| Form N-CSR Cover | 6 Months Ended |
| Sep. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | Fidelity Aberdeen Street Trust |
| Entity Central Index Key | 0000880195 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Sep. 30, 2024 |
| Shareholder Report | 6 Months Ended |
| Sep. 30, 2024 USD ($) shares | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | Fidelity Aberdeen Street Trust |
| Entity Central Index Key | 0000880195 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Sep. 30, 2024 |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2070 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2070 Fund Class M |
| Trading Symbol | FRCYX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2070 Fund for the period June 28, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M A $ 0.99 % A Expenses for the full reporting period would be higher. |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.99% |
| Expenses Short Period Footnote [Text Block] | Expenses for the full reporting period would be higher. |
| Net Assets | $ 571,788 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 1% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover A 1 % A Amount not annualized |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2070 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2070 Fund |
| Class Name | Fidelity® Sustainable Target Date 2070 Fund Class K |
| Trading Symbol | FRCRX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2070 Fund for the period June 28, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K A $ 0.39 % A Expenses for the full reporting period would be higher. |
| Expenses Paid, Amount | $ 11 |
| Expense Ratio, Percent | 0.39% |
| Expenses Short Period Footnote [Text Block] | Expenses for the full reporting period would be higher. |
| Net Assets | $ 571,788 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 1% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover A 1 % A Amount not annualized |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2015 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2015 Fund Class M |
| Trading Symbol | FSVTX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2015 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.92 % |
| Expenses Paid, Amount | $ 47 |
| Expense Ratio, Percent | 0.92% |
| Net Assets | $ 1,141,685 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 60.7 International Equity Funds 20.4 Domestic Equity Funds 17.9 Short-Term Funds 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 37.7 Fidelity Series Sustainable U.S. Market Fund 17.9 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 12.9 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 10.9 Fidelity Series Sustainable Emerging Markets Fund 7.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 5.5 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.6 Fidelity Series Treasury Bill Index Fund 1.0 100.0 |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2060 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2060 Fund Class A |
| Trading Symbol | FSZTX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2060 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.74 % |
| Expenses Paid, Amount | $ 39 |
| Expense Ratio, Percent | 0.74% |
| Net Assets | $ 4,581,235 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2070 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2070 Fund Class C |
| Trading Symbol | FRDCX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2070 Fund for the period June 28, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C A $ 1.48 % A Expenses for the full reporting period would be higher. |
| Expenses Paid, Amount | $ 40 |
| Expense Ratio, Percent | 1.48% |
| Expenses Short Period Footnote [Text Block] | Expenses for the full reporting period would be higher. |
| Net Assets | $ 571,788 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 1% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover A 1 % A Amount not annualized |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2055 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2055 Fund |
| Class Name | Fidelity® Sustainable Target Date 2055 Fund Class K6 |
| Trading Symbol | FSZRX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2055 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.29 % |
| Expenses Paid, Amount | $ 15 |
| Expense Ratio, Percent | 0.29% |
| Net Assets | $ 5,261,234 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 8 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2045 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2045 Fund Class M |
| Trading Symbol | FSYPX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2045 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.99 % |
| Expenses Paid, Amount | $ 52 |
| Expense Ratio, Percent | 0.99% |
| Net Assets | $ 5,918,268 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 15% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 15 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2025 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2025 Fund Class A |
| Trading Symbol | FSWQX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2025 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.70 % |
| Expenses Paid, Amount | $ 36 |
| Expense Ratio, Percent | 0.70% |
| Net Assets | $ 2,211,356 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 44.4 Domestic Equity Funds 28.1 International Equity Funds 27.5 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 28.1 Fidelity Series Sustainable Investment Grade Bond Fund 25.0 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 18.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 10.6 Fidelity Series Sustainable Emerging Markets Fund 9.3 Fidelity Series Long-Term Treasury Bond Index Fund 4.9 Fidelity Series International Developed Markets Bond Index Fund 3.9 100.0 |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2030 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2030 Fund Class A |
| Trading Symbol | FSXBX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2030 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.71 % |
| Expenses Paid, Amount | $ 37 |
| Expense Ratio, Percent | 0.71% |
| Net Assets | $ 4,820,166 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 8 % |
| Holdings [Text Block] | Bond Funds 37.8 Domestic Equity Funds 32.0 International Equity Funds 30.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 32.0 Fidelity Series Sustainable Investment Grade Bond Fund 22.2 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 20.0 Fidelity Series Sustainable Emerging Markets Fund 10.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 6.5 Fidelity Series Long-Term Treasury Bond Index Fund 5.3 Fidelity Series International Developed Markets Bond Index Fund 3.8 100.0 |
| Fidelity Sustainable Target Date 2020 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2020 Fund |
| Class Name | Fidelity® Sustainable Target Date 2020 Fund Class K |
| Trading Symbol | FSWMX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2020 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.33 % |
| Expenses Paid, Amount | $ 17 |
| Expense Ratio, Percent | 0.33% |
| Net Assets | $ 1,914,543 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 52.3 International Equity Funds 24.2 Domestic Equity Funds 23.3 Short-Term Funds 0.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 32.3 Fidelity Series Sustainable U.S. Market Fund 23.3 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 15.6 Fidelity Series Sustainable Emerging Markets Fund 8.6 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 8.0 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 4.3 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 3.7 Fidelity Series Treasury Bill Index Fund 0.2 100.0 |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date Income Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date Income Fund Class M |
| Trading Symbol | FSUHX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date Income Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.91 % |
| Expenses Paid, Amount | $ 47 |
| Expense Ratio, Percent | 0.91% |
| Net Assets | $ 1,165,797 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 72.1 International Equity Funds 14.0 Domestic Equity Funds 8.1 Short-Term Funds 5.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 44.1 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 21.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 8.4 Fidelity Series Sustainable U.S. Market Fund 8.1 Fidelity Series Treasury Bill Index Fund 5.8 Fidelity Series Sustainable Emerging Markets Fund 5.6 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 0.7 100.0 |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2045 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2045 Fund Class Z |
| Trading Symbol | FSYSX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2045 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.39 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.39% |
| Net Assets | $ 5,918,268 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 15% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 15 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2020 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2020 Fund Class M |
| Trading Symbol | FSWHX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2020 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.93 % |
| Expenses Paid, Amount | $ 48 |
| Expense Ratio, Percent | 0.93% |
| Net Assets | $ 1,914,543 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 52.3 International Equity Funds 24.2 Domestic Equity Funds 23.3 Short-Term Funds 0.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 32.3 Fidelity Series Sustainable U.S. Market Fund 23.3 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 15.6 Fidelity Series Sustainable Emerging Markets Fund 8.6 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 8.0 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 4.3 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 3.7 Fidelity Series Treasury Bill Index Fund 0.2 100.0 |
| Fidelity Sustainable Target Date 2070 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2070 Fund |
| Class Name | Fidelity® Sustainable Target Date 2070 Fund |
| Trading Symbol | FRCQX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2070 Fund for the period June 28, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2070 Fund A $ 0.49 % A Expenses for the full reporting period would be higher. |
| Expenses Paid, Amount | $ 13 |
| Expense Ratio, Percent | 0.49% |
| Expenses Short Period Footnote [Text Block] | Expenses for the full reporting period would be higher. |
| Net Assets | $ 571,788 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 1% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover A 1 % A Amount not annualized |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2050 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2050 Fund Class M |
| Trading Symbol | FSZAX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2050 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.99 % |
| Expenses Paid, Amount | $ 52 |
| Expense Ratio, Percent | 0.99% |
| Net Assets | $ 5,660,101 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2045 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2045 Fund Class A |
| Trading Symbol | FSYLX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2045 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.74 % |
| Expenses Paid, Amount | $ 39 |
| Expense Ratio, Percent | 0.74% |
| Net Assets | $ 5,918,268 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 15% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 15 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2015 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2015 Fund |
| Class Name | Fidelity® Sustainable Target Date 2015 Fund |
| Trading Symbol | FSVNX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2015 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2015 Fund $ 0.42 % |
| Expenses Paid, Amount | $ 22 |
| Expense Ratio, Percent | 0.42% |
| Net Assets | $ 1,141,685 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 60.7 International Equity Funds 20.4 Domestic Equity Funds 17.9 Short-Term Funds 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 37.7 Fidelity Series Sustainable U.S. Market Fund 17.9 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 12.9 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 10.9 Fidelity Series Sustainable Emerging Markets Fund 7.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 5.5 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.6 Fidelity Series Treasury Bill Index Fund 1.0 100.0 |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2015 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2015 Fund Class I |
| Trading Symbol | FSVUX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2015 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.42 % |
| Expenses Paid, Amount | $ 22 |
| Expense Ratio, Percent | 0.42% |
| Net Assets | $ 1,141,685 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 60.7 International Equity Funds 20.4 Domestic Equity Funds 17.9 Short-Term Funds 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 37.7 Fidelity Series Sustainable U.S. Market Fund 17.9 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 12.9 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 10.9 Fidelity Series Sustainable Emerging Markets Fund 7.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 5.5 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.6 Fidelity Series Treasury Bill Index Fund 1.0 100.0 |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2060 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2060 Fund Class Z |
| Trading Symbol | FTDLX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2060 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.39 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.39% |
| Net Assets | $ 4,581,235 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2065 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2065 Fund Class I |
| Trading Symbol | FTHBX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2065 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.49 % |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.49% |
| Net Assets | $ 3,007,785 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 9% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 9 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2050 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2050 Fund Class Z |
| Trading Symbol | FSZCX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2050 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.39 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.39% |
| Net Assets | $ 5,660,101 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2015 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2015 Fund Class Z |
| Trading Symbol | FSVWX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2015 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.32 % |
| Expenses Paid, Amount | $ 17 |
| Expense Ratio, Percent | 0.32% |
| Net Assets | $ 1,141,685 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 60.7 International Equity Funds 20.4 Domestic Equity Funds 17.9 Short-Term Funds 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 37.7 Fidelity Series Sustainable U.S. Market Fund 17.9 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 12.9 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 10.9 Fidelity Series Sustainable Emerging Markets Fund 7.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 5.5 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.6 Fidelity Series Treasury Bill Index Fund 1.0 100.0 |
| Fidelity Sustainable Target Date 2050 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2050 Fund |
| Class Name | Fidelity® Sustainable Target Date 2050 Fund |
| Trading Symbol | FSYWX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2050 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2050 Fund $ 0.49 % |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.49% |
| Net Assets | $ 5,660,101 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2015 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2015 Fund |
| Class Name | Fidelity® Sustainable Target Date 2015 Fund Class K |
| Trading Symbol | FSVZX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2015 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.32 % |
| Expenses Paid, Amount | $ 17 |
| Expense Ratio, Percent | 0.32% |
| Net Assets | $ 1,141,685 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 60.7 International Equity Funds 20.4 Domestic Equity Funds 17.9 Short-Term Funds 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 37.7 Fidelity Series Sustainable U.S. Market Fund 17.9 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 12.9 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 10.9 Fidelity Series Sustainable Emerging Markets Fund 7.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 5.5 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.6 Fidelity Series Treasury Bill Index Fund 1.0 100.0 |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2015 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2015 Fund Class C |
| Trading Symbol | FSVPX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2015 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.42 % |
| Expenses Paid, Amount | $ 73 |
| Expense Ratio, Percent | 1.42% |
| Net Assets | $ 1,141,685 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 60.7 International Equity Funds 20.4 Domestic Equity Funds 17.9 Short-Term Funds 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 37.7 Fidelity Series Sustainable U.S. Market Fund 17.9 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 12.9 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 10.9 Fidelity Series Sustainable Emerging Markets Fund 7.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 5.5 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.6 Fidelity Series Treasury Bill Index Fund 1.0 100.0 |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2055 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2055 Fund Class I |
| Trading Symbol | FSZMX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2055 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.49 % |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.49% |
| Net Assets | $ 5,261,234 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 8 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2040 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2040 Fund Class Z |
| Trading Symbol | FSYDX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2040 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.38 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.38% |
| Net Assets | $ 5,907,996 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 17% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 17 % |
| Holdings [Text Block] | Domestic Equity Funds 46.8 International Equity Funds 40.0 Bond Funds 13.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 46.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 27.0 Fidelity Series Sustainable Emerging Markets Fund 13.0 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series Sustainable Investment Grade Bond Fund 5.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.2 Fidelity Series International Developed Markets Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2055 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2055 Fund |
| Class Name | Fidelity® Sustainable Target Date 2055 Fund |
| Trading Symbol | FSZHX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2055 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2055 Fund $ 0.49 % |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.49% |
| Net Assets | $ 5,261,234 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 8 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2065 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2065 Fund |
| Class Name | Fidelity® Sustainable Target Date 2065 Fund |
| Trading Symbol | FTGPX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2065 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2065 Fund $ 0.49 % |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.49% |
| Net Assets | $ 3,007,785 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 9% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 9 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2070 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2070 Fund Class Z |
| Trading Symbol | FRDEX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2070 Fund for the period June 28, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z A $ 0.39 % A Expenses for the full reporting period would be higher. |
| Expenses Paid, Amount | $ 11 |
| Expense Ratio, Percent | 0.39% |
| Expenses Short Period Footnote [Text Block] | Expenses for the full reporting period would be higher. |
| Net Assets | $ 571,788 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 1% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover A 1 % A Amount not annualized |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2040 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2040 Fund Class C |
| Trading Symbol | FSXYX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2040 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.48 % |
| Expenses Paid, Amount | $ 77 |
| Expense Ratio, Percent | 1.48% |
| Net Assets | $ 5,907,996 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 17% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 17 % |
| Holdings [Text Block] | Domestic Equity Funds 46.8 International Equity Funds 40.0 Bond Funds 13.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 46.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 27.0 Fidelity Series Sustainable Emerging Markets Fund 13.0 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series Sustainable Investment Grade Bond Fund 5.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.2 Fidelity Series International Developed Markets Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2010 Fund |
| Class Name | Fidelity® Sustainable Target Date 2010 Fund Class K6 |
| Trading Symbol | FSVMX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2010 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.21 % |
| Expenses Paid, Amount | $ 11 |
| Expense Ratio, Percent | 0.21% |
| Net Assets | $ 1,137,784 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 67.1 International Equity Funds 16.7 Domestic Equity Funds 12.4 Short-Term Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 41.3 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 16.6 Fidelity Series Sustainable U.S. Market Fund 12.4 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 10.3 Fidelity Series Sustainable Emerging Markets Fund 6.4 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Treasury Bill Index Fund 3.8 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.8 Fidelity Series Long-Term Treasury Bond Index Fund 2.4 100.0 |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2040 Fund |
| Class Name | Fidelity® Sustainable Target Date 2040 Fund Class K6 |
| Trading Symbol | FSYGX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2040 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.28 % |
| Expenses Paid, Amount | $ 15 |
| Expense Ratio, Percent | 0.28% |
| Net Assets | $ 5,907,996 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 17% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 17 % |
| Holdings [Text Block] | Domestic Equity Funds 46.8 International Equity Funds 40.0 Bond Funds 13.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 46.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 27.0 Fidelity Series Sustainable Emerging Markets Fund 13.0 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series Sustainable Investment Grade Bond Fund 5.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.2 Fidelity Series International Developed Markets Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2025 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2025 Fund |
| Class Name | Fidelity® Sustainable Target Date 2025 Fund Class K |
| Trading Symbol | FSWYX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2025 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.35 % |
| Expenses Paid, Amount | $ 18 |
| Expense Ratio, Percent | 0.35% |
| Net Assets | $ 2,211,356 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 44.4 Domestic Equity Funds 28.1 International Equity Funds 27.5 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 28.1 Fidelity Series Sustainable Investment Grade Bond Fund 25.0 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 18.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 10.6 Fidelity Series Sustainable Emerging Markets Fund 9.3 Fidelity Series Long-Term Treasury Bond Index Fund 4.9 Fidelity Series International Developed Markets Bond Index Fund 3.9 100.0 |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2010 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2010 Fund Class A |
| Trading Symbol | FSUZX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2010 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.66 % |
| Expenses Paid, Amount | $ 34 |
| Expense Ratio, Percent | 0.66% |
| Net Assets | $ 1,137,784 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 67.1 International Equity Funds 16.7 Domestic Equity Funds 12.4 Short-Term Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 41.3 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 16.6 Fidelity Series Sustainable U.S. Market Fund 12.4 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 10.3 Fidelity Series Sustainable Emerging Markets Fund 6.4 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Treasury Bill Index Fund 3.8 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.8 Fidelity Series Long-Term Treasury Bond Index Fund 2.4 100.0 |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2055 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2055 Fund Class Z |
| Trading Symbol | FSZNX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2055 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.39 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.39% |
| Net Assets | $ 5,261,234 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 8 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2020 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2020 Fund Class I |
| Trading Symbol | FSWJX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2020 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.43 % |
| Expenses Paid, Amount | $ 22 |
| Expense Ratio, Percent | 0.43% |
| Net Assets | $ 1,914,543 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 52.3 International Equity Funds 24.2 Domestic Equity Funds 23.3 Short-Term Funds 0.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 32.3 Fidelity Series Sustainable U.S. Market Fund 23.3 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 15.6 Fidelity Series Sustainable Emerging Markets Fund 8.6 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 8.0 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 4.3 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 3.7 Fidelity Series Treasury Bill Index Fund 0.2 100.0 |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date Income Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date Income Fund Class I |
| Trading Symbol | FSUJX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date Income Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.41 % |
| Expenses Paid, Amount | $ 21 |
| Expense Ratio, Percent | 0.41% |
| Net Assets | $ 1,165,797 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 72.1 International Equity Funds 14.0 Domestic Equity Funds 8.1 Short-Term Funds 5.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 44.1 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 21.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 8.4 Fidelity Series Sustainable U.S. Market Fund 8.1 Fidelity Series Treasury Bill Index Fund 5.8 Fidelity Series Sustainable Emerging Markets Fund 5.6 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 0.7 100.0 |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2035 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2035 Fund Class Z |
| Trading Symbol | FSXRX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2035 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.37 % |
| Expenses Paid, Amount | $ 19 |
| Expense Ratio, Percent | 0.37% |
| Net Assets | $ 4,481,900 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 22% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 22 % |
| Holdings [Text Block] | Domestic Equity Funds 38.1 International Equity Funds 34.2 Bond Funds 27.7 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 38.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 22.9 Fidelity Series Sustainable Investment Grade Bond Fund 16.4 Fidelity Series Sustainable Emerging Markets Fund 11.3 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series International Developed Markets Bond Index Fund 3.3 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.3 100.0 |
| Fidelity Sustainable Target Date 2055 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2055 Fund |
| Class Name | Fidelity® Sustainable Target Date 2055 Fund Class K |
| Trading Symbol | FSZQX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2055 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.39 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.39% |
| Net Assets | $ 5,261,234 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 8 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date Income Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date Income Fund Class A |
| Trading Symbol | FSUEX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date Income Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.66 % |
| Expenses Paid, Amount | $ 34 |
| Expense Ratio, Percent | 0.66% |
| Net Assets | $ 1,165,797 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 72.1 International Equity Funds 14.0 Domestic Equity Funds 8.1 Short-Term Funds 5.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 44.1 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 21.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 8.4 Fidelity Series Sustainable U.S. Market Fund 8.1 Fidelity Series Treasury Bill Index Fund 5.8 Fidelity Series Sustainable Emerging Markets Fund 5.6 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 0.7 100.0 |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2030 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2030 Fund Class I |
| Trading Symbol | FSXEX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2030 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.46 % |
| Expenses Paid, Amount | $ 24 |
| Expense Ratio, Percent | 0.46% |
| Net Assets | $ 4,820,166 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 8 % |
| Holdings [Text Block] | Bond Funds 37.8 Domestic Equity Funds 32.0 International Equity Funds 30.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 32.0 Fidelity Series Sustainable Investment Grade Bond Fund 22.2 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 20.0 Fidelity Series Sustainable Emerging Markets Fund 10.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 6.5 Fidelity Series Long-Term Treasury Bond Index Fund 5.3 Fidelity Series International Developed Markets Bond Index Fund 3.8 100.0 |
| Fidelity Sustainable Target Date Income Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date Income Fund |
| Class Name | Fidelity® Sustainable Target Date Income Fund |
| Trading Symbol | FSUDX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date Income Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date Income Fund $ 0.41 % |
| Expenses Paid, Amount | $ 21 |
| Expense Ratio, Percent | 0.41% |
| Net Assets | $ 1,165,797 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 72.1 International Equity Funds 14.0 Domestic Equity Funds 8.1 Short-Term Funds 5.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 44.1 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 21.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 8.4 Fidelity Series Sustainable U.S. Market Fund 8.1 Fidelity Series Treasury Bill Index Fund 5.8 Fidelity Series Sustainable Emerging Markets Fund 5.6 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 0.7 100.0 |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2070 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2070 Fund Class A |
| Trading Symbol | FRCWX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2070 Fund for the period June 28, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A A $ 0.74 % A Expenses for the full reporting period would be higher. |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.74% |
| Expenses Short Period Footnote [Text Block] | Expenses for the full reporting period would be higher. |
| Net Assets | $ 571,788 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 1% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover A 1 % A Amount not annualized |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2065 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2065 Fund Class A |
| Trading Symbol | FTGUX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2065 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.74 % |
| Expenses Paid, Amount | $ 39 |
| Expense Ratio, Percent | 0.74% |
| Net Assets | $ 3,007,785 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 9% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 9 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2010 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2010 Fund Class C |
| Trading Symbol | FSVCX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2010 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.41 % |
| Expenses Paid, Amount | $ 73 |
| Expense Ratio, Percent | 1.41% |
| Net Assets | $ 1,137,784 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 67.1 International Equity Funds 16.7 Domestic Equity Funds 12.4 Short-Term Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 41.3 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 16.6 Fidelity Series Sustainable U.S. Market Fund 12.4 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 10.3 Fidelity Series Sustainable Emerging Markets Fund 6.4 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Treasury Bill Index Fund 3.8 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.8 Fidelity Series Long-Term Treasury Bond Index Fund 2.4 100.0 |
| Fidelity Sustainable Target Date 2020 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2020 Fund |
| Class Name | Fidelity® Sustainable Target Date 2020 Fund |
| Trading Symbol | FSWDX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2020 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2020 Fund $ 0.43 % |
| Expenses Paid, Amount | $ 22 |
| Expense Ratio, Percent | 0.43% |
| Net Assets | $ 1,914,543 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 52.3 International Equity Funds 24.2 Domestic Equity Funds 23.3 Short-Term Funds 0.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 32.3 Fidelity Series Sustainable U.S. Market Fund 23.3 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 15.6 Fidelity Series Sustainable Emerging Markets Fund 8.6 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 8.0 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 4.3 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 3.7 Fidelity Series Treasury Bill Index Fund 0.2 100.0 |
| Fidelity Sustainable Target Date Income Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date Income Fund |
| Class Name | Fidelity® Sustainable Target Date Income Fund Class K6 |
| Trading Symbol | FSUWX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date Income Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.21 % |
| Expenses Paid, Amount | $ 11 |
| Expense Ratio, Percent | 0.21% |
| Net Assets | $ 1,165,797 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 72.1 International Equity Funds 14.0 Domestic Equity Funds 8.1 Short-Term Funds 5.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 44.1 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 21.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 8.4 Fidelity Series Sustainable U.S. Market Fund 8.1 Fidelity Series Treasury Bill Index Fund 5.8 Fidelity Series Sustainable Emerging Markets Fund 5.6 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 0.7 100.0 |
| Fidelity Sustainable Target Date 2060 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2060 Fund |
| Class Name | Fidelity® Sustainable Target Date 2060 Fund Class K |
| Trading Symbol | FTGKX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2060 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.39 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.39% |
| Net Assets | $ 4,581,235 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2030 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2030 Fund Class C |
| Trading Symbol | FSXCX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2030 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.46 % |
| Expenses Paid, Amount | $ 76 |
| Expense Ratio, Percent | 1.46% |
| Net Assets | $ 4,820,166 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 8 % |
| Holdings [Text Block] | Bond Funds 37.8 Domestic Equity Funds 32.0 International Equity Funds 30.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 32.0 Fidelity Series Sustainable Investment Grade Bond Fund 22.2 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 20.0 Fidelity Series Sustainable Emerging Markets Fund 10.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 6.5 Fidelity Series Long-Term Treasury Bond Index Fund 5.3 Fidelity Series International Developed Markets Bond Index Fund 3.8 100.0 |
| Fidelity Sustainable Target Date 2050 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2050 Fund |
| Class Name | Fidelity® Sustainable Target Date 2050 Fund Class K6 |
| Trading Symbol | FSZGX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2050 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.29 % |
| Expenses Paid, Amount | $ 15 |
| Expense Ratio, Percent | 0.29% |
| Net Assets | $ 5,660,101 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2060 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2060 Fund Class I |
| Trading Symbol | FSZYX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2060 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.49 % |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.49% |
| Net Assets | $ 4,581,235 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2055 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2055 Fund Class M |
| Trading Symbol | FSZLX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2055 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.99 % |
| Expenses Paid, Amount | $ 52 |
| Expense Ratio, Percent | 0.99% |
| Net Assets | $ 5,261,234 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 8 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2050 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2050 Fund |
| Class Name | Fidelity® Sustainable Target Date 2050 Fund Class K |
| Trading Symbol | FSZFX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2050 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.39 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.39% |
| Net Assets | $ 5,660,101 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2065 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2065 Fund Class C |
| Trading Symbol | FTGYX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2065 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.49 % |
| Expenses Paid, Amount | $ 78 |
| Expense Ratio, Percent | 1.49% |
| Net Assets | $ 3,007,785 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 9% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 9 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2020 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2020 Fund Class A |
| Trading Symbol | FSWEX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2020 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.68 % |
| Expenses Paid, Amount | $ 35 |
| Expense Ratio, Percent | 0.68% |
| Net Assets | $ 1,914,543 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 52.3 International Equity Funds 24.2 Domestic Equity Funds 23.3 Short-Term Funds 0.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 32.3 Fidelity Series Sustainable U.S. Market Fund 23.3 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 15.6 Fidelity Series Sustainable Emerging Markets Fund 8.6 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 8.0 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 4.3 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 3.7 Fidelity Series Treasury Bill Index Fund 0.2 100.0 |
| Fidelity Sustainable Target Date 2045 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2045 Fund |
| Class Name | Fidelity® Sustainable Target Date 2045 Fund |
| Trading Symbol | FSYHX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2045 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2045 Fund $ 0.49 % |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.49% |
| Net Assets | $ 5,918,268 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 15% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 15 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2025 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2025 Fund Class Z |
| Trading Symbol | FSWVX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2025 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.35 % |
| Expenses Paid, Amount | $ 18 |
| Expense Ratio, Percent | 0.35% |
| Net Assets | $ 2,211,356 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 44.4 Domestic Equity Funds 28.1 International Equity Funds 27.5 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 28.1 Fidelity Series Sustainable Investment Grade Bond Fund 25.0 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 18.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 10.6 Fidelity Series Sustainable Emerging Markets Fund 9.3 Fidelity Series Long-Term Treasury Bond Index Fund 4.9 Fidelity Series International Developed Markets Bond Index Fund 3.9 100.0 |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2025 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2025 Fund Class M |
| Trading Symbol | FSWSX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2025 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.95 % |
| Expenses Paid, Amount | $ 49 |
| Expense Ratio, Percent | 0.95% |
| Net Assets | $ 2,211,356 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 44.4 Domestic Equity Funds 28.1 International Equity Funds 27.5 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 28.1 Fidelity Series Sustainable Investment Grade Bond Fund 25.0 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 18.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 10.6 Fidelity Series Sustainable Emerging Markets Fund 9.3 Fidelity Series Long-Term Treasury Bond Index Fund 4.9 Fidelity Series International Developed Markets Bond Index Fund 3.9 100.0 |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2010 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2010 Fund Class I |
| Trading Symbol | FSVGX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2010 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.41 % |
| Expenses Paid, Amount | $ 21 |
| Expense Ratio, Percent | 0.41% |
| Net Assets | $ 1,137,784 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 67.1 International Equity Funds 16.7 Domestic Equity Funds 12.4 Short-Term Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 41.3 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 16.6 Fidelity Series Sustainable U.S. Market Fund 12.4 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 10.3 Fidelity Series Sustainable Emerging Markets Fund 6.4 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Treasury Bill Index Fund 3.8 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.8 Fidelity Series Long-Term Treasury Bond Index Fund 2.4 100.0 |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2060 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2060 Fund Class C |
| Trading Symbol | FSZVX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2060 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.49 % |
| Expenses Paid, Amount | $ 78 |
| Expense Ratio, Percent | 1.49% |
| Net Assets | $ 4,581,235 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2010 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2010 Fund |
| Class Name | Fidelity® Sustainable Target Date 2010 Fund Class K |
| Trading Symbol | FSVKX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2010 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.31 % |
| Expenses Paid, Amount | $ 16 |
| Expense Ratio, Percent | 0.31% |
| Net Assets | $ 1,137,784 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 67.1 International Equity Funds 16.7 Domestic Equity Funds 12.4 Short-Term Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 41.3 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 16.6 Fidelity Series Sustainable U.S. Market Fund 12.4 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 10.3 Fidelity Series Sustainable Emerging Markets Fund 6.4 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Treasury Bill Index Fund 3.8 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.8 Fidelity Series Long-Term Treasury Bond Index Fund 2.4 100.0 |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2040 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2040 Fund Class A |
| Trading Symbol | FSXWX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2040 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.73 % |
| Expenses Paid, Amount | $ 38 |
| Expense Ratio, Percent | 0.73% |
| Net Assets | $ 5,907,996 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 17% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 17 % |
| Holdings [Text Block] | Domestic Equity Funds 46.8 International Equity Funds 40.0 Bond Funds 13.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 46.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 27.0 Fidelity Series Sustainable Emerging Markets Fund 13.0 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series Sustainable Investment Grade Bond Fund 5.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.2 Fidelity Series International Developed Markets Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2030 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2030 Fund |
| Class Name | Fidelity® Sustainable Target Date 2030 Fund |
| Trading Symbol | FSXAX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2030 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2030 Fund $ 0.46 % |
| Expenses Paid, Amount | $ 24 |
| Expense Ratio, Percent | 0.46% |
| Net Assets | $ 4,820,166 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 8 % |
| Holdings [Text Block] | Bond Funds 37.8 Domestic Equity Funds 32.0 International Equity Funds 30.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 32.0 Fidelity Series Sustainable Investment Grade Bond Fund 22.2 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 20.0 Fidelity Series Sustainable Emerging Markets Fund 10.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 6.5 Fidelity Series Long-Term Treasury Bond Index Fund 5.3 Fidelity Series International Developed Markets Bond Index Fund 3.8 100.0 |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2020 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2020 Fund Class C |
| Trading Symbol | FSWGX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2020 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.43 % |
| Expenses Paid, Amount | $ 74 |
| Expense Ratio, Percent | 1.43% |
| Net Assets | $ 1,914,543 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 52.3 International Equity Funds 24.2 Domestic Equity Funds 23.3 Short-Term Funds 0.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 32.3 Fidelity Series Sustainable U.S. Market Fund 23.3 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 15.6 Fidelity Series Sustainable Emerging Markets Fund 8.6 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 8.0 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 4.3 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 3.7 Fidelity Series Treasury Bill Index Fund 0.2 100.0 |
| Fidelity Sustainable Target Date 2065 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2065 Fund |
| Class Name | Fidelity® Sustainable Target Date 2065 Fund Class K6 |
| Trading Symbol | FTHHX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2065 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.29 % |
| Expenses Paid, Amount | $ 15 |
| Expense Ratio, Percent | 0.29% |
| Net Assets | $ 3,007,785 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 9% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 9 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2030 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2030 Fund |
| Class Name | Fidelity® Sustainable Target Date 2030 Fund Class K |
| Trading Symbol | FSXHX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2030 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.36 % |
| Expenses Paid, Amount | $ 19 |
| Expense Ratio, Percent | 0.36% |
| Net Assets | $ 4,820,166 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 8 % |
| Holdings [Text Block] | Bond Funds 37.8 Domestic Equity Funds 32.0 International Equity Funds 30.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 32.0 Fidelity Series Sustainable Investment Grade Bond Fund 22.2 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 20.0 Fidelity Series Sustainable Emerging Markets Fund 10.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 6.5 Fidelity Series Long-Term Treasury Bond Index Fund 5.3 Fidelity Series International Developed Markets Bond Index Fund 3.8 100.0 |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date Income Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date Income Fund Class C |
| Trading Symbol | FSUFX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date Income Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.41 % |
| Expenses Paid, Amount | $ 72 |
| Expense Ratio, Percent | 1.41% |
| Net Assets | $ 1,165,797 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 72.1 International Equity Funds 14.0 Domestic Equity Funds 8.1 Short-Term Funds 5.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 44.1 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 21.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 8.4 Fidelity Series Sustainable U.S. Market Fund 8.1 Fidelity Series Treasury Bill Index Fund 5.8 Fidelity Series Sustainable Emerging Markets Fund 5.6 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 0.7 100.0 |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date Income Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date Income Fund Class Z |
| Trading Symbol | FSULX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date Income Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.31 % |
| Expenses Paid, Amount | $ 16 |
| Expense Ratio, Percent | 0.31% |
| Net Assets | $ 1,165,797 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 72.1 International Equity Funds 14.0 Domestic Equity Funds 8.1 Short-Term Funds 5.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 44.1 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 21.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 8.4 Fidelity Series Sustainable U.S. Market Fund 8.1 Fidelity Series Treasury Bill Index Fund 5.8 Fidelity Series Sustainable Emerging Markets Fund 5.6 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 0.7 100.0 |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2055 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2055 Fund Class C |
| Trading Symbol | FSZKX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2055 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.49 % |
| Expenses Paid, Amount | $ 78 |
| Expense Ratio, Percent | 1.49% |
| Net Assets | $ 5,261,234 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 8 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2010 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2010 Fund Class Z |
| Trading Symbol | FSVHX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2010 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.31 % |
| Expenses Paid, Amount | $ 16 |
| Expense Ratio, Percent | 0.31% |
| Net Assets | $ 1,137,784 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 67.1 International Equity Funds 16.7 Domestic Equity Funds 12.4 Short-Term Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 41.3 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 16.6 Fidelity Series Sustainable U.S. Market Fund 12.4 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 10.3 Fidelity Series Sustainable Emerging Markets Fund 6.4 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Treasury Bill Index Fund 3.8 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.8 Fidelity Series Long-Term Treasury Bond Index Fund 2.4 100.0 |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2040 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2040 Fund Class M |
| Trading Symbol | FSXZX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2040 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.98 % |
| Expenses Paid, Amount | $ 51 |
| Expense Ratio, Percent | 0.98% |
| Net Assets | $ 5,907,996 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 17% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 17 % |
| Holdings [Text Block] | Domestic Equity Funds 46.8 International Equity Funds 40.0 Bond Funds 13.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 46.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 27.0 Fidelity Series Sustainable Emerging Markets Fund 13.0 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series Sustainable Investment Grade Bond Fund 5.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.2 Fidelity Series International Developed Markets Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2060 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2060 Fund |
| Class Name | Fidelity® Sustainable Target Date 2060 Fund Class K6 |
| Trading Symbol | FTGNX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2060 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.29 % |
| Expenses Paid, Amount | $ 15 |
| Expense Ratio, Percent | 0.29% |
| Net Assets | $ 4,581,235 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2060 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2060 Fund |
| Class Name | Fidelity® Sustainable Target Date 2060 Fund |
| Trading Symbol | FSZSX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2060 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2060 Fund $ 0.49 % |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.49% |
| Net Assets | $ 4,581,235 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2035 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2035 Fund Class I |
| Trading Symbol | FSXQX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2035 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.47 % |
| Expenses Paid, Amount | $ 24 |
| Expense Ratio, Percent | 0.47% |
| Net Assets | $ 4,481,900 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 22% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 22 % |
| Holdings [Text Block] | Domestic Equity Funds 38.1 International Equity Funds 34.2 Bond Funds 27.7 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 38.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 22.9 Fidelity Series Sustainable Investment Grade Bond Fund 16.4 Fidelity Series Sustainable Emerging Markets Fund 11.3 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series International Developed Markets Bond Index Fund 3.3 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.3 100.0 |
| Fidelity Sustainable Target Date 2035 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2035 Fund |
| Class Name | Fidelity® Sustainable Target Date 2035 Fund |
| Trading Symbol | FSXKX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2035 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2035 Fund $ 0.47 % |
| Expenses Paid, Amount | $ 25 |
| Expense Ratio, Percent | 0.47% |
| Net Assets | $ 4,481,900 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 22% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 22 % |
| Holdings [Text Block] | Domestic Equity Funds 38.1 International Equity Funds 34.2 Bond Funds 27.7 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 38.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 22.9 Fidelity Series Sustainable Investment Grade Bond Fund 16.4 Fidelity Series Sustainable Emerging Markets Fund 11.3 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series International Developed Markets Bond Index Fund 3.3 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.3 100.0 |
| Fidelity Sustainable Target Date 2045 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2045 Fund |
| Class Name | Fidelity® Sustainable Target Date 2045 Fund Class K6 |
| Trading Symbol | FSYVX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2045 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.29 % |
| Expenses Paid, Amount | $ 15 |
| Expense Ratio, Percent | 0.29% |
| Net Assets | $ 5,918,268 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 15% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 15 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2030 Fund |
| Class Name | Fidelity® Sustainable Target Date 2030 Fund Class K6 |
| Trading Symbol | FSXJX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2030 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.26 % |
| Expenses Paid, Amount | $ 14 |
| Expense Ratio, Percent | 0.26% |
| Net Assets | $ 4,820,166 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 8 % |
| Holdings [Text Block] | Bond Funds 37.8 Domestic Equity Funds 32.0 International Equity Funds 30.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 32.0 Fidelity Series Sustainable Investment Grade Bond Fund 22.2 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 20.0 Fidelity Series Sustainable Emerging Markets Fund 10.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 6.5 Fidelity Series Long-Term Treasury Bond Index Fund 5.3 Fidelity Series International Developed Markets Bond Index Fund 3.8 100.0 |
| Fidelity Sustainable Target Date 2065 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2065 Fund |
| Class Name | Fidelity® Sustainable Target Date 2065 Fund Class K |
| Trading Symbol | FTHGX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2065 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.39 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.39% |
| Net Assets | $ 3,007,785 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 9% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 9 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2015 Fund |
| Class Name | Fidelity® Sustainable Target Date 2015 Fund Class K6 |
| Trading Symbol | FSWBX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2015 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.22 % |
| Expenses Paid, Amount | $ 11 |
| Expense Ratio, Percent | 0.22% |
| Net Assets | $ 1,141,685 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 60.7 International Equity Funds 20.4 Domestic Equity Funds 17.9 Short-Term Funds 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 37.7 Fidelity Series Sustainable U.S. Market Fund 17.9 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 12.9 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 10.9 Fidelity Series Sustainable Emerging Markets Fund 7.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 5.5 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.6 Fidelity Series Treasury Bill Index Fund 1.0 100.0 |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2055 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2055 Fund Class A |
| Trading Symbol | FSZJX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2055 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.74 % |
| Expenses Paid, Amount | $ 39 |
| Expense Ratio, Percent | 0.74% |
| Net Assets | $ 5,261,234 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 8 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2025 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2025 Fund |
| Class Name | Fidelity® Sustainable Target Date 2025 Fund |
| Trading Symbol | FSWOX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2025 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2025 Fund $ 0.45 % |
| Expenses Paid, Amount | $ 23 |
| Expense Ratio, Percent | 0.45% |
