XML 160 R115.htm IDEA: XBRL DOCUMENT v3.20.4
Goodwill - Additional Information (Detail) - CAD ($)
 3 Months Ended 12 Months Ended
Mar. 31, 2020
Dec. 31, 2020
Dec. 31, 2019
Disclosure Of Information For Individual Asset Or Cashgenerating Unit With Significant Amount Of Goodwill Or Intangible Assets With Indefinite Useful Lives [Line Items]      
Goodwill   $ 2,272,000,000 $ 2,272,000,000
Goodwill impairments $ 0 0 0
Primrose (Foster Creek) [Member]      
Disclosure Of Information For Individual Asset Or Cashgenerating Unit With Significant Amount Of Goodwill Or Intangible Assets With Indefinite Useful Lives [Line Items]      
Goodwill   1,171,000,000 1,171,000,000
Christina Lake [Member]      
Disclosure Of Information For Individual Asset Or Cashgenerating Unit With Significant Amount Of Goodwill Or Intangible Assets With Indefinite Useful Lives [Line Items]      
Goodwill   $ 1,101,000,000 $ 1,101,000,000