Other Current Liabilities (Details) - CAD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Other Current Liabilities [Abstract]
Contract liabilities(Note 18)	$ 12.8	$ 14.7
Trust liability(Note 7)	0.4	4.8
Environmental capital recovery surcharge	4.1	3.8
Employee compensation	4.8	1.1
Final working capital adjustment for Trans Mountain Transaction	37.0	0.0
Other	4.1	3.4
Total	$ 63.2	$ 27.8