| Net Assets | $ 2,211,356 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 44.4 Domestic Equity Funds 28.1 International Equity Funds 27.5 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 28.1 Fidelity Series Sustainable Investment Grade Bond Fund 25.0 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 18.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 10.6 Fidelity Series Sustainable Emerging Markets Fund 9.3 Fidelity Series Long-Term Treasury Bond Index Fund 4.9 Fidelity Series International Developed Markets Bond Index Fund 3.9 100.0 |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2065 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2065 Fund Class M |
| Trading Symbol | FTGZX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2065 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.99 % |
| Expenses Paid, Amount | $ 52 |
| Expense Ratio, Percent | 0.99% |
| Net Assets | $ 3,007,785 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 9% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 9 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2020 Fund |
| Class Name | Fidelity® Sustainable Target Date 2020 Fund Class K6 |
| Trading Symbol | FSWNX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2020 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.23 % |
| Expenses Paid, Amount | $ 12 |
| Expense Ratio, Percent | 0.23% |
| Net Assets | $ 1,914,543 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 52.3 International Equity Funds 24.2 Domestic Equity Funds 23.3 Short-Term Funds 0.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 32.3 Fidelity Series Sustainable U.S. Market Fund 23.3 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 15.6 Fidelity Series Sustainable Emerging Markets Fund 8.6 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 8.0 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 4.3 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 3.7 Fidelity Series Treasury Bill Index Fund 0.2 100.0 |
| Fidelity Sustainable Target Date 2070 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2070 Fund |
| Class Name | Fidelity® Sustainable Target Date 2070 Fund Class K6 |
| Trading Symbol | FRCVX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2070 Fund for the period June 28, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 A $ 0.29 % A Expenses for the full reporting period would be higher. |
| Expenses Paid, Amount | $ 8 |
| Expense Ratio, Percent | 0.29% |
| Expenses Short Period Footnote [Text Block] | Expenses for the full reporting period would be higher. |
| Net Assets | $ 571,788 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 1% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover A 1 % A Amount not annualized |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date Income Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date Income Fund |
| Class Name | Fidelity® Sustainable Target Date Income Fund Class K |
| Trading Symbol | FSUOX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date Income Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.31 % |
| Expenses Paid, Amount | $ 16 |
| Expense Ratio, Percent | 0.31% |
| Net Assets | $ 1,165,797 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 72.1 International Equity Funds 14.0 Domestic Equity Funds 8.1 Short-Term Funds 5.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 44.1 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 21.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 8.4 Fidelity Series Sustainable U.S. Market Fund 8.1 Fidelity Series Treasury Bill Index Fund 5.8 Fidelity Series Sustainable Emerging Markets Fund 5.6 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 0.7 100.0 |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2060 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2060 Fund Class M |
| Trading Symbol | FSZWX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2060 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.99 % |
| Expenses Paid, Amount | $ 52 |
| Expense Ratio, Percent | 0.99% |
| Net Assets | $ 4,581,235 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2035 Fund |
| Class Name | Fidelity® Sustainable Target Date 2035 Fund Class K6 |
| Trading Symbol | FSXUX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2035 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.27 % |
| Expenses Paid, Amount | $ 14 |
| Expense Ratio, Percent | 0.27% |
| Net Assets | $ 4,481,900 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 22% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 22 % |
| Holdings [Text Block] | Domestic Equity Funds 38.1 International Equity Funds 34.2 Bond Funds 27.7 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 38.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 22.9 Fidelity Series Sustainable Investment Grade Bond Fund 16.4 Fidelity Series Sustainable Emerging Markets Fund 11.3 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series International Developed Markets Bond Index Fund 3.3 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.3 100.0 |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2045 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2045 Fund Class C |
| Trading Symbol | FSYOX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2045 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.49 % |
| Expenses Paid, Amount | $ 78 |
| Expense Ratio, Percent | 1.49% |
| Net Assets | $ 5,918,268 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 15% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 15 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2040 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2040 Fund |
| Class Name | Fidelity® Sustainable Target Date 2040 Fund |
| Trading Symbol | FSXVX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2040 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2040 Fund $ 0.48 % |
| Expenses Paid, Amount | $ 25 |
| Expense Ratio, Percent | 0.48% |
| Net Assets | $ 5,907,996 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 17% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 17 % |
| Holdings [Text Block] | Domestic Equity Funds 46.8 International Equity Funds 40.0 Bond Funds 13.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 46.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 27.0 Fidelity Series Sustainable Emerging Markets Fund 13.0 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series Sustainable Investment Grade Bond Fund 5.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.2 Fidelity Series International Developed Markets Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2020 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2020 Fund Class Z |
| Trading Symbol | FSWKX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2020 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.33 % |
| Expenses Paid, Amount | $ 17 |
| Expense Ratio, Percent | 0.33% |
| Net Assets | $ 1,914,543 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 52.3 International Equity Funds 24.2 Domestic Equity Funds 23.3 Short-Term Funds 0.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 32.3 Fidelity Series Sustainable U.S. Market Fund 23.3 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 15.6 Fidelity Series Sustainable Emerging Markets Fund 8.6 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 8.0 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 4.3 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 3.7 Fidelity Series Treasury Bill Index Fund 0.2 100.0 |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2050 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2050 Fund Class A |
| Trading Symbol | FSYYX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2050 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.74 % |
| Expenses Paid, Amount | $ 39 |
| Expense Ratio, Percent | 0.74% |
| Net Assets | $ 5,660,101 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2030 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2030 Fund Class Z |
| Trading Symbol | FSXFX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2030 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.36 % |
| Expenses Paid, Amount | $ 19 |
| Expense Ratio, Percent | 0.36% |
| Net Assets | $ 4,820,166 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 8 % |
| Holdings [Text Block] | Bond Funds 37.8 Domestic Equity Funds 32.0 International Equity Funds 30.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 32.0 Fidelity Series Sustainable Investment Grade Bond Fund 22.2 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 20.0 Fidelity Series Sustainable Emerging Markets Fund 10.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 6.5 Fidelity Series Long-Term Treasury Bond Index Fund 5.3 Fidelity Series International Developed Markets Bond Index Fund 3.8 100.0 |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2035 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2035 Fund Class C |
| Trading Symbol | FSXNX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2035 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.47 % |
| Expenses Paid, Amount | $ 76 |
| Expense Ratio, Percent | 1.47% |
| Net Assets | $ 4,481,900 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 22% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 22 % |
| Holdings [Text Block] | Domestic Equity Funds 38.1 International Equity Funds 34.2 Bond Funds 27.7 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 38.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 22.9 Fidelity Series Sustainable Investment Grade Bond Fund 16.4 Fidelity Series Sustainable Emerging Markets Fund 11.3 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series International Developed Markets Bond Index Fund 3.3 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.3 100.0 |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2030 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2030 Fund Class M |
| Trading Symbol | FSXDX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2030 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.96 % |
| Expenses Paid, Amount | $ 50 |
| Expense Ratio, Percent | 0.96% |
| Net Assets | $ 4,820,166 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 8% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 8 % |
| Holdings [Text Block] | Bond Funds 37.8 Domestic Equity Funds 32.0 International Equity Funds 30.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 32.0 Fidelity Series Sustainable Investment Grade Bond Fund 22.2 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 20.0 Fidelity Series Sustainable Emerging Markets Fund 10.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 6.5 Fidelity Series Long-Term Treasury Bond Index Fund 5.3 Fidelity Series International Developed Markets Bond Index Fund 3.8 100.0 |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2050 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2050 Fund Class C |
| Trading Symbol | FSYZX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2050 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.49 % |
| Expenses Paid, Amount | $ 78 |
| Expense Ratio, Percent | 1.49% |
| Net Assets | $ 5,660,101 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2045 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2045 Fund |
| Class Name | Fidelity® Sustainable Target Date 2045 Fund Class K |
| Trading Symbol | FSYUX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2045 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.39 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.39% |
| Net Assets | $ 5,918,268 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 15% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 15 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2025 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2025 Fund Class I |
| Trading Symbol | FSWUX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2025 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.45 % |
| Expenses Paid, Amount | $ 24 |
| Expense Ratio, Percent | 0.45% |
| Net Assets | $ 2,211,356 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 44.4 Domestic Equity Funds 28.1 International Equity Funds 27.5 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 28.1 Fidelity Series Sustainable Investment Grade Bond Fund 25.0 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 18.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 10.6 Fidelity Series Sustainable Emerging Markets Fund 9.3 Fidelity Series Long-Term Treasury Bond Index Fund 4.9 Fidelity Series International Developed Markets Bond Index Fund 3.9 100.0 |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2045 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2045 Fund Class I |
| Trading Symbol | FSYQX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2045 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.49 % |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.49% |
| Net Assets | $ 5,918,268 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 15% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 15 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2010 Fund | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2010 Fund |
| Class Name | Fidelity® Sustainable Target Date 2010 Fund |
| Trading Symbol | FSUYX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2010 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Fidelity® Sustainable Target Date 2010 Fund $ 0.41 % |
| Expenses Paid, Amount | $ 21 |
| Expense Ratio, Percent | 0.41% |
| Net Assets | $ 1,137,784 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 67.1 International Equity Funds 16.7 Domestic Equity Funds 12.4 Short-Term Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 41.3 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 16.6 Fidelity Series Sustainable U.S. Market Fund 12.4 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 10.3 Fidelity Series Sustainable Emerging Markets Fund 6.4 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Treasury Bill Index Fund 3.8 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.8 Fidelity Series Long-Term Treasury Bond Index Fund 2.4 100.0 |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2025 Fund |
| Class Name | Fidelity® Sustainable Target Date 2025 Fund Class K6 |
| Trading Symbol | FSWZX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2025 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K6 $ 0.25 % |
| Expenses Paid, Amount | $ 13 |
| Expense Ratio, Percent | 0.25% |
| Net Assets | $ 2,211,356 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 44.4 Domestic Equity Funds 28.1 International Equity Funds 27.5 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 28.1 Fidelity Series Sustainable Investment Grade Bond Fund 25.0 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 18.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 10.6 Fidelity Series Sustainable Emerging Markets Fund 9.3 Fidelity Series Long-Term Treasury Bond Index Fund 4.9 Fidelity Series International Developed Markets Bond Index Fund 3.9 100.0 |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2010 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2010 Fund Class M |
| Trading Symbol | FSVEX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2010 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.91 % |
| Expenses Paid, Amount | $ 47 |
| Expense Ratio, Percent | 0.91% |
| Net Assets | $ 1,137,784 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 11% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 11 % |
| Holdings [Text Block] | Bond Funds 67.1 International Equity Funds 16.7 Domestic Equity Funds 12.4 Short-Term Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 41.3 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 16.6 Fidelity Series Sustainable U.S. Market Fund 12.4 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 10.3 Fidelity Series Sustainable Emerging Markets Fund 6.4 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Treasury Bill Index Fund 3.8 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.8 Fidelity Series Long-Term Treasury Bond Index Fund 2.4 100.0 |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2035 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2035 Fund Class A |
| Trading Symbol | FSXLX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2035 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.72 % |
| Expenses Paid, Amount | $ 37 |
| Expense Ratio, Percent | 0.72% |
| Net Assets | $ 4,481,900 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 22% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 22 % |
| Holdings [Text Block] | Domestic Equity Funds 38.1 International Equity Funds 34.2 Bond Funds 27.7 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 38.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 22.9 Fidelity Series Sustainable Investment Grade Bond Fund 16.4 Fidelity Series Sustainable Emerging Markets Fund 11.3 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series International Developed Markets Bond Index Fund 3.3 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.3 100.0 |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2065 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2065 Fund Class Z |
| Trading Symbol | FTHDX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2065 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class Z $ 0.39 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.39% |
| Net Assets | $ 3,007,785 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 9% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 9 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2050 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2050 Fund Class I |
| Trading Symbol | FSZBX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2050 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.49 % |
| Expenses Paid, Amount | $ 26 |
| Expense Ratio, Percent | 0.49% |
| Net Assets | $ 5,660,101 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover 13 % |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2040 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2040 Fund Class I |
| Trading Symbol | FSYBX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2040 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I $ 0.48 % |
| Expenses Paid, Amount | $ 25 |
| Expense Ratio, Percent | 0.48% |
| Net Assets | $ 5,907,996 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 17% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 17 % |
| Holdings [Text Block] | Domestic Equity Funds 46.8 International Equity Funds 40.0 Bond Funds 13.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 46.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 27.0 Fidelity Series Sustainable Emerging Markets Fund 13.0 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series Sustainable Investment Grade Bond Fund 5.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.2 Fidelity Series International Developed Markets Bond Index Fund 1.1 100.0 |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2035 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2035 Fund Class M |
| Trading Symbol | FSXOX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2035 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class M $ 0.97 % |
| Expenses Paid, Amount | $ 50 |
| Expense Ratio, Percent | 0.97% |
| Net Assets | $ 4,481,900 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 22% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 22 % |
| Holdings [Text Block] | Domestic Equity Funds 38.1 International Equity Funds 34.2 Bond Funds 27.7 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 38.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 22.9 Fidelity Series Sustainable Investment Grade Bond Fund 16.4 Fidelity Series Sustainable Emerging Markets Fund 11.3 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series International Developed Markets Bond Index Fund 3.3 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.3 100.0 |
| Fidelity Sustainable Target Date 2035 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2035 Fund |
| Class Name | Fidelity® Sustainable Target Date 2035 Fund Class K |
| Trading Symbol | FSXTX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2035 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.37 % |
| Expenses Paid, Amount | $ 19 |
| Expense Ratio, Percent | 0.37% |
| Net Assets | $ 4,481,900 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 22% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 22 % |
| Holdings [Text Block] | Domestic Equity Funds 38.1 International Equity Funds 34.2 Bond Funds 27.7 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 38.1 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 22.9 Fidelity Series Sustainable Investment Grade Bond Fund 16.4 Fidelity Series Sustainable Emerging Markets Fund 11.3 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series International Developed Markets Bond Index Fund 3.3 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 2.3 100.0 |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2025 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2025 Fund Class C |
| Trading Symbol | FSWRX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2025 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class C $ 1.45 % |
| Expenses Paid, Amount | $ 75 |
| Expense Ratio, Percent | 1.45% |
| Net Assets | $ 2,211,356 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 44.4 Domestic Equity Funds 28.1 International Equity Funds 27.5 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 28.1 Fidelity Series Sustainable Investment Grade Bond Fund 25.0 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 18.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 10.6 Fidelity Series Sustainable Emerging Markets Fund 9.3 Fidelity Series Long-Term Treasury Bond Index Fund 4.9 Fidelity Series International Developed Markets Bond Index Fund 3.9 100.0 |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2015 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2015 Fund Class A |
| Trading Symbol | FSVOX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2015 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class A $ 0.67 % |
| Expenses Paid, Amount | $ 35 |
| Expense Ratio, Percent | 0.67% |
| Net Assets | $ 1,141,685 |
| Holdings Count | shares | 9 |
| Investment Company Portfolio Turnover | 13% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 9 Portfolio Turnover 13 % |
| Holdings [Text Block] | Bond Funds 60.7 International Equity Funds 20.4 Domestic Equity Funds 17.9 Short-Term Funds 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable Investment Grade Bond Fund 37.7 Fidelity Series Sustainable U.S. Market Fund 17.9 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 12.9 Fidelity Series 0-5 Year Inflation-Protected Bond Index Fund 10.9 Fidelity Series Sustainable Emerging Markets Fund 7.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 5.5 Fidelity Series International Developed Markets Bond Index Fund 4.0 Fidelity Series Long-Term Treasury Bond Index Fund 2.6 Fidelity Series Treasury Bill Index Fund 1.0 100.0 |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class I | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2070 Fund |
| Class Name | Fidelity Advisor® Sustainable Target Date 2070 Fund Class I |
| Trading Symbol | FRDDX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2070 Fund for the period June 28, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class I A $ 0.49 % A Expenses for the full reporting period would be higher. |
| Expenses Paid, Amount | $ 13 |
| Expense Ratio, Percent | 0.49% |
| Expenses Short Period Footnote [Text Block] | Expenses for the full reporting period would be higher. |
| Net Assets | $ 571,788 |
| Holdings Count | shares | 5 |
| Investment Company Portfolio Turnover | 1% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 5 Portfolio Turnover A 1 % A Amount not annualized |
| Holdings [Text Block] | Domestic Equity Funds 50.8 International Equity Funds 42.6 Bond Funds 6.6 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 50.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 28.8 Fidelity Series Sustainable Emerging Markets Fund 13.8 Fidelity Series Long-Term Treasury Bond Index Fund 5.5 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.1 100.0 |
| Fidelity Sustainable Target Date 2040 Fund - Class K | |
| Shareholder Report [Line Items] | |
| Fund Name | Fidelity® Sustainable Target Date 2040 Fund |
| Class Name | Fidelity® Sustainable Target Date 2040 Fund Class K |
| Trading Symbol | FSYFX |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains information about Fidelity® Sustainable Target Date 2040 Fund for the period April 1, 2024 to September 30, 2024. |
| Shareholder Report Annual or Semi-Annual | semi-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. |
| 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 six months? (based on hypothetical $10,000 investment) Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment Class K $ 0.38 % |
| Expenses Paid, Amount | $ 20 |
| Expense Ratio, Percent | 0.38% |
| Net Assets | $ 5,907,996 |
| Holdings Count | shares | 7 |
| Investment Company Portfolio Turnover | 17% |
| Additional Fund Statistics [Text Block] | Key Fund Statistics (as of September 30, 2024) KEY FACTS Fund Size $ Number of Holdings 7 Portfolio Turnover 17 % |
| Holdings [Text Block] | Domestic Equity Funds 46.8 International Equity Funds 40.0 Bond Funds 13.2 Short-Term Investments and Net Other Assets (Liabilities) 0.0 ASSET ALLOCATION (% of Fund's net assets) |
| Largest Holdings [Text Block] | TOP HOLDINGS (% of Fund's net assets) Fidelity Series Sustainable U.S. Market Fund 46.8 Fidelity Series Sustainable Non-U.S. Developed Markets Fund 27.0 Fidelity Series Sustainable Emerging Markets Fund 13.0 Fidelity Series Long-Term Treasury Bond Index Fund 5.7 Fidelity Series Sustainable Investment Grade Bond Fund 5.2 Fidelity Series 5+ Year Inflation-Protected Bond Index Fund 1.2 Fidelity Series International Developed Markets Bond Index Fund 1.1 100.0 |
| Shareholder Report, Holdings (Details) | Sep. 30, 2024 |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2070 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2070 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2070 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2070 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2070 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2070 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2070 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2070 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2070 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.70% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.50% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.40% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 60.70% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class M | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2055 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2055 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2055 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2055 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2055 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2055 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2055 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2055 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2055 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.50% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.40% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32.30% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.60% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.60% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.20% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 52.30% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2020 Fund - Class K | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.60% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 72.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class M | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.60% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.60% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.20% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 52.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class M | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Sustainable Target Date 2070 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2070 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2070 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2070 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2070 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2070 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2070 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2070 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2070 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2015 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.70% |
| Fidelity Sustainable Target Date 2015 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Sustainable Target Date 2015 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| Fidelity Sustainable Target Date 2015 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.90% |
| Fidelity Sustainable Target Date 2015 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.50% |
| Fidelity Sustainable Target Date 2015 Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2015 Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date 2015 Fund | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| Fidelity Sustainable Target Date 2015 Fund | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Sustainable Target Date 2015 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Sustainable Target Date 2015 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.40% |
| Fidelity Sustainable Target Date 2015 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 60.70% |
