v3.26.1
Accumulated Other Comprehensive Loss ("AOCL") - Reclassifications out of AOCL (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]        
Cost of goods sold [1] $ (524.2) $ (594.5) $ (1,054.6) $ (1,171.1)
Selling, general and administrative expenses (15.9) (14.0) (41.7) (26.5)
Other operating expense - net (0.4) (1.5) (7.3) (3.5)
Income tax effect (12.1) 1.3 (13.9) (0.3)
Net of tax 249.3 (4.6) 586.8 25.1
Reclassification out of accumulated other comprehensive income | Defined benefit plan and other postretirement liabilities        
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]        
Cost of goods sold 0.6 1.5 1.7 2.3
Selling, general and administrative expenses 0.0 0.1 0.1 0.3
Other operating expense - net (1.0) 0.0 (0.3) 0.7
Income tax effect 0.0 0.0 0.0 0.0
Net of tax (0.4) 1.6 1.5 3.3
Reclassification out of accumulated other comprehensive income | Unrealized gain on financial instruments        
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]        
Cost of goods sold (0.1) (0.1) (0.1) (0.1)
Income tax effect 0.0 0.0 0.0 0.0
Net of tax $ (0.1) $ (0.1) $ (0.1) $ (0.1)
[1]
(1) Purchases from related party were $104.3 million and $51.8 million for the three months ended June 30, 2026 and 2025, respectively. Purchases from related party were $168.5 million and $140.1 million for the six months ended June 30, 2026 and 2025, respectively.