INTERIM CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - CAD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 635	$ 724	$ 1,044	$ 1,158
Net gain (loss) in foreign currency translation adjustments, net of hedging activities	31	15	(34)	31
Change in derivatives designated as cash flow hedges	1	4	3	6
Change in pension and post-retirement defined benefit plans	45	21	90	41
Other comprehensive income before income taxes	77	40	59	78
Income tax (expense) recovery on above items	(47)	(22)	13	(44)
Other comprehensive income	30	18	72	34
Comprehensive income	$ 665	$ 742	$ 1,116	$ 1,192