Organization and Basis of Presentation - Additional Information (Detail)	Sep. 30, 2016
NL Industries
Basis Of Presentation And Significant Accounting Policies [Line Items]
Percentage of ownership held by parent company	87.00%
NL Industries | Valhi Inc
Basis Of Presentation And Significant Accounting Policies [Line Items]
Percentage of ownership held by parent company	83.00%
Contran Corporation | Valhi Inc
Basis Of Presentation And Significant Accounting Policies [Line Items]
Percentage of ownership held by parent company	93.00%