Derivatives (Not Designated as Hedges) (Details) - Not Designated as Hedging Instrument - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 35.1	$ 3.6
Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(26.1)	30.2
Specialty Product | Midland crude oil basis swap purchases | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	1.6	0.9
Specialty Product | Midland crude oil basis swap purchases | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(1.0)	1.0
Fuel Product | Midland crude oil basis swap purchases | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	11.3	6.0
Fuel Product | Midland crude oil basis swap purchases | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(7.1)	7.1
Fuel Product | Supply and Offtake Agreements | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0.0	0.0
Fuel Product | Supply and Offtake Agreements | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(8.7)	5.9
Fuel Product | Crude Oil Swaps | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0.0	0.0
Fuel Product | Crude Oil Swaps | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0.0	(0.3)
Fuel Product | WCS Crude Oil Basis Swaps | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	14.7	(1.8)
Fuel Product | WCS Crude Oil Basis Swaps | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(16.2)	14.9
Fuel Product | WCS Crude Oil Percentage Basis Swaps | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	1.0	0.0
Fuel Product | WCS Crude Oil Percentage Basis Swaps | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	6.0	(6.1)
Fuel Product | Gasoline Swaps | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0.0	0.0
Fuel Product | Gasoline Swaps | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0.0	0.2
Fuel Product | Gasoline Crack Spread Swaps | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0.1	(1.0)
Fuel Product | Gasoline Crack Spread Swaps | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	1.3	1.8
Fuel Product | Diesel Swaps | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0.0	0.0
Fuel Product | Diesel Swaps | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0.0	0.2
Fuel Product | Diesel Crack Spread Swaps | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	6.3	(0.7)
Fuel Product | Diesel Crack Spread Swaps | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(6.9)	11.5
Fuel Product | Diesel Percent Basis Crack Spread Swaps | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0.0	0.0
Fuel Product | Diesel Percent Basis Crack Spread Swaps | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	6.0	(6.0)
Fuel Product | 2-1-1 Crack Spread Swap | Realized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0.1	0.2
Fuel Product | 2-1-1 Crack Spread Swap | Unrealized Gain (Loss)
Derivative instruments not designated as cash flow hedges
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 0.5	$ 0.0