XML 110 R79.htm IDEA: XBRL DOCUMENT
v3.23.1

Financial Instruments and Risk Management (Fair Value for Assets and Liabilities) (Details) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($)
Disclosure of fair value measurement of assets [line items] |  |
Financial assets (liabilities) | $ (3,674.2) | $ (3,621.5)
Financial liabilities | 953.1 | 885.9
Esperanza Milestone Payments (i) |  | 0.0
Assets held for sale (note 14) | 5.0 | 0.0
Total financial instrument exposure to credit risk | $ 153.5 | 176.5
Discount rate, milestone payments | 0.0912 |
Profit (loss) before tax | $ 102.4 | 2.3
Change in Assumptions, Effect |  |
Disclosure of fair value measurement of assets [line items] |  |
Profit (loss) before tax | 2.5 |
Concentrate Receivable [Member] |  |
Disclosure of fair value measurement of assets [line items] |  |
Total financial instrument exposure to credit risk |  | 0.0
Level 1 | Recurring fair value measurement |  |
Disclosure of fair value measurement of assets [line items] |  |
Fair value, net asset (liability) | 18.6 | 23.9
Level 2 | Recurring fair value measurement |  |
Disclosure of fair value measurement of assets [line items] |  |
Fair value, net asset (liability) | (4.2) | 3.5
Level 3 | Recurring fair value measurement |  |
Disclosure of fair value measurement of assets [line items] |  |
Fair value, net asset (liability) | 24.1 |
Esperanza Milestone Payments (i) | 19.1 |
Assets held for sale (note 14) | 5.0 |
Derivatives |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial assets, at fair value | (4.3) | 3.0
Derivatives | Gold Options |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial liabilities, at fair value | (0.1) |
Financial assets, at fair value |  | 0.5
Derivatives | Currency Hedging Derivative Instruments |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial liabilities, at fair value | 4.3 |
Financial assets, at fair value |  | 2.6
Derivatives | Fuel Options |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial assets, at fair value | 0.0 | 0.4
Fair value through profit or loss | Gold Options | Level 2 | Recurring fair value measurement |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial liabilities | 0.1 | 0.5
Fair value through OCI | Currency Hedging Derivative Instruments | Level 2 | Recurring fair value measurement |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial liabilities |  | 2.6
Fair value through OCI | Fuel Options | Level 2 | Recurring fair value measurement |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial liabilities |  | 0.4
Fair value through OCI | Trading securities | Level 1 | Recurring fair value measurement |  |
Disclosure of fair value measurement of assets [line items] |  |
Financial assets (liabilities) | $ (18.6) | $ (23.9)

X
- Definition Assets Held for Sale + References No definition available. + Details
Name: | agi_AssetsHeldForSale
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Discount Rate, Milestone Payments + References No definition available. + Details
Name: | agi_DiscountRateMilestonePayments
Namespace Prefix: | agi_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair Value, Net Asset (Liability) + References No definition available. + Details
Name: | agi_FairValueNetAssetLiability1
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Milestone Payments And Cash From Percentage of Silver Produced + References No definition available. + Details
Name: | agi_MilestonePaymentsAndCashFromPercentageOfSilverProduced
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of a present economic resource controlled by the entity as a result of past events. Economic resource is a right that has the potential to produce economic benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2022-03-24 -Paragraph 93 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2022-en-r&anchor=para_93_a&doctype=Standard -URIDate 2022-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2022-03-24 -Paragraph 28 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2022-en-r&anchor=para_28_c&doctype=Standard -URIDate 2022-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2022-03-24 -Paragraph 93 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2022-en-r&anchor=para_93_b&doctype=Standard -URIDate 2022-03-24 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2022-03-24 -Paragraph 93 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2022-en-r&anchor=para_93_e&doctype=Standard -URIDate 2022-03-24 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2022-03-24 -Paragraph 23 -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2022-en-r&anchor=para_23&doctype=Standard -URIDate 2022-03-24 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2022-03-24 -Paragraph 55 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2022-en-r&anchor=para_55&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_Assets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_DisclosureOfFairValueMeasurementOfAssetsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The fair value of financial assets. [Refer: At fair value [member]; Financial assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2022-03-24 -Paragraph 25 -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_25&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_FinancialAssetsAtFairValue
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The fair value of financial liabilities. [Refer: At fair value [member]; Financial liabilities] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2022-03-24 -Paragraph 25 -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_25&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_FinancialLiabilitiesAtFairValue
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of a present obligation of the entity to transfer an economic resource as a result of past events. Economic resource is a right that has the potential to produce economic benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2022-03-24 -Paragraph 93 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2022-en-r&anchor=para_93_a&doctype=Standard -URIDate 2022-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2022-03-24 -Paragraph 93 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2022-en-r&anchor=para_93_b&doctype=Standard -URIDate 2022-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2022-03-24 -Paragraph 93 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2022-en-r&anchor=para_93_e&doctype=Standard -URIDate 2022-03-24 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2022-03-24 -Paragraph 28 -Subparagraph d -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2022-en-r&anchor=para_28_d&doctype=Standard -URIDate 2022-03-24 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2022-03-24 -Paragraph 23 -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2022-en-r&anchor=para_23&doctype=Standard -URIDate 2022-03-24 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2022-03-24 -Paragraph 55 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2022-en-r&anchor=para_55&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_Liabilities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount that best represents the maximum exposure to credit risk without taking into account any collateral held or other credit enhancements (for example, netting agreements that do not qualify for offset in accordance with IAS 32). [Refer: Credit risk [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2022-03-24 -Paragraph 35K -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_35K_a&doctype=Standard -URIDate 2022-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Note Expiry date 2023-01-01 -Name IFRS -Number 7 -IssueDate 2022-03-24 -Paragraph 36 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2017-en-b&anchor=para_36_a&doctype=Standard&book=b -URIDate 2022-03-24 + Details
Name: | ifrs-full_MaximumExposureToCreditRisk
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition The profit (loss) before tax expense or income. [Refer: Profit (loss)] + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 8 -IssueDate 2022-03-24 -Paragraph 28 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2022-en-r&anchor=para_28_b&doctype=Standard -URIDate 2022-03-24 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 8 -IssueDate 2022-03-24 -Paragraph 23 -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2022-en-r&anchor=para_23&doctype=Standard -URIDate 2022-03-24 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 5 -IssueDate 2022-03-24 -Paragraph 33 -Subparagraph b -Clause i -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2022-en-r&anchor=para_33_b_i&doctype=Standard -URIDate 2022-03-24 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2022-03-24 -Paragraph 103 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2022-en-r&anchor=para_103&doctype=Standard -URIDate 2022-03-24 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2022-03-24 -Paragraph 102 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2022-en-r&anchor=para_102&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_ProfitLossBeforeTax
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ifrs-full_AccountingEstimatesAxis=agi_ChangeInAssumptionsEffectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=agi_ConcentrateReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level1OfFairValueHierarchyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MeasurementAxis=ifrs-full_RecurringFairValueMeasurementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level2OfFairValueHierarchyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level3OfFairValueHierarchyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialAssetsAxis=ifrs-full_DerivativesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=agi_GoldOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=agi_CurrencyHedgingDerivativeInstrumentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=agi_FuelOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialAssetsAxis=ifrs-full_FinancialAssetsAtFairValueThroughProfitOrLossCategoryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialLiabilitiesAxis=agi_GoldOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialAssetsAxis=ifrs-full_FinancialAssetsAtFairValueThroughOtherComprehensiveIncomeCategoryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialLiabilitiesAxis=agi_CurrencyHedgingDerivativeInstrumentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialLiabilitiesAxis=agi_FuelOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialAssetsAxis=ifrs-full_TradingSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |