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Marketable Securities - Additional Information (Detail) - Valhi Inc - Common stock - $ / shares shares in Millions | Dec. 31, 2016 | Dec. 31, 2015
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Schedule Of Available For Sale Securities [Line Items] |  |
Number of shares owned | 14.4 | 14.4
Quoted marked price per share | $ 3.46 | $ 1.34

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