Asset Held for Sale (Narrative) (Details) - CAD ($)	12 Months Ended
Aug. 31, 2020	Aug. 31, 2019
Available-for-sale financial assets [abstract]
Cash consideration for the disposition of assets held for sale	$ 5,000,000
Asset held for sale		$ 2,605,147
Amount of recognized net gain on sale	$ 2,373,261

Represents the amount of cash consideration for the disposition of assets held for sale.

No definition available.

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Namespace Prefix:	avl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

The gain on the disposal of property, plant and equipment. [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 c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_98_c&doctype=Standard
-URIDate 2019-03-27

+ Details

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

- Definition

The amount of non-current assets or disposal groups classified as held for sale. [Refer: Disposal groups classified as held for sale [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 5
-IssueDate 2019-01-01
-Paragraph 38
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2019-en-r&anchor=para_38&doctype=Standard
-URIDate 2019-03-27

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant