|**Annual Operating Expenses - FidelityInternationalDiscoveryFund-AMCIZPRO - FidelityInternationalDiscoveryFund-AMCIZPRO - Fidelity International Discovery Fund**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      | Dec. 30, 2024                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|Fidelity Advisor International Discovery Fund - Class A                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|**Operating Expenses:**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Management fee                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0.61%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Distribution and/or Service (12b-1) fees                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 0.25%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Other expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0.01%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Total annual operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 0.87%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Fidelity Advisor International Discovery Fund - Class C                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|**Operating Expenses:**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Management fee                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0.61%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Distribution and/or Service (12b-1) fees                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 1.00%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Other expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0.01%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Total annual operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 1.62%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Fidelity Advisor International Discovery Fund - Class M                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|**Operating Expenses:**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Management fee                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0.61%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Distribution and/or Service (12b-1) fees                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | 0.50%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Other expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0.01%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Total annual operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 1.12%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Fidelity Advisor International Discovery Fund - Class I                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|**Operating Expenses:**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Management fee                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0.60%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Distribution and/or Service (12b-1) fees                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Other expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0.01%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Total annual operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 0.61%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Fidelity Advisor International Discovery Fund - Class Z                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|**Operating Expenses:**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Management fee                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0.48%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Distribution and/or Service (12b-1) fees                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | none                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Other expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | 0.02%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Total annual operating expenses                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | 0.50%                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
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|[1]A            The management fee            comprises      a basic fee            , which may vary by class, that is      adjusted up or down            (subject to      a maximum            rate)      based on the            performance            of the fund or a designated class of the fund relative to that of the MSCI EAFE Index. The basic fee covers administrative services previously provided under separate services agreements with the fund, for which 0.22%, 0.22%, 0.22%, 0.18%, and 0.06% for Class A, Class M, Class C, Class I, and Class Z, respectively, was previously charged under the services agreements      . Please see "Fund Services - Fund Management - Advisory Fee(s)" for additional information.[2]B                          Adjusted to reflect current fees. | [1]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|[1]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | A            The management fee            comprises      a basic fee            , which may vary by class, that is      adjusted up or down            (subject to      a maximum            rate)      based on the            performance            of the fund or a designated class of the fund relative to that of the MSCI EAFE Index. The basic fee covers administrative services previously provided under separate services agreements with the fund, for which 0.22%, 0.22%, 0.22%, 0.18%, and 0.06% for Class A, Class M, Class C, Class I, and Class Z, respectively, was previously charged under the services agreements      . Please see "Fund Services - Fund Management - Advisory Fee(s)" for additional information.
|[2]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    | B                          Adjusted to reflect current fees.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              

X- DefinitionDistribution [and/or Service] (12b-1) Fees" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.+ ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form N-1A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 9+ Details**Name:**rr_DistributionAndService12b1FeesOverAssets**Namespace Prefix:**rr_**Data Type:**rr:NonNegativePure4Type**Balance Type:**na**Period Type:**duration X- DefinitionTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund.  Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."+ ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form N-1A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph d+ Details**Name:**rr_ExpensesOverAssets**Namespace Prefix:**rr_**Data Type:**rr:NonNegativePure4Type**Balance Type:**na**Period Type:**duration X- DefinitionManagement Fees include investment advisory fees (including any fees based on the Fund's performance), any other management fees payable to the investment adviser or its affiliates, and administrative fees payable to the investment adviser or its affiliates that are not included as "Other Expenses."+ ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form N-1A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph a+ Details**Name:**rr_ManagementFeesOverAssets**Namespace Prefix:**rr_**Data Type:**rr:NonNegativePure4Type**Balance Type:**na**Period Type:**duration X- ReferencesNo definition available.+ Details**Name:**rr_OperatingExpensesAbstract**Namespace Prefix:**rr_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration X- Definition"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]).  "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.+ ReferencesReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form N-1A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph c -Clause i+ Details**Name:**rr_OtherExpensesOverAssets**Namespace Prefix:**rr_**Data Type:**rr:NonNegativePure4Type**Balance Type:**na**Period Type:**duration X- Details**Name:**dei_DocumentInformationDocumentAxis=fmr_FidelityInternationalDiscoveryFund-AMCIZPROMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** X- Details**Name:**dei_LegalEntityAxis=fmr_S000007093Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** X- Details**Name:**rr_ProspectusShareClassAxis=fmr_C000019408Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** X- Details**Name:**rr_ProspectusShareClassAxis=fmr_C000019410Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** X- Details**Name:**rr_ProspectusShareClassAxis=fmr_C000019411Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** X- Details**Name:**rr_ProspectusShareClassAxis=fmr_C000019412Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** X- Details**Name:**rr_ProspectusShareClassAxis=fmr_C000130141Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:**