Long-term debt - Summary of Long-Term Debt (Detail) - CAD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
Long-term debt, related party amount		$ 3,447	$ 3,447
Finance leases		564	586
Total long-term debt	[1]	$ 4,011	$ 4,033

[1] (c) Long-term debt included amounts to related parties (note 16). 3,4473,447