Financing and Additional Notes and Loans Payable Information (Detail) - CAD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Debt-related interest		$ 39	$ 30
Capitalized interest		(11)	(7)
Net interest expense		28	23
Other interest
Total financing	[1]	$ 28	$ 23

[1] Amounts to related parties included in financing, (note 6) 28 20