portfolio Turnover | 24% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 509 Total Advisory Fee $ Portfolio Turnover 24 % |
| Holdings [Text Block] | BBB 6.1 BB 28.2 B 34.1 CCC,CC,C 16.0 Not Rated 3.1 Equities 5.4 Short-Term Investments and Net Other Assets (Liabilities) 7.1 QUALITY DIVERSIFICATION (% of Fund's net assets) We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes. Corporate Bonds 79.2 Bank Loan Obligations 6.7 Common Stocks 3.4 Alternative Funds 2.0 Asset-Backed Securities 0.8 Preferred Securities 0.8 Short-Term Investments and Net Other Assets (Liabilities) 7.1 ASSET ALLOCATION (% of Fund's net assets) United States 88.4 Canada 3.0 Luxembourg 1.0 Brazil 0.8 Netherlands 0.7 Panama 0.7 France 0.7 United Kingdom 0.7 Grand Cayman (Uk Overseas Ter) 0.7 Others 3.3 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Private Credit Company LLC 2.0 CHS/Community Health Systems Inc 1.8 TransDigm Inc 1.7 Uber Technologies Inc 1.6 Pacific Gas and Electric Co 1.4 Echo Global Logistics Inc 1.4 Tenet Healthcare Corp 1.3 Mesquite Energy Inc 1.3 DISH Network Corp 1.1 Cloud Software Group Inc 1.0 14.6 |
| Material Fund Change [Text Block] | How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 . The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Operating expenses Effective March 1, 2024, the fund's management contract was amended to remove the fee the investment adviser received from investing funds. The fund added a contractual management fee waiver during the reporting period. |
| Material Fund Change Expenses [Text Block] | The fees associated with this class changed during the reporting year. The variations in class fees are primarily the result of the following changes: • Operating expenses Effective March 1, 2024, the fund's management contract was amended to remove the fee the investment adviser received from investing funds. The fund added a contractual management fee waiver during the reporting period. |
| Summary of Change Legend [Text Block] | This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 . |
| Updated Prospectus Phone Number | 1-800-544-8544</span>" id="sjs-B39"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-8544</span> |
| Updated Prospectus Web Address | fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B40"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:bold;">fundresearch.fidelity.com/prospectus/sec</span> |
| Fidelity Specialized High Income Central Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Specialized High Income Central Fund |
| Class Name | Fidelity® Specialized High Income Central Fund |
| No Trading Symbol Flag | true |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains information about Fidelity® Specialized High Income Central Fund for the period September 1, 2023 to August 31, 2024. |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544. |
| 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 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® Specialized High Income Central Fund $ A 0.00 % B A Amount represents less than $.50 B Amount represents less than 0.005% |
| Expenses Paid, Amount | $ 0 |
| Expense Ratio, Percent | 0% |
| Factors Affecting Performance [Text Block] | What affected the Fund's performance this period? • • • • • • • • |
| Performance Past Does Not Indicate Future [Text] | The Fund's past performance is not a good predictor of the Fund's future performance.</span>" id="sjs-B56"><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 August 31, 2014 through August 31, 2024. Initial investment of $10,000. Fidelity® Specialized High Income Central Fund $10,000 $9,930 $10,664 $11,452 $11,729 $12,753 $13,295 $14,155 $12,743 $13,452 $14,981 ICE® BofA® BB US High Yield Constrained Index $10,000 $9,987 $10,961 $11,738 $11,899 $13,042 $13,870 $14,991 $13,429 $14,199 $15,880 Bloomberg U.S. Universal Bond Index $10,000 $10,113 $10,770 $10,915 $10,814 $11,903 $12,666 $12,778 $11,264 $11,219 $12,108 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® Specialized High Income Central Fund 11.37% 3.27% 4.12% ICE® BofA® BB US High Yield Constrained Index 11.83% 4.02% 4.73% Bloomberg U.S. Universal Bond Index 7.92% 0.34% 1.93% 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 | $ 241,145,314 |
| Holdings Count | shares | 397 |
| Advisory Fees Paid, Amount | $ 0 |
| Investment Company Portfolio Turnover | 17% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of August 31, 2024) KEY FACTS Fund Size $ Number of Holdings 397 Total Advisory Fee $ Portfolio Turnover 17 % |
| Holdings [Text Block] | BBB 7.6 BB 61.4 B 22.0 CCC,CC,C 1.7 Not Rated 0.0 Short-Term Investments and Net Other Assets (Liabilities) 7.3 QUALITY DIVERSIFICATION (% of Fund's net assets) We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes. Corporate Bonds 91.2 Preferred Securities 1.3 Bank Loan Obligations 0.2 Short-Term Investments and Net Other Assets (Liabilities) 7.3 ASSET ALLOCATION (% of Fund's net assets) United States 88.9 Canada 3.4 United Kingdom 1.9 Australia 1.3 Ireland 0.8 Panama 0.6 Luxembourg 0.5 Guatemala 0.4 Finland 0.3 Others 1.9 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) CCO Holdings LLC / CCO Holdings Capital Corp 2.0 Sirius XM Radio Inc 1.5 Royal Caribbean Cruises Ltd 1.5 Albertsons Cos Inc / Safeway Inc / New Albertsons LP / Albertsons LLC 1.4 Tenet Healthcare Corp 1.4 Hilton Domestic Operating Co Inc 1.4 OneMain Finance Corp 1.3 Vistra Operations Co LLC 1.3 Venture Global Calcasieu 1.3 Yum! Brands Inc 1.2 14.3 |
| Material Fund Change [Text Block] | How has the Fund changed? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 . Effective March 1, 2024, the fund's management contract was amended to remove the fee the investment adviser received from investing funds. |
