| **Expense Example - FidelitySeriesSustainableEmergingMarketsSeriesSustainableNon-USDevelopedMarketsFunds-ComboPRO - FidelitySeriesSustainableEmergingMarketsSeriesSustainableNon-USDevelopedMarketsFunds-ComboPRO - Fidelity Series Sustainable Emerging Markets Fund - Fidelity Series Sustainable Emerging Markets Fund** | Dec. 30, 2024 USD ($) |
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| **Expense Example:**                                                                                                                                                                                                                                                                                                        |                  |
| 1 year                                                                                                                                                                                                                                                                                                                      | $ 1                   |
| 3 years                                                                                                                                                                                                                                                                                                                     | 3                     |
| 5 years                                                                                                                                                                                                                                                                                                                     | 69                    |
| 10 years                                                                                                                                                                                                                                                                                                                    | $ 297                 |

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| - References
No definition available.
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| - Definition
The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form N-1A -Section 3 -Subsection instructions -Paragraph 4
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
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| - Definition
The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form N-1A -Section 3 -Subsection example -Paragraph 1 -Subparagraph 2
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form N-1A -Section 3 -Subsection example -Paragraph 1 -Subparagraph 2
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form N-1A -Section 3 -Subsection example -Paragraph 1 -Subparagraph 2
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