| **Average Annual Total Returns - FidelityInternationalDiscoveryFund-AMCIZPRO - FidelityInternationalDiscoveryFund-AMCIZPRO - Fidelity International Discovery Fund** | Dec. 30, 2024 |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|
| Fidelity Advisor International Discovery Fund - Class A | Return Before Taxes                                                                                        |          |
| **Average Annual Return:**                                                                                                                                           |          |
| Past 1 year                                                                                                                                                          | 7.24%         |
| Past 5 years                                                                                                                                                         | 6.48%         |
| Past 10 years                                                                                                                                                        | 3.19%         |
| Fidelity Advisor International Discovery Fund - Class A | After Taxes on Distributions                                                                               |          |
| **Average Annual Return:**                                                                                                                                           |          |
| Past 1 year                                                                                                                                                          | 6.97%         |
| Past 5 years                                                                                                                                                         | 5.65%         |
| Past 10 years                                                                                                                                                        | 2.59%         |
| Fidelity Advisor International Discovery Fund - Class A | After Taxes on Distributions and Sales                                                                     |          |
| **Average Annual Return:**                                                                                                                                           |          |
| Past 1 year                                                                                                                                                          | 4.70%         |
| Past 5 years                                                                                                                                                         | 5.17%         |
| Past 10 years                                                                                                                                                        | 2.55%         |
| Fidelity Advisor International Discovery Fund - Class C | Return Before Taxes                                                                                        |          |
| **Average Annual Return:**                                                                                                                                           |          |
| Past 1 year                                                                                                                                                          | 11.92%        |
| Past 5 years                                                                                                                                                         | 6.91%         |
| Past 10 years                                                                                                                                                        | 3.16%         |
| Fidelity Advisor International Discovery Fund - Class M | Return Before Taxes                                                                                        |          |
| **Average Annual Return:**                                                                                                                                           |          |
| Past 1 year                                                                                                                                                          | 9.53%         |
| Past 5 years                                                                                                                                                         | 6.72%         |
| Past 10 years                                                                                                                                                        | 3.19%         |
| Fidelity Advisor International Discovery Fund - Class I | Return Before Taxes                                                                                        |          |
| **Average Annual Return:**                                                                                                                                           |          |
| Past 1 year                                                                                                                                                          | 14.15%        |
| Past 5 years                                                                                                                                                         | 8.09%         |
| Past 10 years                                                                                                                                                        | 4.15%         |
| Fidelity Advisor International Discovery Fund - Class Z | Return Before Taxes                                                                                        |          |
| **Average Annual Return:**                                                                                                                                           |          |
| Past 1 year                                                                                                                                                          | 14.27%        |
| Past 5 years                                                                                                                                                         | 8.22%         |
| Past 10 years                                                                                                                                                        | 4.28%         |
| MS001                                                                                                                                                                |          |
| **Average Annual Return:**                                                                                                                                           |          |
| Past 1 year                                                                                                                                                          | 18.49%        |
| Past 5 years                                                                                                                                                         | 8.39%         |
| Past 10 years                                                                                                                                                        | 4.48%         |

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