v3.26.1
Other Debt Disclosures Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Aug. 06, 2026
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Feb. 03, 2026
Debt Instrument [Line Items]            
Repayments of Long-term Debt       $ 1,656.4 $ 7.5  
Interest Paid, Excluding Capitalized Interest, Operating Activity       $ 185.4 $ 83.9  
Long-term Debt, Weighted Average Interest Rate, at Point in Time   7.10% 6.80% 7.10%    
Dowlais Group plc            
Debt Instrument [Line Items]            
Business Combination, Recognized Liability Assumed, Long-Term Debt, Noncurrent           $ 1,876.9
Private Placement            
Debt Instrument [Line Items]            
Unsecured Debt   $ 349.0   $ 349.0    
6.875% Notes [Member]            
Debt Instrument [Line Items]            
Unsecured Debt   125.0 $ 250.0 125.0    
Private Placement | Dowlais Group plc            
Debt Instrument [Line Items]            
Business Combination, Recognized Liability Assumed, Long-Term Debt, Noncurrent           $ 500.0
Unsecured Debt [Member] | Private Placement            
Debt Instrument [Line Items]            
Repayments of Long-term Debt       $ 151.0    
Unsecured Debt [Member] | 6.875% Notes [Member]            
Debt Instrument [Line Items]            
Repayments of Long-term Debt   $ 125.0 $ 150.0      
Debt Instrument, Interest Rate, Stated Percentage   6.875% 6.875% 6.875%    
Interest Paid, Excluding Capitalized Interest, Operating Activity   $ 3.0        
Deferred Debt Issuance Cost, Writeoff   0.6        
Unsecured Debt [Member] | 6.875% Notes [Member] | Subsequent Event            
Debt Instrument [Line Items]            
Repayments of Long-term Debt $ 125.0          
Debt Instrument, Interest Rate, Stated Percentage 6.875%          
Interest Paid, Excluding Capitalized Interest, Operating Activity $ 0.8          
Foreign Credit Facilities [Member]            
Debt Instrument [Line Items]            
Long-term Line of Credit   4.6 $ 10.7 $ 4.6    
Debt Instrument, Unused Borrowing Capacity, Amount   $ 100.0   $ 100.0