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| **Risk/Return:**                                 | rr_RiskReturnAbstract    |                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Registrant Name                                  | dei_EntityRegistrantName | FIDELITY INVESTMENT TRUST                                                                                                                                                                                                                                                                                                                                                                                                    |
| Prospectus Date                                  | rr_ProspectusDate        | Dec. 30,				 2013                                                                                                                                                                                                                                                                                                                                                                                                            |
| A T C | Fidelity Emerging Markets Discovery Fund |                          |                                                                                                                                                                                                                                                                                                                                                                                                                         |
| **Risk/Return:**                                 | rr_RiskReturnAbstract    |                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Supplement [Text Block]                          | fit_SupplementTextBlock  | **Supplement to theFidelity Advisor® Emerging Markets Discovery FundClass A, Class T, and Class CDecember 30, 2013Prospectus**
The following information supplements similar information for found in the "Fund Summary" section under the heading "Principal Investment Strategies" on page 4.
-  Allocating the fund's assets across emerging markets sectors, using different Fidelity managers. |

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