Acquisitions - Schedule of Asset Acquisitions (Details) $ in Millions		12 Months Ended
		Dec. 31, 2017 USD ($) acquisition		Dec. 31, 2018 USD ($)
Business Acquisition [Line Items]
Total assets		$ 5,935.2	[1]	$ 5,760.6
Pipelines
Business Acquisition [Line Items]
Number of asset acquisitions | acquisition		2
Asset acquisition, consideration transferred		$ 13.0
Land		0.2
Property, plant and equipment		6.4
Intangible assets	[2]	6.4
Total assets		$ 13.0

[1] Assets held for sale of $160.0 million are included in the corporate, other and eliminations segment as of December 31, 2017.

[2] Intangible assets acquired represent rights-of-way assets with indefinite useful lives. Rights-of-way assets are not subject to amortization.