Goodwill (Details) - USD ($)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill impairment		$ 0	$ 0	$ 0
Accumulated goodwill impairment		0
Goodwill [Roll Forward]
Goodwill, beginning balance		816,600,000	12,200,000	12,200,000
Acquisitions		66,300,000	804,400,000	0
Write-down resulting from asset held for sale impairment	[1]	(25,100,000)
Goodwill, ending balance		857,800,000	816,600,000	12,200,000
Operating Segments | Refining
Goodwill [Roll Forward]
Goodwill, beginning balance		750,900,000	0	0
Acquisitions		50,400,000	750,900,000	0
Write-down resulting from asset held for sale impairment	[1]	0
Goodwill, ending balance		801,300,000	750,900,000	0
Operating Segments | Logistics
Goodwill [Roll Forward]
Goodwill, beginning balance		12,200,000	12,200,000	12,200,000
Acquisitions		0	0	0
Write-down resulting from asset held for sale impairment	[1]	0
Goodwill, ending balance		12,200,000	12,200,000	12,200,000
Operating Segments | Retail
Goodwill [Roll Forward]
Goodwill, beginning balance		30,800,000	0	0
Acquisitions		44,300,000	30,800,000	0
Write-down resulting from asset held for sale impairment	[1]	0
Goodwill, ending balance		44,300,000	30,800,000	0
Corporate, Other and Eliminations
Goodwill [Roll Forward]
Goodwill, beginning balance		22,700,000	0	0
Acquisitions		2,400,000	22,700,000	0
Write-down resulting from asset held for sale impairment	[1]	(25,100,000)
Goodwill, ending balance		$ 0	$ 22,700,000	$ 0

[1] This impairment of goodwill resulted from the write-down of assets held for sale associated with the asphalt business to net realizable value, as discussed in Note 8.