Business Segment Information - Schedule of Segment Assets (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total assets, excluding tax assets	$ 1,649.2	$ 1,659.0
Tax assets	5.6	1.4
Total assets	1,654.8	1,660.4
Operating Segments
Segment Reporting Information [Line Items]
Total assets, excluding tax assets	1,532.5	1,575.8
Operating Segments | Domestic Coke
Segment Reporting Information [Line Items]
Total assets, excluding tax assets	1,366.1	1,405.5
Operating Segments | Brazil Coke
Segment Reporting Information [Line Items]
Total assets, excluding tax assets	9.6	11.9
Operating Segments | Logistics
Segment Reporting Information [Line Items]
Total assets, excluding tax assets	156.8	158.4
Corporate and Other
Segment Reporting Information [Line Items]
Total assets, excluding tax assets	$ 116.7	$ 83.2