Financing and additional notes and loans payable information - Narrative (Detail) - CAD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2023
Financing Activities [Line Items]
Line of credit facility, remaining borrowing capacity		$ 500,000,000
Non-interest bearing, revolving demand loan, outstanding amount	$ 111,000,000
Long Term Line Of Credit Due November Two Thousand And Twenty Four
Financing Activities [Line Items]
Line of credit facility, maximum borrowing capacity		250,000,000
Long-Term Line Of Credit Due November Two Thousand And Twenty Five
Financing Activities [Line Items]
Line of credit facility, maximum borrowing capacity		$ 250,000,000