| Label                                         | **Element**              | Value                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------|--------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Risk/Return:**                              | rr_RiskReturnAbstract    |                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| Registrant Name                               | dei_EntityRegistrantName | FIDELITY INVESTMENT TRUST                                                                                                                                                                                                                                                                                                                                                                                                                             |
| Prospectus Date                               | rr_ProspectusDate        | Dec. 30,				 2013                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| Retail | Fidelity Total Emerging Markets Fund |                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| **Risk/Return:**                              | rr_RiskReturnAbstract    |                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| Supplement [Text Block]                       | fit_SupplementTextBlock  | **Supplement to theFidelity® Emerging Markets Discovery Fund and Fidelity Total Emerging Markets FundDecember 30, 2013Prospectus**
The following information supplements similar information for Fidelity Emerging Markets Discovery Fund 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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| - Definition
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