Other (Income) Expense - Other Income and Expense (Details) - CAD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other Income and Expenses [Abstract]
Foreign exchange (gain) loss on debt and lease liabilities	$ (86)	$ (37)	$ 129	$ (82)
Other foreign exchange losses (gains)	1	(4)	(4)	(6)
Other	(1)	1	0	1
Other (income) expense	$ (86)	$ (40)	$ 125	$ (87)

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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