v3.26.1
Basis of financial statement preparation (Details) - CAD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Related Party Transaction [Line Items]    
Amounts from related parties included in revenues [1] $ 12,416 $ 12,466
Purchases of crude oil and products [2] 8,178 7,756
Related Party    
Related Party Transaction [Line Items]    
Amounts from related parties included in revenues 3,660 3,653
Purchases of crude oil and products $ 1,250 1,206
Previously Reported | Related Party    
Related Party Transaction [Line Items]    
Amounts from related parties included in revenues   2,874
Purchases of crude oil and products   $ 427
[1]
(a) Amounts from related parties included in revenues (note 1)3,660 3,653 
[2]
(b) Amounts to related parties included in purchases of crude oil and products (note 1)1,250 1,206