| Fidelity Sustainable Target Date 2015 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2015 Fund | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.70% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.50% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.40% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 60.70% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class I | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.70% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.50% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.40% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 60.70% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Sustainable Target Date 2050 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2050 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2050 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2050 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2050 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2050 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2050 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2050 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2050 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.70% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.90% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.50% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.40% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 60.70% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2015 Fund - Class K | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.70% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.50% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.40% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 60.70% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class C | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 40% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2055 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2055 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2055 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2055 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2055 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2055 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2055 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2055 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2055 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2065 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2065 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2065 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2065 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2065 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2065 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2065 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2065 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2065 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 40% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 41.30% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.60% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.30% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.70% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 67.10% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2010 Fund - Class K6 | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.20% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 40% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.20% |
| Fidelity Sustainable Target Date 2040 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.50% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.40% |
| Fidelity Sustainable Target Date 2025 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 41.30% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.60% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.30% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.70% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 67.10% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class A | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.60% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.60% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.20% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 52.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class I | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.60% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 72.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class I | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.90% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.20% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.70% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2055 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2055 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2055 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2055 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2055 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2055 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2055 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2055 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2055 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.60% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 72.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class A | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date Income Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.10% |
| Fidelity Sustainable Target Date Income Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.10% |
| Fidelity Sustainable Target Date Income Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Sustainable Target Date Income Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Sustainable Target Date Income Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Sustainable Target Date Income Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.60% |
| Fidelity Sustainable Target Date Income Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date Income Fund | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Fidelity Sustainable Target Date Income Fund | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Sustainable Target Date Income Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Sustainable Target Date Income Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14% |
| Fidelity Sustainable Target Date Income Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 72.10% |
| Fidelity Sustainable Target Date Income Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date Income Fund | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 41.30% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.60% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.30% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.70% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 67.10% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class C | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Sustainable Target Date 2020 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32.30% |
| Fidelity Sustainable Target Date 2020 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Sustainable Target Date 2020 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.60% |
| Fidelity Sustainable Target Date 2020 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.60% |
| Fidelity Sustainable Target Date 2020 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8% |
| Fidelity Sustainable Target Date 2020 Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| Fidelity Sustainable Target Date 2020 Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date 2020 Fund | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| Fidelity Sustainable Target Date 2020 Fund | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Sustainable Target Date 2020 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Sustainable Target Date 2020 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.20% |
| Fidelity Sustainable Target Date 2020 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 52.30% |
| Fidelity Sustainable Target Date 2020 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2020 Fund | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.10% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.10% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.60% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 72.10% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date Income Fund - Class K6 | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Sustainable Target Date 2060 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2060 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2060 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2060 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2060 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2060 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2060 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2060 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2060 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2050 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2050 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2050 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2050 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2050 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2050 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2050 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2050 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2050 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2050 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2050 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2050 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2050 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2050 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2050 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2050 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2050 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2050 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.60% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.60% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.20% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 52.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class A | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Sustainable Target Date 2045 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2045 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2045 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2045 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2045 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2045 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2045 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2045 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2045 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.50% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.40% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.50% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.40% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 41.30% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.60% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.30% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.70% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 67.10% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class I | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 41.30% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.60% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.30% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.70% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 67.10% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2010 Fund - Class K | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 40% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2030 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Sustainable Target Date 2030 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.20% |
| Fidelity Sustainable Target Date 2030 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20% |
| Fidelity Sustainable Target Date 2030 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| Fidelity Sustainable Target Date 2030 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| Fidelity Sustainable Target Date 2030 Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| Fidelity Sustainable Target Date 2030 Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Sustainable Target Date 2030 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Sustainable Target Date 2030 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.20% |
| Fidelity Sustainable Target Date 2030 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.80% |
| Fidelity Sustainable Target Date 2030 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.60% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.60% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.20% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 52.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class C | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Sustainable Target Date 2065 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2065 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2065 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2065 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2065 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2065 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2065 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2065 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2065 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.20% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.20% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.80% |
| Fidelity Sustainable Target Date 2030 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.60% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 72.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class C | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.60% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 72.10% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date Income Fund - Class Z | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 41.30% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.60% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.30% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.70% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 67.10% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 40% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2060 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2060 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2060 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2060 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2060 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2060 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2060 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2060 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2060 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2060 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2060 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2060 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2060 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2060 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2060 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2060 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2060 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2060 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.90% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.20% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.70% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2035 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Sustainable Target Date 2035 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.90% |
