v3.26.1
Business Segment Information - Schedule of Adjusted EBITDA Reportable Segments (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting [Line Items]        
Sales and other operating revenue $ 475.3 $ 434.1 $ 930.4 $ 870.1
Less:        
Selling, general and administrative expenses 31.5 20.6 61.8 35.3
Depreciation and amortization expense 39.9 28.6 84.8 57.4
Interest expense, net 8.5 5.4 17.2 10.6
Loss on derivative forward contracts     0.3  
Restructuring costs 0.3   0.6  
Site closure costs 0.4   6.8  
Income before income tax expense 20.5 4.4 16.2 29.4
Interest expense 9.4 7.0 19.4 13.8
Interest income 0.9 1.6 2.2 3.2
Elimination        
Segment Reporting [Line Items]        
Sales and other operating revenue (5.8) (5.9) (11.3) (11.5)
Operating Segments        
Less:        
Adjusted EBITDA reportable segments 76.9 48.2 138.4 111.8
Depreciation and amortization expense 39.3 28.1 83.6 56.3
Corporate and Other        
Less:        
Other corporate expenses 7.3 9.8 12.5 14.4
Reportable Segment, Aggregation before Other Operating Segment        
Segment Reporting [Line Items]        
Sales and other operating revenue 465.9 425.5 913.0 853.7
Reportable Segment, Aggregation before Other Operating Segment | Elimination        
Segment Reporting [Line Items]        
Sales and other operating revenue (5.8) (5.9) (11.3) (11.5)
Reportable Segment, Aggregation before Other Operating Segment | Operating Segments        
Segment Reporting [Line Items]        
Sales and other operating revenue 471.7 431.4 924.3 865.2
Domestic Coke        
Segment Reporting [Line Items]        
Sales and other operating revenue 367.5 410.4 729.2 816.2
Domestic Coke | Elimination        
Segment Reporting [Line Items]        
Sales and other operating revenue 0.0 0.0 0.0 0.0
Domestic Coke | Operating Segments        
Segment Reporting [Line Items]        
Sales and other operating revenue 367.5 410.4 729.2 816.2
Less:        
Operating and maintenance expense 74.3 71.2 149.1 142.3
Cost of products sold and other expenses 239.6 291.5 485.0 569.5
Selling, general and administrative expenses 11.1 7.2 17.3 14.0
Adjusted EBITDA reportable segments 42.5 40.5 77.8 90.4
Depreciation and amortization expense 22.0 24.9 46.2 50.0
Industrial Services        
Segment Reporting [Line Items]        
Sales and other operating revenue 98.4 15.1 183.8 37.5
Industrial Services | Elimination        
Segment Reporting [Line Items]        
Sales and other operating revenue (5.8) (5.9) (11.3) (11.5)
Industrial Services | Operating Segments        
Segment Reporting [Line Items]        
Sales and other operating revenue 104.2 21.0 195.1 49.0
Less:        
Operating and maintenance expense 60.5 13.0 116.3 27.0
Cost of products sold and other expenses 0.0 0.0 0.0 0.0
Selling, general and administrative expenses 9.3 0.3 18.2 0.6
Adjusted EBITDA reportable segments 34.4 7.7 60.6 21.4
Depreciation and amortization expense 17.3 3.2 37.4 6.3
Corporate and Other        
Segment Reporting [Line Items]        
Sales and other operating revenue $ 9.4 $ 8.6 $ 17.4 $ 16.4