Segment Data - Assets (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total assets	$ 6,437.6	$ 7,016.3
Inter-segment right of use lease assets	(183.9)	$ (183.6)
Total assets, excluding inter-segment notes receivable and right of use assets	6,437.6
Operating Segments | Refining
Segment Reporting Information [Line Items]
Total assets	6,142.9
Total assets, excluding inter-segment notes receivable and right of use assets	4,308.1
Operating Segments | Logistics
Segment Reporting Information [Line Items]
Total assets	973.8
Total assets, excluding inter-segment notes receivable and right of use assets	973.8
Operating Segments | Retail
Segment Reporting Information [Line Items]
Total assets	256.3
Total assets, excluding inter-segment notes receivable and right of use assets	256.3
Consolidation, Eliminations
Segment Reporting Information [Line Items]
Total assets, excluding inter-segment notes receivable and right of use assets	899.4
Intersegment Eliminations
Segment Reporting Information [Line Items]
Inter-segment notes receivable	1,440.3
Inter-segment right of use lease assets	394.5
Intersegment Eliminations | Refining
Segment Reporting Information [Line Items]
Inter-segment notes receivable	1,440.3
Inter-segment right of use lease assets	394.5
Intersegment Eliminations | Logistics
Segment Reporting Information [Line Items]
Inter-segment notes receivable	0.0
Inter-segment right of use lease assets	0.0
Intersegment Eliminations | Retail
Segment Reporting Information [Line Items]
Inter-segment notes receivable	0.0
Inter-segment right of use lease assets	$ 0.0