| Material Fund Change Expenses [Text Block] | Effective March 1, 2024, the fund's management contract was amended to remove the fee the investment adviser received from investing funds. |
| Summary of Change Legend [Text Block] | This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund's next prospectus, which we expect to be available by October 30, 2024 at fundresearch.fidelity.com/prospectus/sec or upon request at 1-800-544-8544 . |
| Updated Prospectus Phone Number | 1-800-544-8544</span>" id="sjs-B70"><span style="font-family:'Fidelity Sans';font-size:11px;color:#000000;font-style:normal;font-weight:normal;">1-800-544-8544</span> |
| Updated Prospectus Web Address | fundresearch.fidelity.com/prospectus/sec</span>" id="sjs-B71"><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 | 120 Months Ended | 132 Months Ended | ||||||||||
| Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2023 | Aug. 31, 2022 | Aug. 31, 2021 | Aug. 31, 2020 | Aug. 31, 2019 | Aug. 31, 2018 | Aug. 31, 2017 | Aug. 31, 2016 | Aug. 31, 2015 | Aug. 31, 2014 | |
| C000064553_1_BBIndexMember_1YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 7.92% | |||||||||||||
| C000064553_1_BBIndexMember_5YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 0.34% | |||||||||||||
| C000064553_1_BBIndexMember_10YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 1.93% | |||||||||||||
| C000023057_1_BBIndexMember_1YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 7.92% | |||||||||||||
| C000023057_1_BBIndexMember_5YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 0.34% | |||||||||||||
| C000023057_1_BBIndexMember_10YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 1.93% | |||||||||||||
| C000064553_LG_ClassMember_11YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Line Graph and Table Measure Name | Fidelity® High Income Central Fund</span>" id="sjs-E23"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® High Income Central Fund</span> | |||||||||||||
| C000064553_ClassMember_AsOf_2014Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 10,000 | |||||||||||||
| C000064553_ClassMember_AsOf_2015Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 9,842 | |||||||||||||
| C000064553_ClassMember_AsOf_2016Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 10,605 | |||||||||||||
| C000064553_ClassMember_AsOf_2017Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 11,623 | |||||||||||||
| C000064553_ClassMember_AsOf_2018Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 12,238 | |||||||||||||
| C000064553_ClassMember_AsOf_2019Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 13,044 | |||||||||||||
| C000064553_ClassMember_AsOf_2020Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 13,233 | |||||||||||||
| C000064553_ClassMember_AsOf_2021Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 15,213 | |||||||||||||
| C000064553_ClassMember_AsOf_2022Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 14,330 | |||||||||||||
| C000064553_ClassMember_AsOf_2023Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 15,315 | |||||||||||||
| C000064553_ClassMember_AsOf_2024Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 17,175 | $ 17,175 | $ 17,175 | $ 17,175 | ||||||||||
| C000064553_LG_1_AdditionalIndexMember_11YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Line Graph and Table Measure Name | ICE® BofA® US High Yield Constrained Index</span>" id="sjs-E59"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">ICE® BofA® US High Yield Constrained Index</span> | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,000 | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 9,692 | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,586 | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 11,516 | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 11,893 | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 12,675 | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 13,134 | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 14,481 | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 12,970 | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 13,882 | |||||||||||||
| C000064553_1_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 15,613 | 15,613 | 15,613 | $ 15,613 | ||||||||||
| C000064553_LG_2_AdditionalIndexMember_11YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Universal Bond Index</span>" id="sjs-E95"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Universal Bond Index</span> | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,000 | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,113 | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,770 | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,915 | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,814 | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 11,903 | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 12,666 | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 12,778 | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 11,264 | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 11,219 | |||||||||||||
| C000064553_2_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 12,108 | $ 12,108 | $ 12,108 | $ 12,108 | ||||||||||
| C000064553_NoLoadClassMember_1YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 12.14% | |||||||||||||
| C000064553_NoLoadClassMember_5YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 5.66% | |||||||||||||
| C000064553_NoLoadClassMember_10YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 5.56% | |||||||||||||
| C000064553_0_AdditionalIndexMember_1YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 12.47% | |||||||||||||
| C000064553_0_AdditionalIndexMember_5YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 4.26% | |||||||||||||
| C000064553_0_AdditionalIndexMember_10YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 4.56% | |||||||||||||
