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Organization and Basis of Presentation - Additional Information (Detail)	Mar. 31, 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%

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- Definition

Basis of presentation and significant accounting policies.

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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