Supplemental Information - Additional Information (Detail) - CAD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Supplemental Information [Line Items]
Operating expense	$ 583,420	$ 1,038,967
General and administrative expense	70,869	104,010
Depreciation and amortization gain on asset disposal loss on asset decommissioning and reversal of impairment of property plant and equipment [Member]
Supplemental Information [Line Items]
Operating expense	293,000	282,000
General and administrative expense	$ 11,000	$ 15,000

The amount of costs relating to expenses directly or indirectly attributed to the goods or services sold, which may include, but are not limited to, costs previously included in the measurement of inventory that has now been sold, unallocated production overheads and abnormal amounts of production costs of inventories.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 99
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_99&doctype=Standard
-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 103
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_103&doctype=Standard
-URIDate 2020-01-01

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration