v3.26.3
Long-term Debt - Schedule of Debt (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Carrying amount          
Debt Instrument [Line Items]          
Unamortized Debt Issuance Expense $ 6.7   $ 6.7   $ 4.4
Total debt 296.6   296.6   336.4
Finance lease obligations 16.2   16.2   20.8
Total debt 296.6   296.6   336.4
Less: Current portion of long-term debt 49.0   49.0   15.2
Long-term debt 247.6   247.6   321.2
Interest Expense, Operating and Nonoperating 18.6 $ 10.0 42.0 $ 32.6  
Cash paid for interest, net of capitalized interest 7.8 10.9 41.1 35.0  
Noncash interest expense, net 5.9 0.9 8.7 4.2  
Capitalized interest 0.0 (2.0) (2.1) (5.9)  
2028 Convertible Notes, including bifurcated conversion option and debt discount          
Debt Instrument [Line Items]          
Interest Expense, Operating and Nonoperating 0.6 2.6 5.2 7.8  
Amortization of Debt Discount (Premium) 4.4 0.0 4.4 0.0  
Finance lease obligations          
Debt Instrument [Line Items]          
Interest Expense, Operating and Nonoperating 0.2 0.4 0.9 1.1  
Financial assurance instruments          
Debt Instrument [Line Items]          
Interest Expense, Operating and Nonoperating 7.9 6.2 20.8 19.8  
Amortization of debt issuance costs          
Debt Instrument [Line Items]          
Interest Expense, Operating and Nonoperating 1.5 1.4 4.3 4.2  
Accounts Receivable Securitization Program          
Debt Instrument [Line Items]          
Interest Expense, Operating and Nonoperating 0.6 0.6      
Other          
Debt Instrument [Line Items]          
Interest Expense, Operating and Nonoperating 3.1 0.8 6.3 3.8  
0.500% Convertible Notes due June 2031          
Debt Instrument [Line Items]          
Interest Expense, Operating and Nonoperating 0.3 0.0 0.4 0.0  
Senior Notes | 2028 Convertible Notes, including bifurcated conversion option and debt discount          
Debt Instrument [Line Items]          
2028 Convertible Notes $ 37.1   $ 37.1   320.0
Stated interest rate 3.25%   3.25%    
Senior Notes | 0.500% Convertible Notes due June 2031          
Debt Instrument [Line Items]          
2028 Convertible Notes $ 250.0   $ 250.0   $ 0.0
Stated interest rate 0.50%   0.50%    
Secured debt | Accounts Receivable Securitization Program          
Debt Instrument [Line Items]          
Interest Expense, Operating and Nonoperating $ 0.6 $ 0.6 $ 1.8 $ 1.8