XML 142 R105.htm IDEA: XBRL DOCUMENT
v3.23.1

INCOME TAX (Schedule of Unrecognized Deductible Temporary Difference and Unused Tax Losses) (Details) - USD ($) | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Income Taxes [line items] |  |
Non capital losses | $ 164,427,000 | $ 136,072,000
Provision | 7,215,000 | 11,657,000
Share issue costs | 306,000 | 1,711,000
Mineral properties, plant and equipment | 184,970,000 | 12,705,000
Lease obligation | 578,000 | 863,000
Derivative liabilities | 335,000 |
Capital losses |  | 4,204,000
Investments in subsidiaries | 1,070,000 | 901,000
Unrecognized deductible temporary differences | 358,901,000 | 168,114,000
MEXICO |  |
Income Taxes [line items] |  |
Non capital losses | 20,000 | 378,000
Investments in subsidiaries | 150,379,000 | 204,283,000
PERU |  |
Income Taxes [line items] |  |
Investments in subsidiaries | 78,505,000 | 59,976,000
WEST AFRICA |  |
Income Taxes [line items] |  |
Investments in subsidiaries | $ 18,122,000 | $ 114,559,000

X
- Definition Income Taxes [line items]. + References No definition available. + Details
Name: | fsm_IncomeTaxesLineItems
Namespace Prefix: | fsm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Unrecognized tax benefits capital loss carryforwards.. + References No definition available. + Details
Name: | fsm_UnrecognizedTaxBenefitsCapitalLossCarryforwards
Namespace Prefix: | fsm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Unrecognized tax benefits related to derivatives. + References No definition available. + Details
Name: | fsm_UnrecognizedTaxBenefitsRelatedToDerivatives
Namespace Prefix: | fsm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Unrecognized tax benefits related to mineral property, plant and equipment. + References No definition available. + Details
Name: | fsm_UnrecognizedTaxBenefitsRelatedToMineralPropertyPlantAndEquipment
Namespace Prefix: | fsm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Unrecognized tax losses deductible temporary differences and tax credits. + References No definition available. + Details
Name: | fsm_UnrecognizedTaxLossesDeductibleTemporaryDifferencesAndTaxCredits
Namespace Prefix: | fsm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Unused tax credits related to lease obligations. + References No definition available. + Details
Name: | fsm_UnusedTaxCreditsRelatedToLeaseObligations
Namespace Prefix: | fsm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Unused tax losses related to provision and other. + References No definition available. + Details
Name: | fsm_UnusedTaxLossesRelatedToProvisionAndOther
Namespace Prefix: | fsm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The aggregate amount of temporary differences associated with investments in subsidiaries, branches and associates and interests in joint arrangements, for which deferred tax liabilities have not been recognised as a result of satisfying both of the following conditions: (a) the parent, investor, joint venturer or joint operator is able to control the timing of the reversal of the temporary difference; and (b) it is probable that the temporary difference will not reverse in the foreseeable future. [Refer: Associates [member]; Subsidiaries [member]; Temporary differences [member]; Investments in subsidiaries reported in separate financial statements] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2022-03-24 -Paragraph 81 -Subparagraph f -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2022-en-r&anchor=para_81_f&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_TemporaryDifferencesAssociatedWithInvestmentsInSubsidiariesBranchesAndAssociatesAndInterestsInJointVentures
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of unused tax credits for which no deferred tax asset is recognised in the statement of financial position. [Refer: Unused tax credits [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2022-03-24 -Paragraph 81 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2022-en-r&anchor=para_81_e&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_UnusedTaxCreditsForWhichNoDeferredTaxAssetRecognised
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of unused tax losses for which no deferred tax asset is recognised in the statement of financial position. [Refer: Unused tax losses [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2022-03-24 -Paragraph 81 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2022-en-r&anchor=para_81_e&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_UnusedTaxLossesForWhichNoDeferredTaxAssetRecognised
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_MX
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_PE
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=fsm_WestAfricaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |