Trade Payables and Accrued Liabilities - Summary of Trade Payables and Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Trade And Other Payables [Abstract]
Trade payables	$ 19,531	$ 24,843
Income taxes payable	257	1,673
Accrued liabilities	6,715	6,407
Deferred revenue	1,229	1,836
Vendor loan	1,725	1,725
Trade payables and accrued liabilities	$ 29,457	$ 36,484

Income tax payable.

No definition available.

Name:	alo_IncomeTaxPayable
Namespace Prefix:	alo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Trade payables and accrued liabilities current

+ References

No definition available.

+ Details

Name:	alo_TradePayablesAndAccruedLiabilitiesCurrent
Namespace Prefix:	alo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of liabilities to pay for goods or services that have been received or supplied but have not been paid, invoiced or formally agreed with the supplier, including amounts due to employees.

+ References

+ Details

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

- Definition

The amount of deferred income classified as current. [Refer: Deferred income]

+ References

+ Details

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

- Definition

The amount of loans received.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2019-03-27

+ Details

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

- Definition

The current amount of payment due to suppliers for goods and services used in entity's business. [Refer: Current liabilities; Trade payables]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 78
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_78&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 70
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_70&doctype=Standard
-URIDate 2019-03-27

+ Details

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

- References

No definition available.

+ Details

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