XML 131 R91.htm IDEA: XBRL DOCUMENT
v3.25.1

Other (Loss) Gain (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023
Disclosure of other gains and losses [Line Items] |  |
Holding and Arbitration Costs | $ (6.5) | $ (2.9)
Loss on disposal of assets | 10.6 | 1.9
Write down of miscellaneous receivables | (4.7) | 0.0
Revision to reclamation for closed sites | (0.2) | (3.3)
Other | (2.7) | (1.4)
Other loss | (39.7) | (22.9)
Silver Stream |  |
Disclosure of other gains and losses [Line Items] |  |
Gain (loss) on fair value adjustment | (9.3) | 0.0
Milestone Payments |  |
Disclosure of other gains and losses [Line Items] |  |
Fair value adjustment on contingent consideration | $ (5.7) | $ (13.4)

X
- Definition Disclosure of other gains and losses [Line Items] + References No definition available. + Details
Name: | agi_DisclosureOfOtherGainsAndLossesLineItems
Namespace Prefix: | agi_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Gain (loss) on fair value adjustment + References No definition available. + Details
Name: | agi_GainLossOnFairValueAdjustment
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Holding and Arbitration Costs + References No definition available. + Details
Name: | agi_HoldingAndArbitrationCosts
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Other Gains (Losses), Other + References No definition available. + Details
Name: | agi_OtherGainsLossesOther
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition other nonoperating income (expense) + References No definition available. + Details
Name: | agi_OtherNonoperatingIncomeExpense1
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Unrealized Gain (Loss) on Derivatives1 + References No definition available. + Details
Name: | agi_UnrealizedGainLossonDerivatives1
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Adjustments for decrease (increase) in trade and other receivables to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Trade and other receivables; Profit (loss)] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 7 -IssueDate 2024-01-01 -Paragraph 20 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2024-en-r&anchor=para_20&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_AdjustmentsForDecreaseIncreaseInTradeAndOtherReceivables
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of expense relating to restructuring. Restructuring is a programme that is planned and controlled by management and materially changes either the scope of a business undertaken by an entity or the manner in which that business is conducted. Such programmes include: (a) the sale or termination of a line of business; (b) closure of business locations in a country or region or the relocation of activities from one country or region to another; (c) changes in management structure; and (d) fundamental reorganisations that have a material effect on the nature and focus of the entity's operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 98 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_98_b&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_ExpenseOfRestructuringActivities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The losses on disposals of non-current assets. [Refer: Non-current assets] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 112 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_112_c&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_LossesOnDisposalsOfNoncurrentAssets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | agi_FairValueAdjustmentAxis=agi_SilverStreamMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | agi_FairValueAdjustmentAxis=agi_MilestonePaymentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |