| Label                                       | **Element**              | Value                                                                                                                                                                                                                                                                                                                                        |
|---------------------------------------------|--------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Risk/Return:**                            | rr_RiskReturnAbstract    |                                                                                                                                                                                                                                                                                                                                         |
| Registrant Name                             | dei_EntityRegistrantName | FIDELITY INVESTMENT TRUST                                                                                                                                                                                                                                                                                                                    |
| Prospectus Date                             | rr_ProspectusDate        | Dec. 29,				 2012                                                                                                                                                                                                                                                                                                                            |
| Inst | Fidelity Total Emerging Markets Fund |                          |                                                                                                                                                                                                                                                                                                                                         |
| **Risk/Return:**                            | rr_RiskReturnAbstract    |                                                                                                                                                                                                                                                                                                                                         |
| Supplement [Text Block]                     | fit_SupplementTextBlock  | **Supplement to the Fidelity Advisor® Total Emerging Markets Fund Institutional Class December 29, 2012 Prospectus**The following information replaces similar information found in the "Fund Summary" section under the heading "Fee Table" beginning on page 3. 1 year$	1433 years$	4865 years$	85710 years$	1,900 |

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