Leases - Narrative (Detail) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Undiscounted Commitments	$ 14	$ 5
Operating and finance leases not yet commenced payments due year one	5
Operating and finance leases not yet commenced payments due year two	$ 5