Buyout price of an equipment lease.

No definition available.

Name:	alo_BuyoutPriceOfEquipmentLease
Namespace Prefix:	alo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Initial recognition of lease liability.

+ References

No definition available.

+ Details

Name:	alo_InitialRecognitionOfLeaseLiability
Namespace Prefix:	alo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Lease liabilities.

+ References

No definition available.

+ Details

Name:	alo_LeaseLiabilitiesLineItems
Namespace Prefix:	alo_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Lease term agreement.

+ References

No definition available.

+ Details

Name:	alo_LeaseTermAgreement
Namespace Prefix:	alo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of lease equipment.

+ References

No definition available.

+ Details

Name:	alo_NumberOfLeaseEquipment
Namespace Prefix:	alo_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of office leases.

+ References

No definition available.

+ Details

Name:	alo_NumberOfOfficeLeases
Namespace Prefix:	alo_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of current lease liabilities. [Refer: Lease liabilities]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 16
-IssueDate 2019-01-01
-Paragraph 47
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2019-en-r&anchor=para_47_b&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_CurrentLeaseLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of depreciation of property, plant and equipment. [Refer: Depreciation and amortisation expense; Property, plant and equipment]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2019-01-01
-Paragraph 73
-Subparagraph e
-Clause vii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2019-en-r&anchor=para_73_e_vii&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2019-01-01
-Paragraph 75
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2019-en-r&anchor=para_75_a&doctype=Standard
-URIDate 2019-03-27

+ Details

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

- Definition

The amount of non-current lease liabilities. [Refer: Lease liabilities]

+ References

+ Details

Name:	ifrs-full_NoncurrentLeaseLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount recognised resulting from the write-down of property, plant and equipment to its recoverable amount or reversals of those write-downs. [Refer: Property, plant and equipment]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 98
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_98_a&doctype=Standard
-URIDate 2019-03-27

+ Details

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

- Details

Name:	ifrs-full_ClassesOfAssetsAxis=alo_EquipmentLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfAssetsAxis=us-gaap_OfficeEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfContractsAxis=alo_MasterServicesAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfAssetsAxis=us-gaap_TrucksMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SegmentsAxis=alo_FloridaCanyonMineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfAssetsAxis=alo_LoadersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Lease Liabilities - Additional Information (Details) $ in Thousands		12 Months Ended
	Oct. 02, 2019 USD ($) Equipment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Lease Liabilities [Line Items]
Depreciation		$ 846	$ 0
Current portion of Equipment Lease liability		10,009
Long-term lease liabilities		29,375
Equipment
Lease Liabilities [Line Items]
Initial recognition of lease liability		41,713
Current portion of Equipment Lease liability		9,842
Long-term lease liabilities		$ 29,158
Office
Lease Liabilities [Line Items]
Number of office leases		2
Current portion of Equipment Lease liability		$ 167	0
Long-term lease liabilities		$ 217	$ 0
Master Services Agreement
Lease Liabilities [Line Items]
Lease term agreement	72 months
Buyout price of an equipment lease	$ 1,986
Estimated net recoverable value of equipment	$ 500
Master Services Agreement \| Trucks \| Florida Canyon Mine
Lease Liabilities [Line Items]
Number of lease equipment \| Equipment	13
Master Services Agreement \| Loaders \| Florida Canyon Mine
Lease Liabilities [Line Items]
Number of lease equipment \| Equipment	3
Master Services Agreement \| Equipment
Lease Liabilities [Line Items]
Initial recognition of lease liability	$ 41,713