Segment Data - Operating Performance (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net revenues (excluding inter-segment fees and sales)	$ (1,535.5)	$ (2,480.3)	$ (3,356.7)	$ (4,680.2)
Operating costs and expenses:
Cost of materials and other	1,277.8	2,067.7	3,188.4	3,767.1
Operating expenses (excluding depreciation and amortization presented below)	127.8	162.3	282.3	329.0
Segment contribution margin	129.9	250.3	(114.0)	584.1
Depreciation and amortization	59.6	50.1	112.2	96.9
General and administrative expenses	61.7	69.5	127.4	131.7
Other operating (income) expense, net	(14.2)	(3.6)	(14.9)	(1.2)
Operating income (loss)	22.8	134.3	(338.7)	356.7
Capital spending (excluding business combinations)	15.0	86.0	203.3	214.3
Total assets	6,437.6		6,437.6		$ 7,016.3
Refining
Segment Reporting Information [Line Items]
Net revenues (excluding inter-segment fees and sales)	(1,001.9)	(2,152.5)	(2,571.1)	(4,059.9)
Logistics
Segment Reporting Information [Line Items]
Net revenues (excluding inter-segment fees and sales)	(27.3)	(93.1)	(84.2)	(182.9)
Retail
Segment Reporting Information [Line Items]
Net revenues (excluding inter-segment fees and sales)	(165.4)	(224.5)	(344.0)	(421.7)
Operating Segments | Refining
Operating costs and expenses:
Operating expenses (excluding depreciation and amortization presented below)	88.7	115.0	200.4	236.0
Segment contribution margin	59.7	198.1	(230.7)	500.0
Depreciation and amortization	44.8	33.2	82.0	64.3
Capital spending (excluding business combinations)	12.2	48.9	180.3	130.5
Total assets	6,142.9		6,142.9
Operating Segments | Logistics
Operating costs and expenses:
Operating expenses (excluding depreciation and amortization presented below)	12.4	17.3	27.2	33.4
Segment contribution margin	61.4	44.2	108.7	84.3
Depreciation and amortization	8.7	6.7	15.0	13.2
Capital spending (excluding business combinations)	0.7	1.3	3.7	2.2
Total assets	973.8		973.8
Operating Segments | Retail
Operating costs and expenses:
Operating expenses (excluding depreciation and amortization presented below)	21.5	24.8	43.7	48.4
Segment contribution margin	24.3	17.6	36.6	27.8
Depreciation and amortization	3.3	4.2	6.2	8.5
Capital spending (excluding business combinations)	1.3	5.4	7.5	10.5
Total assets	256.3		256.3
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Net revenues (excluding inter-segment fees and sales)	(340.9)	(10.2)	(357.4)	(15.7)
Operating costs and expenses:
Operating expenses (excluding depreciation and amortization presented below)	5.2	5.2	11.0	11.2
Depreciation and amortization	2.8	6.0	9.0	10.9
Capital spending (excluding business combinations)	0.8	30.4	11.8	71.1
Corporate, Other and Eliminations
Operating costs and expenses:
Segment contribution margin	(15.5)	(9.6)	(28.6)	(28.0)
Total assets	(935.4)		(935.4)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Net revenues (excluding inter-segment fees and sales)	165.5	277.5	430.7	524.8
Intersegment Eliminations | Refining
Segment Reporting Information [Line Items]
Net revenues (excluding inter-segment fees and sales)	75.1	215.3	233.8	399.9
Intersegment Eliminations | Logistics
Segment Reporting Information [Line Items]
Net revenues (excluding inter-segment fees and sales)	90.4	62.2	196.9	124.9
Intersegment Eliminations | Retail
Segment Reporting Information [Line Items]
Net revenues (excluding inter-segment fees and sales)	0.0	0.0	0.0	0.0
Product
Operating costs and expenses:
Cost of materials and other	1,277.8	2,067.7	3,188.4	3,767.1
Product | Operating Segments | Refining
Operating costs and expenses:
Cost of materials and other	928.6	2,054.7	2,835.2	3,723.8
Product | Operating Segments | Logistics
Operating costs and expenses:
Cost of materials and other	43.9	93.8	145.2	190.1
Product | Operating Segments | Retail
Operating costs and expenses:
Cost of materials and other	119.6	182.1	263.7	345.5
Product | Corporate, Non-Segment [Member]
Operating costs and expenses:
Cost of materials and other	185.7	(262.9)	(55.7)	(492.3)
Commodity Contract [Member]
Operating costs and expenses:
Net gains related to cash flow hedges	$ (1.4)	(16.5)	$ 0.3	(3.4)
Commodity Contract [Member] | Refining
Operating costs and expenses:
Net gains related to cash flow hedges		$ 19.8		$ 27.4