Derivatives - Schedule of Derivative Instruments Not Designated as Hedges Gains (Losses) (Details) - Derivative instruments not designated as hedges: - Income Statement Location [Axis]: us-gaap:GainLossOnDerivativeInstrumentsNetPretax - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Amount of Realized Gain (Loss) Recognized in Gain (Loss) on Derivative Instruments
Derivative instruments not designated as cash flow hedges
Derivative instruments not designated as hedges, gain (loss), net	$ (35.0)	$ (2.7)	$ (47.7)	$ (10.0)
Amount of Unrealized Gain (Loss) Recognized in Gain (Loss) on Derivative Instruments
Derivative instruments not designated as cash flow hedges
Derivative instruments not designated as hedges, gain (loss), net	9.0	7.0	(93.7)	7.1
Specialty Products and Solutions \| Inventory financing obligation \| Amount of Realized Gain (Loss) Recognized in Gain (Loss) on Derivative Instruments
Derivative instruments not designated as cash flow hedges
Derivative instruments not designated as hedges, gain (loss), net	(11.9)	(2.7)	(18.9)	(4.4)
Specialty Products and Solutions \| Inventory financing obligation \| Amount of Unrealized Gain (Loss) Recognized in Gain (Loss) on Derivative Instruments
Derivative instruments not designated as cash flow hedges
Derivative instruments not designated as hedges, gain (loss), net	23.9	7.0	(22.1)	7.1
Specialty Products and Solutions \| Crack spread swaps \| Amount of Realized Gain (Loss) Recognized in Gain (Loss) on Derivative Instruments
Derivative instruments not designated as cash flow hedges
Derivative instruments not designated as hedges, gain (loss), net	(23.1)		(28.8)
Specialty Products and Solutions \| Crack spread swaps \| Amount of Unrealized Gain (Loss) Recognized in Gain (Loss) on Derivative Instruments
Derivative instruments not designated as cash flow hedges
Derivative instruments not designated as hedges, gain (loss), net	$ (14.9)		$ (71.6)
Montana/ Renewables \| Inventory financing obligation \| Amount of Realized Gain (Loss) Recognized in Gain (Loss) on Derivative Instruments
Derivative instruments not designated as cash flow hedges
Derivative instruments not designated as hedges, gain (loss), net		$ 0.0		$ (5.6)