Newly-Formed Joint Ventures, Acquisitions and Divestitures - Additional Information Divestitures (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Assets And Liabilities Held For Sale [Line Items]
Gain (loss) on sale or disposal of assets	[1]	$ (61.1)	$ (0.3)	$ (14.3)	$ (16.6)
Refined Products And Crude Oil Storage And Terminaling Facilities [Member] | Tacoma, WA, And Baltimore, MD [Member]
Assets And Liabilities Held For Sale [Line Items]
Proceeds from sale of property		160.0
Gain (loss) on sale or disposal of assets		(57.5)
Refined Products And Crude Oil Storage And Terminaling Facilities [Member] | Tacoma, WA, And Baltimore, MD [Member] | Other Operating Income (Expense) [Member]
Assets And Liabilities Held For Sale [Line Items]
Gain (loss) on sale or disposal of assets		$ (57.5)		$ (57.5)

[1] Comprised primarily of a $57.5 million loss on sale of our refined products and crude oil storage and terminaling facilities in Tacoma, WA, and Baltimore, MD during the third quarter of 2018 as disclosed in Note 4 — Newly-Formed Joint Ventures, Acquisitions and Divestitures, offset by a $48.1 million gain on sale of our inland marine barge business to a third party during the second quarter of 2018 as disclosed in Note 6 — Property, Plant and Equipment and Intangible Assets. Also includes a $16.1 million loss in the first quarter of 2017 due to the sale of our ownership interest in VGS.