Reportable Segments Capital Expenditures (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Capital expenditures	$ 528.4	$ 618.5	$ 269.1
Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Capital expenditures	426.6	438.5	165.4
Pipelines
Segment Reporting Information [Line Items]
Capital expenditures	1.4	7.1	6.3
Terminals
Segment Reporting Information [Line Items]
Capital expenditures	$ 100.4	$ 172.9	$ 97.4

The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration