Business Combination, Miles Of Rail Lines Acquired

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Business Combination, Miles Of Rail Tunnel Acquired

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Reduction of operating costs related to movements through the DRTP

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Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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Fair value at acquisition-date of the equity interest in the acquiree held by the acquirer, immediately before the acquisition date for businesses combined in stages.

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Percentage of equity in the acquiree held by the acquirer immediately before the acquisition date in a business combination.

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Business combination - Narrative (Details) $ in Millions				5 Months Ended	12 Months Ended
Business combination - Narrative (Details) $ in Millions	Dec. 22, 2020 CAD ($) mi	Jun. 03, 2020 CAD ($)	Dec. 30, 2019 CAD ($) mi	Jun. 02, 2020 CAD ($)	Dec. 31, 2020 CAD ($)	Dec. 31, 2019 CAD ($)	Dec. 31, 2018 CAD ($)
Business Acquisition [Line Items]
Investment in Detroit River Tunnel Partnership					$ 398	$ 0	$ 0
Book value of previously held equity method investment					150	166
Goodwill					329	194	$ 194
DRTP
Business Acquisition [Line Items]
Percentage of Voting Interests Acquired	83.50%
Investment in Detroit River Tunnel Partnership	$ 398
Reduction of operating costs related to movements through the DRTP					(34)
Miles of rail tunnel acquired \| mi	1.6
Previously held equity interest, Percentage	16.50%
Gain on remeasurement of DRTP equity interest	$ 68
Fair value of previously held equity method investment	81
Book value of previously held equity method investment	13
Goodwill	90
Intangible assets	4
Acquired cash and equivalents	$ 6
CMQ
Business Acquisition [Line Items]
Investment in Detroit River Tunnel Partnership						174
Book value of previously held equity method investment					$ 0	$ 127
Additional consideration paid, working capital adjustment				$ 3
CMQ U.S.
Business Acquisition [Line Items]
Fair value of previously held equity method investment		$ 138
Goodwill		52
Intangible assets		27
Acquired cash and equivalents		$ 22
Finite-Lived Intangible Asset, Useful Life		20 years
CMQ Canada
Business Acquisition [Line Items]
Investment in Detroit River Tunnel Partnership			$ 47
Goodwill			10
Intangible assets			$ 5
Canada \| CMQ
Business Acquisition [Line Items]
Miles of rail lines acquired \| mi			237
United States \| CMQ
Business Acquisition [Line Items]
Miles of rail lines acquired \| mi			244