| C000023057_LG_ClassMember_11YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Line Graph and Table Measure Name | Fidelity® Specialized High Income Central Fund</span>" id="sjs-E149"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® Specialized High Income Central Fund</span> | |||||||||||||
| C000023057_ClassMember_AsOf_2014Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,000 | |||||||||||||
| C000023057_ClassMember_AsOf_2015Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 9,930 | |||||||||||||
| C000023057_ClassMember_AsOf_2016Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,664 | |||||||||||||
| C000023057_ClassMember_AsOf_2017Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 11,452 | |||||||||||||
| C000023057_ClassMember_AsOf_2018Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 11,729 | |||||||||||||
| C000023057_ClassMember_AsOf_2019Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 12,753 | |||||||||||||
| C000023057_ClassMember_AsOf_2020Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 13,295 | |||||||||||||
| C000023057_ClassMember_AsOf_2021Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 14,155 | |||||||||||||
| C000023057_ClassMember_AsOf_2022Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 12,743 | |||||||||||||
| C000023057_ClassMember_AsOf_2023Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 13,452 | |||||||||||||
| C000023057_ClassMember_AsOf_2024Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 14,981 | $ 14,981 | $ 14,981 | $ 14,981 | ||||||||||
| C000023057_LG_1_AdditionalIndexMember_11YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Line Graph and Table Measure Name | ICE® BofA® BB US High Yield Constrained Index</span>" id="sjs-E185"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">ICE® BofA® BB US High Yield Constrained Index</span> | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,000 | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 9,987 | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 10,961 | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 11,738 | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 11,899 | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 13,042 | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 13,870 | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 14,991 | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 13,429 | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 14,199 | |||||||||||||
| C000023057_1_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | 15,880 | 15,880 | 15,880 | $ 15,880 | ||||||||||
| C000023057_LG_2_AdditionalIndexMember_11YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Universal Bond Index</span>" id="sjs-E221"><span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Bloomberg U.S. Universal Bond Index</span> | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2014Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 10,000 | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2015Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 10,113 | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2016Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 10,770 | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2017Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 10,915 | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2018Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 10,814 | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2019Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 11,903 | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2020Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 12,666 | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2021Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 12,778 | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2022Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 11,264 | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2023Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 11,219 | |||||||||||||
| C000023057_2_AdditionalIndexMember_AsOf_2024Member | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Account Value | $ 12,108 | $ 12,108 | $ 12,108 | $ 12,108 | ||||||||||
| C000023057_NoLoadClassMember_1YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 11.37% | |||||||||||||
| C000023057_NoLoadClassMember_5YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 3.27% | |||||||||||||
| C000023057_NoLoadClassMember_10YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 4.12% | |||||||||||||
| C000023057_0_AdditionalIndexMember_1YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 11.83% | |||||||||||||
| C000023057_0_AdditionalIndexMember_5YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 4.02% | |||||||||||||
| C000023057_0_AdditionalIndexMember_10YRMember | ||||||||||||||
| Account Value [Line Items] | ||||||||||||||
| Average Annual Return, Percent | 4.73% |
| Shareholder Report, Holdings (Details) | Aug. 31, 2024 |
| Fidelity High Income Central Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| Fidelity High Income Central Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.80% |
| Fidelity High Income Central Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.70% |
| Fidelity High Income Central Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.60% |
| Fidelity High Income Central Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| Fidelity High Income Central Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| Fidelity High Income Central Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| Fidelity High Income Central Fund | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| Fidelity High Income Central Fund | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity High Income Central Fund | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity High Income Central Fund | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.10% |
