Reportable Segments EBDA (Details) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
D&A	$ (82.6)	$ (71.7)	$ (64.2)
General and administrative	(39.0)	(30.9)	(25.7)
Interest income (expense), net	(27.2)	8.2	18.5
Income tax expense	(37.8)	(20.8)	(23.4)
Income from Continuing Operations	100.0	50.5	70.4
Income from Discontinued Operations, Net of Tax	1,318.2	110.2	131.4
Net income	1,418.2	160.7	201.8
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
D&A	(82.6)	(71.7)	(64.2)
Foreign exchange gain on KMI Loans(c)	0.0	0.2	13.2
General and administrative	(39.0)	(30.9)	(25.7)
Interest income (expense), net	27.2	(8.2)	(18.5)
Income tax expense	(37.8)	(20.8)	(23.4)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment EBDA(a)(b)(c)	232.2	181.9	189.0
Pipelines
Segment Reporting Information [Line Items]
D&A	(4.1)	(6.0)	(4.0)
Pipelines | Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment EBDA(a)(b)(c)	39.0	19.1	29.8
Terminals
Segment Reporting Information [Line Items]
D&A	(78.5)	(65.7)	(60.2)
Terminals | Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment EBDA(a)(b)(c)	193.2	162.8	159.2
Continuing Operations [Member]
Segment Reporting Information [Line Items]
Income from Continuing Operations	$ 100.0	$ 50.5	$ 70.4