XML 102 R84.htm IDEA: XBRL DOCUMENT
v3.22.4

Financial Instruments and Risk Management (Currency Contracts) (Details) oz in Thousands, $ in Millions, $ in Millions, $ in Millions | 2 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Feb. 23, 2023 $ / oz oz | Dec. 31, 2022 USD ($) $ / oz | Dec. 31, 2021 USD ($) $ / oz | Dec. 31, 2022 CAD ($) | Dec. 31, 2022 $ / $ | Dec. 31, 2022 MXN ($) | Dec. 31, 2022 $ / $
Contract Options |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Ounce of gold | oz | 12 |  |  |  |  |  |
Collars and Forwards |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Financial liabilities, at fair value | $ |  |  | $ 2.6 |  |  |  |
Gains (losses) on change in fair value of derivatives | $ |  | $ (1.1) | (3.8) |  |  |  |
Gold Options | Commodity price risk |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Financial assets, at fair value | $ |  |  | 0.5 |  |  |  |
Gains (losses) on change in fair value of derivatives | $ |  | $ (3.5) | $ (0.5) |  |  |  |
Gold Options | Commodity price risk | Contract Options | Maximum |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Average realized price per ounce | $ / oz | 2,163 |  |  |  |  |  |
Gold Options | Commodity price risk | Contract Options | Minimum |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Average realized price per ounce | $ / oz | 1,800 |  |  |  |  |  |
2018 | Gold Options | Commodity price risk | Purchase Put Options |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Average realized price per ounce | $ / oz |  | 1,755 |  |  |  |  |
2019 | Collars | Currency risk |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Notional amount |  |  |  | $ 558.0 |  | $ 1,020.0 |
2019 | Bought Puts | Currency risk |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Notional amount | $ |  |  |  | $ 30.0 |  |  |
Bottom of range | Gold Options | Market risk |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Average realized price per ounce | $ / oz |  |  | 1,629 |  |  |  |
Bottom of range | 2019 | Collars | Currency risk |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Average rate of hedging instrument |  |  |  |  | 129.00% |  | 2046.00%
Bottom of range | 2019 | Bought Puts | Currency risk |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Average rate of hedging instrument | $ / $ |  |  |  |  | 131.00% |  |
Top of range | Gold Options | Market risk |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Average realized price per ounce | $ / oz |  |  | 2,039 |  |  |  |
Top of range | 2019 | Collars | Currency risk |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Average rate of hedging instrument |  |  |  |  | 135.00% |  | 2259.00%
Top of range | 2019 | Bought Puts | Currency risk |  |  |  |  |  |  |
Disclosure of detailed information about hedged items [line items] |  |  |  |  |  |  |
Average rate of hedging instrument | $ / $ |  |  |  |  | 0.00% |  |

X
- Definition Average Realized Price Per Ounce + References No definition available. + Details
Name: | agi_AverageRealizedPricePerOunce
Namespace Prefix: | agi_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Ounces of Gold + References No definition available. + Details
Name: | agi_NumberOfOuncesOfGold
Namespace Prefix: | agi_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The average rate of a hedging instrument. [Refer: Hedging instruments [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2022-03-24 -Paragraph 23B -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2022-en-r&anchor=para_23B_b&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_AverageRateOfHedgingInstrument
Namespace Prefix: | ifrs-full_
Data Type: | dtr-types:percentItemType
Balance Type: | na
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_DisclosureOfDetailedInformationAboutHedgedItemsLineItems
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 gains (losses) resulting from change 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_GainsLossesOnChangeInFairValueOfDerivatives
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The nominal or face amount of a financial instrument, used to calculate payments made on that instrument. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2022-03-24 -Paragraph 112 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2022-en-r&anchor=para_112_c&doctype=Standard -URIDate 2022-03-24 + Details
Name: | ifrs-full_NotionalAmount
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | ifrs-full_NonadjustingEventsAfterReportingPeriodAxis=agi_ContractOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_HedgingInstrumentsAxis=agi_CollarsandForwardsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | ifrs-full_TypesOfRisksAxis=ifrs-full_CommodityPriceRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=ifrs-full_NotLaterThanOneYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ContinuingInvolvementInDerecognisedFinancialAssetsByTypeOfInstrumentAxis=agi_PurchasePutOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=ifrs-full_LaterThanTwoYearsAndNotLaterThanThreeYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_HedgingInstrumentsAxis=agi_CollarsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfRisksAxis=ifrs-full_CurrencyRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_HedgingInstrumentsAxis=agi_BoughtPutsMember
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_TypesOfRisksAxis=ifrs-full_MarketRiskMember
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: |