XML 134 R97.htm IDEA: XBRL DOCUMENT
v3.23.1

SALES (Mitigating Price Risk) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021
Disclosure of major customers [line items] |  |
Realized loss | $ 700 | $ 1,500
Unrealized loss | $ 1,200 | $ 1,300

X
- Definition The difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings. + References No definition available. + Details
Name: | fsm_IfrsGainLossOnSaleOfDerivatives
Namespace Prefix: | fsm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfMajorCustomersLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The losses resulting from changes in the fair value of derivatives recognised in profit or loss. [Refer: Derivatives [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2022-03-24 -Paragraph 85 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2022-en-r&anchor=para_85&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_LossesOnChangeInFairValueOfDerivatives
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration