v3.25.3
Commitments and Contingencies (Narrative) (Detail)
$ in Millions
1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended 13 Months Ended
Jul. 31, 2023
plaintiff
Sep. 30, 2025
USD ($)
a
Sep. 30, 2024
USD ($)
Sep. 30, 2014
USD ($)
Sep. 30, 2025
USD ($)
a
Sep. 30, 2024
USD ($)
Dec. 31, 2019
USD ($)
component
Sep. 30, 2025
USD ($)
a
Dec. 31, 2024
USD ($)
Loss Contingencies [Line Items]                  
Accrued environmental loss contingencies current   $ 7.8     $ 7.8     $ 7.8 $ 7.9
Insurance proceeds for lost profits   2.7 $ 0.0   6.7 $ 0.0      
Loss from Catastrophes                  
Loss Contingencies [Line Items]                  
Total expenses and losses   0.5 3.7   6.3 3.7   29.6  
Insurance recoveries receivable, net of deductible   0.0     0.0     0.0 2.8
Insurance recoveries received   0.5 $ 0.0   6.3 $ 0.0   29.1  
LyondellBasell                  
Loss Contingencies [Line Items]                  
Number of victims | plaintiff 58                
Environmental Claims For A Site In Goodyear Arizona                  
Loss Contingencies [Line Items]                  
Accrual for environmental loss contingencies, revision in estimates       $ 49.0     $ 18.9    
Number of main remedial components | component             2    
Estimated liability   13.7     13.7     13.7 16.4
Accrued environmental loss contingencies current   $ 7.8     $ 7.8     $ 7.8 7.8
Loss contingency reimbursement rate   21.00%     21.00%     21.00%  
Other receivables   $ 2.2     $ 2.2     $ 2.2 $ 3.0
Environmental Claims For Crab Orchard National Wildlife Refuge Superfund Site                  
Loss Contingencies [Line Items]                  
Approximate size of referenced site | a   55,000     55,000     55,000