v3.26.1
Organization and basis of presentation - Additional Information (Detail)
6 Months Ended
Jun. 30, 2026
Valhi Inc | Parent Company  
Organization and basis of presentation  
Parent company ownership interest 50.00%
Valhi Inc | NLI  
Organization and basis of presentation  
Ownership percentage in company 83.00%
NLI | Parent Company  
Organization and basis of presentation  
Parent company ownership interest 31.00%
Contran  
Organization and basis of presentation  
Controlling interest description Consequently, at June 30, 2026, Ms. Simmons and the Family Trust may be deemed to control Contran, and therefore may be deemed to indirectly control the wholly-owned subsidiary of Contran, Valhi, NLI and us.
Contran | Valhi Inc  
Organization and basis of presentation  
Ownership percentage of parent company held by related party 91.00%