| Fidelity High Income Central Fund | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.20% |
| Fidelity High Income Central Fund | QDBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.10% |
| Fidelity High Income Central Fund | QDCCCCCCMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16% |
| Fidelity High Income Central Fund | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.10% |
| Fidelity High Income Central Fund | QDEquitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.40% |
| Fidelity High Income Central Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.10% |
| Fidelity High Income Central Fund | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 88.40% |
| Fidelity High Income Central Fund | Canada | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3% |
| Fidelity High Income Central Fund | Luxembourg | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity High Income Central Fund | Brazil | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity High Income Central Fund | Netherlands | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity High Income Central Fund | Panama | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity High Income Central Fund | France | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity High Income Central Fund | United Kingdom | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity High Income Central Fund | GrandCaymanUkOverseasTerMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity High Income Central Fund | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity High Income Central Fund | AACorporateBondsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 79.20% |
| Fidelity High Income Central Fund | AABankLoanObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.70% |
| Fidelity High Income Central Fund | AACommonStocksMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| Fidelity High Income Central Fund | AAAlternativeFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| Fidelity High Income Central Fund | AAAssetBackedSecuritiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity High Income Central Fund | AAPreferredSecuritiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity High Income Central Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.10% |
| Fidelity Specialized High Income Central Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2% |
| Fidelity Specialized High Income Central Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.50% |
| Fidelity Specialized High Income Central Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.50% |
| Fidelity Specialized High Income Central Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| Fidelity Specialized High Income Central Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| Fidelity Specialized High Income Central Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.40% |
| Fidelity Specialized High Income Central Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| Fidelity Specialized High Income Central Fund | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| Fidelity Specialized High Income Central Fund | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| Fidelity Specialized High Income Central Fund | TH9Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Specialized High Income Central Fund | QDBBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.60% |
| Fidelity Specialized High Income Central Fund | QDBBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 61.40% |
| Fidelity Specialized High Income Central Fund | QDBMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22% |
| Fidelity Specialized High Income Central Fund | QDCCCCCCMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.70% |
| Fidelity Specialized High Income Central Fund | QDNotRatedMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Specialized High Income Central Fund | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.30% |
| Fidelity Specialized High Income Central Fund | United States | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 88.90% |
| Fidelity Specialized High Income Central Fund | Canada | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.40% |
| Fidelity Specialized High Income Central Fund | Luxembourg | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.50% |
| Fidelity Specialized High Income Central Fund | Panama | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.60% |
| Fidelity Specialized High Income Central Fund | United Kingdom | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| Fidelity Specialized High Income Central Fund | OtherMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.90% |
| Fidelity Specialized High Income Central Fund | Australia | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| Fidelity Specialized High Income Central Fund | Ireland | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.80% |
| Fidelity Specialized High Income Central Fund | Guatemala | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.40% |
| Fidelity Specialized High Income Central Fund | Finland | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.30% |
| Fidelity Specialized High Income Central Fund | AACorporateBondsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 91.20% |
| Fidelity Specialized High Income Central Fund | AABankLoanObligationsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Specialized High Income Central Fund | AAPreferredSecuritiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.30% |
| Fidelity Specialized High Income Central Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.30% |
