Trans Mountain Transaction (Details) - CAD ($) $ / shares in Units, $ in Millions			3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 03, 2019	Aug. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Jan. 04, 2019	May 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Proceeds from Sale of the Trans Mountain Asset Group						$ 3,921.2
Working capital adjustments							$ 37.0
Stockholders Equity, Return Of Capital	$ 2,800.0
Operating Income			$ 24.1	$ 26.4	$ 84.2	79.4
Income from Discontinued Operations, net of tax				1,327.2		1,347.8
Common Stock [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stockholders Equity, Return Of Capital	$ 1,200.0
Stockholders Equity, Return of Capital, Per Share	$ 11.40
Common Stock Including Additional Paid in Capital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reduction of Capital								$ 1,450.0
Kinder Morgan, Inc. [Member] \| Common Stock [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners									70.00%
Trans Mountain Transaction [Member] \| Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Proceeds from Sale of the Trans Mountain Asset Group		$ 4,430.0
Contracted Purchase Price		$ 4,500.0
Revenue				56.4		214.3
Depreciation and amortization				(11.8)		(46.8)
Operating Expenses, including general and administrative				(27.5)		(89.8)
Interest and other income (expense), net				11.3		(22.9)
Operating Income				28.4		54.8
Gain on sale of Trans Mountain Asset Group before income tax				1,235.1		1,235.1
Income from Discontinued Operations before income taxes				1,263.5		1,289.9
Income tax benefit				63.7		57.9
Income from Discontinued Operations, net of tax				$ 1,327.2		1,347.8
Net Cash provided by Operating activities						182.3
Net cash used in Investing activities						$ (507.3)

Kinder Morgan Canada Ltd 10-Q