| Fidelity Sustainable Target Date 2035 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| Fidelity Sustainable Target Date 2035 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.30% |
| Fidelity Sustainable Target Date 2035 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Sustainable Target Date 2035 Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity Sustainable Target Date 2035 Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Fidelity Sustainable Target Date 2035 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Sustainable Target Date 2035 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.20% |
| Fidelity Sustainable Target Date 2035 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.70% |
| Fidelity Sustainable Target Date 2035 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2045 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2045 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2045 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2045 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2045 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2045 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2045 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2045 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2045 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.20% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.20% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.80% |
| Fidelity Sustainable Target Date 2030 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2065 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2065 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2065 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2065 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2065 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2065 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2065 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2065 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2065 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.70% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.90% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.50% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.40% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 60.70% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2015 Fund - Class K6 | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2055 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2025 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Sustainable Target Date 2025 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25% |
| Fidelity Sustainable Target Date 2025 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| Fidelity Sustainable Target Date 2025 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| Fidelity Sustainable Target Date 2025 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| Fidelity Sustainable Target Date 2025 Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Fidelity Sustainable Target Date 2025 Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| Fidelity Sustainable Target Date 2025 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Sustainable Target Date 2025 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.50% |
| Fidelity Sustainable Target Date 2025 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.40% |
| Fidelity Sustainable Target Date 2025 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32.30% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.60% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.60% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.20% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 52.30% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2020 Fund - Class K6 | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Sustainable Target Date 2070 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2070 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2070 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2070 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2070 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2070 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2070 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2070 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2070 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date Income Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.10% |
| Fidelity Sustainable Target Date Income Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 21.10% |
| Fidelity Sustainable Target Date Income Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.40% |
| Fidelity Sustainable Target Date Income Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Sustainable Target Date Income Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Sustainable Target Date Income Fund - Class K | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.60% |
| Fidelity Sustainable Target Date Income Fund - Class K | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date Income Fund - Class K | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.20% |
| Fidelity Sustainable Target Date Income Fund - Class K | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| Fidelity Sustainable Target Date Income Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.10% |
| Fidelity Sustainable Target Date Income Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 14% |
| Fidelity Sustainable Target Date Income Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 72.10% |
| Fidelity Sustainable Target Date Income Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date Income Fund - Class K | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2060 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.90% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.30% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.20% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.70% |
| Fidelity Sustainable Target Date 2035 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2040 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Sustainable Target Date 2040 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27% |
| Fidelity Sustainable Target Date 2040 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| Fidelity Sustainable Target Date 2040 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Sustainable Target Date 2040 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.20% |
| Fidelity Sustainable Target Date 2040 Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Sustainable Target Date 2040 Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2040 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Sustainable Target Date 2040 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 40% |
| Fidelity Sustainable Target Date 2040 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.20% |
| Fidelity Sustainable Target Date 2040 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 15.60% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8.60% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 8% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.70% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 23.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 24.20% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 52.30% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.20% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.90% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.20% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.70% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.50% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.30% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 32% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.20% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.80% |
| Fidelity Advisor Sustainable Target Date 2030 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2045 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2045 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Sustainable Target Date 2045 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Sustainable Target Date 2045 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Sustainable Target Date 2045 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2045 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Sustainable Target Date 2045 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Sustainable Target Date 2045 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Sustainable Target Date 2045 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.50% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.40% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2045 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2010 Fund | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 41.30% |
| Fidelity Sustainable Target Date 2010 Fund | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.60% |
| Fidelity Sustainable Target Date 2010 Fund | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Sustainable Target Date 2010 Fund | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.30% |
| Fidelity Sustainable Target Date 2010 Fund | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| Fidelity Sustainable Target Date 2010 Fund | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Sustainable Target Date 2010 Fund | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Sustainable Target Date 2010 Fund | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| Fidelity Sustainable Target Date 2010 Fund | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Sustainable Target Date 2010 Fund | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Sustainable Target Date 2010 Fund | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.70% |
| Fidelity Sustainable Target Date 2010 Fund | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 67.10% |
| Fidelity Sustainable Target Date 2010 Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2010 Fund | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.50% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.40% |
| Fidelity Sustainable Target Date 2025 Fund - Class K6 | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 41.30% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.60% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.30% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.80% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.40% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.70% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 67.10% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2010 Fund - Class M | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.80% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.90% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.20% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.70% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2050 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 40% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.20% |
| Fidelity Advisor Sustainable Target Date 2040 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.90% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.20% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.70% |
| Fidelity Advisor Sustainable Target Date 2035 Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 22.90% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 16.40% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 11.30% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.30% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.30% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 38.10% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 34.20% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.70% |
| Fidelity Sustainable Target Date 2035 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 25% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 18.20% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.60% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.30% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4.90% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.90% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.10% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27.50% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 44.40% |
| Fidelity Advisor Sustainable Target Date 2025 Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 37.70% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 12.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 10.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 7.50% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 4% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | TH7Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | TH8Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.90% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 20.40% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 60.70% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Advisor Sustainable Target Date 2015 Fund - Class A | AAShortTermFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class I | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class I | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class I | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class I | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.50% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class I | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class I | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 50.80% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class I | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 42.60% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class I | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6.60% |
| Fidelity Advisor Sustainable Target Date 2070 Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | TH0Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | TH1Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 27% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | TH2Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | TH3Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.70% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | TH4Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 5.20% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | TH5Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.20% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | TH6Member | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 1.10% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | AADomesticEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 46.80% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | AAInternationalEquityFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 40% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | AABondFundsMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 13.20% |
| Fidelity Sustainable Target Date 2040 Fund - Class K | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0% |
