XML 134 R107.htm IDEA: XBRL DOCUMENT
v3.25.1

INCOME TAX (Schedule of Tax Losses Expiry Dates) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023
Income Taxes [line items] |  |
Non capital losses | $ 174,195 | $ 138,736
Canada |  |
Income Taxes [line items] |  |
Non capital losses | $ 200,452 | $ 210,847
Canada | Bottom of range |  |
Income Taxes [line items] |  |
Year of Expiry | 2025 | 2024
Canada | Top of range |  |
Income Taxes [line items] |  |
Year of Expiry | 2044 | 2043
Mexico |  |
Income Taxes [line items] |  |
Non capital losses | $ 22,997 | $ 6,623
Mexico | Bottom of range |  |
Income Taxes [line items] |  |
Year of Expiry | 2025 | 2024
Mexico | Top of range |  |
Income Taxes [line items] |  |
Year of Expiry | 2034 | 2033

X
- Definition Expiry year of tax loss carryforwards. + References No definition available. + Details
Name: | fsm_ExpiryYearOfTaxLossCarryforwards
Namespace Prefix: | fsm_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

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 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 2024-01-01 -Paragraph 81 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2024-en-r&anchor=para_81_e&doctype=Standard -URIDate 2024-03-27 + 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_CA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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