XML 85 R55.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Income Taxes (Tax Reconciliation) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018
Disclosure of income tax [Abstract] |  |
(Loss) earnings before income taxes |  | $ (38.4)
Statutory tax rate | 25.00% | 25.00%
Expected income tax (recovery) expense based on above rates | $ 32.2 | $ (9.6)
Effect of higher tax rates in foreign jurisdictions | 1.0 | (2.4)
Non-deductible expenses | (1.4) | 4.4
Impact of local mining taxes | 7.2 | 6.0
Impact of foreign exchange | (13.2) | 28.8
Impact of renouncement of flow through share expenditures | 0.8 | 0.3
Withholding tax | 1.2 | 1.2
Change in unrecognized temporary differences | 4.6 | 5.2
Other | 0.4 | 0.3
Income tax expense (recovery) recognized in net (loss) earnings | $ 32.8 | $ 34.2

X
- Definition Disclosure of income tax [Abstract] + References No definition available. + Details
Name: | agi_DisclosureofincometaxAbstract
Namespace Prefix: | agi_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tax Effect Of Foreign Exchange + References No definition available. + Details
Name: | agi_TaxEffectOfForeignExchange
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Tax Effect Of Local Mining Taxes + References No definition available. + Details
Name: | agi_TaxEffectOfLocalMiningTaxes
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Tax Effect Of Renouncement of Flow Through Share Expenditures + References No definition available. + Details
Name: | agi_TaxEffectOfRenouncementofFlowThroughShareExpenditures
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Tax Effect Of Withholding Tax + References No definition available. + Details
Name: | agi_TaxEffectOfWithholdingTax
Namespace Prefix: | agi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of profit (loss) for a period before deducting tax expense. [Refer: Profit (loss)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 81 -Subparagraph c -Clause ii -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_81_c_ii&doctype=Standard -URIDate 2019-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 81 -Subparagraph c -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_81_c_i&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_AccountingProfit
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The applicable income tax rate. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 81 -Subparagraph c -Clause ii -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_81_c_ii&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_ApplicableTaxRate
Namespace Prefix: | ifrs-full_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate amount included in the determination of profit (loss) for the period in respect of current tax and deferred tax. [Refer: Current tax expense (income); Deferred tax expense (income)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2019-01-01 -Paragraph 23 -Subparagraph h -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_23_h&doctype=Standard -URIDate 2019-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 26 -IssueDate 2019-01-01 -Paragraph 35 -Subparagraph b -Clause viii -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=26&code=ifrs-tx-2019-en-r&anchor=para_35_b_viii&doctype=Standard -URIDate 2019-03-27 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 79 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_79&doctype=Standard -URIDate 2019-03-27 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 81 -Subparagraph c -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_81_c_i&doctype=Standard -URIDate 2019-03-27 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 82 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_82_d&doctype=Standard -URIDate 2019-03-27 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 81 -Subparagraph c -Clause ii -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_81_c_ii&doctype=Standard -URIDate 2019-03-27 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2019-01-01 -Paragraph B13 -Subparagraph g -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2019-en-r&anchor=para_B13_g&doctype=Appendix&subtype=B -URIDate 2019-03-27 + Details
Name: | ifrs-full_IncomeTaxExpenseContinuingOperations
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that the entity does not separately disclose in the same statement or note. [Refer: Accounting profit; Applicable tax rate] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 81 -Subparagraph c -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_81_c_i&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_OtherTaxEffectsForReconciliationBetweenAccountingProfitAndTaxExpenseIncome
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of benefit arising from a previously unrecognised tax loss, tax credit or temporary difference of a prior period that is used to reduce current tax expense. [Refer: Temporary differences [member]; Unused tax losses [member]; Unused tax credits [member]] + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 80 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_80_e&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_TaxBenefitArisingFromPreviouslyUnrecognisedTaxLossTaxCreditOrTemporaryDifferenceOfPriorPeriodUsedToReduceCurrentTaxExpense
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to expenses not deductible in determining taxable profit (tax loss). [Refer: Accounting profit] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 81 -Subparagraph c -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_81_c_i&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_TaxEffectOfExpenseNotDeductibleInDeterminingTaxableProfitTaxLoss
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to foreign tax rates. [Refer: Accounting profit] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 81 -Subparagraph c -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_81_c_i&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_TaxEffectOfForeignTaxRates
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The product of the accounting profit multiplied by the applicable tax rate(s). [Refer: Accounting profit; Applicable tax rate] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2019-01-01 -Paragraph 81 -Subparagraph c -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2019-en-r&anchor=para_81_c_i&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_TaxExpenseIncomeAtApplicableTaxRate
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration