Segments and Related Information - Schedule of Reportable Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Reportable segment information
Sales	$ 1,026.6	$ 1,133.7	$ 2,020.5	$ 2,139.5
Cost of sales	1,070.2	1,069.9	2,145.5	1,997.2
Gross profit (loss)	(43.6)	63.8	(125.0)	142.3
Adjusted EBITDA	55.1	74.8	93.2	102.9
Reconciling items to net loss:
Depreciation and amortization	47.9	45.9	94.6	91.3
LCM / LIFO (gain) loss	(1.9)	(9.5)	(2.0)	(0.5)
Gain on sale of business			(62.2)
Interest expense	52.9	56.8	111.4	117.6
Debt extinguishment costs	0.1	0.1	47.7	0.3
Unrealized gain on derivatives	(7.0)	(3.0)	(7.1)	(38.7)
RINs incurrence expense	15.3	8.0	45.7	14.5
RINs mark-to-market loss	79.1	12.2	165.9	(58.9)
Other non-recurring income	4.2	(0.8)	7.4	60.0
Equity-based compensation and other items	10.1	4.7	(3.4)	(2.6)
Income tax expense	0.2	0.5	0.6	0.7
Noncontrolling interest adjustments	2.1	(1.0)	4.5	(0.1)
Net loss	(147.9)	(39.1)	(309.9)	(80.7)
Capital expenditures	19.0	24.7	39.4	50.2
PP&E, net	1,387.7	1,467.2	1,387.7	1,467.2	$ 1,438.8
External customers
Reportable segment information
Sales	1,026.6	1,133.7	2,020.5	2,139.5
Eliminations
Reportable segment information
Sales	(5.2)	(7.1)	(10.0)	(12.2)
Eliminations | Inter-segment sales
Reportable segment information
Sales	(5.2)	(7.1)	(10.0)	(12.2)
Specialty Products and Solutions | Operating Segments
Reportable segment information
Sales	633.0	753.2	1,287.9	1,439.8
Cost of sales	642.8	707.1	1,326.9	1,303.4
Gross profit (loss)	(14.9)	39.1	(48.9)	124.4
Adjusted EBITDA	66.8	72.7	123.1	119.9
Reconciling items to net loss:
Depreciation and amortization	18.2	18.1	34.9	35.7
LCM / LIFO (gain) loss	4.9	0.7	4.2	(2.9)
Interest expense	4.7	3.9	9.3	11.7
Debt extinguishment costs		0.1		0.1
Unrealized gain on derivatives	(7.0)	(3.0)	(7.1)	(38.7)
RINs incurrence expense	12.0	6.9	34.3	12.3
RINs mark-to-market loss	55.4	8.4	116.1	(39.5)
Capital expenditures	14.3	17.5	26.3	31.6
PP&E, net	339.6	363.0	339.6	363.0
Specialty Products and Solutions | Operating Segments | External customers
Reportable segment information
Sales	627.9	746.2	1,278.0	1,427.8
Specialty Products and Solutions | Operating Segments | Inter-segment sales
Reportable segment information
Sales	5.1	7.0	9.9	12.0
Performance Brands | Operating Segments
Reportable segment information
Sales	80.8	96.2	162.9	176.0
Cost of sales	58.6	71.0	118.5	128.4
Gross profit (loss)	22.1	25.1	44.3	47.4
Adjusted EBITDA	13.5	14.1	29.3	27.5
Reconciling items to net loss:
Depreciation and amortization	1.3	2.2	3.2	4.3
LCM / LIFO (gain) loss	(0.5)	(0.2)	0.8
Gain on sale of business			(64.4)
Interest expense		0.1		0.1
Capital expenditures	0.4	0.3	0.6	0.6
PP&E, net	30.4	32.5	30.4	32.5
Performance Brands | Operating Segments | External customers
Reportable segment information
Sales	80.7	96.1	162.8	175.8
Performance Brands | Operating Segments | Inter-segment sales
Reportable segment information
Sales	0.1	0.1	0.1	0.2
Montana/Renewables | Operating Segments
Reportable segment information
Sales	318.0	291.4	579.7	535.9
Cost of sales	368.8	291.8	700.1	565.4
Gross profit (loss)	(50.8)	(0.4)	(120.4)	(29.5)
Adjusted EBITDA	(5.1)	8.7	(18.7)	(4.7)
Reconciling items to net loss:
Depreciation and amortization	28.2	25.4	56.1	50.8
LCM / LIFO (gain) loss	(6.3)	(10.0)	(7.0)	2.4
Interest expense	15.1	16.0	33.4	33.0
Debt extinguishment costs	0.0		47.6
RINs incurrence expense	3.3	1.1	11.4	2.2
RINs mark-to-market loss	23.7	3.8	49.8	(19.4)
Capital expenditures	3.8	5.2	11.7	16.2
PP&E, net	1,012.6	1,068.2	1,012.6	1,068.2
Montana/Renewables | Operating Segments | External customers
Reportable segment information
Sales	318.0	291.4	579.7	535.9
Corporate | Operating Segments
Reportable segment information
Adjusted EBITDA	(20.1)	(20.7)	(40.5)	(39.8)
Reconciling items to net loss:
Depreciation and amortization	0.2	0.2	0.4	0.5
Gain on sale of business			2.2
Interest expense	33.1	36.8	68.7	72.8
Debt extinguishment costs	0.1		0.1	0.2
Capital expenditures	0.5	1.7	0.8	1.8
PP&E, net	$ 5.1	$ 3.5	$ 5.1	$ 3.5