| **Average Annual Total Returns - FidelityInternationalSmallCapOpportunitiesFund-AMCIZPRO - FidelityInternationalSmallCapOpportunitiesFund-AMCIZPRO - Fidelity International Small Cap Opportunities Fund** | Dec. 30, 2023 |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|
| Fidelity Advisor International Small Cap Opportunities Fund - Class A | Return Before Taxes                                                                                                                |          |  |
| **Average Annual Return:**                                                                                                                                                                                 |          |  |
| Past 1 year                                                                                                                                                                                                | (33.24%)      |  |
| Past 5 years                                                                                                                                                                                               | 0.60%         |  |
| Past 10 years                                                                                                                                                                                              | 6.35%         |  |
| Fidelity Advisor International Small Cap Opportunities Fund - Class A | After Taxes on Distributions                                                                                                       |          |  |
| **Average Annual Return:**                                                                                                                                                                                 |          |  |
| Past 1 year                                                                                                                                                                                                | (34.19%)      |  |
| Past 5 years                                                                                                                                                                                               | (0.20%)       |  |
| Past 10 years                                                                                                                                                                                              | 5.85%         |  |
| Fidelity Advisor International Small Cap Opportunities Fund - Class A | After Taxes on Distributions and Sales                                                                                             |          |  |
| **Average Annual Return:**                                                                                                                                                                                 |          |  |
| Past 1 year                                                                                                                                                                                                | (18.97%)      |  |
| Past 5 years                                                                                                                                                                                               | 0.61%         |  |
| Past 10 years                                                                                                                                                                                              | 5.24%         |  |
| Fidelity Advisor International Small Cap Opportunities Fund - Class C | Return Before Taxes                                                                                                                |          |  |
| **Average Annual Return:**                                                                                                                                                                                 |          |  |
| Past 1 year                                                                                                                                                                                                | (30.38%)      |  |
| Past 5 years                                                                                                                                                                                               | 1.02%         |  |
| Past 10 years                                                                                                                                                                                              | 6.32%         |  |
| Fidelity Advisor International Small Cap Opportunities Fund - Class M | Return Before Taxes                                                                                                                |          |  |
| **Average Annual Return:**                                                                                                                                                                                 |          |  |
| Past 1 year                                                                                                                                                                                                | (31.83%)      |  |
| Past 5 years                                                                                                                                                                                               | 0.81%         |  |
| Past 10 years                                                                                                                                                                                              | 6.31%         |  |
| Fidelity Advisor International Small Cap Opportunities Fund - Class I | Return Before Taxes                                                                                                                |          |  |
| **Average Annual Return:**                                                                                                                                                                                 |          |  |
| Past 1 year                                                                                                                                                                                                | (28.93%)      |  |
| Past 5 years                                                                                                                                                                                               | 2.10%         |  |
| Past 10 years                                                                                                                                                                                              | 7.30%         |  |
| Fidelity Advisor International Small Cap Opportunities Fund - Class Z | Return Before Taxes                                                                                                                |          |  |
| **Average Annual Return:**                                                                                                                                                                                 |          |  |
| Past 1 year                                                                                                                                                                                                | (28.86%)      |  |
| Since Inception                                                                                                                                                                                            | 2.86%         | [1] |
| MS141                                                                                                                                                                                                      |          |  |
| **Average Annual Return:**                                                                                                                                                                                 |          |  |
| Past 1 year                                                                                                                                                                                                | (21.25%)      |  |
| Past 5 years                                                                                                                                                                                               | 0.11%         |  |
| Past 10 years                                                                                                                                                                                              | 6.35%         |  |
|                                                                                                                                                                                                            |
| [1]AFrom October 2, 2018.                                                                                                                                                                                  |

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