v3.25.4
Commitments and contingencies - Lead Pigment Litigation-NL and Environmental Matters and Litigation - Additional Information (Details)
 1 Months Ended 3 Months Ended 12 Months Ended
Jul. 24, 2019
USD ($)
defendant
Oct. 31, 2025
USD ($)
Feb. 28, 2025
USD ($)
company
Mar. 31, 2025
USD ($)
Dec. 31, 2025
USD ($)
site
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Jul. 14, 2019
USD ($)
Commitments and contingencies                  
Accrual for reasonably estimable environmental remediation and related matters         $ 17,500,000 $ 74,600,000 $ 96,900,000 $ 97,300,000  
Accrued litigation settlement           16,400,000      
Insurance recoveries           1,400,000 3,000,000    
Other Environmental Cleanup Matters                  
Commitments and contingencies                  
Accrual for reasonably estimable environmental remediation and related matters         4,000,000        
Raritan Bay Slag Superfund Site                  
Commitments and contingencies                  
Number of private companies to pay to resolve all federal and state law claims | company     22            
Settlement amount     $ 151,100,000            
NL Industries                  
Commitments and contingencies                  
Litigation settlement interest expense (income)       $ 500,000          
Litigation settlement, current       9,600,000          
Aggregate income           31,400,000      
Settlement amount payable       $ 56,100,000          
Insurance recoveries         0 1,400,000 500,000    
NL Industries | Environmental Remediation Sites NL Named As PRP Or Defendant                  
Commitments and contingencies                  
Accrual for reasonably estimable environmental remediation and related matters         $ 13,000,000        
Number of sites associated with remediation and related costs | site         27        
Number of sites for which NL not currently able to reasonably estimate range of costs | site         5        
NL Industries | Maximum | Environmental Remediation Sites NL Named As PRP Or Defendant                  
Commitments and contingencies                  
Upper end range, estimate costs for remediation and related matters         $ 26,000,000        
C A Lead Paint Litigation                  
Commitments and contingencies                  
Accrued litigation settlement                 $ 101,700,000
Litigation settlement charge upon approval of settlement terms                 25,000,000
Remaining litigation settlement charge                 76,700,000
C A Lead Paint Litigation | NL Industries                  
Commitments and contingencies                  
Settlement amount $ 305,000,000                
Accrued interest received on restricted cash treated as non-operating   $ 1,600,000              
Description of defendants         July 24, 2019, an order approving a global settlement agreement entered into among all of the plaintiffs and the three defendants remaining in the case (the Sherwin Williams Company, ConAgra Grocery Products and NL) was entered by the court and the case was dismissed with prejudice. The global settlement agreement provided that an aggregate $305 million would be paid collectively by the three co-defendants in full satisfaction of all claims resulting in a dismissal of the case with prejudice and the resolution of (i) all pending and future claims by the plaintiffs in the case, and (ii) all potential claims for contribution or indemnity between NL and its co-defendants in respect to the case.        
Number of Defendant | defendant 3                
Remaining litigation settlement charge         $ 101,700,000        
Number of annual installment payments 6                
Remaining litigation settlement charge due in first installment                 12,000,000
Remaining litigation settlement charge due in third installment                 12,000,000
Remaining litigation settlement charge due in fourth installment                 12,000,000
Remaining litigation settlement charge due in fifth installment                 12,000,000
Remaining litigation settlement charge due in sixth installment                 $ 16,700,000
Discounted rate for estimated present value of remaining litigation amount         1.90%        
Long-term litigation settlement         $ 96,300,000        
Accretion expense         $ 200,000 $ 500,000 $ 700,000