XML 113 R98.htm IDEA: XBRL DOCUMENT v3.8.0.1

Subsequent Event (Details) - 2 months ended Feb. 27, 2018 - Other disposals of assets [member] CAD / shares in Units, $ in Millions	CAD CAD / shares	USD ($)
Corex Gold Corp [Member]
Disclosure of non-adjusting events after reporting period [line items]
Sale of stock (CAD per share) | CAD / shares	CAD 0.13
Proceeds from divestiture of businesses		$ 2.6
Gain on sale of business		0.6
Weighted average share price | CAD	CAD 0.10
AuRico Metals [Member]
Disclosure of non-adjusting events after reporting period [line items]
Sale of stock (CAD per share) | CAD / shares	CAD 1.80
Proceeds from divestiture of businesses		22.1
Gain on sale of business		$ 13.2
Weighted average share price | CAD	CAD 0.72

X

- Definition

Sale of Stock, Price Per Share1

+ References

No definition available.

+ Details

Name:	agi_SaleofStockPricePerShare1
Namespace Prefix:	agi_
Data Type:	num:perShareItemType
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 domain members defined in one or many axes of the table.

+ References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The gains (losses) on available-for-sale financial assets. [Refer: Financial assets available-for-sale]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2018-01-01
-Name IFRS
-Number 7
-IssueDate 2017-01-01
-Paragraph 20
-Subparagraph a
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-02&anchor=para_20_a_ii&doctype=Standard&book=B
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_GainsLossesOnAvailableforsaleFinancialAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The cash inflow from the disposal or maturity of available-for-sale financial assets. [Refer: Financial assets available-for-sale]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2017-01-01
-Paragraph 16
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2017-03-01&anchor=para_16&doctype=Standard
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_ProceedsFromDisposalOrMaturityOfAvailableforsaleFinancialAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The weighted average share price. [Refer: Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2017-01-01
-Paragraph 45
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2017-03-01&anchor=para_45_c&doctype=Standard
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_WeightedAverageSharePrice
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	ifrs-full_NonadjustingEventsAfterReportingPeriodAxis=ifrs-full_OtherDisposalsOfAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	agi_DisposalGroupName1Axis=agi_CorexGoldCorpMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	agi_DisposalGroupName1Axis=agi_AuRicoMetalsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: