CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - CAD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Earnings	$ 1,060	$ 213	$ 4,913	$ 2,050
Other comprehensive income/(loss), net of tax
Change in unrealized gain/(loss) on cash flow hedges	(170)		(597)
Change in unrealized gain/(loss) on cash flow hedges		57		150
Change in unrealized gain/(loss) on net investment hedges	(74)	83	147	(200)
Other comprehensive income from equity investees	2	(1)	19	18
Reclassification to earnings of loss on cash flow hedges	28		74
Reclassification to earnings of loss on cash flow hedges		31		104
Reclassification to earnings of pension and other postretirement benefits (OPEB) amounts	1	5	44	28
Foreign currency translation adjustments	704	(989)	(1,898)	1,637
Other comprehensive income/(loss), net of tax	491	(814)	(2,211)	1,737
Comprehensive income/(loss)	1,551	(601)	2,702	3,787
Comprehensive (income)/loss attributable to noncontrolling interests and redeemable noncontrolling interests	(41)	(102)	23	(546)
Comprehensive income/(loss) attributable to controlling interests	1,510	(703)	2,725	3,241
Preference share dividends	(96)	(94)	(287)	(272)
Comprehensive income/(loss) attributable to common shareholders	$ 1,414	$ (797)	$ 2,438	$ 2,969