Segments and Related Information - Schedule of Product Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Major product category sales
Sales	$ 1,026.6	$ 1,133.7	$ 2,020.5	$ 2,139.5
Product Concentration Risk | Sales
Major product category sales
Sales	$ 1,026.6	$ 1,133.7	$ 2,020.5	$ 2,139.5
Concentration risk, percentage	100.00%	100.00%	100.00%	100.00%
Product Concentration Risk | Specialty Products and Solutions | Sales
Major product category sales
Sales	$ 627.9	$ 746.2	$ 1,278.0	$ 1,427.8
Concentration risk, percentage	61.10%	65.80%	63.20%	66.80%
Product Concentration Risk | Montana/Renewables | Sales
Major product category sales
Sales	$ 318.0	$ 291.4	$ 579.7	$ 535.9
Concentration risk, percentage	31.00%	25.70%	28.70%	25.00%
Product Concentration Risk | Performance Brands | Sales
Major product category sales
Sales	$ 80.7	$ 96.1	$ 162.8	$ 175.8
Concentration risk, percentage	7.90%	8.50%	8.10%	8.20%
Lubricating oils | Product Concentration Risk | Specialty Products and Solutions | Sales
Major product category sales
Sales	$ 190.3	$ 215.9	$ 392.5	$ 405.6
Concentration risk, percentage	18.50%	19.00%	19.40%	19.00%
Solvents | Product Concentration Risk | Specialty Products and Solutions | Sales
Major product category sales
Sales	$ 101.5	$ 109.5	$ 206.2	$ 211.9
Concentration risk, percentage	9.90%	9.70%	10.20%	9.90%
Waxes | Product Concentration Risk | Specialty Products and Solutions | Sales
Major product category sales
Sales	$ 40.2	$ 40.1	$ 78.4	$ 79.1
Concentration risk, percentage	3.90%	3.50%	3.90%	3.70%
Fuels, asphalt and other by-products | Product Concentration Risk | Specialty Products and Solutions | Sales
Major product category sales
Sales	$ 295.9	$ 380.7	$ 600.9	$ 731.2
Concentration risk, percentage	28.80%	33.60%	29.70%	34.20%
Gasoline | Product Concentration Risk | Montana/Renewables | Sales
Major product category sales
Sales	$ 33.5	$ 37.6	$ 66.0	$ 69.2
Concentration risk, percentage	3.30%	3.30%	3.30%	3.20%
Diesel | Product Concentration Risk | Montana/Renewables | Sales
Major product category sales
Sales	$ 26.4	$ 29.0	$ 49.8	$ 56.9
Concentration risk, percentage	2.60%	2.60%	2.50%	2.70%
Jet fuel | Product Concentration Risk | Montana/Renewables | Sales
Major product category sales
Sales	$ 4.7	$ 4.9	$ 8.9	$ 9.5
Concentration risk, percentage	0.50%	0.40%	0.40%	0.40%
Asphalt, heavy fuel oils and other | Product Concentration Risk | Montana/Renewables | Sales
Major product category sales
Sales	$ 44.6	$ 37.1	$ 80.6	$ 67.2
Concentration risk, percentage	4.30%	3.30%	4.00%	3.10%
Renewable fuels | Product Concentration Risk | Montana/Renewables | Sales
Major product category sales
Sales	$ 208.8	$ 182.8	$ 374.4	$ 333.1
Concentration risk, percentage	20.30%	16.10%	18.50%	15.60%